Oct 21, 2011 (CIDRAP News) – A few of the world's tropical countries are reporting active flu transmission, as the flu season continues in Australia and New Zealand, though activity is declining, the World Health Organization (WHO) reported today.
Countries in the tropical areas of the Americas, including Cuba, Honduras, and El Salvador, saw flu activity peak in mid to late September, with the influenza A (H3N2) strain responsible for most infections, the WHO said.
Meanwhile, in tropical parts of Asia, flu—primarily type B—is active in localized areas in countries such as India, Bangladesh, and Cambodia. In Thailand and Laos, flu activity dominated by H3N2 strains peaked in mid to late September, while Vietnam is reporting sustained transmission of the 2009 H1N1 virus.
Flu transmission is continuing in Cameroon, with most of it influenza B, the WHO reported.
In temperate areas of South America, flu is declining to baseline levels. Argentina and Chile both reported that the severity of their flu seasons was similar to previous years.
Australia has reported 24,049 confirmed flu cases, which exceeds the number reported for previous years, except during the 2009 H1N1 pandemic. Though Australia's flu activity peaked in early August, the timing varied in different parts of the country.
Countries in the Northern Hemisphere's temperate zones are still in their preseason period for flu, and though some recently resumed monitoring, none are reporting active community transmission, according to the WHO.
Flu activity in the United States last week remained at low levels, with most indicators well below epidemic thresholds, the Centers for Disease Control and Prevention (CDC) said today. Only 0.5% of respiratory specimens were positive for influenza, and the percentage of doctor's visits for flu-like illness in the CDC's flu surveillance network was 1%.
No pediatric flu deaths were reported, and the percentage of deaths from flu and pneumonia was 6.4%, putting it below the epidemic threshold.
Sporadic flu activity was reported by 18 states, along with the District of Columbia, Guam, Puerto Rico, and the US Virgin Islands.
Oct 21 WHO global flu update
Oct 21 CDC weekly flu update