Flu activity on rise in Southern Hemisphere

Influenza activity has experienced a significant upswing in some countries in the Southern Hemisphere, including Brazil, Bolivia, New Zealand and Australia, according to the World Health Organization.

The proportion of positive respiratory samples doubled to approximately 30 percent in Australia compared to the last reporting period. The highest number of positive samples was found in South Australia, Queensland and New South Wales. The most dominant virus in the country is H3N2, with some detection of influenza B virus, CIDRAP News reports.

Doctor visits for flu-like illness rose above the national baseline of 50 consultations per 100,000 population in New Zealand for the first time all season. More than 70 percent of the detections are H3N2, while the rest are evenly split between un-subtyped influenza A, 2009 H1N1 and influenza B.

In South Africa, approximately half of respiratory specimens at the end of June tested positive for influenza. Most reported specimens were the H3N2 virus, followed by influenza B.

Health officials have identified a sustained flu detection growth near La Paz in Bolivia. The 2009 H1N1 virus is the dominant one in the central South American country, CIDRAP News reports.

Brazil also reported a jump in influenza infections, mostly involving the former pandemic virus, with some severe cases.

Flu activity is also on the rise in Paraguay, while it is dropping in Chile and there is little activity being reported in Argentina.