Recalculating the Tally in Swine Flu Deaths

By DONALD G. McNEIL Jr.

Published: November 10, 2009

About 4,000 Americans — rather than about 1,200 — have died of swine flu since the disease emerged in April, according to new figures being calculated by epidemiologists for the Centers for Disease Control and Prevention.

The larger number of deaths does not mean the virus is more dangerous. Rather, it is a new estimate made by combining deaths from laboratory-confirmed cases of the flu and deaths that appear to be brought on by flu, even though the patient may have ultimately died of bacterial pneumonia, other infections or organ failure.

The new estimate of deaths — actually a range both larger and smaller than 4,000 — will not be released until sometime next week because the centers’ consultants are still looking over the figures, said Glen Nowak, a C.D.C. spokesman.

The new estimate will be a more accurate comparison to the 36,000 deaths from seasonal flu each year, he said. That estimate is also based on confirmed cases as well as hospital reports of people who appear to have died after a bout of flu. Over 90 percent of seasonal flu victims are over 65, and many are bedridden or in nursing homes or have serious medical problems like cancer or heart disease that the flu worsens.

The new estimate “does sound much more reasonable,” said Ira M. Longini Jr., a flu epidemiologist at the University of Washington. “It doesn’t surprise me that it’s higher.”

Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said the new estimate was more accurate “but doesn’t change the decisions you’d make from a public health perspective.”

“If it was 40,000 deaths rather than 4,000, that would be different,” Dr. Osterholm said.

A much higher death rate would mean more drastic measures to keep people apart and could mean, for example, adding immune-boosting adjuvants to the vaccine so more people could get it.

Both Dr. Osterholm and Dr. Longini said the new figure does not suggest that the epidemic will eventually kill as many as 90,000 Americans, as was envisioned in one forecast widely publicized in August in a report issued by the President’s Council of Advisers on Science and Technology. That report posited a range of 30,000 to 90,000 deaths.

Dr. Longini said he thought deaths were likely to be in the 30,000-to-40,000 range, and Dr. Osterholm said they would “have a long way to go to even get there.”

The vaccine, Dr. Longini said, should also cut the death rate. About 10 million new doses are shipped each week.