Every six months, the CDC issues an HIV/AIDS surveillance report describing the occurrence of AIDS in the U.S. The most recent report provides information on U.S. Aids cases reported through June 1998.
Reported cases and exposure categories
There have been 665,356 persons with AIDS reported to the CDC - 557,324 males and 108,032 females. In about 8 percent of the total number of AIDS cases, a risk category has not been reported or identified. The exposure category accounting for the highest number of AIDS cases (48 percent) is men who have sex with men. The exposure category of injecting drug user accounts for 26 percent of the cases. Men who have sex with men and who inject drugs account for 6 percent, and those who had a hemophilia/coagulation disorder or had received blood transfusions or tissue transplants each represent 1 percent.
The exposure category of heterosexual contact accounts for about 9 percent of the AIDS cases, or a total of 62,599. This group consists of 21,855 males and 40,744 females. While 25,276 (17,548 females) of these heterosexual cases resulted after sex with an injecting drug user, 3,009 cases occurred after sex with a bisexual male and 1,327 after sex with a person with hemophilia or with a transfusion recipient. The risk has not been specified for the remaining 32,987 heterosexual cases. There have been a total of 8,280 pediatric AIDS cases (persons under the age of 13) reported, with 91 percent in children of mothers with or at risk for AIDS.
Annual incidence and deaths
The annual incidence of AIDS first decreased (since 1985) during 1995 to 1996 and again from 1996 to 1997. In 1996, there were 68,808 cases of AIDS reported and 60,634 cases reported in 1997. This decrease has continued for the first six months of 1998. CDC indicates that these decreases mostly are due to the effective therapies that have slowed down progression from HIV infection to AIDS. The reported AIDS cases increasingly represent persons who were not diagnosed with HIV infection until they developed AIDS, people who did not access treatment, or people for whom treatment failed. Thus, the ability of AIDS surveillance data (such as those summarized here) to represent the characteristics of affected populations and project the need for prevention and treatment has diminished. The incidence of pediatric AIDS cases also continues to decline with 669 cases diagnosed in 1995, 500 cases in 1996, and 299 cases in 1997.
AIDS deaths continue to decline as well. A total of 401,028 AIDS deaths have been reported, which is about 60 percent of the total U.S. AIDS cases. There were 49,985 AIDS deaths in 1995, 37,525 in 1996, and 21,909 in 1997.
Occupational AIDS/HIV infection
Through June of 1998, there have been 54 cases of documented occupational transmission of AIDS/HIV infection in healthcare workers reported to CDC. This has included 22 nurses, 19 laboratory technicians, six physicians, two surgical technicians, and five others. There has been no documented occupational transmission among dental workers.
Percutaneous exposures (i.e., sharps injuries) accounted for 46 of the 54 cases ? five were from mucous-membrane exposures, two from both percutaneous and mucous-membrane exposure, and one had an unknown route of exposure. Blood was the body fluid involved in 49 of these cases. This number of 54 documented cases was the same as that reported in the previous six months, but has increased from the 46 cases reported through June 1995.
There have been 133 OpossibleO occupational HIV transmissions among health-care workers. However, since a baseline-HIV test was not performed at the time of exposure, their HIV seroconversion specifically resulting from an occupational exposure cannot be documented. Thus, they are placed in the OpossibleO occupational-exposure category. Six dental workers are in this group, along with 33 nurses, 17 physicians, and 12 paramedics. There have been no new cases of possible occupational HIV transmission in dental workers since the early 1990s.
Chris Miller is director of Infection Control Research and Services and professor of oral biology at Indiana University.