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Catching Ebola: mistakes, messages and madness [amended]

contacts, Ebola virus, Ebola virus disease, EVD, transmission

Written by Dr. Ian M. Mackay and Dr. Katherine E. Arden

Despite obvious community and media fear, speculation and exclamation that Ebola virus would enter and spread widely within countries outside the hotzone, such an event did not come to pass in 2014. The early public health messaging on Ebola virus and disease were, for the most part, spot on.

In 2014 and 2015, thousands of cases of Ebola virus disease (EVD) ravaged Guinea, Sierra Leone and Liberia in 2014 (the "hotzone"). A smaller outbreak was defeated in Nigeria [8] and another distinct Ebola virus variant drove an outbreak of EVD in the Democratic Republic of the Congo[7] - they too controlled spread of the virus. Ebola virus travelled from the hotzone to other countries including Senegal, Nigeria, the United States of America (USA), Mali and most recently, the United Kingdom. It did this by hitching a ride in a usually unknowingly infected human host.

Over 40 people have been intentionally evacuated or repatriated for observation or more aggressive supportive care - and perhaps the use of experimental therapies - to France, the USA, Spain, Sweden, Norway, Denmark, Germany, Netherlands, Italy, Switzerland and the United Kingdom.[1,18]

Recently, the last country outside of Africa to have unintentionally acquired a case of EVD, the United Kingdom, passed a milestone; 42 days since the last ill patient tested negative for Ebola virus. They were declared free of known virus transmission.[17]

Containing the spread of each imported case has relied upon stringent infection prevention and control measures and the identification and monitoring of each and every contact of an Ebola virus infected person. And these have been used with great success. No country, apart from the three in which transmission has been widespread and intense, has seen the appearance of multiple and continuing rounds of new EVD cases. A rough calculation of the numbers of contacts falling ill from each EVD index case who travelled outside the hotzone is shown in the table. It only includes those with data available publicly.

On average, fewer than 1 in 100 contacts (0.8%) came down with EVD. Not the easiest virus to catch? If you compare that to measles, 9 in 10 non-immune people close to an infectious measles case will acquire disease (90%).[19]

Table 1. Index cases and the proportion of contacts they infected

a-man travelled overland from Guinea while infected; b-man with EVD repatriated from Liberia; c-man who flew while symptomatic to Lagos, Nigeria with a stopover in Lome, Togo; d-man flew from Liberia while infected; e-male healthcare worker returned from Guinea; f-a 2 year old girl travelling overland while infected; g-male travelled by car to a clinic in Bamako, Mali from Guinea (assumed Ebola case); h-female healthcare worker returning from deployment in Sierra Leone; i-this figure may indicate all contacts for both Mali cases

The extent of the fear inspired by the first imported EVD case was especially clear from the massive spike in social media content from the United States which followed the arrival from Liberia of an individual with EVD; far more social media activity than had been seen in the United States to that point, or since.[14,10] This month, even though 11 contacts/associates are being flown back to the United States for observation; on the heels of the index case, social media activity has barely responded � in fact Twitter is possibly more positive/neutral about Ebola in the US in March 2015 than in August 2014, rather than excessively fearful, mean or just plain hysterical.[10]

Some of the heat may have been taken out of the emotional response to Ebola outside Africa because it is now clear that a catastrophic pandemic is not going to happen. Kinda like we were told. I know; it;s so uncool to be reminded that you were told something by a grown up - and it was right!

Well...THEY TOLD YOU SO!!!

Nations with better (some!) healthcare infrastructure, preparedness, healthcare to patient ratios and those who got advice and help quickly, curtailed the spread of EVD. Kicked it out. Stomped on it. Terminated it. This was true even when contacts had been classified as at high risk of getting sick.[15]

Public health messaging made some big calls early on. Some examples include tweets by Head of Public Relations for the WHO, Gregory H�rtl, and later by the Centers for Disease Control and Prevention�s Director, Dr Tom Freiden.[11] They made it clear that Ebola virus was not easy to catch and that measures to stop an outbreak were known.[16] At the time, this didn't jibe with other voices and the unprecedented number of EVD cases and deaths, especially from August onwards, that were tallying up at an exponential rate in west Africa. But those messages, while technically correct, probably didn't convey enough of some of the biggest factors in a disease outbreak - fear, ignorance (meant only in the sense of no specific knowledge of Ebola virus and EVD), tradition and history - the human factors rather than the viral ones. Some comments about transmission suggested essentially no chance of even a single new case happening on the home soil of richer countries - they were overly enthusiastic. They were unjustifiable and when some hospital workers in non-African countries became infected, they were ultimately seen for the mistake in message crafting that they were.

Much of the science of the Ebola epidemic is yet to be written, but what we know today is that it is unlikely that Ebola transmission is any different from what was observed decades ago. Direct, physical contact with a very ill person�s fluids is the overwhelmingly biggest risk factor to target in reducing disease spread. And even then there's no guarantee that disease will result from all instances of contact. We still have much to learn.

What has changed since the bad old days? We�ve learned how to better manage and support EVD cases. EVD is a disease that caught us a little unawares in its combination of "skills" - it spreads by care and through direct contact, accrues a lot of virus in the blood but also vast quantities in explosively propelled fluids produced from "both ends"; virus that remains infectious for even longer in urine and semen than in blood. Quite the mix of issues to deal with.

EVD is no longer a death sentence, and this needs to become part of the new messaging paradigm. It's a message that may still be highly relevant to those in Guinea and Sierra Leone who seemingly would still rather risk death than seek care at a treatment unit. Post-mortem detection of EVD cases is ongoing, although may be on the decrease but also nearly a third of cases in Guinea and Sierra Leone are arising from unknown human sources.[21] Contextual communication is needed from within each country and region. That aspect cannot be allowed to wane.

With early care, and active care, rather than the palliative model that seemed to occur when the ratio of EVD cases to healthcare workers was too high, patients mostly survive. The EVD treatment center at the Hastings Police Training School near Freetown, Sierra Leone stands as a model for successful life saving and is the best described example of this from the west Africa epidemic to date.[20]

Ebola virus infection is not easy to catch, it can be survived much more often than was generally accepted and its spread can indeed be stopped. Stopping an Ebola outbreak quickly seems to be helped mostly by prior education, ongoing communication, forewarning and preparation but also needs ongoing surveillance, functional healthcare infrastructure, a range of experienced workers and all of that must all be under-written by money.

But even with all that help in place, mistakes will be made and lessons will be learned, by everyone, all the time. Embrace that. We're all human.

References

MERS-CoV around the house-yes, it does transmit at home

contacts, household, MERS, MERS-CoV, seroprevalence

Click on graph to enlarge.

Some Middle East respiratory syndrome coronavirus (MERS-CoV) questions remain stubbornly unanswered even after two and a half years.

Today comes a study from Prof Christian Drosten and colleagues, including Prof Ziad Memish, released by the New England Journal of Medicine.[1] This study takes a look at MERS-CoV infection among the contacts of MERS cases.

We already know that asymptomatic or "silent" MERS-CoV infections are not rare. At least 17% of detections of this virus have occurred in people with no overt signs or reported symptoms of disease. That's not to say that they didn't have a slightly raised temperature, headache, sniffle or something very mild that got overlooked or forgotten, but nothing noted or noteworthy. I'd love to see a study on asymptomatic MERS-CoV infected people that looked into fine detail signs and symptoms by the way-that might tell a nice little story about "silent" infections.

This new study looks at the contacts of infected cases from 26 different households, each with a single confirmed MERS-CoV infected case, with MERS. These households provided throat swabs from 280 contacts and antibody test results on at least 1 sample (only 44 permitted a second voluntary blood sample be taken-a shame) from the 280 contacts as well.

Some interesting findings included:

Median age of cases (65.4% male) was 55-years
Median age of contacts (52% male) was 29-years
Cases 7 household contacts (2.5%) were viral RNA-positive (RT-PCR) within 2-weeks of the index patient's illness onset. Similar to what PCR-based studies conducted previously have yielded.
5 household contacts (1.7%) were considered antibody positive after a series of different tests were used. 3 were positive between 2-3 weeks after the index case's onset, and 1 each before or after that period.
some indication that neutralizing antibodies against MERS-CoV might be low level and short lived in mild or asymptomatic infections and that previous antibody studies may have missed some cases if the took blood too long after a mild infection

Overall, 12 (4%) contacts acquired MERS-CoV infection from an index case, across 6 of 26 households (23.1%).

Among others, one question I'd like answered is whether symptomatic cases being kept in home isolation, which was occurring during the Jeddah-2104 outbreak when they don't need hospital-based supportive care, is the best option for stopping transmission? We don't know whether mild or silent infections can transmit virus, which remains another important question. While 4% seems like a small proportion, it's big enough to perhaps explain some of the sporadic case occurrences. Also, we should be mindful that MERS-CoV infection is associated with the death of a third of the people it infects. I'd want to be pretty sure I wasn't letting a house-bound shedding mild/silent person spread MERS-CoV to a visiting old uncle with a co-morbidity.

References

http://www.nejm.org/doi/full/10.1056/NEJMoa1405858
If this is what MERS-CoV detections look like with more testing...what is the "normal" community level of virus?? [UPDATED]
http://newsmedicalnet.blogspot.com.au/2014/04/if-this-is-what-mers-cov-detections.html
Guidelines for home isolation related to MERS Corona Virus infections | May 2014http://www.moh.gov.sa/en/Documents/3-Isolation.pdf

MERS-CoV infection control: the French connection.

contacts, France, MERS, MERS-CoV, transmission

A Eurosurveillance article by Mailles and colleagues describes the procedures used to lock down spread of MERS-CoV once confirmed.

Confirmed cases were isolated in negative pressure rooms (they suck air in, instead of pushing air out of a room as usually occurs in an air-conditioned room, ensuring virus-laden particles cannot escape) with dedicated staff using contact and aerosol precautions (e.g. personal protective gear which may have included back fastening gowns, disposable gloves, filtering masks, glasses etc).

A close contact was asked not to return to work and to wear a surgical mask when with other people. Other close contacts had to carry a ask and do nit if they developed symptoms, but could otherwise continue with life as usual.

Airborne transmission was strongly suspected but other routes, including the possible contamination of surfaces from the stools of the index case who initially presented with diarrhoea.

41 HCoV-EMC Cases.

contacts, MERS-CoV, transmission

The numbers rise again and "foreign specialists" have been hired (?perhaps invited) to help the Kingdom contain the spread of MERS-CoV.

While human-to-human transmission is very likely occurring, sustained transmission that is, infection going beyond the immediate close contact, to their contacts and so on, is not. See the figure - circles represent a person; yellow represents spread beyond immediate and close contacts.MERS-CoV transmission seems to be limited to close contact and perhaps long exposure.

Medical News Blog

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Catching Ebola: mistakes, messages and madness [amended]

MERS-CoV around the house-yes, it does transmit at home

MERS-CoV infection control: the French connection.

41 HCoV-EMC Cases.

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