16 September- Update number 194
• Influenza activity in the northern hemisphere temperate zones remained at inter-seasonal levels. The United States of America reported 18 cases of human infection with influenza A(H3N2)v this year, with the first case reported in June. More details can be found at http://www.cdc.gov/flu/swineflu/h3n2v-cases.htm.
• In most regions of tropical Asia influenza activity decreased.
• In the Caribbean region of Centreal America and tropical South America the influenza season appeared to have come to an end. Respiratory Syncytial Virus, influenza A(H1N1)pdm09 and influenza A(H3N2) were the main respiratory viruses reported since May of this year.
• Influenza activity peaked in the temperate countries of South America and in South Africa in late June. Influenza activity in these areas was primarily associated with influenza A(H1N1)pdm09 throughout the season, but since July greater numbers of influenza A(H3N2) and influenza type B viruses were observed.
• In Australia and New Zealand, numbers of influenza viruses detected and rates of influenza-like illness were lower than those at same time in previous years, but showed an increasing trend since early August. Influenza A(H3N2) and type B were much more commonly detected than A(H1N1)pdm09 in both countries.
• As of 16 September, a total of 135 cases of influenza A(H7N9) virus infection were reported. For more details see link below
Source of data
The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.
The updates are based on available epidemiological and virological data sources, including FluNet (reported by the Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.