The Sierra Leone government has announced the discovery of a sixth Ebola species, the Bombali virus, named after bats found in the Bombali region. According to Amara Jambai, a senior ministry of health official, “At this time, it is not yet known if the Bombali Ebola virus has been transmitted to people or if it causes disease in people but it has the potential to infect human cells.”
Like any good scientist, Tracey Goldstein, of the One Health Institute at UC Davis, described the discovery as “exciting” but cautioned that “I think we have a lot of work to do to really understand if it is a pathogen and whether it does or doesn’t pose a threat.”
There are five other known Ebola viruses, four of which can cause the disease in people: Zaire ebolavirus, Sudan ebolavirus, Taï Forest ebolavirus, Bundibugyo ebolavirus, and Reston ebolavirus, “known to cause disease in nonhuman primates and pigs, but not in people.”
Reston ebolavirus, for those of you living in the U.S., is notable not only because an outbreak occurred in Reston, Virginia not far from D.C., but also because it was the inspiration for one of my favorite books: The Hot Zone. Highly recommended bedtime reading.
Here is some good news: The WHO says the Ebola outbreak in the Congo is “largely contained” and likely over. So far 53 people have been infected and 29 have died. The last confirmed case was treated and released on June 12th. According to NBC News:
“More than 3,300 people had been given an experimental Ebola vaccine, using a technique called ring vaccination, in which cases of the disease are tracked down and all the people they have been in direct contact with are vaccinated. Then the contacts of those vaccinated people are tracked down and vaccinated. This method eradicated smallpox at the end of the 1970s.”
According to The New York Times, other methods used to fight the outbreak included deploying over 250 experts, three mobile laboratories, four treatment centers, equipment donations, and money.
“Donors provided four ambulances, numerous motorcycles and megaphones, and thousands of bleach tablets. Dozens of educational talks explaining the disease were organized…Donors gave $34 million toward stopping the outbreak. The W.H.O. initially spent $4 million from its emergency fund and asked for $26 million; as the outbreak expanded, the organization sought $57 million.”
The outbreak will not officially be declared over until one more 21-day incubation period has passed, but things are looking up, which is more than many of us can say for a lot of things in the world right now.
Actually it never left. Ebola is endemic in the Democratic Republic of Congo. The government has declared an outbreak after 17 people in the town of Bikoro are suspected of dying of the gruesome disease. The WHO statement says:
All cases were reported from iIkoko Iponge health facility located about 30 kilometres from Bikoro. Health facilities in Bikoro have very limited functionality, and rely on international organizations to provide supplies that frequently stock out…We know that addressing this outbreak will require a comprehensive and coordinated response. WHO will work closely with health authorities and partners to support the national response.
According to BBC News, “this is the ninth time an Ebola outbreak has been recorded in the DR Congo. The virus was first discovered there in 1976 (when the country was known as Zaire) and is named after the Ebola river.”
Ebola is thought to be transmitted to humans via contact with infected animals such as the fruit bat, or eating infected bushmeat. However, it is worth noting that scientists aren’t exactly sure how Ebola is spread, at least initially, so let that thought fester. Once a person is infected, the virus can be spread through blood or body fluids or objects contaminated with body fluids.
The biggest outbreak of Ebola occurred in West Africa from roughly 2014 to 2016 and killed over 11,000 people. According to the CDC, “Many of these survivors suffer from persistent medical conditions after recovery from Ebola, including joint pain, eye problems, headaches, and other chronic health issues.”
A large outbreak of Lassa fever in Nigeria has people worried. The area is observing an unusually high number of cases this year. As of February 18, there have been 913 cases and 73 deaths, compared to 733 cases and 71 deaths in all of 2017.
Like Ebola, Lassa fever is a hemorrhagic fever, though considered less serious than Ebola. According the WHO, Lassa fever usually starts with a fever and progresses to a headache, muscle pain, nausea, vomiting, and diarrhea. In severe cases there may fluid in the lungs, and bleeding from the mouth, nose or other areas. In the most advanced stage of the disease shock, seizures, and coma may occur. In fatal cases, death usually occurs within 14 days of the onset. The drug Ribavirin, given via IV, is considered an effective treatment for Lassa fever if given within 6 days of the onset of symptoms.
What’s causing such a large outbreak? According to Dr. Chikwe Ihekweazu, director of the Nigeria Centre for Disease Control, a couple things may be at play: Improved detection, and that Nigeria’s growing population has brought people closer to the disease host: the infamous rat.
According to NPR:
“West Africa’s dry winters push rodents closer to people to scavenge for food. Virus-carrying rats may defecate or urinate in grains and other food; people can pick up the virus from contact with contaminated products. The virus can also spread between people via bodily fluids. And there are a lot of rats – which means there’s a lot of potential for outbreaks.”
The WHO is scaling up its response to the outbreak, and heath officials are urging people to keep food in sealed containers, as well as limit the proximity of garbage to homes.
Fourteen survivors from the first known Ebola outbreak in 1976 appear to have developed immunity against the disease, according to a study published this week in the Journal of Infectious Diseases. The study showed that the survivors blood contains antibodies that protect against, and in some cases even destroy, the Ebola virus.
An earlier study had shown that Ebola survivors have some immunity after 14 years, but this new study shows that protection lasts for at least 40 years. The Ebola virus is known for hanging around longer than anyone would like, frequently hibernating in eyes and semen. This “tenacity might explain why survivors continue to produce antibodies against it, long after they’ve finally cleared it from their bodies.”
All of the 14 people they studied still carry antibodies that recognize at least one of the Ebola virus’s proteins, and four had antibodies that could completely neutralize the virus. “Those are the kinds of responses you’d like to see in a vaccine—long-lasting and robust,” says Rimoin, “which means that these antibodies are of great value to science.”