Water-logged soils in the monsoon season make carcass burial problematic in Bangladesh Wikimedia
The month of May 2016 has seen over 100 human anthrax cases in Bangladesh, the seventh such outbreak in the past eight years. The Bacillus anthracis bacteria that cause anthrax began wreaking havoc in Bangladesh beginning in 2009, reportedly a quarter century after the last known human case of the disease in the country.
Community-based animal health worker among Fellata nomads of Sudan/South Sudan Charles Hoots
With 70% of emerging infectious diseases estimated by the World Health Organisation to be zoonotic in nature, livestock and wildlife often fall ill from these pathogens before they spread to people. As a result, veterinarians and other animal health workers (AHWs) can play a crucial role in early detection of emerging zoonotic diseases, especially in remote areas of poorer countries where human health care infrastructure is sparse or absent.
Yet, despite significant numbers of livestock in rural areas of developing countries, AHWs are few and far between, unable to generate sufficient income to make a living. Well-intentioned policies from national and international organizations in some cases end up driving AHWs away, or into more lucrative pursuits. As a result, animal disease outbreaks, many with public health impacts, may run their course for weeks before being detected and addressed by the authorities.
Construction of the Panama Canal spurred research to develop a yellow fever vaccine Library of Congress
With yellow fever vaccine in short supply in the face of an ongoing outbreak in Angola, we might be reminded of the fortuitous, and by no means inevitable, circumstances that led to the development of the yellow fever vaccine in the first place. Vaccines for mosquito-borne diseases are hard to come by, and no less so for the flaviviruses that include yellow fever, dengue, West Nile, and Zika viruses. A serendipitous event in a yellow fever virus isolated from a single person 90 years ago has given rise to all yellow fever vaccines in use today, though at a heavy cost to many of those who played a role in its discovery.
Human cases of H7N9 avian influenza virus FAO
A new avian influenza virus now rivals H5N1 as a candidate for the potential cause of a human pandemic one day. H7N9 first appeared in people three years ago and shares many characteristics with H5N1. But some key differences make this newer virus more difficult to keep tabs on as it circulates quietly through poultry flocks.
France announced last month a new case of bovine spongiform encephalopathy (BSE), popularly known as “Mad Cow Disease,” in a four year old female cow. This is the first case of this type of BSE in France since 2011, but follows on the heels of two other cases in Europe just last year, one in Ireland and the other in Wales. BSE cases are very rare today, but the French case raises some interesting, and slightly disturbing, questions.
Goats at water hole, South Sudan Charles Hoots
Rift Valley Fever outbreaks have long been predicted in Uganda. But when the nation declared its first ever outbreak of this zoonotic virus last week, it could hardly have occurred in a more unlikely part of the country. This is just the latest in several surprises this mosquito-borne virus has thrown at us over the past few decades.
Lake Victoria from Entebbe, Uganda, near the forest for which the Zika virus is named. Charles Hoots
With concern of a possible connection between Zika virus and microcephaly in Brazilian babies, researchers are racing to fill in the many blanks about the virus in order to better control it. But predicting the future of Zika virus in the Americas is fraught with difficulties. The behavior of closely related, recently introduced viruses offers clues. But despite similarities, the differences are many and prevent sweeping generalities. Though not reassuring to couples contemplating starting a family right now, it is this uncertainty that makes these viruses so fascinating.
Villagers in Uganda bringing their chickens for avian influenza testing, 2009 Stephanie Smith
We don’t hear much any more about fears of an avian influenza pandemic sweeping the world. But the unique characteristics of avian influenza viruses and their expanding global presence make them as likely as ever to acquire the ability to thrive in people. This post and the next explain why these viruses are different and what can – and cannot – be done to stop them.
