Study: H1N1 Death Rate Lower than ExpectedSeptember 18, 2009 - 2:41 PM | by: Jonathan Serrie
The death rate from the H1N1 flu virus is lower than originally expected, according to a study led by a prominent Harvard researcher.
Epidemiology Professor Marc Lipsitch has yet to publish his study, pending peer review. But he presented key findings to influenza experts at a recent workshop in Washington.
According to Reuters, Lipsitch compared H1N1’s death rate to a moderate year of seasonal flu and said that the virus is “mildest in kids.”
“It conforms reasonably well to the impression of those of us who are working in the field of public health,” said William Schaffner, MD, who chairs Vanderbilt University’s Department of Preventive Medicine.
Because most people who get H1N1 experience only mild symptoms and recover at home, most cases go unreported. Lipsitch’s study attempts to take these silent numbers into account, instead of simply relying on statistics of physician visits.
“That was the Mexican mistake,” Schaffner said. “They initially looked at only the patients who were admitted to the hospital and who were in intensive care units. So, we got an inaccurate estimate of the severity of this viral infection. And that’s because the Mexican public health authorities really didn’t have a handle on all those people who were ill, but never went to the hospital.”
While praising Lipsitch’s work, Schaffner said the Americans should not interpret the study as reason for complacency. “Any outbreak that has the severity of an average influenza year is noteworthy,” he said.
Even though seasonal flu has a death rate of less than one-tenth of one percent, it infects so many people that an average of 36-thousand die in the U.S. each year.
Even if H1N1 symptoms are mild in most children, younger people are more likely to get the virus. And, inevitably, some will die of a potentially preventable disease.
“We can’t always anticipate who those children are,” Schaffner said. “The American Academy of Pediatrics, the American Academy of Family Physicians and CDC all say that every child age 6 months through 18 years of age should be vaccinated annually against influenza. And that’s to prevent all of the illness, all those doctor visits, the unnecessary use of antibiotics to combat complications, but also the deaths.”