Most of North America, Europe, and Central Asia started the new year with rising rates of influenza virus, according to the latest global flu update published by the World Health Organization (WHO).
"In the temperate zone of the northern hemisphere, respiratory illness indicators and influenza activity continued to increase overall," the WHO said.
Though influenza B is dominating in Canada and the United States, 68.7% of global lab specimens were typed as influenza A and 31.3% as influenza B during the last week of December, the WHO said.
Of the A viruses, 28.9% were 2009 H1N1 and 71.1% were H3N2. Of the characterized B viruses, 1.5% belonged to the Yamagata lineage and 98.5% to the Victoria lineage.
Influenza B rising in Canada, US, Cuba
According to the WHO, influenza B viruses accounted for half of the detections in Canada were the predominant influenza type detected in the United States, followed 2009 H1N1. Typically, influenza B strains are seen later in the flu seasons in North America.
Hospitalization rates in Canada increased, and in the United States, flu levels have reached the peak level of last influenza season. The number of US deaths attributed to influenza is also on the rise, but has not yet reached epidemic levels.
"In the Caribbean and Central American countries, influenza activity was low in general, except for Cuba that continued to report detections of predominately influenza B/Victoria lineage viruses," the WHO said.
Europe, Asia sees more influenza A
In most of Europe, influenza A is the dominant strain, with H3N2 predominant in Ireland and the United Kingdom, and Finland and Iceland are reporting both 2009 H1N1 and H3N2. England reported mid-levels of hospitalizations due to flu.
In China, influenza-like illness activity continued to increase, earlier and at higher rates than the previous three flu seasons. H3N2 is the predominant strain, followed by a smaller proportion of influenza B viruses.
In South Korea 2009 H1N1 and H3N2 were co-circulating, while Japan detected influenza activity slightly earlier than in previous seasons.
Most regions of Africa reported low or slightly increasing levels of flu.
Jan 6 WHO global flu update