H5N1 bird flu has invaded Nigeria on at least three separate occasions, the first genetic analysis of the virus shows. Each time, wild birds were probably responsible, which means that its continued spread across Africa is likely to be difficult to halt.
After spreading west across Asia, the highly pathogenic virus was identified in Africa in February, in the northern Nigerian state of Kaduna. Outbreaks multiplied quickly, reaching Lagos in April. Last week Taraba became the 14th of Nigeria’s 36 states to report an outbreak.
This inexorable spread has been blamed on the transport of poultry across the country, but…
