People who die after getting swine flu are 100 times more likely, compared to seasonal flu, to have been killed by the virus itself rather than secondary causes, a top French researcher said Monday.
People who die after getting swine flu are 100 times more likely, compared to seasonal flu, to have been killed by the virus itself rather than secondary causes, a top French researcher said Monday.
The findings -- published on a research-sharing platform, PLoS Currents: Influenza, vetted by flu experts -- could help health officials manage critical care resources if infection rates climb in the autumn and winter.It could also provide important clues as to the new swine flu's potential virulence, said author Antoine Flahault, a leading epidemiologist and director of France's School for Advanced Studies in Public Health.
"The direct lethality due to viral pneumonia probably gives the best estimate of an influenza strain's virulence, since it may vary from strain to strain and is not due to a country's level of health development," he said.
With regular seasonal flu, which claims up to 500,000 lives each year worldwide, most deaths are attributed either to secondary bacterial infections such as pneumonia, or pre-existing chronic conditions that boost vulnerability.
Only about one-in-a-million infections result in death due to a rare condition known as acute respiratory disease syndrome (ARDS).
"ARDS is frighteningly lethal -- it is like drowning," Flahault told AFP by phone. The condition requires intensive-care treatment for an average of thee weeks. "Statistically, only one in two patients survive."
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Experts also caution that the pandemic flu could become more lethal as it continues to mutate.
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In New Caledonia, local health authorities have reported 30,000 infections and two deaths attributed directly to the pandemic virus.
Flahault said that some 70,000 persons have been infected in Mauritius, with seven reported deaths from ARDS, five of them confirmed.
"These surveillance data allow for a first estimate of direct lethality due to H1N1 of one-per-10,000 infections, about 100 times more than regular seasonal flu," he said.
Flahault cautioned that these are only "preliminary and rough estimates," and acknowledged that his findings -- based on a limited number of cases on two isolated islands -- may not extend to much larger, continental countries.
"But we have a terrible lack of data," he said.
"It may be useful to deliver such estimates ... as early as possible so health authorities can check availability of intensive care units and artificial ventilation devices in case of a wave of similar virulence this fall in the northern hemisphere," he said.
Source-AFP
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