The New England Journal of Medicine published a "preliminary report" yesterday on the emergence of Ebola in West Africa. Today, two responses to it. First, from Reuters: West African Ebola outbreak caused by new strain of disease - study. Excerpt:
An Ebola outbreak blamed for 135 deaths in West Africa in the past month was not imported from Central Africa but caused by a new strain of the disease, a study in a U.S. medical journal said, raising the spectre of further regional epidemics.
The spread of Ebola from a remote corner of Guinea to the capital and into neighbouring Liberia, the first deadly outbreak reported in West Africa, has caused panic across a region struggling with weak healthcare systems and porous borders.
Ebola is endemic to Democratic Republic of Congo, Uganda, South Sudan and Gabon, and scientists initially believed that Central Africa's Zaire strain of the virus was responsible for the outbreak.
Using analysis of blood samples from infected patients, however, researchers determined that while the Guinean form of the Ebola virus (EBOV) showed a 97 percent similarity to the Zaire strain, the disease was not introduced from Central Africa.
"This study demonstrates the emergence of a new EBOV strain in Guinea," wrote the group of more than 30 doctors and scientists, who published their preliminary findings on the website of the New England Journal of Medicine.
There is no vaccine or cure for Ebola - a haemorrhagic fever with a fatality rate of up to 90 percent that causes symptoms ranging from flu-like pains to internal and external bleeding caused by kidney and liver failure. Its suspected origin is forest bats and it can be transmitted between humans by touching victims or through bodily fluids.
"It is possible that EBOV has circulated undetected in this region for some time. The emergence of the virus in Guinea highlights the risk of EBOV outbreaks in the whole West African subregion," the report continued.
Second, a useful blog post from Maia Majumder, who uses the NEJM report as a springboard for some informed speculation on how habitat displacement may have increased Ebola prevalence among bats; this in turn could have increased the chance of humans contracting the disease.