NFLUENZA (27): WHO GLOBAL UPDATE ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: Mon 8 Sep 2014 Source: WHO, surveillance & monitoring [abridged, edited] Influenza Update No. 219 ------------------------ Summary ----- Globally, the influenza season is ongoing in the southern hemisphere. Elsewhere, influenza activity remained low. - In Europe and North America, overall influenza activity remained at inter-seasonal levels. - In Africa (except the southern cone) and western Asia, influenza activity was low. - In eastern Asia, influenza activity remained low in most countries with influenza A(H3N2) the main detected virus subtype. Influenza A(H3N2) and some influenza B activity continued in south China. - In the southern hemisphere, the influenza season was ongoing. In the temperate zone of South America, influenza activity mainly associated with A(H3N2) virus decreased. In Australia and New Zealand, the influenza season was ongoing. Australia reported a sharp increase in activity associated with A(H1N1)pdm09 and A(H3N2) viruses in recent weeks with the highest number of influenza-like illness (ILI) rates and weekly notifications of influenza confirmed cases in the last 5 years. In South Africa, the influenza season continued with A(H3N2) most frequently detected. - Based on FluNet reporting (as of 4 Sep 2014, 13:35 UTC), during weeks 33 to 34 (10 Aug 2014 to 23 Aug 2014), National Influenza Centres (NICs) and other national influenza laboratories from 51 countries, areas or territories reported data. The WHO GISRS laboratories tested more than 26 262 specimens. 3222 were positive for influenza viruses, of which 2632 (81.7 percent) were typed as influenza A and 590 (18.3 percent) as influenza B. Of the sub-typed influenza A viruses, 416 (17.8 percent) were influenza A(H1N1)pdm09 and 1920 (82.2 percent) were influenza A(H3N2). Of the characterized B viruses, 88 (98.9 percent) belonged to the B-Yamagata lineage and 1 (1.1 percent) to the B-Victoria lineage. Countries in the temperate zone of the northern hemisphere -------------------------------------------- North America, Europe, Northern Africa and the Western and Central Asia region In the majority of the countries in the northern hemisphere, influenza activity was at inter-seasonal levels. Eastern Asia In the eastern Asian region, influenza activity remained low with influenza A(H3N2) as the main virus in circulation. In southern China, influenza activity decreased compared to previous weeks. The influenza virus detections reported were mostly influenza A(H3N2) with few influenza B viruses. In northern China, Japan, Mongolia, and the Republic of Korea, influenza activity remained at inter-seasonal levels. Countries in the tropical zone ------------------------------ Tropical countries of the Americas/Central America and the Caribbean Overall in this region, influenza activity remained low. Circulation of influenza B virus was observed in several of the Caribbean and Central American countries, with co-circulation of influenza A(H1N1)pdm09 reported in Guatemala and Panama and co-circulation of influenza A(H3N2) in the Dominican Republic, Honduras, and Jamaica. Tropical countries in South America reported influenza-like illness (ILI) and severe acute respiratory infection (SARI) activity within the expected range. Respiratory syncytial virus (RSV) continued to circulate but with decreasing trends. The influenza detections increased in most countries in the subregion. In the Plurinational State of Bolivia, influenza was the most frequently detected respiratory virus in the last 2 months, with co-circulation of influenza A(H3N2) and influenza A(H1N1)pmd09 detections; the trend has decreased over the last few weeks. In Brazil, the percent of specimens positive for influenza virus was lower than at the beginning of August 2014. Influenza activity was predominantly in the southeastern region where influenza A(H3N2) was the most commonly reported virus. In Africa, influenza activity reported from most countries in eastern, middle and western Africa was at low levels. In most Southern Asian and Southeastern Asian countries, activity declined or remained low. In Lao Peoples Democratic republic and Viet Nam, few influenza detections were reported. Thailand reported mainly influenza B activity, with decreased activity since the beginning of August 2014. India reported increased influenza detections, mostly due to influenza A(H3N2) and influenza B viruses. Bhutan reported a decrease in influenza activity after a small peak in July and August 2014, also due mainly to co-circulation of influenza A(H3N2) and influenza B viruses. Countries in the temperate zone of the southern hemisphere -------------------------------------------- Temperate Zone of South America In the temperate zone of South America, influenza activity decreased. Influenza A(H3N2) was the most frequently detected influenza virus. In Chile, ILI activity as well as number of influenza detections decreased compared to the beginning of August 2014 and was within the expected range for this time of the year. During this winter season, RSV predominated among SARI cases, accounting for 60 percent of the positive respiratory specimens, followed by influenza A(H3N2) (19 percent). Of the influenza viruses detected, 66 percent were influenza A and 34 percent were influenza B. In Paraguay, the ILI consultation rate remained at high levels (alert zone). The proportion of SARI-associated hospitalizations decreased in recent weeks, and the percentage of influenza positive specimens decreased slightly. Among the influenza viruses, 94.4 percent were influenza A and 5.6 percent were influenza B. South Africa In South Africa, influenza activity remained high, and influenza A(H3N2) was the most detected virus. Oceania, Melanesia and Polynesia In both Australia and New Zealand, ILI activity and the number of influenza detections increased. The most frequently detected virus was influenza A(H1N1)pmd09. In Australia, ILI activity and the notification of laboratory confirmed cases showed a sharp increase in the last few weeks; both ILI activity and laboratory confirmed cases were the highest in the last 5 years. In most jurisdictions in Australia, influenza A(H1N1)pdm09 predominated, except in New South Wales and the Australian Capital Territory, where influenza A(H3N2) was most common. The severity of the influenza season was greater in New South Wales. In New Zealand, the ILI consultation rate remained above the seasonal threshold and was slightly above the average epidemic curve. Of 1172 ILI specimens tested since 28 Apr 2014, 402 (34 percent) were positive for influenza, and influenza A(H1N1)pdm09 was the most frequently detected influenza virus. In the Pacific Islands, ILI activity was variable, with a decreasing trend observed in several islands. ILI activity was above the threshold (90 percent of historical values) in the Federated States of Micronesia, New Zealand, and Tuvalu. -- Communicated by: ProMED-mail [See: Influenza reports from WHO Regional Offices: AMRO: EURO: WPRO: Epidemiological Influenza updates: Epidemiological Influenza updates archives 2012: Virological surveillance updates: Virological surveillance updates archives: Contact: In the current Southern Hemisphere outbreaks, no antigenically novel influenza viruses have been reported. Currently, Australia appears to be the worst affected country. It appears likely the new northern hemisphere vaccine will be well-matched with influenza viruses likely to be circulating early in the next northern hemisphere outbreak. Respiratory syncytial virus continues to be prominent in some regions of South America. It is unclear whether this is a real situation or merely a consequence of local interests and expertise. Avian-derived influenza viruses are not currently a problem. Readers are recommended to access the original text at source URL to view the data in graphic form. - Mod.CP]
Posted on: Tue, 09 Sep 2014 23:36:17 +0000
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