Saturday, February 13, 2010

Flu death rate drops again below epidemic threshold in U.S.

2010-02-13

HOUSTON, Feb. 12 (Xinhua) -- The proportion of deaths attributed to pneumonia and influenza (P&I) in the United States dropped again below the epidemic threshold during the week ending Feb. 6, the federal Centers for Disease Control and Prevention ( CDC) said on Friday.

"During week five (Jan. 31 to Feb. 6), 7.3 percent of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was below the epidemic threshold of 7.8 percent for week five," the CDC said on its web site.

Since last October, when the A/H1N1 pandemic peaked and as many as 48 states had widespread activity of the new virus, the proportion of deaths attributed to P&I based on the 122 Cities Report had been above the epidemic threshold for 11 weeks running.

As the A/H1N1 flu began to wane in December, the proportion of deaths linked to P&I based on the 122 Cities Report was dipping below the epidemic threshold in week 50 of 2009, but bouncing back in week 51. After that, it remained below the epidemic threshold for two more weeks, but bounced back again during the second week of 2010 and remained above the threshold for three more weeks.

The epidemic threshold is the point at which the observed proportion of deaths attributed to pneumonia or influenza is significantly higher than would be expected at that time of the year in the absence of substantial influenza-related mortality.

Latest statistics released by the CDC show that, from Aug. 30, 2009 to Feb. 6, 2010, there were 40,030 laboratory-confirmed influenza-associated hospitalizations and 1,937 laboratory- confirmed influenza-associated deaths, including 260 of young patients under age of 18, that have been reported to the federal agency.

But health officials believe the actual death toll have been much higher than the figures of laboratory-confirmed influenza- associated deaths.

Also on Friday, the CDC estimated 8,330 to 17,160 people had died between April 2009 and January 16, 2010 from the A/H1N1 virus, with a middle range of about 12,000, including 880 to 1,800 children.

According to the newly released CDC estimates, 41 million to 84 million people were infected with the A/H1N1 virus, while 183,000 to 378,000 people were hospitalized with the new virus during the same period.

"The estimates are actually much more accurate than the confirmed numbers," the CDC director Dr. Thomas Frieden said earlier. "The number of confirmed deaths is really just a small proportion of the number of total deaths," he explained.

On the whole, the CDC reported on Friday that the A/H1N1 flu infections continue to be on the wane nationally and there had been no states reporting widespread activity across the country for the first five months of 2010.

The proportion of outpatient visits for influenza-like illness (ILI) was 2.1 percent during the week ending Feb. 6, which remained below the national baseline of 2.3 percent since the beginning of the new year.

Although the A/H1N1 flu infections are declining, federal and state health officials still urge the American parents to get their children fully vaccinated as soon as possible.

In Ohio, statistics released by the state health department show that among 331,000 Ohio children aged 6 months to 10, roughly 25 percent had gotten the first dose while only seven percent had gotten the second.

The second dose of A/H1N1 vaccine for the youngsters under 10, recommended by the CDC, would achieve maximum protection against the new virus.

Experts said that parents are aware of the need to get kids fully vaccinated at the height of influenza breakouts but their attention drops when things normalized.

Ohio state health officials stress that vaccination is still important because another wave or two of flu are possible this winter or spring.

"I know flu is not on people's minds right now, but we really need to get these children vaccinations," said Dr. Mary Diorio, assistant state epidemiologist.

"We're still seeing (regional, local and sporadic) activity across the country. It's certainly not at the levels of late October, early November, but activity is still going on, and we have many weeks left in our flu season," CDC spokesman Tom Skinner warned the general public last week, saying "it would be too early to say the virus has disappeared."

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