Sierra Leone confirmed a new Ebola death just hours after the World Health Organization (WHO) declared the outbreak over in West Africa. A statement released today said that a women who died earlier this month in the north of the country tested positive for Ebola. It is yet another flare-up that experts warned would occur.
“The Sierra Leone government acted rapidly to respond to this new case. Through the country’s new emergency operations center, a joint team of local authorities, WHO and partners are investigating the origin of the case, identifying contacts and initiating control measures to prevent further transmission,” according to a statement today from the WHO.
It reiterated yesterday’s warning made by Bruce Aylward, WHO’s special representative for Ebola response, that flare-ups of Ebola are anticipated and vigilance must remain in the region. Sierra Leone was declared Ebola-free on Nov. 7, after passing 42 days without a reported case. A 90-day enhanced surveillance followed to monitor the potential return of Ebola.
It is estimated that 99 percent of cases are cleared by the time the 42-day mark is reached – representing two incubation cycles for the virus. Given the fact that the outbreak infected nearly 29,000 people and killed 11,315, the odds are good that cases will emerge after the 42 day period is passed.
“If you do the math, with an epidemic affecting approximately 30,000 cases, you can still anticipate 300 cases beyond that (42-day) period,” said Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, in an interview with USA Today. “And then you have a small proportion that seem to harbor the virus in a persistent state.”
Beyond the numbers, new knowledge about the Ebola virus reveals that it can stay in the bodies of men for up to nine months. Those survivors can unwittingly spread the virus to their partners through sex. It also can remain in the central nervous system, making it seem like patients are free of the virus. But it can re-infect the person, as was the case for the Scottish nurse who survived an initial infection and fell ill months later.