Yet again, Ebola has infected a caregiver: a nurse who gave extensive care to Thomas Duncan in Dallas. She wore full protective gear and is not aware of any breach of anti-infection protocol. [NYT 10/13/14] This is worrisome, but consistent with the pattern we have previously noted: How Contagious is Ebola?

Update 10/15/14: Another nurse has been diagnosed. This is tragic, and unnecessary, but completely predictable given the criminally shambolic conditions under which Duncan was treated. [AP / Mashable 10/15/14]  Obviously, America has to do a lot better. But there’s every reason to think that we will rise to the occasion. What cannot continue is for Ebola patients — especially in the last stage of the illness — to be treated casually or on an ad hoc basis. Ebola will bite you if you don’t respect it! But MSF knows how to handle Ebola patients with minimal risk to caregivers. CDC simply needs to take the lessons of Africa and Spain and Dallas to heart. The solution is simple:

  1. All healthcare providers must be trained to identify and isolate potential Ebola patients, with minimal risk to themselves and others, and
  2. Confirmed Ebola patients must be treated by fully-trained professionals, with top-notch equipment, in well-designed facilities, following clear and prudent protocols.  At the moment there are plenty of beds in the four bio-containment hospitals but at least one hospital should gear up in each major city to be able to safely treat Ebola patients. Full bio-containment isn’t necessary for Ebola.

Some facts about Ebola are becoming clear:

  • Those at greatest risk are caregivers — either healthcare providers or those who care for a seriously ill patient in the home. Intense focus and attention to detail are needed to protect a caregiver, especially when a patient is in the last stage of the illness.
    • The African protocol developed by Médecins Sans Frontières / Doctors Without Borders (“MSF”) has been extraordinarily successful, although some members of their staff have nevertheless been infected.
    • The protocols used in Spain and in the U.S., as implemented so far, have not given caregivers complete protection.
  • Patients are most infectious in the last stage of the disease. There is no evidence of transmission before a person becomes symptomatic, and even after symptoms begin patients seem to be remarkably non-contagious until the final stage. The main focus should be on where patients are, and who has contact with them, in the final stage of the illness.
  • Corpses are also highly infectious. African customs of washing and touching corpses present a second important channel of infection, that needs to be discouraged. Developed countries should not encounter this issue, however, so long as suitable precautions are taken.

These lead to a few specific conclusions:

  • In the developed world the main risk presented by Ebola is to healthcare providers. There are plenty of beds, and nobody is going to try to care for an extremely ill patient in their home. CDC needs to refine its anti-infection protocol and to provide better training and support to hospitals and staff who treat Ebola patients, and similar steps need to be taken in other developed countries. There’s every reason to think that this will happen, and indeed is already happening. Ebola will teach us, as I’m sure it taught MSF in the early outbreaks, what we need to do to stop it. I still see no reason — apart from possible mutation — why the developed world should have any problem snuffing out little Ebola outbreaks as they inevitably occur.  (I’m still quite concerned about the ability of other poor countries, with crowded slums, to do the same.)

    • Healthcare providers need to be monitored for 21 days after their last contact with an Ebola patient. Duh!
  • West African healthcare providers also need to be better protected, ideally with identical gear and an identical protocol to those in the developed world.
  • In West Africa the key to stopping Ebola is isolation beds for patients in the last stage of illness. The best feasible standard of care should be provided for humanitarian reasons, but from the perspective of stopping the epidemic the critical element is isolation. The only way to bring the Effective Reproduction Number down below one is to break the cycle of transmission to home caregivers, by isolating patients and caring for them under the anti-infection protocol. Again, this issue has been identified and is being dealt with. The big question is whether beds can be provided fast enough to get ahead of the epidemic.
  • West African funeral practices also need to be addressed, and of course corpses must continue to be buried or cremated, which may prove problematic if the numbers of deaths mount as currently predicted. [NYT 10/14/14]
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There are really only three things you need to know about Ebola. Each of them is a serious problem, of a distinct type. But the only solution to all three issues is to end the epidemic in West Africa as soon as possible.

1. Humanitarian Crisis in West Africa

In case you’ve been distracted by the news from Dallas, the real issue is in Liberia, Sierra Leone and Guinea, where the epidemic is continuing to grow exponentially. In case you aren’t aware how bad it is my last blog post will better inform you. These countries urgently need our help to moderate and eventually end this terrible situation.

2. Risk of Spread to Other Poor Countries

There will continue to be isolated cases of Ebola in the Western world: A traveler will occasionally fall ill, as in Dallas. A healthcare worker will occasionally be infected, as in Spain. Each patient may possibly infect a few more people, but with care and attention any little outbreak should be readily brought under control. Hard though it is to believe, Ebola really isn’t very contagious, relative to common diseases like measles and the flu. The total number of people affected in developed countries will probably be on the order of how many people are struck by lightning. Accidents, suicides, and many other diseases present far greater risks in our world.

In a poor country, however, with weak healthcare infrastructure, and crowded slums, Ebola might gain a foothold. It is hard to imagine that the world would ever again allow an epidemic to get as far out of hand as the one in West Africa, but it’s possible. And that has the potential to multiply the disruption, sickness and death of the current epidemic many fold.

3. Risk of Mutation

The last worry is the possibility that Ebola could mutate to become more infectious. The Ebola Reston strain seemed to pass between monkeys through the air, so this anxiety isn’t entirely fanciful. [CNN 10/6/14] The best way to prevent such a mutation is to stop the cycle of human-to-human infection in West Africa. The more rolls of the dice Ebola gets the greater the risk that a mutation will increase its ability to infect. Which could obviously be a big problem.

Conclusion: We Must Stop the Epidemic

The brouhaha about Dallas, and most recently about the Spanish nurse’s puppy, is predictable, but we need to return our attention to the main point. For all three of the reasons mentioned above job #1 is ending the epidemic in West Africa. Cutting off travel and the like may seem to make us safer, but in fact they make us less safe, by exacerbating all three of these primary issues. We’ve got to stop the epidemic!

(I’ve oversimplified a bit: If you’re a healthcare worker you need to know more, precisely in order to avoid as many as possible of the blunders which have characterized the responses in Dallas and in Spain. And if you’re in West Africa of course you need to think about a lot of additional issues.)

The main purpose of this blog is to analyze Ebola as rationally and dispassionately as possible. In this post, however, I’m going to collect some of the most moving and stirring items I’ve encountered in connection with the West African epidemic. I’ll start with the most ghastly images I’ve seen, then mention some pieces that are harrowing but less horrible, and end with stories that are inspiring and even hopeful. I plan to add to each category as the epidemic develops, with the hope that eventually everything will be added to the final group.

Horror

These are the most dreadful items I’ve read. I don’t recommend reading more than one or two at a time, and if you are at all squeamish just skip to the next section.

Disorder

Cultural Damage

Survival

Inspiration

Hope

Note: Thanks to the EbolaReport blog for collecting several of these items.

Like sparks from a burning building, travelers are carrying Ebola around the world. What’s been happening? What will happen? What can we do?

The Ebola Diaspora

People travel for lots of reasons, some related to the epidemic, some not.

  • Now as always people will want to travel for business, tourism, or to spend time with family or friends. With Ebola increasingly out of control more and more of the people traveling from West Africa will turn out to be infected. I’ll address later in this post the idea of stopping travel altogether, but in short it wouldn’t work, except perhaps to delay the inevitable.
  • As life becomes more difficult in the affected countries people will have an additional reason to travel, seeking either a temporary respite or an extended or permanent refuge. If things get really bad this could change from a trickle to a panicky exodus.
  • People who have been exposed to Ebola, but are not yet symptomatic, may have a special incentive to travel to a country with a modern healthcare system. Such passengers also have a strong incentive to lie about their Ebola exposure, as the traveler from Liberia to Texas apparently did. [CNN 10/3/14] This could be a particular problem for developed Western countries, but also for more prosperous African countries such as Nigeria and South Africa.
  • Fever monitors in airports should prove to be an effective method of barring symptomatic patients from air travel. Update 10/6/14: It has been suggested that ibuprofen could be used to hide a person’s fever in order to get a symptomatic patient through airport screening. [Reuters 10/3/14]  I don’t know whether this is true, but if so it would be a weakness in the screening process.
  • Symptomatic patients may still slip across porous borders on the ground, but airport controls somewhat reduce the spread of Ebola and nearly eliminate the already-low risk to the airplane’s crew and passengers. Port authorities in the affected countries and their neighbors are attempting to do the same type of screening of ship’s crews. [AFP 9/29/14]

The bottom line is that people infected with Ebola will travel to other countries, on the ground and by air and by sea. Wherever they go they will fall ill, and potentially infect others, setting off local Ebola outbreaks. Everything will depend on the location and the response. Stable countries with capable healthcare systems and effective governments should be able to snuff out their Ebola outbreaks fairly easily, depending on the the level of noncompliance they encounter. Poor countries with crowded slums and limited healthcare may not be so lucky.

What’s Been Happening?

Apart from medical evacuations we know of just three cases in which someone infected with Ebola traveled outside of Guinea, Liberia and Sierra Leone.

Nigeria – Patrick Sawyer

Patrick Sawyer, a Liberian-American diplomat, traveled on July 20 from Monrovia to Lagos via Togo despite having severe Ebola symptoms, including vomiting repeatedly during his flights. He collapsed in the airport and was taken to a hospital where he died a few days later, but not before infecting half a dozen people who themselves went on to infect a dozen more. Nigeria identified and tracked 894 contacts of Sawyer and other infected people, of which 20 came down with Ebola and 8 died. [Washington Post 9/30/14] Details are in my earlier posts: Arrogance and Privilege Imperil Nigeria’s Attempt to Contain Ebola and How Contagious is Ebola?

This story involves multiple instances of noncompliance with quarantine orders and lying, as well as many cases in which hospital staff were unnecessarily infected. Nevertheless, Nigeria’s persistent contact tracing and isolation measures, and capable healthcare system, eventually brought the outbreak (apparently) to a close.

Senegal – A Guinean Student

A 21-year-old student named Mamadou Alimuo Diallo was under surveillance in Guinea because several relatives had fallen ill with Ebola. He nevertheless traveled by car to Dakar, Senegal, despite the fact that the border between Guinea and Senegal was supposed to be closed. He arrived in Dakar on August 20, and stayed in the large household of his uncle. He began feeling ill on the 23rd and went to a medical facility seeking treatment for fever, diarrhea and vomiting, but concealed his contact with Ebola patients, and was sent back to his uncle’s home. He was eventually admitted to a hospital for Ebola treatment on the 26th. [USNews 9/1/14]  Some 67 people with whom the student had been in contact were monitored, but none came down with the disease. The student recovered and returned to Guinea. [Modern Ghana 9/10/14]

Senegal apparently did a good job of contact tracing but really just got lucky, since this situation illustrated a lot of problems:

  • The student broke quarantine in Guinea.
  • The student was able to get into Senegal despite the fact that the border was supposedly closed.
  • The student lied about contact with Ebola patients on the 23rd, putting medical staff and family members at risk by going back to his uncle’s home.

It may be that Senegal’s medical facilities used better precautions than those in other countries, or it may be that the student was for some reason just not very infectious. But you couldn’t even call this an outbreak since there was no transmission of the virus in Senegal.

Dallas – Thomas E. Duncan

Thomas Duncan is a Liberian who traveled by plane from Monrovia to Dallas, Texas, arriving on Sept. 20. He lied on an exit form which asked whether he had had any contact with Ebola patients, since on Sept. 15 he had helped carry a stricken neighbor back into her apartment (after she had been turned away from a hospital). His temperature was taken at the Monrovia airport but was not elevated. [NYT 10/2/14]  On the 24th he developed symptoms and on the 26th went to the Texas Health Presbyterian Hospital Dallas. Although he told hospital staff that he had recently traveled from Liberia this information didn’t reach the diagnostic team and they sent him home. Update 10/4/14: The hospital has changed its story and admitted that in fact the entire diagnostic team had access to the fact that Duncan came from Liberia. [NYT 10/3/14] Reportedly, however, on his first hospital visit Duncan falsely denied having contact in Liberia with anyone who was ill. [AP 10/2/14]  On the 28th Duncan was taken to the hospital by ambulance and placed in isolation, with laboratory confirmation of Ebola on the 30th. [NYT 9/30/14]

The people at greatest risk were the four people in the apartment where he stayed in Dallas. They were initially told to stay at home, but were “noncompliant,” including sending at least one of their children to school! [Dallas Business Journal 10/2/14] Formal quarantine orders were then issued requiring them to stay home and not to receive visitors, and a police guard was posted. [Yahoo 10/3/14] Bureaucratic snags delayed cleaning of the contaminated apartment for several days after Duncan went into hospital. They subsequently have been moved to a lovely isolated home donated by a member of “a Dallas faith community.” [NYT 10/3/14]

A total of 12 to 18 people are believed to have had direct contact with Duncan, and they may in turn have had contact with around 100 other people. Those with direct contact are being monitored. This includes 5 school-age children. [Dallas Business Journal 10/1/14Updated 10/4/14: About 50 people are being monitored daily, of which 10 had direct contact with Duncan. [CDC 10/4/14]

Lots of mistakes have been made already, and it’s reasonable to guess that several people will pay for them with their lives:

  • Duncan shouldn’t have traveled or stayed with his relatives so soon after his contact with an Ebola patient, and he shouldn’t have lied about it on the exit form.
  • It’s incredibly stupid that the hospital sent Duncan home after he presented with a fever and told them he had come from Liberia.
    • Very possibly inadequate infection prevention procedures were taken while he was in the hospital, which presents a risk that healthcare workers were infected. Patrick Sawyer infected several doctors and nurses and the entire hospital had to be closed for a month-long decontamination! [Africa Independent Television 9/9/14]
    • This also of course increased the risk to the family where he was staying and any other people he contacted over the next couple of days.
  • It’s mind-boggling that students who had direct contact with Duncan might have been sent to school! And the other unstated “noncompliance” by the household where Duncan had been staying is worrisome.
    • Nigeria closed all schools in the entire country at the height of its Ebola outbreak to protect its children!  [BBC 8/27/14]
  • The delay in cleaning the apartment is inept but in point of fact those people are all so thoroughly exposed that it may not make a difference.

Since the mean incubation period is 11 days and Duncan’s symptoms started on Sept. 24 we can expect the first wave of infections in a few days, with hospital staff following a few days later. That’s if he’s as infectious as Patrick Sawyer; if instead he’s like the Senegal student nobody will be infected!

Mali – The Little Girl With a Nosebleed

Added 10/29/14. On October 19 a two-year-old girl was taken by her grandmother on public transport from a funeral in Guinea to Kayes in western Mali, including a two-hour stopover in Bamako, Mali’s capital and largest city. The child had developed a nosebleed in Guinea, so was symptomatic for the entire trip. The child was examined by a healthcare worker on Oct. 20, admitted to a hospital on Oct. 21, tested positive for Ebola on Oct. 23, and died the next day. Initially, some 43 close contacts were monitored, including 10 healthcare providers. [WHO 10/24/14]  This unfortunately has the potential for several to many infections, especially including the healthcare workers. The silver lining is the fact that the initial case was — eventually — identified, so her contacts could be traced. “If you have one case very early on and you catch it, you’re actually lucky,” says [Dr. Samba Sow from the National Center for Disease Control, CNAM, in Bamako] “If you don’t detect that first case you run the risk of people who are contagious staying in the community without being reported and that’s when you run the risk of an epidemic.” [VoA 10/29/14] At last report 82 contacts were being monitored. [Reuters 10/28/14]

Update 10/31/14: It now appears that the little girl traveled on buses and taxis or otherwise had contact with 141 people, of whom 57 have not yet been identified and found. [Reuters 10/31/14] This could be a disaster for Mali, or wherever those people were going. Or the day could be saved once again by the limited contagiousness of the Ebola virus.

What Will Happen?

Travelers infected with Ebola will continue to pop up from time to time, all over the world. The outcome in each case will depend on intelligence, resources, compliance with quarantines and luck.

  • One assumes that the resources available will enable developed countries to stop Ebola fairly quickly. The classic technique of isolation, contact tracing and monitoring has worked in dozens of rural outbreaks as well as in Nigeria, despite serious noncompliance. 
  • This should be true in Dallas, despite stupidity at the hospital and noncompliance by the family which have increased risk, and may cause unnecessary deaths.
  • The real problem is when Ebola pops up in a poor country with a weak healthcare system, especially in a crowded slum, and especially when there are endemic diseases like malaria that can cause similar symptoms. If Ebola gets established in such a situation it could become another Liberia.

Update 10/6/14: Northeastern University researcher Alessandro Vespignani has developed a computer model which predicted, as of Oct. 1, the likelihood of an infected person traveling to particular countries over the first three weeks of October. [Boston Globe 10/1/14] The ten countries with the highest probabilities are, in order: Ghana (46%), France, Senegal, U.S. (25%), Ivory Coast, U.K., Nigeria, Mali, Belgium and Morocco (about 10%). Of course the U.S. has already identified one such traveler, but it would seem that we still have about a one in four chance of encountering another by the end of the month. One question which isn’t clear from the article is whether the investigators took into account the possibility of a travel bias towards countries with good healthcare systems by people who are concerned about the possibility of having been exposed to the virus. The investigators are posting updating predictions at this link: Ebola – MoBS.

As noted above, the big concern is when one of these people arrives in a poor country with a weak healthcare system. The biggest worry is Ghana, followed by Senegal, Ivory Coast, Mali and Morocco. Nigeria is also high on the list but they showed considerable skill in quashing the Patrick Sawyer outbreak so may be somewhat less at risk (unless the virus gets loose in the ungovernable northern region). The slums of India or South America would also be quite vulnerable but the likelihood of travel there is much less.

What Can We Do?

There are just a few things we can — and must — do.

Limit Travel From Affected Countries?

There will no doubt be a move in America to bar travelers from the three affected countries (Guinea, Liberia and Sierra Leone). This has a superficial appeal, on the same reasoning as the cordon sanitaire around an epidemic ravaged city. (This is discussed in an earlier post: Ebola Quarantines) WHO takes the view, however, that travel bans are counter-productive. [AlJazeera 9/22/14] Not only do travel bans have detrimental economic consequences, but they can worsen the epidemic itself by hindering relief efforts. 
This article makes the case rather persuasively:

It’s also questionable how effective a travel ban would be. The Guinean student demonstrated how porous African land borders are, even when theoretically “closed.” Someone who really wanted to leave the affected countries could get out. Rich and privileged people may have multiple passports, that could be used to conceal their nationalities and/or their itineraries. And there would always have to be exceptions, of one sort or another. A ban might slow the process of seeding Ebola all around the world, but it wouldn’t altogether stop it. Update 10/6/14: The Northeastern University computer model mentioned above elegantly quantifies this. Even with an 80% reduction in flights from the affected countries the probability of an infected person arriving in a given country is only delayed by 3 to 4 weeks. [MoBS Lab 10/1/14]

Update 10/6/14: Despite the arguments against it, I see two possible reasons why a travel ban may nevertheless happen: (1) it may be forced on politicians by a panicky electorate, and/or (2) the numbers of infected travelers may become excessive, due either to a general exodus or medical tourism by people who suspect (or know) that they are infected.

The five-day Hajj (Muslim pilgrimage to Mecca) started on Oct. 2. Saudi Arabia denied visas to residents of the three West African countries, and asked travelers to fill out a medical screening form that details their travels for the previous three weeks. [BBC 10/2/14] Of course people may lie, but it certainly is to be hoped that this year’s Hajj at least will be Ebola-free.

Quarantine Arriving Travelers

Travelers from suspect countries could be quarantined for 21 days before being allowed into the country. This is a tried and true Medieval technique but it’s a really poor fit with our fast-paced globalized world. A non-starter.

Continue to Screen Travelers

Thomas Duncan’s temperature was taken at the Monrovia airport as part of the screening system put in place following the Patrick Sawyer debacle. This part of the process worked as intended, to keep symptomatic travelers off planes. He was asked all the right questions; though unfortunately he lied. This sort of screening is the best you can do, and it’s helpful, even though it can’t prevent pre-symptomatic people like Duncan from traveling.

It would be helpful to add arrival screening of people who have been in affected countries (or U.S. states!) but it’s difficult to identify those people and it would be a huge project to screen everyone on arrival.

Be Prepared

Healthcare providers all over the world must be alert to the possibility of Ebola. In this case Duncan didn’t lie about coming from Liberia (although there’s no indication he told anyone about his contact with an Ebola patient) but there was a lapse in communication within the hospital. This sort of mistake can be fatal! Both to healthcare providers and others who may be needlessly exposed when an Ebola patient is sent home.

Poor countries with weak healthcare systems must be especially vigilant to spot any unusual patterns of disease or death before Ebola has a chance to get intrenched.

There’s not much we can do as individuals, except perhaps to practice good general hygiene, including frequent hand washing. Oh, and if someone is visiting from West Africa feel free to ask whether they’ve had close contact with Ebola patients in the last three weeks…

End the Epidemic

The only definitive solution is to end the West African epidemic. In addition to compelling humanitarian reasons we need to wipe out Ebola everywhere (in humans, anyway) in order to feel fully safe in our own lives.

In April, early in the West African epidemic, the New York Times published an Op-Ed piece entitled “Ebola Virus: A Grim, African Reality.” It closed with this paragraph:

Ebola in Guinea is not the Next Big One, an incipient pandemic destined to circle the world, as some anxious observers might imagine. It’s a very grim and local misery, visited upon a small group of unfortunate West Africans, toward whom we should bow in sympathy and continue sending help. It’s not about our fears and dreads. It’s about them.

I felt then as I feel now: Ebola is not just an African problem, it’s a human problem.

Ebola is obviously much less contagious than airborne viruses like influenza, and much more contagious than some other viruses, such as HIV, the virus which causes AIDS. What can we say at this point about how contagious Ebola really is?

The Official Statements

Through mid-September the WHO’s web page included this unfortunate paragraph, which is still widely quoted:

The risk of Ebola transmission is low. Becoming infected requires direct, physical contact with the bodily fluids (vomit, faeces, urine, blood, semen, etc.) of people who have been infected with or died from Ebola virus disease (EVD). [WHO 9/16/14]

As of September 20 this language had disappeared, and WHO’s current fact sheet has a more detailed and sobering description of how Ebola is transmitted between people:

Ebola … spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.

Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD. This has occurred through close contact with patients when infection control precautions are not strictly practiced.

Burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in the transmission of Ebola.

People remain infectious as long as their blood and body fluids, including semen and breast milk, contain the virus. Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness. [WHO 9/19/14]

The U.S. Centers for Disease Control (CDC) Transmission web page roughly parallels WHO’s fact sheet:

When an infection does occur in humans, the virus can be spread in several ways to others. Ebola is spread through direct contact (through broken skin or mucous membranes) with

  • blood or body fluids (including but not limited to urine, saliva, feces, vomit, and semen) of a person who is sick with Ebola
  • objects (like needles and syringes) that have been contaminated with the virus
  • infected animals
  • Ebola is not spread through the air or by water, or in general, food. However, in Africa, Ebola may be spread as a result of handling bushmeat (wild animals hunted for food) and contact with infected bats.

Healthcare providers caring for Ebola patients and the family and friends in close contact with Ebola patients are at the highest risk of getting sick because they may come in contact with infected blood or body fluids of sick patients.

During outbreaks of Ebola, the disease can spread quickly within healthcare settings (such as a clinic or hospital). Exposure to Ebola can occur in healthcare settings where hospital staff are not wearing appropriate protective equipment, including masks, gowns, and gloves and eye protection. …

Once someone recovers from Ebola, they can no longer spread the virus. However, Ebola virus has been found in semen for up to 3 months. People who recover from Ebola are advised to abstain from sex or use condoms for 3 months. [CDC 9/20/14]

This post will try to tease out what these texts mean, and how well they square with the way in which the West African epidemic has developed. Public information needs to be clear, simple and not dangerously misleading. But it also tries to avert panic; it isn’t always the “whole truth.”

Reading Between the Lines

Both WHO and CDC state that contact with bodily fluids, etc. must be “(through broken skin or mucous membranes).” Apart from a cut this refers to the mouth, nose, eyes and anal and genital openings. What neither statement emphasizes is the importance of the hands as a means for the virus to get to a mucous membrane. A touch to the lips or the eye with a contaminated hand could do the trick, as could also a stray droplet of any sort of bodily fluid.

The examples given of contaminated surfaces differ oddly between the two descriptions. WHO mentions “bedding and clothing” while CDC mentions “needles and syringes.” Both obviously have the potential for transmission. Possibly the WHO fact sheet is directed to individuals while the CDC was thinking more about healthcare providers.

The CDC fact sheet says that “Ebola is not spread through the air.”

  1. It is obviously possible for someone to be infected by a droplet that passes “through the air” onto a mucous membrane. Various experiments have shown such transmission between animals in a laboratory setting. CDC acknowledged this in an earlier fact sheet, but explained, “While all Ebola virus species have displayed the ability to be spread through airborne particles (aerosols) under research conditions, this type of spread has not been documented among humans in a real world setting, such as a hospital or household.” [CDC 4/9/10]
  2. Ebola is obviously not spreading through the air anywhere near as easily as flu. This is the current phrasing of the CDC guidance for managing ill airplane passengers that originally was cited as evidence that the CDC believed in airborne transmission: “Ebola does NOT spread through the air like flu.” [CDC 9/20/14]
  3. The key question is whether Ebola is in fact being transmitted during the current epidemic through the air, and if so how significant this mode of transmission is, and how much it is affected by the condition of the patient. We’ll consider this further below.
  4. Mutation could in principle affect contagiousness by air, and we must remain vigilant about this possibility.

WHO advises that men use condoms for 7 weeks after recovery, while CDC recommends 3 months. That’s a pretty big difference! The Public Health Agency of Canada states that, “Ebolavirus has been isolated from semen 61 to 82 days after the onset of illness, and transmission through semen has occurred 7 weeks after clinical recovery.” [PHAC 9/20/14] This would seem to be a situation in which WHO is minimizing a risk that might exist for more than 7 weeks. At the moment sexual transmission by survivors is the least of our worries, but it may become important in the final phase of ending the epidemic.

The West African Experience

The current epidemic has provided a treasure trove of information about how Ebola does — and doesn’t — spread. Hopefully someone is collecting as much of this information as possible for scientific analysis. Only a few specific cases have been well enough described in the press for any conclusions to be drawn by outsiders, however. While anecdotal, they are nevertheless highly suggestive. For this purpose we are as interested in who didn’t get infected as in who did.

The Super-Spreader Funeral

All cases of Ebola in Sierra Leone have been traced to 14 women who were infected at the funeral of a traditional healer in Guinea. [NYT 8/28/14] It is customary at traditional funerals for people to wash, touch and even kiss the body, so it’s not surprising that they were infected. What’s interesting is that dozens of people attended the funeral — presumably quite a few more than the 40 who agreed to give blood samples — and it’s reasonable to suppose that many of them also had contact with the body. The corpse was clearly quite infectious, but even so it infected only perhaps 1/4 of those who attended the funeral.

The Nigerian Outbreak

Patrick Sawyer was a sociopath who caused the death of a dozen people, and very nearly unleashed Ebola on the most populous country in Africa. [EbolaStrategy 8/31/14] He was also a naturalized American citizen, and the Coordinator of the Economic Community Of West African States (ECOWAS) Unit of the Liberian Finance Ministry. [Note: Nigeria reported a total of 19 Ebola cases. I’ve been able to identify only 14 from the press. The others may be secondary infections plus a handful of additional primary infections, but they don’t much change the picture painted below. I’ll update this post if I’m able to sort out this discrepancy.]

Princess

The story begins with Sawyer’s sister, known as Princess, who was bleeding uncontrollably when her fiancé brought her to St. Joseph Catholic hospital in Monrovia. Her symptoms were recognized and hospital staff initially refused to touch her, but the Chief Administrator of the hospital, Brother Patrick Nshamdze, decided to treat her as if she presented a simple case of a miscarriage. [NationalChronicle 7/29/14] [FrontPageAfrica 8/13/14] Princess continued to bleed, however, and she was about to be moved to an isolation ward when Sawyer arrived. “He insisted that she be given a private room and plunked down $500 to secure it. He proceeded to personally change her gown and placed her in a wheelchair for the move. He was seen to get her blood on his own clothes as well as his shoes in the process.” [DailyBeast 8/14/14] Princess died on July 7. Understandably, Sawyer, Nshamdze and other healthcare staff who treated her without precautions became infected. Then the same thing happened when Nshamdze himself fell ill – doctors, nurses, a social worker and a lab technician fell ill. There’s no special information about contagiousness here, however, since there was lots of blood and few precautions.

Patrick Sawyer

Because of close contact with his sister, Sawyer was monitored daily and told not to leave Liberia. On July 20, after he began showing serious Ebola symptoms, including fever and vomiting, he got on a plane to Lagos, Nigeria, with a layover in Togo, as part of a nine-member ECOWAS delegation to a conference. He vomited repeatedly during the flight, then collapsed in Lagos airport. He was helped into a taxi and taken to First Consultant Hospital, where he initially told the medical staff that he had malaria and denied contact with any Ebola cases. Only two days later was he tested and found tentatively positive for Ebola, at which point he was quarantined.

One of the nurses who treated him, Obi Justina Ejelonu, became infected even though: “I never contacted his fluids. I checked his vitals, helped him with his food (he was too weak). … I basically touched where his hands touched and that’s the only contact. Not directly with his fluids. At a stage, he yanked off his infusion and we had blood everywhere on his bed … But the ward maids took care of that and changed his linens with great precaution.” Another hospital source “told [Front Page Africa] that in addition to yanking the infusion tubes, Sawyer took off his pants and urinated on the floor as nurses fled from his presence.” [FrontPageAfrica 8/11/14] He died five days later, on July 25.

A doctor who treated him, Dr. Ada Igonoh, also became infected. She gives an extremely detailed account of Sawyer’s stay at her hospital (and of her own illness and recovery) in a moving Front Page Africa article. [FPA 9/18/14] She felt that, “my contact with Sawyer was minimal. I only touched his I.V. fluid bag just that once without gloves. The only time I actually touched him was when I checked his pulse and confirmed him dead, and I wore double gloves and felt adequately protected.” The first several days in which Sawyer was treated for malaria without full precautions could explain her infection, however, as well as that of Dr. A.S. Adadeveoh, who treated Sawyer during the same period. [FPA 8/25/14]

“In total, Sawyer reportedly came in direct contact with 59 persons, 44 of whom were at the hospital… Sawyer came in contact with three ECOWAS officials – a driver, a liaison officer and a protocol officer. Also in the list are two nursing staff and five airport handlers.” [FrontPageAfrica 7/31/14]

Out of all his 59 contacts Sawyer appears to have directly infected just 5 people: The nurse and two doctors already mentioned, an ECOWAS official who picked Sawyer up at the airport and took him to the hospital, and an ECOWAS diplomat who was part of the group who greeted him on his arrival. All his other contacts did not get infected. That includes both passengers and crew on two flights, during which he was repeatedly vomiting, and everyone else in the Monrovia, Togo and Lagos airports. He was capable of infecting others, obviously, but on balance Sawyer was not very contagious.

The ECOWAS Diplomat

The ECOWAS diplomat escaped from quarantine in Lagos on July 26, traveled to Port Harcourt, and arranged to receive secret treatment in a hotel room by a local doctor, Iyke Enemuo. The diplomat recovered but the doctor was infected. There’s no indication that any other contacts of the diplomat were infected, however, so once again the healthcare providers bear the brunt of transmission. Apart from infecting Enemuo, the ECOWAS Diplomat was not very contagious.

Dr. Iyke Enemuo

Dr. Enemuo was yet another sociopath, following in Patrick Sawyer’s footsteps. He kept his contact with the infected ECOWAS diplomat secret and continued to pursue an active medical practice and social life, even after falling ill. WHO recounted the shocking details (apologies for the duplication from my first post):

After onset of symptoms, on 11 August, and until 13 August, the physician continued to treat patients at his private clinic, and operated on at least two. On 13 August, his symptoms worsened; he stayed at home and was hospitalized on 16 August. Prior to hospitalization, the physician had numerous contacts with the community, as relatives and friends visited his home to celebrate the birth of a baby.
Once hospitalized, he again had numerous contacts with the community, as members of his church visited to perform a healing ritual said to involve the laying on of hands. During his 6 day period of hospitalization, he was attended by the majority of the hospital’s health care staff.
On 21 August, he was taken to an ultrasound clinic, where 2 physicians performed an abdominal scan. He died the next day.
[WHO 9/3/14]

Nigeria had to track some 255 contacts, 60 of whom had high-risk or very high-risk exposure!

Of all those many contacts, Dr. Enemuo actually infected only 5 people: his wife (also a doctor), his younger sister, a doctor who treated him at the hospital, a pharmacy technician, and an older woman who shared his hospital room. [NigeriaTimes 9/19/14]  [Reuters 9/1/14]  He was certainly capable of infecting people, but considering the number of people he was in contact with after falling ill, Dr. Enemuo was not very contagious. Once again, caregivers and immediate family members were at greatest risk.

The Senegal Student

A 21-year-old college student was under observation in Guinea because he had helped care for several family members who had fallen ill with Ebola. Nevertheless, he traveled in a six-passenger vehicle to Dakar, Senegal, arriving on August 20. He stayed with his uncle in a crowded household for three days, then went to a local hospital, but did not mention his exposure to Ebola. He was initially sent home, but the following day “the Guinean health services reported ‘the disappearance of a person infected with Ebola who reportedly traveled to Senegal,’ according to Senegal’s health minister,” and the student was quarantined. [BBC 8/29/14] [Bloomberg 8/31/14] 67 close contacts were placed under observation: people he was in contact with during his journey, members of his uncle’s extended household, healthcare providers at the hospital, etc. [WHO 9/12/14]

The striking feature of this case is that none of the student’s 67 close contacts became infected! This is very different from other situations. My best guess is as follows: The student was never terribly sick, and has fully recovered. Consequently, he may not have had the same viral load as other patients, and may not have been throwing off bodily fluids as prolifically. It’s also possible that the main hospital in Dakar follows more rigorous universal precautions than those in the other affected countries. Whatever the reason, this is a striking instance of how non-contagious Ebola can sometimes be.

Healthcare Providers

More than 240 healthcare providers have been infected during the West African epidemic, half of whom have died. [WHO 8/25/14] The great majority were local doctors and nurses who did not wear full protective gear, often because they were not yet aware that a patient had Ebola and sometimes because of a shortage of supplies. In a few cases, however, healthcare providers who were apparently following standard procedure nevertheless became infected. These cases raise concerns about the mode of transmission.

Dr. Kent Brantly

Brantly became infected working with patients at a Monrovia hospital operated by evangelical Christian organization Samantha’s Purse. He asserts that he followed all CDC recommended procedures, including wearing a standard N-95 face mask, the type also used by Médecins Sans Frontières/Doctors Without Borders (“MSF”).  [MSF 7/28/14]  This raises a question of whether Brantly was infected by airborne droplets that passed through his mask. This point is pressed in a tendentious but interesting article, written by a doctor who argues that Ebola healthcare providers should use the more expensive and uncomfortable P-100 (HEPA) face masks to fully protect against airborne droplets. [AmericanThinker 8/24/14]

The N-95 mask is designed to block 95% of “solid and water-based particulates (i.e., non-oil aerosols)”. The P-100 (HEPA) face mask blocks 99.97% of particulates and aerosols, whether or not oil-based. [CDC Jan, 1996]

  • Maybe Brantly made some other mistake, of which he wasn’t aware. This seems frighteningly possible, with the odds of an error — small though they may be — relentlessly adding up as he worked day after day in close contact with Ebola patients.
  • Maybe airborne transmission is indeed very rare, but Brantly got unlucky.
  • Maybe airborne transmission is easier than we have thought, and MSF has been very, very lucky.
  • Maybe the virus has mutated to become more easily transmitted by air — though obviously still vastly less easily than the flu.

The French MSF Volunteer

MSF announced on Sept. 17 that a French volunteer at one of its treatment centers in Monrovia had become infected, despite their strict infection-prevention protocol. She is the first international MSF staff member to be infected in the West African epidemic, although 7 local staff members had previously fallen ill, out of more than 2,000 MSF staff members in the region. The treatment center is turning away new patients pending an investigation into how the volunteer became infected. [Reuters 9/17/14]

From one perspective eight people out of 2,000 is less than half of one percent. But, as MSF President Joanne Liu had previously pointed out, the entire control effort can fall apart if healthcare providers feel personally unsafe.

We have no further information about how this volunteer may have been infected, but the announcement of the MSF investigation implies that it wasn’t due to anything obvious. Airborne transmission is a possibility.

The American Journalist

Added 10/6/14: An American journalist, Ashoka Mukpo, tested positive for Ebola on Oct. 2. He believes that he may have become infected when he was splashed while spray-washing a car in which an Ebola patient had died. [ABC 10/6/14]  This seems credible and consistent. He is, by the way, being treated in the high-level biocontainment unit at the University of Nebraska Medical Center. This unit is the largest of four U.S. biocontainment units, and has 10 beds, which means that the U.S. has a total of less than 40 bio-containment beds in the entire country. Hmm…  [NPR 10/6/14]

Ebola Transmission in the Developed World

At this writing there have been only two instances of transmission of Ebola outside of Africa, both involving nurses who cared for Ebola patients in the last stages of the illness. Both wore full anti-infection gear; this is not like the West African cases in which healthcare providers were infected before precautions started being taken, or because proper gear wasn’t available. Both nurses — at least initially — said they were not aware of any breach of the anti-infection protocol.

The Spanish Nurse

Added 10/6/14: A nurse (more precisely, a volunteer auxiliary nurse) contracted Ebola while treating a Spanish missionary in Madrid’s Carlos III hospital, where he died on Sept. 25. She is the first person known to have contracted Ebola outside of Africa. Reportedly she only entered the patient’s room twice, once after his death. [NYT 10/6/14] We have no information about what precautions the nurse used, and whether a mistake may have been made. Update 10/8/14: The nurse initially said that she had followed the anti-infection protocol to the letter, which would have undermined confidence in the protocol and increased the anxiety of healthcare personnel. She then said that she “might have” touched her face with a contaminated glove as she was taking the protective suit off. [NYT 10/8/14]  It’s reassuring — if also a bit too convenient — to have an explanation for how the nurse was contaminated.

The infection of the Spanish nurse is worrisome but not inconsistent with the experience in Africa, where hundreds of healthcare workers have contracted Ebola, and several Western medical personnel have been infected without noticing a failure of protocol. We do need to figure out why this is happening, but the extreme infectiousness of corpses and people in the last phase of the disease is known, and there’s nothing about this case which changes the picture.

The real issue in her case has nothing to do with contagion: it’s the fact that Spain took nearly a week to test her for Ebola after she reported that she was running a fever. This casual attitude will have to stop! Western countries have ample resources to contain Ebola, but it will bite anyone who treats it with laziness or contempt.

The Dallas Nurses

Added 10/14/14: Nina Pham, a Dallas nurse who gave extensive care to Thomas Eric Duncan throughout his hospitalization is the first person known to have contracted Ebola in the U.S. As noted above, she was not aware of any breach of protocol. This is of course worrisome, and affords further evidence that the CDC needs to focus more closely on the protocol, and the way in which training is given. But it isn’t a new issue. [NYT 10/13/14]

Again, the important issue isn’t contagion, but the fact that Ms. Pham wasn’t monitored as a contact. Fortunately, she self-monitored, detected a low-grade fever, and had herself admitted to the hospital. She tested positive for Ebola on the evening of 10/11.

Added 10/20/14: A second nurse who treated Duncan, Amber Joy Vinson, was confirmed as having contracted Ebola on Oct. 15. She had been self-monitoring and had reported a low grade fever, but was nevertheless allowed to fly to Cleveland on Oct. 10 and back to Dallas on Oct. 13. That was obviously stupid, and put at minor risk a large number of people in both cities and on both flights. But once again, the fact that an inadequately trained and protected nurse got infected from a later-stage Ebola patient is nothing new. [NYT 10/20/14]

Added 10/29/14: Both nurses have now been declared Ebola-free and discharged from hospital.

The Other Contacts of Thomas Eric Duncan

Added 10/8/14: It’s too early to say, but the fact that none of Duncan’s other contacts have yet shown symptoms is notable. He was very ill before being taken to the hospital the second time, and lived in close quarters with his girlfriend, her son, and her two nephews. He wasn’t as sick the first time he went to the hospital, but it seem clear that several doctors and nurses were in contact with him without taking exceptional precautions. It would be a remarkable confirmation of how infectious Ebola isn’t if all of these folks escape infection.

Added 10/20/14: Happily, nearly all of the 50 contacts with Duncan before his second hospitalization have now completed their 21-day quarantine period, with no Ebola symptoms! As well as being great news for them and for Dallas it confirms once again that Ebola is remarkably noncontagious until the final stage of the illness. Dozens Declared Free of Ebola Risk in Texas [NYT 10/20/14].

One nuance doesn’t change this conclusion, but could lead to a further little outbreak: As noted below, 5% of people infected with Ebola don’t show symptoms until more than 21 days from exposure. [NEJM 9/23/14]  If someone released from quarantine turns up with symptoms after the 21-day period CDC might end up with egg on its face, and public confidence could be seriously eroded. I understand why 21 days has been chosen as a way of sending a simple message to the public but taking this approach is a somewhat risky strategy.

The Contacts of the Dallas Nurses

Added 10/29/14: Nina Pham apparently had only a few contacts, chief among them being her boyfriend. Amber Joy Vinson, however, flew to Cleveland and — after reporting a low-grade fever — back to Dallas. Vinson accordingly placed at theoretical risk a large number of people. It will be interesting to see whether any of these contacts became infected. My own guess — based on the other cases described above — that nobody else will come down with the disease based on contact with either of the nurses. If so, that should alleviate the public’s anxieties, but probably won’t.

The Bottom Line

Here are a few concluding observations:

  • Even though the epidemic is growing exponentially, the individual cases we’ve been able to review support the official position that Ebola is not very contagious, and generally requires contact with bodily fluids or contaminated surfaces. Even a corpse only infected about a quarter of the attendees at a traditional funeral in which touching the body was customary.
  • Caregivers and immediate family members are at highest risk, and others are at relatively low risk.
  • Infectiousness depends on how ill the patient is, both from the perspective of viral load and the amount and character of emitted bodily fluids. There is no evidence of transmission before the patient becomes symptomatic; very little evidence of transmission before the last stage of the illness; but a high risk of transmission to caregivers and others who have direct contact with a patient during the last stage of illness.
  • It isn’t clear to what extent the virus can be transmitted through the air, but:
    • Casual contact such as sharing an airplane or even mingling in a social setting rarely or never seems to be enough to infect. Added 10/20/14: As noted above it’s astonishing that Duncan’s girlfriend and the three boys who also shared the apartment where Duncan stayed avoided infection.
    • Something is infecting healthcare providers, even when they believe that they are following CDC guidelines. It is urgently necessary to determine why so many healthcare personnel who claim to be following CDC procedures are getting infected. We have to figure out what’s happening with that and fix it, whether or not it involves airborne transmission.

Update 10/3/14: A survey article by the WHO Ebola Response Team in the New England Journal of Medicine provides a lot more information, although it doesn’t greatly change our understanding of the situation. [NEJM 9/23/14]  Here are a few key points:

  • The mean incubation period is 11 days, and 95% had symptoms within 21 days of exposure, the recommended period for follow-up of contacts. Accordingly, 5% of infected contacts will first present symptoms after follow-up ends.
  • The article estimates the current effective reproduction numbers at 1.81 in Guinea, 1.51 in Liberia and 1.38 in Sierra Leone. This basically means that each infected person is infecting on average between one and two more people, thus causing the epidemic to grow exponentially. See my earlier post, The Ebola Chain Reaction, for a more detailed explanation. The article rather cheerfully comments that : “This means that transmission has to be a little more than halved to achieve control of the epidemic and eventually to eliminate the virus from the human population. Considering the prospects for a novel Ebola vaccine, an immunization coverage exceeding 50% would have the same effect.”
  • Without changes in control measures, their estimated doubling times range between 15 days for Guinea and 30 days for Sierra Leone.
  • Case fatality has been 70% in Guinea, Liberia and Sierra Leone, in contrast with earlier reports closer to 55%. It was lower in Nigeria but the number of patients was so small that this might be a fluke.

Also, here’s a very clear statement, in the Oct. 2 New York Times, of what is considered “direct contact” with the bodily fluids of an Ebola patient: Understanding the Risks of Ebola, and What ‘Direct Contact’ Means

Update 10/8/14: An article in the LA Times collects questions about whether Ebola might be more contagious than is currently believed: [LA Times 10/7/14]

  • Mutation is of course a wild card, which could make the virus somewhat or much more contagious. This is one of several good reasons for devoting resources to stopping the epidemic as soon as possible. But I don’t see any evidence of significant change in contagiousness, and nobody is claiming specific evidence of relevant mutations.
  • What we do see is a pattern of poorly-explained infections of healthcare providers, especially when patients are in the last stage of illness. This might involve small highly-infections droplets passing through the air, and conceivably might lead to further tightening of the anti-infection protocol. Added 10/14/14: In any case one must welcome CDC’s plan to improve training and to send a team to any hospital treating an Ebola patient. [NYT 10/13/14]
  • What we do not see is large numbers of infections of people who have casual contact with patients, or who have contact with patients before they have become symptomatic. So long as that pattern holds Western nations should have little difficulty keeping Ebola under control, so long as they treat it with the great respect and vigilance that it deserves.

Update 3/24/15: Liberia has identified a single Ebola patient who appears to have been infected by her partner, a male survivor. [NYT 3/24/15]  This presumably came through his semen, which is known to contain Ebola virus for several months after recovery. This will make the disease a bit more difficult to eradicate, but is not cause for panic. The fact that just one infection of this type has come to light suggests that this mode of transmission is infrequent. Additionally, now that an example exists one might expect many “discordant couples” (in which the male is a survivor and the female is not) to use condoms, which should further reduce the risk. One question that calls for further research is how long the virus can persist in the semen of a male survivor, and whether a negative semen test is sufficient to make unprotected intercourse safe for the survivor’s partners.

It’s relatively easy to think of ways in which things could go wrong, especially when dealing with a deadly disease like Ebola. I’m not optimistic about the likely course of events in West Africa, as you might gather from previous posts. But in this post I want to make an honest effort to envision what success would look like, then work backwards to see how it might be possible to get there from here. What follows is fantasy, but with a serious purpose.

Victory Over Ebola!

It has been 42 days and there have been no new cases in any of the countries affected by the West African epidemic! The last patient has either recovered or, sadly, died. Temporary facilities have been disassembled or burned, and hospital buildings thoroughly disinfected. Everyone has been through a harrowing experience but generous aid and technical assistance from around the world should help the affected countries get back on their feet.

Animal reservoirs of Ebola still exist; it would be wonderful to extinguish the virus worldwide but it’s really hard to imagine that. Ongoing efforts will be needed to discourage contact with infected animals, such as bush meat and fruit that may have been partially eaten by infected bats. Vaccination may reduce the risk of future outbreaks, although it will be difficult to maintain universal immunity in still-poor countries, and a vaccine might not confer immunity against a new strain. So as long as Ebola exists in the wild there will continue to be occasional rural outbreaks. The world obviously must never again let Ebola get out of control!

Mopping Up

The “Effective Reproduction Rate” (Re) [Discussed in The Ebola Chain Reaction] was held down below one, month after month. That is, each person who came down with Ebola infected on average less than one other susceptible person. This was true not only in the aggregate but also in each country and region and neighborhood. The number of patients being cared for peaked, then began a slow but consistent decline, as the number of new patients each day was fewer than the day before. American troops were drawn down, then withdrawn completely, as there was no more need for additional beds.

Winning the War

Gradually, Re was forced lower and lower, down below one and then well below. How was this accomplished? Some combination of these factors:

  1. There were enough Ebola isolation beds for everyone who came down with the disease, in all affected countries, and the public had so much confidence in the care in those facilities that just about everyone who came down with Ebola was admitted to one before other family members were infected. Treatment measures and drugs like ZMapp improved the survival rate somewhat; this reduced suffering and contributed to confidence but didn’t otherwise help bring the epidemic to a stop.
  2. An Ebola vaccine, though not available in sufficient quantities to immunize everyone, was strategically given to American soldiers, healthcare providers and others who were likely to be exposed. Except for President Ellen Johnson Sirleaf and her husband the vaccine was not given out based on money or position.
  3. Infection of healthcare providers was almost completely stopped by:
    1. Universal availability of infection control gear.
    2. Comprehensive training of staff at all healthcare facilities.
    3. Procedures to minimize exposure of unprotected staff during admission or when an admitted patient begins showing Ebola symptoms.
    4. The Ebola vaccine, when it became available.
  4. Traditional funeral and burial practices were suspended by general consent after a massive public information campaign.
  5. People stopped breaking quarantine and/or lying about their Ebola exposure [Discussed in my first post], due to a broad consensus supported by religious and other opinion leaders.
  6. Urban modes of transmission turned out not to be significant, or were greatly reduced by changes in behaviors and other measures.

It would be great if one could imagine the final stage taking place before a vaccine is available, since that won’t be until around the end of the year at the earliest. Please comment if you think I’m too pessimistic, but I just don’t see how you get Re down below one in Liberia and Sierra Leone without a vaccine. Guinea is different, since their problem in recent weeks has been rural flare-ups due to infected citizens returning there from the other two countries. If Guinea can keep snuffing out these outbreaks — using the classic techniques of isolation, contact-tracing and monitoring —  it might be able to get its part of the epidemic under control before the vaccine arrives.

Boots on the Ground

President Obama announced his plan to send 3,000 U.S. troops to Monrovia on September 16, 2014. [CNN 9/16/14] The troops were outfitted and trained in record time and arrived in Monrovia on [wildly hopeful] October 16, 2014. At that time Monrovia needed [a wildly optimistic guess] 1,000 additional beds to accommodate all current Ebola sufferers. The troops set to work building facilities for 1,700 beds, which became ready for patients between [optimistically] November 1 and November 16. By then all the beds were needed, and new patients kept seeking treatment at an increasing rate since Re was still over one. The U.S. identified the problem early and built another 1,700 beds (and trained all necessary staff), also in record time. This time around they got ahead of the curve and Monrovia was finally able to offer isolated care to all Ebola sufferers.

This was the most difficult period of the epidemic, when cases were still growing exponentially, and civil order was progressively undermined. The arrival of Americans had a wonderful effect on the public mood, however. American know-how and money ensured the provision of reliable water, electricity, trash removal and in particular food supplies.While there were a few situations in which small mobs gathered around American installations it was never necessary for a U.S. serviceman to file a single shot, and nobody was injured.

Due to their excellent training and high discipline, only a handful of U.S. troops became infected with Ebola. Those who did fall ill were medevaced back to the U.S., where a combination of excellent care and their own fitness led to a much lower mortality rate than experienced in Africa. Political blow-back from these Ebola casualties was muted due to a national consensus that American needed to do whatever it could to help with the humanitarian crisis in Western Africa. Once the vaccine became available U.S. troops were protected against Ebola and this problem stopped.

Meanwhile, home care kits that had been sent to rural areas proved helpful in reducing Re somewhat, but the key to success in those areas was the addition of more beds, in this case provided and staffed by Médecins Sans Frontières.

The African Union played the same role in Sierra Leone as the U.S. did in Liberia, with the same happy effects. (This strains credulity. The U.S. may have to do the same thing in Sierra Leone itself, which will be exponentially harder the longer it is delayed.)

Guinea continued to experience flare-ups due to travelers from Liberia and Sierra Leone, but it was able to snuff each of them out, and prevent the disease from getting established in its cities.

And They Lived Happily Ever After

Is this a fairy tale or can it happen? There are a lot of ways in which it could fail. To mention just a few:

  • Every day counts when you’re battling an exponentially-growing problem. Any delay in any part of the process risks the numbers growing beyond anyone’s ability to manage them. Liberia may already be beyond the point of no return, but we’ll never know if we don’t try.
  • Sierra Leone is about as bad off as Liberia. Is someone else really going to step in there, or does the U.S. have to go there as well?
  • Political support for the U.S. intervention is likely to be tepid at the outset and could turn sharply against the project after there are casualties. This could force an early withdrawal even if the program seems to be working.
  • There could be a further breakdown of civic order that would make it impossible to get the situation under control.
  • Mistrust and rumor, or arrogance and privilege, could sabotage the program.

The scenario certainly could fail, but it might just work. We must hope against hope that it will succeed.

Quarantine has always been a principal weapon against epidemics: isolate ailing people so they cannot spread illness. Quarantines come in various types, however, which have different effects:

  1. When an individual falls ill they need to be cared for in a facility that minimizes the risk that the virus will be spread to other susceptible people. This is the medical isolation that has been the key to defeating all past Ebola outbreaks. People who are suspected of having Ebola may also be kept isolated from others until their status becomes clear. I’ll call this a precautionary quarantine. A third situation is when a contact of an Ebola patient is cautioned to stay at home, or not to travel, during the 21-day incubation period. I’ll call this a monitoring quarantine.
  2. When an entire neighborhood or region is blocked off, the barrier is referred to by the French term, cordon sanitaire. This may be an urban neighborhood, such as the poor West Point district of Monrovia, or an entire region, such as the remote area at the intersection of Guinea, Liberia and Sierra Leone. Or it may be a de facto cordon sanitaire imposed by the closing of borders and the discontinuance of transport links.
  3. It is also possible to impose a curfew that limits when people can interact outside the home, in the hope that this will reduce transmission.
  4. Finally, Sierra Leone has announced a nationwidewide three-day lock-down, starting September 19, during which everyone will be required to stay home so as to allow a house to house inspection for hidden Ebola patients. [AFP 9/6/14]

Medical isolation is essential and effective, though in West Africa there have been many issues:

  • Some rural “red” villages either doubted that Ebola is real or feared that the doctors brought it. They forced Médecins Sans Frontières/Doctors Without Borders (“MSF”) to withdraw, and in some cases physically blocked road access — a do-it-yourself (reverse) cordon sanitaire! [NYT 7/27/14]  There was no choice but to let the epidemic burn itself out in those villages. I haven’t seen a report of what happened, but it will be illuminating to eventually find out.
  • Urban neighborhoods have resisted siting of Ebola care facilities nearby. Residents of the poor West Point district of Monrovia attacked and ransacked a holding facility [NYT 8/19/14], which lead to the attempted cordon sanitaire around their entire neighborhood described below.
  • People who fear letting ill family members go into Ebola care facilities often try to treat them at home, hiding them from authorities. This increases the risk of infection to home caregivers as well as other family members. Concern about this issue has led Sierra Leone to declare the country-wide lock down described below.
  • There aren’t enough beds in Ebola care facilities, at least in Monrovia. Medical isolation fails if there’s nowhere for people to go. It’s not clear how it will be possible to get on top of this issue since the epidemic is growing exponentially and the construction of facilities — and especially provision of trained staff — is not.

Precautionary quarantines and monitoring quarantines are also essential elements of infection control. The main problem I’ve noticed there is the issue of people breaking quarantine and subsequently infecting some or many other people. The experience of Nigeria is horrific: the outbreak started with one man who broke quarantine in Liberia to fly to Lagos, but it was spread by a series of additional quarantine breakers, one after another. See my earlier post: Arrogance and Privilege Imperil Nigeria’s Attempt to Contain Ebola

On August 1, Guinea, Liberia and Sierra Leone announced a regional cordon sanitaire, to be enforced by their military forces, around the remote area where the outbreak began. The New York Times described it as an infection-control strategy that has not been employed for a century. [NYT 8/12/14] A few days later, however, a writer in the New Republic described as “heartless but effective” a similar cordon sanitaire used in 1995 to control an Ebola outbreak in Zaire. [New Republic 8/14/14] Reuters expressed the concern that the cordon could create abandoned “plague villages.” [Reuters 8/17/14]  The World Food program has been struggling to provide adequate food supplies to 1.3 million people in limited access areas, including classic quarantines as well as cordons sanitaire. [WFP 9/2/14] There has been little mention of the regional cordon sanitaire in recent weeks, perhaps because the battle in the capital cities has taken center stage. The regional cordon may simply become a dead letter if Ebola continues to spread outside it.

On August 20, Liberia imposed urban cordons sanitaire on two poor and crowded neighborhoods of Monrovia: West Point and Dolo Town. Hundreds of young men in West Point rioted, throwing rocks at police, who used tear gas and live gunfire to disperse the crowd. [SaharaReporters 8/21/14] Several residents were injured, and a 15-year-old boy died. During the closure there were many stories of evasion, including a couple who bribed a soldier $10 to get out and a man who swam around the cordon each weekday to go to work in a government office. Ten days later the West Point cordon was lifted. [NYT 8/29/14] The West Point cordon would have to be called a failure. Meanwhile Dolo Town had accepted the restriction more calmly, although grumbling was reported three weeks later about continuing to be an “Ebola Jail Town.” [AFP 9/7/14]

Liberia also imposed a nationwide curfew on August 20, from 6 pm to 9 am. [AFP 8/20/14]  There has been a report that nighttime armed burglaries have increased during the curfew. [The New Dawn Liberia 9/8/14] The value of the curfew is debatable. It depends on the importance of urban transmission modes, and how many potential transmission events are prevented by keeping people home at night.

A de facto cordon sanitaire around the entire region has been developing over the past couple of months through a series of border closings and flight suspensions, along with regulations barring entry to ships that had touched at ports in the affected countries. In the past week a plea has been made for flights to continue and for borders to be opened to screened transit. It will become increasingly difficult to get necessary materiel and personnel into the affected countries if transport restrictions aren’t eased.

Most recently, Sierra Leone has announced a three-day nationwide lockdown, starting Sept. 19, during which everyone is expected to stay in their homes, with exceptions only for essential travel. During this period a house-to-house inspection will be conducted to find patients that are being hidden from the authorities. A government spokesman is quoted as saying that, “We intend to ensure that the dreaded disease is checked.” [AFP 9/6/14] MSF has expressed concern that this sort of measure will do more harm than good: “It has been our experience that lockdowns and quarantines do not help control Ebola, as they end up driving people underground and jeopardizing the trust between people and health providers…” But the top U.N. official in Sierra Leone supported the idea. [NYT 9/6/14] My own view is that the idea is daring but a lot could go wrong:

  • Households that are concealing an Ebola patient are likely to resist a thorough inspection, thus frustrating the purpose.
  • Even if a household doesn’t harbor an Ebola patient, it may have some other secret that will lead it to resist inspection.
  • People who are angry anyway will have three full days to sit at home and get angrier and angrier. This could burst out into violence.
  • How will the inspectors distinguish people who just have malaria or colds from people who really do have Ebola?
  • Will the inspectors all be wearing full protective gear, and will they be trained in procedures for putting them on and taking them off? The arrival of a moon-suited team would not be a warm and fuzzy experience, but if they aren’t protected the inspectors themselves could be the next wave of victims.
  • If a lot of patients are found where will they go? I’m not sure about the situation in Sierra Leone, but in Monrovia there aren’t nearly enough beds in Ebola treatment facilities. [WSJ 9/7/14]

All that said, a desperate situation calls for desperate measures. I hope the lockdown works!