June Health News
EBOLA
The national news has been busy covering the latest Ebola outbreak. The most recent estimates are approximately 1000 cases and 250 deaths. Some background on the disease and its spread seems worthwhile.
The disease is caused by Ebola viruses. The genus is an RNA virus called orthoebolavirus with half a dozen species. The main reservoir for the genus is in animals. Four of the species can jump to humans. The current outbreak is being caused by the bundibugyoense species. A different species (zairense)has the highest case fatality rate and caused an outbreak in 2014 in West Africa.
The primary animal reservoir is in African bats and does not appear to cause them serious illness. Mode of transmission to humans is less than clear. “Bushmeat” (hunting local animal for food: bats, apes, rats, antelope, birds, reptiles, monkeys, etc.) consumption is conjectured to be a vector. Once a human is infected the virus appears in sweat, blood, vomitus, diarrhea, breast milk, semen – all body fluids are infectious. It does not seem to enter human lungs, so generally not airborne. It can infect pigs, and cause pneumonia, so pig sections from coughing or sneezing may be potentially infectious.
Exposed healthy appearing people do not transmit the virus unless they fall ill. Human to human transmission is a serious problem in outbreaks from secretions from the sick. Personal protective equipment (PPE) manages this, so isolation, fluid decontamination and case isolation are mainstays. If viral invasion occurs, virus infects white cells, the liver, spleen and the lining of blood vessels, causing hemorrhage and seems to block usual anti-viral human immune mechanisms. Death is from shock, intravascular coagulation or secondary bacterial infection. Treatment is supportive.
There are no specific bundibugyoense anti-viral agents approved yet although investigations are occurring. There is a vaccine for the zairense variant but nothing yet for the bundibugyoense.
Based on its animal reservoir biology, its modes of transmission, and the effectiveness of PPE, the chances of this being a world pandemic is very low.
Submitted by: Jon Gell