H1N1 Continues to Circulate in the Southeast

The 2009 pandemic influenza A(H1N1) virus has declined but continues to circulate, particularly in the southeastern United States.

Influenza-associated hospitalizations and deaths are still being reported, and the 2009 H1N1 vaccine is still recommended, the Centers for Disease Control and Prevention said (MMWR 2010;59:423-30).

From Aug. 30, 2009, through March 27, 2010, 21% of 422,648 specimens collected in the United States were positive for influenza. Nearly all (99.7%) were influenza A; of the 66,978 subtyped, nearly all (99.4%) were 2009 H1N1 viruses.

From Feb. 14 to March 27, H1N1 continued to account for nearly all cases. In that period, states in the Southeast—Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee—accounted for approximately 55% of the influenza positives reported but only 20% of the specimens tested, the CDC said. Georgia in particular has seen a steady rise in hospitalizations from mid February through March 27, with a median of 38 reported hospitalizations during the first 5 weeks. However, hospitalizations then dropped to just 16 during the week ending March 27.

A total of 64 oseltamivir-resistant 2009 H1N1 viruses have been identified in the United States since April 2009, with 55 of those identified since Aug. 30, 2009.

The percentage of outpatient visits for influenza-like illness peaked at 7.7% in the week ending Oct. 24, 2009, and has declined since. The rate was 1.6% for the week ending March 27, 2010.

The CDC is continuing to monitor and report influenza activity weekly at www.cdc.gov/flu/weekly

The 2009 pandemic influenza A(H1N1) virus has declined but continues to circulate, particularly in the southeastern United States.

Influenza-associated hospitalizations and deaths are still being reported, and the 2009 H1N1 vaccine is still recommended, the Centers for Disease Control and Prevention said (MMWR 2010;59:423-30).

From Aug. 30, 2009, through March 27, 2010, 21% of 422,648 specimens collected in the United States were positive for influenza. Nearly all (99.7%) were influenza A; of the 66,978 subtyped, nearly all (99.4%) were 2009 H1N1 viruses.

From Feb. 14 to March 27, H1N1 continued to account for nearly all cases. In that period, states in the Southeast—Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee—accounted for approximately 55% of the influenza positives reported but only 20% of the specimens tested, the CDC said. Georgia in particular has seen a steady rise in hospitalizations from mid February through March 27, with a median of 38 reported hospitalizations during the first 5 weeks. However, hospitalizations then dropped to just 16 during the week ending March 27.

A total of 64 oseltamivir-resistant 2009 H1N1 viruses have been identified in the United States since April 2009, with 55 of those identified since Aug. 30, 2009.

The percentage of outpatient visits for influenza-like illness peaked at 7.7% in the week ending Oct. 24, 2009, and has declined since. The rate was 1.6% for the week ending March 27, 2010.

The CDC is continuing to monitor and report influenza activity weekly at www.cdc.gov/flu/weekly

The 2009 pandemic influenza A(H1N1) virus has declined but continues to circulate, particularly in the southeastern United States.

Influenza-associated hospitalizations and deaths are still being reported, and the 2009 H1N1 vaccine is still recommended, the Centers for Disease Control and Prevention said (MMWR 2010;59:423-30).

From Aug. 30, 2009, through March 27, 2010, 21% of 422,648 specimens collected in the United States were positive for influenza. Nearly all (99.7%) were influenza A; of the 66,978 subtyped, nearly all (99.4%) were 2009 H1N1 viruses.

From Feb. 14 to March 27, H1N1 continued to account for nearly all cases. In that period, states in the Southeast—Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee—accounted for approximately 55% of the influenza positives reported but only 20% of the specimens tested, the CDC said. Georgia in particular has seen a steady rise in hospitalizations from mid February through March 27, with a median of 38 reported hospitalizations during the first 5 weeks. However, hospitalizations then dropped to just 16 during the week ending March 27.

A total of 64 oseltamivir-resistant 2009 H1N1 viruses have been identified in the United States since April 2009, with 55 of those identified since Aug. 30, 2009.

The percentage of outpatient visits for influenza-like illness peaked at 7.7% in the week ending Oct. 24, 2009, and has declined since. The rate was 1.6% for the week ending March 27, 2010.

The CDC is continuing to monitor and report influenza activity weekly at www.cdc.gov/flu/weekly