Plagues,
Pestilences and Diseases
Deadly Dual flu infections in Cambodia raise concern
by Staff Writers
Washington (AFP) Nov 2, 2011
A rare case of people being infected with both swine and seasonal
flu has been documented in Cambodia, raising concern about the
possibility of a potent combination strain, said a study out
Wednesday.
The unusual diagnoses were made in a 23-year-old teacher and one
of his young male students, who had H1N1 and a human season flu
H3N2 at the same time, said the findings in the American Journal
of Tropical Medicine and Hygiene.
Neither patient was hospitalized and their illnesses did not
appear any more severe than in typical patients who are afflicted
with a single strain.
The cases date back to 2009, the year the pandemic H1N1 flu
emerged, and do not pose a current threat, but rather remind
experts of the dangers that a strain such as H5N1 bird flu could
mix with human flu and sicken millions.
"Influenza viruses are continually changing," said study author
Patrick Blair, director of respiratory diseases at the US Naval
Health Research Center in San Diego, California.
"Finding a co-infection in an area where there is considerable
seasonal flu, pandemic flu and H5N1 avian flu shows there is an
opportunity for co-mingling in swine or human hosts that could
create an ominous global health problem."
In the Cambodian case, researchers analyzed and sequenced both
virus genomes and found there had been no "genetic recombination,"
or mingling of the two.
Other case studies included in the report also show that such
co-infections are rare.
One study in 2010 of 2,000 samples turned up no cases of dual
infections and another pointed to fewer than two dozen
co-infections with H1N1 -- one in Singapore, six in China, and 11
in New Zealand.
Infectious disease expert Peter Hotez, president of the American
Society of Tropical Medicine and Hygiene, said the research
provides more reason for world governments to "remain vigilant"
and share information.
"Highly infectious strains of the virus against which humans have
little defense can spread from one continent to another with 24
hours," he said.
The study noted that southeast Asia "has proven to be a critical
region for the adaptation and emergence of variants of seasonal
influenza viruses as well as an area of zoonotic virus
transmission in humans."
Since 2005, the World Health Organization has counted 566 human
infections with H5N1 avian flu and 332 deaths, most of them in the
Near East and southeast Asia.
In Cambodia, where vaccination against the flu is rare, 16 of the
18 people infected with H5N1 flu have died, with the most recent
fatal case in August.