While virologists were hyperventilating over an Andes virus outbreak on a cruise ship (13 cases, three deaths - not great for the buffet line), the Democratic Republic of the Congo was quietly hosting a Bundibugyo virus outbreak, currently clocking in at over 1,250 cases and at least 362 deaths. Because why have one crisis when you can have two?
Bundibugyo virus is a horrifying, highly fatal pathogen. Symptoms include headaches, diarrhea, malfunctioning kidneys and liver, and, less frequently, internal and external bleeding - because Ebola isn't scary enough without the word "hemorrhagic" in its description. Grimly, contagiousness persists after death, so family members who wash and clothe the body for funerals get an unwelcome souvenir.
The immediate priority is containing the outbreak. Without a proven vaccine, health workers must isolate patients and trace contacts - basically, the public health equivalent of whack-a-mole. But when the dust settles, two questions demand answers: why did this happen, and where did it come from? The answers are critical to preventing the next outbreak, assuming we're not too busy cutting research funds.
The virus is a relative of the more infamous Zaire Ebola virus, which has sporadically caused outbreaks since the 1970s but exploded into a West African pandemic from 2014 to 2016. Terrifyingly, despite Ebola's high ranking on bioterror lists, we know very little about these viruses in the wild. Marburg virus, a distant cousin, is known to persist in large fruit bats, leading to the reasonable but unproven assumption that bats are the reservoir for the whole Ebola family.
Fruit bats are widespread, abundant, and easily blamed for each outbreak. Yet proof that bats harbor Zaire Ebola virus remains frustratingly elusive. Arguing that bats are the source of Bundibugyo virus is currently just conjecture - as the author notes, having a distant cousin who wears a kilt doesn't make you Scottish.
Historically, first human cases in Ebola outbreaks were linked to exposure to forest antelopes, gorillas, and chimpanzees. Experimentally infected pigs can shed infectious Ebola viruses and infect primates. So Ebola viruses have a varied approach to host animals. It's also possible the virus hides in the same host for years before re-emerging, explaining those long vanishing acts.
How would you determine Bundibugyo transmission patterns in tropical forests? Capture wary monkeys? Shoot them? Analyze their feces? Target herds of bush pigs? Giant fruit bats? All of the above? And if the disease is rare and spills over from wildlife, how do you catch it red-handed? These muddy waters are familiar from the controversies surrounding Covid-19's origins. Now imagine doing this research in a politically unstable region while the US and UK slash research and health funds.
Yet these questions need answers. Before 2010, the largest Ebola outbreaks rarely exceeded 300 cases; since then, three outbreaks have numbered in the thousands. The trend is undeniably toward larger epidemics. If we knew how Ebola worked, we could reduce human exposure - using wildland buffers, discouraging bushmeat consumption, or implementing integrated surveillance for wildlife, livestock, and humans.
Without knowing the source, humans remain at risk, and wildlife suffers needless retaliation. After Covid-19, bat-killing sprees erupted: Cubans set fire to roosts, Rwandan officials aimed water cannons at bats, and many other countries attacked bat roosts. This achieves nothing if the species isn't involved, and disturbing wildlife can inadvertently exacerbate disease spread - whether it's Marburg, rabies, or bovine tuberculosis. And if habitat destruction drives recurrent Ebola outbreaks, we ought to get smarter at answering these questions.
The links between humans, wildlife, and environment are the crux of the "one health" approach, which recognizes these connections. Optimizing health for one element can boost health in another - not just for Bundibugyo, but for chicken farms, wild swimming in the Wye, or bovine tuberculosis in badgers and cows. The burning question is whether this outbreak will provide the incentive to act before the next one.