Flu activity on the rise in the Northern Hemisphere

According to the most recent World Health Organization update, flu activity is increasing in many temperate-zone countries in the Northern Hemisphere, with influenza B and influenza A teaming up in Canada and the United States.

Across Europe, influenza B is co-circulating with the 2009 pandemic H1N1 virus while countries like Morocco, Algeria and Tunisia report mostly influenza B. Pakistan and Iran are mostly experiencing the effects of the 2009 H1N1 strain as of January 14, CIDRAP News reports.

While the last few weeks have seen a steady rise in hospitalizations and deaths from the 2009 H1N1 strain, other European countries, including the Netherlands, Portugal, France and Denmark, are reporting more serious cases of both H1N1 and influenza B. South Korea and Japan are reporting that the 2009 H1N1 is currently the dominant viral strain.

While the Northern Hemisphere suffers through the ascent of flu season, countries in the tropical zones and the Southern Hemisphere's temperate zones have little flu activity to report, CIDRAP News reports. Severe 2009 H1N1 infections that had occurred in Sri Lanka and H3N2 circulation in Paraguay are believed to be on the decline. The one exception is Australia, where influenza B and H3N2 continue to circulate.

Some resistance is believed to be growing among the 2009 H1N1 viruses with what is called the H275Y substitution, which gives the virus resistance to oseltamivir, also known as Tamiflu. To date, there are 319 reported cases of this kind of resistance.