WHO : Influenza update - 20 May 2011

WHO's latest influenza update - Update 134, excerpt, go to the site for full detailed report :

" Summary

• The influenza season is largely finished in the temperate countries of the northern hemisphere with transmission now either undetectable or at very low levels in most areas.

• A few tropical countries are experiencing low grade transmission including the Dominican Republic, Venezuela (influenza A(H1N1)2009) and Jamaica (influenza type B) in the Americas, Rwanda (influenza A(H3N2) and Madagascar (influenza type B) in Sub-Saharan Africa.

• The influenza season has not yet started in the temperate countries of the southern hemisphere. Australia has reported a small increase in reports of influenza-like illness however actual detections of influenza virus have decreased in most jurisdictions in recent weeks, including in the northern tropical states.

• A summary review of the northern hemisphere 2010/11 winter influenza season will be published in the World Health Organization's Weekly Epidemiological Report on May 26, 2011.

Countries in the temperate zone of the northern hemisphere

North America:

Influenza activity in both the United States of America (USA) and Canada has now largely returned to baseline levels. Rates of influenza-like illness, reports of influenza related deaths, and influenza related hospitalizations all continue to decrease in both countries, though some localized activity persists in the Canadian provinces of Nova Scotia and Newfoundland. The percentage of respiratory specimens testing positive for influenza virus is low, 5% in Canada and less than 2% in the USA, and are predominantly influenza type B."