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Update: Influenza Activity -- United States

Influenza type A(H1N1) virus has now been reported from sporadic cases or outbreaks in all regions of the country except the northwest Pacific states (Figure 3). In contrast, influenza B virus has been isolated primarily in the western half of the country, as well as in parts of the northeast (Figure 4). As previously indicated (1), in those regions where circulation of both viruses is occurring, mixed outbreaks have now been confirmed. In Texas, types A(H1N1) and B viruses have been isolated from students at four colleges where outbreaks have been occurring, and similar results have been reported from at least one school outbreak each in Illinois and Wyoming. Other locations where approximately equivalent numbers of influenza types A(H1N1) and B viruses have been isolated from recent community activity include Honolulu, Hawaii, and Houston, Texas.

The elderly have been infrequently reported in this season's influenza outbreaks. In Utah County, Utah, a single influenza type B virus was isolated from an outbreak affecting eight of 79 residents in one nursing home late in January. Further laboratory studies are pending. In addition, no consistent elevation of deaths attributed to pneumonia and influenza in the 121 reporting cities has been seen through the end of January. Influenza A(H3N2) virus remains generally dormant; however, during January, sporadic isolates were reported in Alaska, Arizona, Massachusetts, Minnesota, New Mexico, Pennsylvania, Tennessee, and Texas. Reported by P Glezen, MD, Baylor University School of Medicine, Houston, J Taylor, MPH, Texas Dept of Health; J Miner, MD, Utah County Health Dept, B Haslam, CR Nichols, Utah Dept of Health; State Epidemiologists and Laboratory Directors; Statistical Svcs Activity, Influenza Br, Div of Viral Diseases, Center for Infectious Diseases, CDC.


  1. CDC. Update: influenza activity--United States. MMWR 1984;33:51-2.

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