The H5N1 bird flu virus has been confirmed in north-central Nigeria. Scientists had feared the virus would reach Africa, where human poverty and disease could combine with millions of highly susceptible backyard poultry to produce many human infections, and potentially a human pandemic virus.
But New Scientist can reveal that the location of Africa’s first reported outbreak should not come as a surprise. The region affected is right beside a major wintering ground for two relatively common species of duck. Those ducks shared breeding grounds in Siberia last summer with birds that winter in Turkey and around the Black Sea, where the virus also appeared recently.
“We are facing a serious international crisis,” said Samuel Jutzi, head of animal health at the UN Food and Agriculture Organisation in Rome, Italy. He is pleading for any further die-offs of poultry in the region to be reported immediately.
The World Animal Health Organization (OIE) in Paris, France, reported on Wednesday that 40,000 poultry, mainly laying hens, have died since 10 January at a commercial farm near Igabi in Kaduna state, a small town 150 kilometres south of the northern city of Kano. The owners initially tried antibiotics.
But the cause has now been confirmed as highly pathogenic H5N1 by the OIE’s collaborating centre for bird flu in Padua, Italy. Moreover, it is the same strain that appeared in wild birds at Qinghai Lake in China in spring 2005, and has since travelled across Siberia to Turkey and the Black Sea.
Summer breeding grounds
As it has everywhere it has gone, the virus is devastating poultry in the region, with Nigerian agricultural authorities reporting the death of 150,000 birds in Kano and Kaduna states, and more outbreaks reported in other parts of Nigeria.
Furthermore, Kano is near the Hadejia-Nguru inland river delta, which is a major wintering location for Northern pintail and garganey ducks. These species summer in breeding grounds across Siberia, where the Qinghai strain of H5N1 infected poultry and wild birds in summer 2005. They then winter in Turkey, around the Black Sea, and in West Africa. The Qinghai strain has already broken out in Turkey and around the Black Sea, apparently carried by migrants..
The authoritative 1996 Atlas of Anatidae [ducks, geese and swans] Populations of Africa and Western Europe says the Northern pintail wintering in the Black Sea and Mediterranean basins “are lumped with those wintering in West Africa as a single large population”. On average, 18,000 pintails winter each year at Hadejia-Nguru. Similar numbers of garganey ducks follow the same migration and 500,000 of each species winter at nearby Lake Chad.
Some of the Northern pintail wintering now in Britain and along Europe’s North Sea and Atlantic coasts also spent last summer on the same breeding grounds as the pintail that subsequently flew to the Black Sea, Turkey and West Africa.
