Northern Hemisphere flu activity remains high but appears past peak
Flu activity in the Northern Hemisphere remains high but has likely peaked, with several regions detecting increases in flu B, the World Health Organization (WHO) said in an Apr 4 update.
Flu levels in North America remain elevated because of H1N1 circulation, and Canada reported increasing proportions of flu B.
Europe continues to experience increases in flu B detections, especially in northern countries, though flu levels appear to have peaked in most regions, the WHO said.
Activity is elevated in northern temperate Asia, with rising detections of flu B, particularly in China and South Korea, the WHO said. Mongolia reported elevated flu B detections and high numbers of flu-related deaths. Flu levels remained low elsewhere in Asia, with flu B predominating, the WHO said.
Flu levels in the tropical Americas were low, with the exception of elevated severe illness associated with H1N1 in Jamaica and with respiratory syncytial virus (RSV) in Ecuador. Brazil and Guatemala reported high H1N1 circulation.
Activity in northern Africa appears to have peaked, although Tunisia reported increased detections of flulike illness. Ghana and Kenya saw mild rises in H1N1 and flu B, respectively, the WHO said.
Globally, influenza A made up 61.7% of 40,448 flu detections in recent weeks, and of the subtyped samples, 87.5% were the 2009 H1N1 virus and 12.5% were H3N2. Of the 15,475 subtyped flu B samples, only 18.3% were from the Yamagata lineage, the B strain used in this season's trivalent Northern Hemisphere flu vaccines.
Apr 4 WHO update
More H5N1 poultry outbreaks reported in central Nigeria
Nigeria continues to battle highly pathogenic H5N1 avian flu in poultry, with the country's government yesterday reporting three new outbreaks to the World Organization for Animal Health (OIE).
Two outbreaks, beginning on Mar 31 and Apr 1, occurred on farms in Nigeria's central Plateau province. The first outbreak involved 13,536 pullets and layers in the town of Ranya Lowcost, of which 200 birds became infected and died; the remaining poultry were culled to prevent the spread of the virus. The second outbreak, in the town of Bamkap, killed 76 layers out of a flock of 4,878, and the rest were destroyed.
A third outbreak involving a backyard flock of 204 pullets, also in Plateau province, began on Mar 31. Two birds died, and the remainder of the flock was culled.
"Poor farm biosecurity" is listed as a contributor to all three outbreaks. A resurgence of H5N1 has occurred in several parts of Africa over the past year, with Nigerian farms and flocks particularly affected.
Apr 5 OIE report