During the Conference on Retroviruses and Opportunistic Infections held in Boston this last February (CROI), there was a special session focusing on Ebola (though a filovirus) that examined the virus one year after the outbreak in West Africa. This session focused on four things: longterm effects of infection, viral longevity in semen, the possibility of asymptomatic infection, and the success of ZMapp (Science).
What was found in the outbreak analysis is that 83% of the 475 individuals studied post infection experienced “at least one long-lasting symptom, the most common being joint or muscle pain, headaches, and fatigue” and viral RNA was found in some of the subjects’ semen over 9 months later. Furthermore, Eugene Richardson, a researcher at Stanford, examined a village in Sierra Leone and found 12 people who were symptomless, but had Ebola antibodies. While these antibodies could be the result of other infections, this study likely supports other research that indicated how it may be possible for Ebola infection to be asymptomatic. This possibility, combined with the longevity of viral RNA in semen, is concerning in that another outbreak could result from unknowing sexual contact, which is why the WHO has recommended that condoms be used for an extended period of time after infection (Science).
The final focus of the Ebola session centered around the results of the ZMapp study. ZMapp is an antibody based treatment for Ebola that proved to be effective in animal studies in 2014 (ZMapp). In the ZMapp study mentioned during the CROI session, a limited number of Ebola patients enrolled (72) and it was found that standard care plus ZMapp resulted in 22% of patients dying versus 33% with only standard care. While the results of this study were deemed statistically insignificant, ZMapp research will continue (Science).
- Devon Z.
- Devon Z.
Science - http://www.sciencemag.org/news/2016/02/new-reports-highlight-long-term-risks-ebola-infection-limits-zmapp
ZMapp - http://mappbio.com/zmapp-faq/