H1N1: Novel human influenza virus resurfaces in India, doctors suspect minor drift

Syed Akbar
Hyderabad: The novel human influenza virus has resurfaced in
the country, this time quite early, with dozens of sporadic cases
reported from different States including Andhra Pradesh and
Maharashtra, even as authorities plan to screen passengers at airports
if there was no let up in the spread of the disease.

With the novel human influenza or H1N1 virus choosing summer to create
panic, virologists are busy decoding the genome of the circulating
strain to ascertain whether it has mutated since the 2009 pandemic to
adapt itself to dry climate conditions.

Though influenza viruses strike round the year, they normally become
active during monsoon and winter as they are better adapted to wet
climatic conditions and low temperatures. Summer has caught up in many
parts of the country with mercury soaring past 35 degrees C. That the
novel human influenza virus has chosen summer to strike with large
number of sporadic cases has forced scientists to think if the virus
has mutated, and if so, to what extent. If the mutation in the virus
is a major one, a new vaccine has to be developed.

The National Institute of Virology in Pune has taken up the task of
sequencing the genome of the latest strain. The results are expected
later this week. Andhra Pradesh recorded about 50 cases of novel human
influenza so far this year with three patients succumbing to the
virus. Maharashtra and Rajasthan have been worst hit so far, and
authorities in Andhra Pradesh, given the havoc the virus had caused in
the past, have increased surveillance in border areas and major cities
like Hyderabad, Vijayawada and Visakhapatnam.

“We will think of screening passengers at airports for swine flu if
the number of cases increase rapidly. The vaccine administered earlier
has lost its potency since influenza vaccine protects for one year
only. People will have to take vaccine again if they need fresh
protection,” said Dr Uma Maheshwari, Hyderabad district medical and
health officer. She said depending on the need special camps would be
set up to prevent spread of the disease.

Allaying fears Hyderabad district immunization officer Dr C
Srinivasulu said there was no cause for panic as only sporadic cases
have been reported. There is no outbreak as of now. He said it was not
clear whether the virus had mutated. Dr Srinivasulu, however, said the
virus had been responding to drugs like Tami flu.

The virus has undergone mutation in the West and Indian health experts
believe that the mutation in the virus circulating in the country is a
minor one. In Mumbai, doctors have observed a change in the clinical
manifestation of H1N1 with not many patients reporting fever.
Scientists at NIV agree that there is a change in the antigenicity of
the virus, but since the mutation is a small one scientifically called
“drift”, the virus responds to the present drugs.