Pandemic (H1N1) 2009 - update 107

[Guest guest]

http://www.who.int/csr/don/2010_07_02/en/index.html

Pandemic (H1N1) 2009 - update 107

Weekly update

2 July 2010 -- As of 27 June, worldwide more than 214 countries and overseas

territories or communities have reported laboratory confirmed cases of pandemic

influenza H1N1 2009, including over 18239 deaths.

WHO is actively monitoring the progress of the pandemic through frequent

consultations with the WHO Regional Offices and Member States and through

monitoring of multiple sources of information.

Situation update:

Summary: Worldwide, overall pandemic and seasonal influenza activity remains

low. In the temperate regions of the Southern Hemisphere, Chile, and Argentina

report low activity and only sporadic detections of both pandemic and seasonal

influenza viruses during the early part of winter. South Africa, New Zealand,

and Australia have all recently noted slight increases in the rate of

respiratory disease. South Africa recently reported their first case of

confirmed H1N1; however, the predominant influenza virus there currently is

seasonal influenza A(H3N2). The H3N2 virus detected in South Africa is similar

to the Perth-like strain, which is currently a component of the trivalent

seasonal influenza vaccine. Active transmission of pandemic influenza virus

still persists in localized areas of the tropics, particularly in South and

Southeast Asia, the Caribbean and West Africa. During the last 2 to 3 weeks,

seasonal influenza H3N2 viruses have also been detected at increasing levels in

Nicaragua, and low levels or sporadically in Australia, Central America, South

Africa and East Africa. Global circulation of seasonal influenza virus type B

viruses persists at low levels in parts of East Asia, Central Africa, and

Central America.

Regional Details: In most countries of the temperate zone of the southern

hemisphere (Chile, Argentina, South Africa, Australia, and New Zealand) pandemic

and seasonal influenza viruses have been detected only sporadically in June 2010

and activity is low, indicating a late start of the influenza season compared to

2008. Overall levels of respiratory disease in the population remain low. In

Argentina, small numbers of influenza type B viruses were detected during mid

June 2010. In both Chile and Argentina, respiratory syncitial virus (RSV)

continued to be the predominant circulating respiratory virus resulting in high

rates of respiratory illness in children. In South Africa, small and slightly

increasing numbers of seasonal H3N2 and type B viruses were detected during mid

June 2010. In both Australia and New Zealand, levels of ILI are increasing, but

still below recent historical seasonal levels.

In Asia, the most active areas of pandemic influenza virus transmission

currently are in parts of southern India, Bangladesh, Singapore, and Malaysia.

Rates are decreasing in the latter three countries but in India, the number of

laboratory confirmed cases of pandemic influenza has increased since mid June.

This activity has been primarily observed in Southern state of Kerala, and

includes reports of a number of severe and fatal cases, particularly among

pregnant women. In Bangladesh, pandemic and seasonal influenza type B viruses

co-circulated at low levels during early June 2010. In Singapore, during the

third week of June 2010, the levels of ARI remained below warning levels and the

proportion of patients with ILI testing positive for pandemic influenza virus

fell from 19% to 15%. In Malaysia, data suggests that overall pandemic influenza

activity has declined throughout June 2010 though pandemic virus continues to

circulate at low levels. Throughout East Asia, influenza activity remained very

low. In China and Japan, levels of ILI remained at or below baseline levels for

the summer months. Low and declining levels of influenza type B viruses

continued to circulate across China, Hong Kong SAR (China), Chinese Taipei and

Republic of Korea.

In the tropical regions of the Americas, overall pandemic and seasonal influenza

activity remained very low. In Cuba, pandemic influenza virus transmission

remains active but has declined substantially since peaking during mid-April to

mid-May 2010; no new fatal cases have been reported over the past five reporting

weeks. In several countries of the region, there has been recent circulation of

seasonal influenza A (H3N2) viruses (Venezuela during May 2010) and B viruses

(Bolivia during March and May 2010; El Salvador during late May and early June

2010). Nicaragua notably has seen a sharp increase in the detection of seasonal

influenza A (H3N2) and Panama has detected low numbers of the same. In addition,

after 20 weeks with no circulating pandemic virus, Panama reported the detection

of pandemic influenza (H1N1) 2009 in early June. Many countries in the area also

report ongoing co-circulation of other respiratory viruses, most notably RSV.

In sub-Saharan Africa, pandemic and seasonal influenza activity has been

observed in several countries. Ghana, in West Africa, continues to have active

circulation of pandemic influenza virus several weeks after activity peaked

during early April 2010. Seasonal influenza type B viruses continue to circulate

in parts of central and southern Africa, most notably in Cameroon. As reported

in previous updates, small numbers of seasonal H3N2 viruses continue to be

detected across Africa, particularly in eastern Africa; the most recent

detections have been reported in Ghana, Kenya, and South Africa during mid June

2010. The persistence of H3N2 in this area over time very likely represents

sustained community transmission of the virus.

Overall, in the temperate regions of the northern hemisphere (North America and

Europe), pandemic and seasonal influenza viruses have been detected sporadically

or at very low levels during the past month.