Ebola infects 3 more in DRC; virus evidence found in West Africa bat

Long-fingered bat
Long-fingered bat

chunt01 / Flickr cc

Three more people in the Democratic Republic of the Congo (DRC) were confirmed as having Ebola in the country's ongoing outbreak, and in a related development, researchers from Liberia and the United States today reported genetic evidence of the Ebola outbreak virus in a bat in Liberia, the first such detection in West Africa.

Also, the DRC media reported another security incident in the outbreak region, and researchers published new findings on clinical patterns and health worker vaccination from studies conducted in Sierra Leone during its outbreak in 2014-16.

Cases continue in Katwa hot spot

The DRC's health ministry today said two of the latest patients are from Katwa, one of the latest outbreak hot spots located just southeast of Butembo, and Biena health zone, which is west of Butembo.

The illnesses bring the overall outbreak total to 715, but the ministry noted that it has removed a duplicate case from Mabalako from its count. The number includes 666 confirmed and 49 probable cases.

Health officials are still investigating 236 suspected cases, and teams have now immunized 65,963 people with the Merck's unlicensed VSV-EBOV vaccine.

Also, the ministry said 4 more people died from their infections, including a patient from Biena who died in the community setting and 3 who died in Ebola treatment centers—2 in Butembo and 1 in Katwa. So far 443 deaths have been reported in the DRC outbreak.

In Beni, which was the main Ebola hot spot but has recently shown a steep drop in cases, a group of people vandalized a local hospital the night of Jan 21, apparently targeting Ebola responders that they thought were inside, according to a translation of a local media report.

The attackers threatened to burn the facility and destroyed the door and windows before they were scared off, the report said. A nurse quoted in the story said the facility had hosted Ebola vaccinators, that they felt safe there, and that she welcomed their help in fighting the epidemic.

Bat findings provide more reservoir clues

Liberia's government and its partners, which include Center for Infection and Immunity (CII) at the Columbia University Mailman School of Public Health and EcoHealth Alliance, announced the bat findings today in a press release.

As part of bat sampling with the US Agency for International Development (USAID) PREDICT project, scientists found Ebola genetic material and Ebola antibodies in a greater long-fingered bat from Nimba district in northeastern Liberia, according to a press release from Columbia University's Mailman School of Public Health. The project also included researchers from Columbia's Center for Infection and Immunity and EcoHealth Alliance.

The bat species that yielded Ebola evidence is found in West Africa and other regions and is important to agriculture, because they eat insects that damage crops. Unlike other bats, the long-fingered type doesn't roost in homes or building and instead are found in forests, caves, and mines. According to the report, Liberia's government is using that information to teach the public about how to avoid exposure and increase their awareness of the animals' positive impact on the environment.

Evidence from 20% of the bat's genome suggests that it is closely related to the Zaire Ebola virus species, which was involved in West Africa's massive  2014-16 outbreak and is also implicated in the current DRC outbreak. Researchers at CII are trying to determine if the strain from the bat is a genetic match with the one that caused West Africa's outbreak.

The researchers said the finding brings scientists closer to understanding the source of Ebola in humans.

Simon Anthony, DPhil, assistant professor of epidemiology at CII, said in the release that there has been speculation that Ebola in humans came from bats, but no direct evidence has yet been found. "It is possible that there are also other bat species that carry Ebola. Going forward, we will be analyzing additional specimens to fill in the picture," he said.

According to a news report on the discovery in Science today, two other Ebola species were found in a related insect-eating bat, but other indications have pointed to fruit bats as a possible reservoir. Jon Epstein, DVM, with EcoHealth Alliance and who leads the USAID-PREDICT project in Liberia, told Science that the new finding hints at the possibility that Ebola has multiple hosts that may vary by region.

Another researcher not involved in the work, Fabian Leendertz, DVM, with the Robert Koch Institute in Berlin, told Science that a next step would be to sample the insects that the bats eat to see if they harbor the virus.

Studies on kids' infections, health worker vaccination

In other Ebola research developments, scientists reported new findings related to clinical disease in kids and vaccination in health workers, both based on experiences in Sierra Leone's outbreak:

  • A review of clinical disease and treatment outcomes in 139 patients younger than 15 years found that 56.1% were girls and 51.1% were students and that certain factors at the time of admission were associated with greater odds of dying from the disease, according to the report today in BMC Infectious Diseases. The factors included male gender, abdominal pain, vomiting, conjunctivitis, and difficulty breathing.

  • A 2018 survey on staff turnover and Ebola vaccine acceptance in 305 health workers in Sierra Leone found that 76% of them had a positive opinion of Ebola vaccination and that vaccination against Ebola is feasible if employment is stable, but repeated vaccination at the start of employment may be needed to maintain high vaccination coverage. Researchers reported their findings yesterday in Vaccine.

See also:

Jan 24 DRC update

Jan 22 Radio Moto Butembo-Beni news report

Jan 24 Columbia University Mailman School of Public Health press release

Jan 24 Science story

Ja 24 BMC Infect Dis abstract

Jan 23 Vaccine abstract

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