STUDY Research shows rise in flu cases

Health officials are recommending that infants be vaccinated.
KNIGHT RIDDER NEWSPAPERS
SAN JOSE, Calif. -- The number of people hospitalized with the flu has increased substantially over the past two decades, with an average of 226,000 Americans each year experiencing complications serious enough to require monitored care, a new study shows.
Several factors are driving the increase. At a time when the population has been aging -- thereby becoming more vulnerable to complications -- more virulent viruses have been circulating, government scientists have found.
The bugs have also tended to hang around for longer periods of time, ensuring a more thorough spread through the population, according to the researchers, whose findings appear today in the Journal of the American Medical Association.
Underscoring the seriousness of the persistent respiratory disease, federal health officials are recommending for the first time that babies between the ages of 6 months and 23 months be vaccinated against influenza. Research indicates that infants, and not just the elderly, are especially at risk for pneumonia and other influenza-related health problems.
Preparation
Local hospitals and health clinics have been gearing up for this year's flu season, with vaccination clinics scheduled to start in the middle of next month and run through the winter.
"Influenza is a yearly epidemic. I think that we sometimes get a little blas & eacute; about something that comes around every year," said Dr. Randy Bergen, a pediatric infectious disease physician at Kaiser-Walnut Creek hospital. "But I feel very strongly there's no such thing as a mild flu season."
"We often underestimate the effect of influenza on health," said William Thompson, an epidemiologist at the Centers for Disease Control and Prevention and lead author of the new study. "Influenza has a real impact on people's lives and causes a significant amount of morbidity and mortality every year."
Indeed, the scientists found that by the late 1990s, more than 375,000 Americans were being hospitalized each year for respiratory and circulatory problems exacerbated by the flu.
The average annual number of cases that Thompson's team found -- 226,054 -- was more than double previous government estimates, in part because the researchers broadened their definition of influenza-associated hospitalizations.
Affects any age
Seniors 85 years or older were most likely to wind up in the hospital after a bout with the flu. But children under age 5 and middle-aged adults between 50 and 64 years old also had high hospitalization rates.
"Influenza is pretty nasty, regardless of at which age you get it," said Dr. Keith Powell, a member of the American Academy of Pediatrics' committee on infectious diseases.
During last year's flu season, which started early but sickened fewer people than some previous seasons, 152 children died, according to the CDC.
Among children, those under age 2 have been found to be the most at-risk for influenza complications, but the vaccine is licensed only for those age 6 months and older. Children are given two shots, the second coming one month after the first, Powell said.
Because no vaccine is available for newborn babies under 6 months of age, it is particularly important for parents, older siblings and caregivers to be vaccinated, Kaiser's Bergen said.
Increased availability
This year, federal health officials are anticipating that a record number of vaccine doses will be available to the public, with about 100 million shots being distributed throughout the country.
Manufacturing problems at Chiron, the Emeryville, Calif., maker of nearly half the nation's vaccine supply, have caused some delays in production this year. A small number of the company's doses were found last month to be contaminated.
Chiron has been working with health officials to ensure the vaccine is safe, but the company will not be able to start shipping doses to doctors and hospitals until next month, said Alison Marquiss, a Chiron spokeswoman.
But even with the new recommendation that toddlers from age 6 months to 23 months be inoculated, along with their immediate family members and caregivers, health officials are not expecting a run on the flu vaccine. The advice to get the annual immunization has often gone unheeded by the public, Bonnie Hebert, a CDC spokeswoman, said.
"We want everybody to get it," she said, "but not everybody will."