Trends in encephalitis-associated deaths in the United States.

The United States national mortality statistics and HIV/AIDS surveillance data were analysed to determine trends in encephalitis-associated deaths and to assess the impact of HIV infection on those deaths during 1979-1998, a period when ICD-9 codes were used for coding deaths in the United States. A total of 25125 encephalitis deaths were reported; 4779 of them (19%) had concurrent HIV infection. Overall encephalitis death rates remained stable, but they increased for groups where HIV infection was common and declined or remained unchanged for others. For persons without HIV infection, the rates declined in all demographic groups. Encephalitis deaths in HIV-infected persons followed general trends for HIV deaths in the United States. The rates in the HIV-infected population were several hundred- to thousand-fold higher than in the HIV-uninfected population. HIV infection was largely responsible for the lack of overall decline in the considerable mortality associated with encephalitis in the United States during 1979-1998.