Many, if not most, infectious diseases that afflict humans start out as animal diseases. That’s what the field of zoonotics is about — and why so many human disease experts worry about a flu that afflicts mostly birds (H5N1, aka avian influenza).
A mysterious killer of children in Cambodia is big news at the moment and it may well be a zoonotic disease.
A new study that mapped zoonotic hotspots reports one general finding that may challenge common wisdom — the finding that India and parts of Africa are responsible for most of the global animal-human disease transfer phenomenon.
News reports and expert commentary tend to focus on Asia, China especially, as central station for infectious disease (which does appear to be the case for bird flu anyway). This report may alter perspectives.
As this one map from the report showing poultry density indicates, India is actually a much bigger contributor to zoonotic disease:
Other countries in sub-Saharan Africa like Ethiopia, Nigeria and Tanzania are also major zoonotic hotspots. As Reuters reports, this is an increasing problem that is not limited to poor or middle-income countries:
A global study mapping human diseases that come from animals like tuberculosis, AIDS, bird flu or Rift Valley fever has found that just 13 such diseases are responsible for 2.4 billion cases of human illness and 2.2 million deaths a year…. It also found the United States and Europe – especially Britain – Brazil and parts of Southeast Asia may be becoming hotspots of “emerging zoonoses”, which are infecting humans for the first time, are especially virulent or are becoming drug resistant.