Last Flu Season Was Mild, But Child Deaths Worrying
Dangerous co-infection with drug-resistant staph is on the rise, CDC says
FRIDAY, Aug. 10, 2007 (HealthDay News) -- Although the 2006-07 flu season was comparatively mild in the United States, it still claimed the lives of 68 children, and experts say more must be done to reduce the death toll.
They're especially concerned about the steady rise in a potentially lethal combination of infection with flu and drug-resistant staphylococcus, or "staph."
"While waiting to see what this year will bring, we should all plan to roll our sleeves up and get vaccinated and in no way let our guard down," said Dr. David Katz, director of Yale University School of Medicine's Prevention Research Center.
In a report released Thursday by the U.S. Centers for Disease Control and Prevention, experts said the 2006-07 flu season peaked in mid-February. And there were actually fewer pediatric deaths and fewer children hospitalized with influenza than in the past three flu seasons, according to the CDC.
But, among the 68 children whose deaths were associated with flu from Oct. 1, 2006, to May 19, 2007, 21 had influenza plus Stapholococcus aureus ("staph") that was resistant to a leading antibiotic, methicillin, according to the report in the Aug. 10 issue of the CDC's Morbidity and Mortality Weekly Report.
In comparison, only one child died from flu coupled with S. aureus infection in 2004 through 2005, and three died during the 2005-06 season, the CDC said.
"We are looking into the number of deaths of children combined with staff bacterial infection," said Dr. Joe Bresee, CDC's chief of the Epidemiology and Prevention Branch in the Influenza Division. "From our perspective, it looks like it has increased."
Bresee said the CDC isn't sure if the number of deaths is actually rising, or the increase is due to better reporting. "The actual risk to kids from this is not known, but it is concerning," he said.
Bresee thinks that increasing the number of young children who get flu shots is key to reducing the problem. "They would be less likely to get influenza and, therefore, less likely to get co-infections with S. aureus," he said.
Despite the troubling news that such dual infections may be on the rise, the past season's flu statistics were relatively positive, Katz said.
"Data from the last flu season provide mostly good news," he said. "The number of cases was never unusually high. The strains were mostly of the expected varieties, and vaccine composition was just right. The death toll from complications of influenza was a bit lower than average."
The reasons for the milder flu season aren't clear, said Dr. Marc Siegel, an associate professor of medicine at New York University School of Medicine. "It could be increased surveillance and improved care and more awareness of what influenza can do," he said. "It may also be a less virulent strain of the virus."
Katz noted that, even in a good year, the average number of deaths from flu in the United States totals about 30,000, mostly among the elderly.
During the 2006-07 flu season, the influenza A (H1) virus was most common in the United States, but the A (H3) virus was found to be more common late in the season, according to the CDC.
For the 2007-08 vaccine, the U.S. Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee has recommended that the trivalent flu vaccine contain A/Solomon Islands/3/2006-like (H1N1), A/Wisconsin/67/2005-like (H3N2), and B/Malaysia/2506/2004-like viruses, the CDC reported.
The influenza A (H3N2) and influenza B components remain the same for the new vaccine. These recommendations were based on antigenic analyses of recently isolated influenza viruses, epidemiologic data, vaccination studies in humans, and the availability of vaccine strains and reagents, the CDC said.
Last season, around the world, influenza A (H1), A (H3), and B viruses were most common. In Africa, small amounts of influenza A and B were seen. In Europe and Asia, influenza A (H3) virus was most common, but low levels of A (H1) were seen. Influenza B viruses were seen at lower levels in Asia and Europe but were most common in some countries, according to the CDC.
The best way to protect yourself from flu is to get vaccinated, experts said. "We had a good flu year. But that was last year," Katz noted.
In terms of the H5N1 bird flu virus, from December 2003 to mid-July 2007, 319 cases of bird flu in humans were reported to the World Health Organization. Among these cases, 60 percent (192) were fatal. To date, no human cases of bird flu have been reported in the United States.
All human cases were reported from Asia (Azerbaijan, Cambodia, China, Indonesia, Iraq, Laos, Thailand, Turkey, and Vietnam) and Africa (Djibouti, Egypt, and Nigeria).
But, "the threat of an avian flu pandemic still looms," Katz said. "To date, deaths from avian flu have been few, and limited to Asia. But no one knows for sure when that might change."
Siegel, author of Bird Flu: Everything You Need to Know About the Next Pandemic, noted that although H5N1 has a high mortality rate, "we see year after year that it is confined to birds. There is no indication that it is about to become a massive human problem. There is no indication that it is on the verge of transforming."
For more on flu, visit the U.S. Centers for Disease Control and Prevention.