EbolaEbola epidemic ebbing: WHO

The World Health Organization (WHO) has reported fewer than 100 new cases of Ebola in West Africa in the last week, which means the outbreak could soon reach its end. Some of the resources allocated to building treatment centers for thousands of sick people are now being diverted to contact-tracing efforts.

“Efforts have moved from rapidly building infrastructure to ensuring that capacity for case finding, case management, safe burials and community engagement is used as effectively as possible,” read the WHO’s latest situation report.

The Guardian reports that all previous outbreaks, although on a far smaller scale, have been stopped by tracing and monitoring people who might have made physical contact with someone infected with the virus. Currently, only 50 percent of new cases in Liberia are from people who are known contacts of those who were sick. The figure is 30 percent in Guinea.

The shift in tactics is occurring just as scientists in Guinea report that the virus is mutating. “We know the virus is changing quite a lot,” human geneticist Dr. Anavaj Sakuntabhai told the BBC. “That’s important for diagnosing (new cases) and for treatment. We need to know how the virus (is changing) to keep up with our enemy.”

Researchers at the Institut Pasteur in France are now trying to track mutations that could make it easier or harder for the virus to infect others.

Viruses mutate to increase their chances of survival. With Ebola, there have been cases of people who were infected but showed no symptoms. “These people may be the people who can spread the virus better, but we still don’t know that yet. A virus can change itself to less deadly but more contagious, and that’s something we are afraid of,” Sakuntabhai said.

The reduction in new Ebola cases will make it challenging to trial vaccines against the disease. Trials of the vaccine by GlaxoSmithKline, were due to start among health and burial workers in Liberia, but the country only received four new cases last week. Sierra Leone had sixty-five new cases, while Guinea had thirty. The trial will compare the numbers of people who will become ill among vaccinated and unvaccinated groups of people. The New England Journal of Medicine recently published resultsfrom a second round of safety trials of the same vaccine conducted by Oxford University. The results showed no safety concerns, but researchers claim the sixty human volunteers did not experience “as strong an immune system response to the vaccine as scientists would have liked.”

“These results show that the vaccine has the potential to work, particularly in the people who responded strongly, but I have some doubts about its ultimate effectiveness as the vaccine moves into tests in Africa,” said Dr. Ben Neuman, a lecturer in virology at the University of Reading.

Since the start of the epidemic, about 8,800 people have died out of the 22,000 Ebola cases reported in West Africa.