WHO points out that influenza viruses A (H3N2) and subtype B are circulating in India, besides neighbouring China, Bangladesh and Sri Lanka

By Syed Akbar
Hyderabad: India along with neighbouring countries continues
to report “notable” human influenza (flu) activity, says the latest
release on flu by the World Health Organisation (WHO).

The WHO has pointed out that influenza viruses – A (H3N2) and subtype
B - are circulating in India, besides neighbouring China, Bangladesh
and Sri Lanka.

Though human influenza cases related to the 2009 pandemic A (H1N1) are
on the decline, still many pockets report a considerable number of
infections. Andhra Pradesh alone reported 145 cases related to the
2009 pandemic virus with 18 deaths so far this year. India reported
2393 cases with 134 deaths during January 1 and August 5.

The WHO has found that persistent low number of pandemic virus and
influenza type B cases, in almost equal number, is reported from the
country. After a lull during 2011, the influenza virus became
relatively active during 2012, with Andhra Pradesh and Karnataka
reporting large number of cases including deaths.

Interestingly, health authorities in the country conduct diagnostic
tests for the 2009 pandemic virus, leaving the other two sub-types, A
(H3N2) and subtype B, which the WHO has found to be circulating in
tropical countries including India. Diagnostic tests for H3N2 will
help in finding out if the virus had mutated in the country too, as it
did in the USA. The H3N2 has turned into H3N2v (v for variant) in the
USA after obtaining a gene from the 2009 pandemic influenza virus.

“Some tropical countries are reporting notable flu activity,” the WHO
said in its biweekly flu update, adding that two subtypes are
circulating in Bangladesh, southern China, India, Singapore, Sri
Lanka, and Vietnam.

Of flu virus isolates that were subtyped, 81.2 per cent were type A
and 18.8 per cent were type B. Of the type A viruses, 91.5 per cent
were H3N2 and 8.5 per cent were 2009 H1N1. The WHO also referred to
cases of swine-origin variant, H3N2v, in the United States, where it
is spreading to newer areas.