Antiviral drugs may help protect people from developing Ebola after exposure to the deadly virus, a new case study suggests.
"We are excited to publish the first report of an antiviral-based post-exposure treatment against Ebola-virus infection in humans. We believe this work justifies further study of this postexposure treatment to protect health care workers accidentally exposed to Ebola virus in the field," lead author Dr. Michael Jacobs, of the Royal Free NHS Foundation Trust, London, said in a news release from The Lancet Infectious Diseases.
"What is more, a similar approach to treat household contacts of Ebola cases may work to prevent a major route of spread during an epidemic," he added.
The new research included eight British health care workers who were possibly exposed to the Ebola virus while working in Sierra Leone between January and March 2015. After their possible exposure, they were evacuated to the Royal Free Hospital in London.
Four of the health care workers had needlestick injuries and were believed to be at significant risk of exposure to Ebola. They were treated with the antiviral drug favipiravir. The drug is approved in Japan to treat severe flu, the researchers said.
Previous lab tests and experiments in mice suggested the drug could be effective against Ebola, according to background information in the news release.
The other four health care workers were considered to be at lower risk for Ebola. They weren't given the drug, but were closely monitored instead.
All eight patients remained healthy over 42 days of follow-up, the study authors said. None had any detectable levels of the Ebola virus in their blood and no one showed any signs of disease. There were no serious side effects among the four patients who took the antiviral drug, the researchers found.
The results were published Aug. 25 in The Lancet Infectious Diseases.
"It is possible that none of these health care workers were infected with Ebola virus. Therefore, we cannot know for sure whether or not postexposure prophylaxis prevented the onset of Ebola-virus disease," Jacobs said.
"However, two of the workers had needlestick injuries contaminated with fresh blood from patients with Ebola virus disease putting them at very high risk of transmission," he added.
The researchers noted that health care workers dealing with Ebola in West Africa are at high risk for infection.
In 2014, the largest Ebola outbreak in history began in West Africa. In the three most-affected countries -- Guinea, Liberia and Sierra Leone -- an estimated 27,900 people have been infected and more than 11,000 people have died in the epidemic, according to the U.S. Centers for Disease Control and Prevention.