National report: During week 47 (November 18-24, 2001), 3 specimens tested by the World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories across the United States were positive for influenza. Since September 30, a total of 8,140 specimens for influenza viruses have been tested and 74 (0.9%) were positive. Of the 74 isolates identified, 71 were influenza A viruses and 3 were influenza B viruses. Forty-five (63%) of the influenza A viruses were subtyped, 44 were influenza A (H3N2) and one was an influenza A (H1N1) virus. Thirty-nine (55%) of the influenza A isolates were isolated in Alaska. Influenza A have also been identified in Alabama, Arizona, Colorado, Florida, Hawaii, Kentucky, Louisiana, Minnesota, New York, North Carolina, North Dakota, Texas, Utah, Washington and Wisconsin. The influenza B isolates were identified in Louisiana, Michigan and Texas.  The proportion of patient visits to sentinel physicians for influenza-like illness (ILI) overall was 1.4%, which is less than the national baseline of 1.9%. The proportion of deaths attributed to pneumonia and influenza as reported by the vital statistics offices of 122 U.S. cities was 6.1% during week 47. This percentage is below the epidemic threshold of 7.4% for this time. The state health department in Alaska reported regional influenza activity this week. Sporadic activity was reported from 21 states (Arizona, California, Colorado, Florida, Georgia, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Missouri, Nevada, New Mexico, New York, North Carolina, Texas, Vermont, West Virginia, Wisconsin and Wyoming), 18 states reported no influenza activity.