Human immunodeficiency virus (HIV) disease
Caused by infection with a cytopathic retrovirus, which in turn leads to destruction of parts of the immune system. A surveillance case for HIV requires laboratory-confirmed evidence of infection, including a positive result on a screening test for HIV antibody, followed by a positive result on a confirmatory test, or a positive result or detectable quantity on an HIV virologic test (see: Centers for Disease Control and Prevention. HIV Surveillance Report, 2019; vol 32. 2021. Available from: https://www.cdc.gov/hiv/library/reports/hiv-surveillance/vol-32/index.html).
HIV Surveillance
As of April 2008, all reporting areas (50 states, District of Columbia, and the 6 U.S. territories of American Samoa, Guam, Northern Mariana Islands, Puerto Rico, Republic of Palau, and U.S. Virgin Islands) had implemented HIV case surveillance using a confidential system for name-based case reporting for both HIV infection and AIDS.
In 2014, the HIV surveillance case definition was updated to adapt to changes in diagnostic criteria used by laboratories and clinicians (see: Selik RM, Mokotoff ED, Branson B, Owen SM, Whitmore S, Hall HI. Revised surveillance case definition for HIV infection—United States, 2014. MMWR Recomm Rep 63(RR–03):1–10. 2014. Available from: https://www.cdc.gov/mmwr/pdf/rr/rr6303.pdf).
The 2008 case definition was used to classify cases diagnosed from the beginning of the epidemic through 2013. The 2014 case definition is used to classify cases diagnosed beginning in 2014 and is similar to the 2008 case definition except for the following: (a) inclusion of criteria for stage 0, (b) inclusion of CD4 testing criteria for stage 3 in children, and (c) changes in cutoffs for CD4 percentages of total lymphocytes used for classifications of stages 1 and 2 in people aged 6 years and over.
Mortality coding
Starting with 1999 data and the introduction of the 10th revision of the International Classification of Diseases (ICD–10), the title for this cause of death has been changed from HIV infection to HIV disease, and the ICD codes are changed to B20–B24. Starting with 1987 data, the National Center for Health Statistics had introduced category numbers *042–*044 for classifying and coding HIV infection as a cause of death in ICD–9. The asterisks before the category numbers indicate that these codes were not part of the original ICD–9. HIV infection was formerly referred to as human T-cell lymphotropic virus-III/lymphadenopathy-associated virus (HTLV–III/LAV) infection. Before 1987, deaths involving HIV infection were classified to “Deficiency of cell-mediated immunity” (ICD–9 code 279.1) contained in the category “All other diseases”; to “Pneumocystosis” (ICD–9 code 136.3) contained in the category “All other infectious and parasitic diseases”; to “Malignant neoplasms, including neoplasms of lymphatic and hematopoietic tissues”; and to a number of other causes. Because of these coding changes, death statistics for HIV infection before 1987 are not strictly comparable with data for 1987 and subsequent years, and consequently are not shown in Health, United States.
(Also see Sources and Definitions, Acquired immunodeficiency syndrome [AIDS]; Cause of death; International Classification of Diseases [ICD]; International Classification of Diseases, Clinical Modification [ICD–CM].)