Seasonal Influenza: International Situation Update

Global Influenza Activity Update

July 27, 2012

The following summary of key influenza-related updates is based upon regional World Health Organization (WHO) reports, country reports, CDC field staff updates and other sources. Updates are listed by region. Reporting weeks may vary by country.

Southern Temperate Region

• Influenza activity is low but increasing. A number of countries reported increases in recent weeks. This is normal for this time of year, as this region’s influenza season is now underway. Below are updates from selected countries.

Chile

• Activity: increased steadily from the beginning of May through early July
• Virology: influenza A (H3N2) viruses have predominated
• Source: WHO

Australia

• Activity: increased steadily from mid-May through early July
• Virology: mix of influenza A (H3N2) and influenza B viruses
• Source: Australia Department of Health and Ageing

South Africa

• Activity: increased from mid-May through mid-July
• Virology: mix of influenza A (H3N2) and influenza B viruses
• Source: South Africa National Institute for Communicable Diseases

New Zealand

• Activity: increased steadily from mid-June through the third week in July
• Virology: influenza A (H3N2) viruses have predominated
• Source: WHO

Tropical Region

Influenza activity is increasing or high (though not unusually high) in Bolivia, Brazil, Ghana and Madagascar. Activity that was previously unseasonably high in Hong Kong Special Administrative Region in early June has decreased steadily since then. Below are updates from selected countries.

Brazil

• Activity: increased from mid-June through mid-July
• Virology: mix of influenza A (H3N2) and influenza A (H1N1)pdm09 viruses
• Source: WHO

Ghana

• Activity: persistent from late June through mid-July
• Virology: mix of influenza A (H3N2) and influenza B viruses
• Source: African networking influenza laboratories, CDC Influenza Division field staff

Madagascar

• Activity: between mid-June and mid-July, over half of respiratory samples tested were influenza-positive
• Virology: majority of influenza-positive samples were influenza A (H3N2) viruses
• Source: African networking influenza laboratories

Northern Temperate Region

• Activity: mostly low. The region’s influenza season is over
• Sources: WHO