WHO - Pandemic (H1N1) 2009 - update 97

World Health's Organization latest H1N1 update, excerpt:

" 23 April 2010 -- As of 18 April 2010, worldwide more than 214 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including over 17853 deaths.

Situation update:

Currently the most active areas of transmission of pandemic influenza are in parts of West and Central Africa but transmission is also still occurring in South East Asia, and Central America. Pandemic influenza activity remains low in much of the temperate zone of both the northern and southern hemispheres. Seasonal influenza type B viruses have been increasingly detected over a larger area and are now the predominant circulating influenza viruses across East Asia, Central Africa and Northern and Eastern Europe. Very small numbers of type B viruses have also recently been detected in Central America. Seasonal influenza H3N2 is still being detected in South and Southeast Asia (mainly Indonesia), as well as sporadically in several countries of West Africa, and Eastern Europe.


In Europe, most countries reported a low intensity of respiratory diseases with only 6.8% of respiratory specimens testing positive for influenza. This week the total number of influenza B virus detections continued to exceed that of influenza A, as in recent weeks, although at low levels. Of note, some sporadic detections of seasonal H1N1 and H3N2 viruses were reported in Eastern Europe.

In East Asia, very few pandemic influenza viruses are being detected. In China, Mongolia, and Republic of Korea most influenza like illness (ILI) cases are now due primarily to influenza type B viruses. In China, overall influenza activity continues to decline and no pandemic influenza virus was detected this week. In Mongolia, influenza type B virus continues to circulate but is declining since a recent peak. An increased trend of respiratory disease activity associated with increasing circulation of influenza type B viruses has been reported in the Republic of Korea during the past few weeks. Small numbers of seasonal influenza H1N1 and H3N2 viruses continue to be sporadically reported in some countries of the region.

In South and Southeast Asia, the most active areas of transmissions of pandemic influenza are in Malaysia, Singapore, and Thailand. Although pandemic influenza virus is the predominant circulating influenza virus in the region, influenza H3N2 and influenza type B continue to co-circulate in Singapore and Thailand and Indonesia. In Singapore, rates of influenza-like illness (ILI) and acute respiratory infections (ARI) increased compared to previous week but are still below the epidemic threshold. In Indonesia, in contrast to other countries of the area, the predominant virus circulating continues to be influenza H3N2, with few detections of influenza type B and pandemic influenza viruses. In Malaysia, an increase in the number of respiratory disease consultations due to influenza-like-illness (ILI) was reported in the majority of the states compared to previous week. In Bangladesh, a small but slightly increased (compared to the previous week) numbers of pandemic influenza cases continues to be detected."