Ebola is currently raging in West Africa, with at least 1,200 cases and about 672 deaths since the outbreak began in February, and controlling the disease’s continued spread is the top goal of public health authorities.
The virus already made it to Lagos, Nigeria, a city of 21 million. So what are the chances it could leave the continent of Africa all together?
“The risk (of Ebola spreading to Europe or the United States) is not zero, but it is very small,” Bruce Hirsch, an infectious diseases expert at North Shore University Hospital, told Kate Kelland of Reuters.
But as it turns out, Ebola already jumped from Africa to Europe once before — 20 years ago. Here’s the story behind the strange case.
It Started With A Dead Chimp
In 1994, several chimpanzees were found dead and decomposing in Taï National Park, in the Côte d’Ivoire. On November 16 of that year, three researchers who had been studying the park’s community of chimps wanted to figure out what was happening, so they dissected the body of one who had been dead for less than 12 hours.
And that’s where the trouble started.
“They found signs of hemorrhage and non-clotting blood,” a case report, published in the Journal of Infectious Diseases, explains. “Eight days later, 1 of the researchers, a 34-year-old woman, became ill.”
The woman, a Swiss zoologist, started “shivering with fever,” and thought she had come down with malaria. But malaria medication didn’t help, and three days later, after no signs of improvement, she was driven to a city clinic more than 300 miles away.
She still had the chills; her head was throbbing; and her muscles were sore. But “physical examination of the abdomen, heart, lung, throat, and tongue was normal,” and her condition was considered “satisfactory.” Ebola hadn’t emerged in Africa in 15 years, and never been detected in the region — and, in any case, doctors still suspected malaria.
But then two days later, five days after she first felt feverish, everything started falling apart.
She got diarrhoea and started vomiting. She stopped eating, and soon after stopped urinating. A rash showed up on her shoulder, spread to her back, and then all over her body. She became confused, irritable, and anxious, and started forgetting things.
Doctors checked her for parasites and didn’t find any. They rehydrated her and administered antibiotics. But her condition didn’t improve.
That’s when a dramatic decision was made: She would be flown out of the Côte d’Ivoire and back to Switzerland.
Wladyslaw / Wikipedia
The University Hospital of Basel
Ebola Flew Swiss Air
Nobody could be sure what was wrong with the woman, but they suspected it could be Lassa fever, a hemorrhagic fever similar to (though generally less deadly than) Ebola. The Swiss Air Ambulance jet that transported her took extensive precautions.
“During the flight,” the case report notes, “the patient wore a mask, and the physician and nurse wore surgical masks, gloves, and gowns.”
The plane finally landed in Switzerland, and the patient was swiftly transported to Basel, a Swiss city near the borders of France and Germany.
On the eighth day of the zoologist’s illness, “tired but awake,” she was admitted to the University Hospital of Basel, where doctors placed her in a tightly sealed isolation room. “All health care workers wore high-quality gloves, gowns, and dust-and-mist masks,” the case report explains. Nobody was taking any chances.
Upon examination, doctors found her liver and spleen were “tender,” but an abdominal ultrasound looked normal. Her medical team was unable to make a conclusive diagnosis, but considered all that “viral or bacterial infection of unknown origin, dengue fever, rickettsial disease, hantavirus infection, leptospirosis, typhoid fever, and malaria” were all strong possibilities.
According to the case report, “a form of hemorrhagic fever (Lassa fever or EBO virus [another name for Ebola]) was considered as unlikely.”
Finally, on the ninth and tenth days of the illness, her fever subsided. The diarrhoea stopped, and she began to eat normally. Her clothes were double-bagged and thrown away, and eventually the strict isolation rules were relaxed.
On day 15, she got to leave the hospital, 13 pounds lighter than when she first fell ill. She recovered completely in six weeks, though after about four weeks, her hair became brittle and fell out in large chunks — an after-effect that lasted for three months.
Back To The Monkeys
Though the patient was better, doctors still hadn’t figured out what had gone wrong in the first place. The best they could do was come up with a long list of possibilities.
To begin to untangle her mystery illness, researchers had to look back to where it started: Taï National Park in the Côte d’Ivoire.
In December 1994, they launched an epidemiological investigation to try to determine what had been killing the chimpanzees in the park — including the chimpanzee the zoologist had dissected. An analysis concluded that it was “a highly lethal epidemic with hemorrhagic syndrome,” though the possibilities were still somewhat broad: “a viral infection of unknown origin, anthrax, dengue, and African hemorrhagic fevers” were all considered.
On December 14, serum samples from infected chimps and from the zoologist on day three of her illness were shipped to a specialised lab in Paris. Researchers isolated the virus from the patient’s serum sample and found something surprising: a novel version of the Ebola virus, one that had never been seen before. They dubbed it the Côte d’Ivoire strain (EBO-CI), also called the Taï Forest strain.
What’s more, they found the very same virus in the organs of the chimpanzees. Luckily for the zoologist, EBO-CI may have been less dangerous than the deadly Ebola Zaire virus that’s infecting people now.
The Taï Forest strain has not been found in humans since her infection 20 years ago.
While the researchers had figured out that Ebola was what had killed the chimps and sickened the zoologist, there were still some lingering questions.
How, exactly, did she become infected? Why was she infected but not the other two zoologists who had participated in the dissection? And — perhaps most importantly — had she spread the deadly disease to anyone else?
First, the investigators learned, all three zoologists had worn gloves but not masks or gowns when they dissected the dead chimp. And the zoologist who fell sick had made what might have been a critical error. While the other two zoologists wore latex examination gloves, she wore ordinary “household gloves.”
“Therefore,” the case report concludes, “it is highly probable that she became contaminated during the [dissection] by direct contact with chimpanzee blood on her hand or by projection of droplets onto her face.”
The next step was tracking down anyone who had contact with the infected patient or with the virus. In Côte d’Ivoire, that included 18 people who had been with the patient face-to-face — including a man who had eaten from her plate and a woman who had comforted her — plus four laboratory technicians who had handled organs taken from the chimpanzee. In Switzerland, investigators interviewed 52 contacts, including eight family members and friends, four aeroplane crew members, and many staff members from the hospital and lab.
In the end, they tested serum samples from all 74 people who had been exposed. All were negative.
The virus had been contained.
How Ebola affects the body
The Bottom Line
Although the zoologist suffered tremendously during the course of her illness, everyone was very lucky. Doctors called her manifestation of the disease a “mild form” of Ebola, perhaps due to “the virus subtype, the mode of contamination, or the biologic response of the patient (or a combination of all three factors).”
And despite the dozens of people exposed, nobody else fell sick — even though, as investigators note in the case report, “containment measures were not always tight and there were no specific precautions taken during laboratory tests (blood specimens were not inactivated prior to analysis).”
While the outcome of the 1994 case may reinforce the idea that the chance of an Ebola outbreak in Europe or the United States is almost vanishingly small, the story should also serve as a cautionary tale: Just one patient can have far-reaching effects.
“Air travel allows viruses to travel from continent to continent within hours,” the investigators caution. “The case presented herein highlights the threat of importation of a disease by a sporadic case.”
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