Every key indicator for measuring Novel H1n1 is higher than last week.

For some indicators, the level is up sufficiently to be “unusual,” as classified by the CDC.

• Visits to doctors for influenza-like illness (ILI) are up.
• Hospitalization rates for adults and children are up.
• Proportion of deaths attributed to pneumonia and influenza are up.
• 37 states are reporting widespread influenza activity, “very unusual” for this time of year, says CDC.
• Almost all of the viruses typed by the CDC are Novel H1N1, meaning the vaccine arriving now matches well with the strain in circulation. The closer the match between vaccine and influenza, the more protection you receive. This also means that this virus has not continued to change or mutate, also helpful.
• To date, Tamiflu and Relenza (brand names of anti-viral drugs) are working. The strain has not developed a resistance to these drugs, which is what experts hoped for.

CDC

Below is a summary of the most recent key indicators as reported by the CDC for the week ending October 3, 2009.

• Visits to doctors for influenza-like illness (ILI) continued to increase in the United States, and overall, are higher than levels expected for this time of the year. (Emphasis added)

• Total influenza hospitalization rates for laboratory-confirmed influenza are higher than expected for this time of year for adults and children. And for children 5-17 and adults 18-49 years of age, hospitalization rates from April – October 2009 exceed average flu season rates (for October through April).(Emphasis added)

• The proportion of deaths attributed to pneumonia and influenza (P&I) based on the 122 Cities Report has increased and now exceeds what is normally expected at this time of year. In addition, 19 flu-related pediatric deaths were reported this week; 16 of these deaths were confirmed 2009 H1N1 and 3 were unsubtyped influenza A and likely to be 2009 H1N1. A total of 76 laboratory confirmed 2009 H1N1 pediatric deaths have been reported to CDC since April. (Emphasis added)

• Thirty-seven states are reporting widespread influenza activity at this time. They are: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Texas, Tennessee, Virginia, Washington, and Wyoming. Any reports of widespread influenza activity in September and October are very unusual. (Emphasis added)

• Almost all of the influenza viruses identified so far are 2009 H1N1 influenza A viruses. These viruses remain similar to the virus chosen for the 2009 H1N1 vaccine, and remain susceptible to the antiviral drugs oseltamivir and zanamivir with rare exception. (Emphasis added)

Source: Centers for Disease Control and Prevention, October 9, 2009, H1N1 Influenza: Situation Update