HOUSTON, Feb. 5 (Xinhua) -- The proportion of deaths attributed to pneumonia and influenza (P&I) in the United States remained above the epidemic threshold for three weeks running following a short decrease since the beginning of 2010, the federal Centers for Disease Control and Prevention (CDC) said on Friday.
"During week four (Jan. 24 to 30), 8.1 percent of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7. 8 percent for week four," the CDC said on its web site, adding that "this is the third consecutive week that the percentage of P& I deaths has been above the epidemic threshold."
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.
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.
The latest statistics released by the CDC show that, from August 30, 2009 to January 30, 2010, there were 39,794 laboratory- confirmed influenza-associated hospitalizations and 1,905 laboratory-confirmed influenza-associated deaths, including 257 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.
The CDC estimated 55 million Americans became ill from the A/ H1N1 flu between last April and mid-December -- the first eight months of the pandemic. About 246,000 Americans were hospitalized and 11,160 killed.
"The estimates are actually much more accurate than the confirmed numbers," the CDC director Dr. Thomas Frieden said. "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 month of 2010.
Although the A/H1N1 flu infections are declining, But CDC spokesman Tom Skinner warned that it would be too early to say the virus has disappeared.
"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," he stated.
| Editor: Xiong Tong |
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