For University of California, Los Angeles, epidemiologist Anne Rimoin, 2007 was a rough year. Rebel forces opened fire on her headquarters in Kinshasa, in the Democratic Republic of the Congo. An Ebola outbreak spread across her field site. And the cargo plane she charters to get there crashed, killing all passengers.
Yet none of that has slowed Rimoin or her Monkeypox Project, the most ambitious disease surveillance program ever conducted in the equatorial rainforests of the Congo, the cradle of such emerging infectious diseases as Marburg, HIV and Ebola. Rimoin is so resistant to calamity that her Congolese collaborators dubbed her Mama Etete, "the unstoppable woman."
Then came "the vampire situation."
One day, Rimoin was manning her makeshift lab behind a dilapidated jungle hospital and received word that villagers in one hamlet were refusing to give blood. "A rumor spread that the blood we were taking for the study was to be sent to Europe for white people to drink as an elixir of youth," she says. The rumor proved impossible to squelch and Rimoin moved on to another village, accepting her defeat.
Ninety percent of the world's monkeypox cases come from Congo, and the vast majority of those from the Sankuru district. Last August, Rimoin launched a serosurvey in Sankuru to gather blood samples from the entire population of 12 villages with high rates of the smallpox-like disease, which causes aches, fevers, and painful lesions that crack and fester all over the body.
The smallpox vaccine protects against monkeypox, but most Congolese were born after mass smallpox vaccinations stopped in 1980. There is currently no treatment and no cure. One out of ten cases are fatal. When scientists first identified monkeypox in humans in 1970, they believed it would succumb to the strong herd immunity to smallpox. But when civil war broke out in the 1990s, many Congolese moved deeper into the jungle. "They are now more dependent on bush meat like rats, squirrels and monkeys and those animals are the reservoirs for this disease," Rimoin says.
Traveling by motorbike down treacherous rutted trails, Rimoin discovered a growing threat. Between 2001 and 2004 only 137 suspected cases of monkeypox were reported in all of Congo. But in the last 18 months of disease surveillance, the Monkeypox Project has investigated over 1,300 cases in the Sankuru district alone - home to 1.4 million, just 2% of the total Congo population.
"Monkeypox was once considered a sporadic zoonotic infection," Rimoin says. "My research has demonstrated that monkeypox is, in fact, an endemic disease that represents a significant health problem." The National Institutes of Health-funded project addresses a dangerous void in a place extraordinarily susceptible to zoonotic infections. Because the Sankuru is so remote and health resources so scarce, cases typically go unreported and infected persons are neither identified, nor helped.
When the recent Ebola outbreak began in June 2007 in the Mweka district, word didn't reach health officials until August, hundreds of cases later. Even Rimoin, just 100 km away, was in the dark. "Nobody knew for sure what was happening," she says. "And here we are up to our elbows in blood." (None of her staff were infected.)
Monkeypox is not as virulent as Ebola or smallpox, nor is it as easily transmitted from person to person. Most infections probably come from contact with blood and bodily fluids of animals. "This is a virus that is clearly jumping species quite a bit," says Kate Rubins, a fellow at the Whitehead Institute for Biomedical Research who works with Rimoin in Congo. "And when you have many constant reintroductions, it could acquire the ability to transmit more easily," she said.
Due to severe reactions, the old smallpox vaccine is no longer considered suitable for mass vaccinations. But the threat of a smallpox bioterror attack has spurred research for a new vaccine. And if Rimoin's Sankuru blood samples confirm an ongoing history of monkeypox, those villagers will be the ideal test group. And the vampires will be back.