Skip to 0 minutes and 13 secondsPETER PIOT: In 1976, I was in training in clinical microbiology. I'd just finished medical school. And one day in September, we received blood samples from a Belgian nun in what was then called Zaire, now the Democratic Republic of Congo, who had died with a clinical diagnosis of yellow fever. So we did the usual things for how to isolate the virus in the old days, which took quite a while-- on cell lines and injecting it in mice and so on. And, to our big surprise, what came out of it was a virus that didn't look at all like anything we knew. Under the electron microscope, it looked more like a worm but then, of course, much smaller.
Skip to 0 minutes and 56 secondsAnd in these days, only one similar virus was known, and that was Marburg virus. We got the news from WHO that a major epidemic with a very high mortality rate was happening in Zaire, and we were instructed to stop all the investigations because our laboratory was not equipped to work with dangerous viruses. So we sent the virus to CDC in Atlanta, Centre for Disease Control, who confirmed that this was a new virus. The next step was to stop the epidemic because it was clear that the thought was that a few hundred people had died. And also to figure out how this new virus was transmitted.
Skip to 1 minute and 42 secondsBecause normally, when you go into an epidemic, you know exactly how the virus or the pathogen is transmitted, and you know what to do. In this case, we had no clue. So I went with a team of far more experienced people from CDC, from Institut Pasteur, and Congolese colleagues to the epidemic zone in the northern part of Congo in the equatorial forest. This was my first time ever in Africa. I was just 27, so I had zero experience. And what you do when you arrive in a situation like that-- first of all, try to stop the epidemic, which was not too difficult then because people had figured out that something fishy was going on at the hospital.
Skip to 2 minutes and 33 secondsAnd so they had abandoned the hospital, and that was absolutely important in terms of stopping the epidemic. And they had put everybody in quarantine. Going back to the smallpox days, that was in the collective memory. And what we did was trying to define the epidemic, then, in terms of three questions. And that's time, place, and person. And on the basis of that, you can already draw some conclusions. Time, and I was seeing, how is this epidemic evolving? Is it slowly growing? Is it still expanding, or is it coming down? And from the shape of that curve, you can already get some idea of transmission.
Skip to 3 minutes and 13 secondsTwo, place: where are the people who are infected and who died with Ebola? And it turned out that the closer you were living to the hospital, the higher the risk was of acquiring Ebola infection. And thirdly, person, who are the people who get it? You do then something very, very simple. And that is you divide everybody up by age and sex. And what we found was that there were more women than men infected. There were no children, or hardly any, which is interesting to see because that nearly excludes an insect transmission. And that, particularly in the age group between 20 and 30 years old, about 50% more women had Ebola and had died from it than men.
Skip to 4 minutes and 3 secondsSince we were a bunch of men, it took us a couple of hours to figure out, what's the difference between men and women at that age? And of course, women can get pregnant, certainly, there. And when we had seen that, what we did was we matched the hospital records of the antenatal clinic consultation and our observations in the villages. And indeed, the surplus, the excess of women at that age who came down with Ebola infection were all pregnant and/or had just delivered and had consulted the antenatal clinic. So then we wondered, "what is going on there?"
Skip to 4 minutes and 45 secondsAnd so, to make a long story short, what we found was that every morning, the mother superior-- this was a nuns' hospital-- would distribute five needles and syringes to this clinic. And nearly everybody who came there got an injection with something. And that's how it's really exploded. And then, another thing we found was that, about a week after a funeral of someone with Ebola, you would see several members of that family who would come down with Ebola. And so we said, OK, something is going on at the funerals there, and that is still the case now today in West Africa.
Skip to 5 minutes and 27 secondsIt's through touching the body of someone who just died from Ebola and when that corpse is extremely contagious, that can give rise to secondary epidemics.
Peter Piot investigating the first outbreak
In this video, which uses archive footage from 1976 and narration from 2014, Professor Peter Piot, co-discoverer of the Ebola virus, describes the first known outbreak in Zaire, now the Democratic Republic of the Congo (DRC). He describes the steps used to investigate the outbreak of disease and how these gave clues to the mode of transmission.
In this first outbreak there were 318 cases of Ebola and 280 deaths. Outbreak investigation includes describing the disease in time, place and person.
Time: How is the epidemic evolving? Assessing if the number of cases is increasing or decreasing over time can give you an idea of how the virus is transmitted.
Place: Where are the people that are infected? In this outbreak there was a clear link to the hospital for most cases, and a link to funerals was also noted.
Person: Is there a difference in the age and sex of those infected? In this outbreak, adults were affected more than children. This gives clues to the type of transmission and makes insect-borne or air-borne disease unlikely. Also, healthcare workers were affected, reinforcing the link to the hospital.
In this particular outbreak pregnant women were at high risk due to the use of unsterilised needles in hospitals. Since the use of disposable needles has become widespread following the HIV epidemic, this should not be an issue in the current outbreak.
© Video: Institute of Tropical Medicine in Antwerp. Audio: London School of Hygiene & Tropical Medicine