Human immunodeficiency virus type-1 seroconversion trends among young adults serving in the United States Army, 1985-1993. United States Military Medical Consortium for Applied Retroviral Research.

The direct measurement of the incidence of new infections with the human immunodeficiency virus type 1 (HIV-1) can be made among soldiers because of the routine and periodic nature of HIV-1 testing in the United States Army. Between November 1985 and October 1993, 978 HIV-1 seroconversions were seen among 1,061,768 soldiers, contributing over 3.6 million person-years of follow-up [seroconversion rate (95% confidence interval) = 0.27/1,000 person-years (0.25-0.29)]. A significant decreasing trend in HIV-1 seroconversion rates was seen over the analysis period. The rate of new infections declined significantly from the first interval, 1985-1987, (0.43/1,000 person-years) to the second interval, 1987-1988, (0.28/1,000 person-years), but stabilized at approximately 0.22/1,000 person-years after 1988, representing new infections in approximately 100-150 soldiers annually. The risk of seroconversion among active duty soldiers was significantly associated with racial/ethnic group, age, gender, and marital status. Surveillance of HIV-1 seroconversion rates in the U.S. Army continues to offer a unique opportunity to assess temporal trends in the evolving HIV-1 infection epidemic. Monitoring the rate of new HIV-1 infections allows for identification of subgroups in need of intervention, refocusing of intervention strategies, and evaluation of their effectiveness.

HIV infection among members of the Army Reserve components residing in New York City.

A total of 10,722 members of the US Army Reserve and Army National Guard residing within the five boroughs of New York City (NYC) were tested for antibody to human immunodeficiency virus (HIV). The crude prevalence in NYC was found to be 10.6 per 1,000, compared with a national prevalence of 1.6 per 1,000. The highest prevalences were found among Blacks and Hispanics, males, and among those aged 30-39 years. Patterns of infection were found to be similar to those found among heterosexual and drug abusing populations. Prevalence was highest in the Bronx and varied by less than twofold over all boroughs. Comparisons with reported cases of acquired immunodeficiency syndrome (AIDS) in New York City indicated differences in the demographic and geographic characteristics of the current epidemic of AIDS and HIV infection among members of the Army Reserve components.

Trends of HIV seroconversion among young adults in the US Army, 1985 to 1989. US Army Retrovirus Research Group.

Because soldiers in the US Army are recurrently tested for the presence of antibody to the human immunodeficiency virus (HIV), HIV seroconversion rates can be directly measured. From November 1985 through October 1989, 429 HIV seroconversions were detected among 718,780 soldiers who contributed 1,088,447 person-years of follow-up time (HIV seroconversion rate, 0.39 per 1000 person-years). Period-specific seroconversion rates declined significantly from 0.49 per 1000 person-years (November 1985 through October 1987) to 0.33 per 1000 person-years (November 1987 through October 1988) to 0.29 per 1000 person-years (November 1988 through October 1989). The HIV seroconversion risk among active-duty soldiers was significantly associated with race/ethnic group, age, gender, and marital status. Based on these trends, we estimate that approximately 220 soldiers (95% confidence interval, 160 to 297 soldiers) were infected with HIV during 1989 and 1990, with potentially fewer in future years.

Human immunodeficiency virus infection among members of the reserve components of the US Army: prevalence, incidence, and demographic characteristics. The Walter Reed Retrovirus Research Group.

Since routine testing began, 677,463 members of the Reserve Components of the US Army have been tested for antibody to human immunodeficiency virus (HIV). Of these, 1063 were positive, for a crude prevalence of 1.57/1000 tested. Prevalence varied greatly among different groups as defined by sex, ethnicity, marital status, age, and geographic location. Multivariate analysis indicated that prevalence was higher among men, blacks, and unmarried men and peaked at ages 30-34. The crude incidence density was 0.20/1000 person-years, and multivariate analysis of incidence revealed patterns similar to those for prevalence. Comparison of prevalence and incidence data provides evidence that an increasing proportion of infection is occurring among women and in nonmetropolitan and small urban areas.

Direct measurement of human immunodeficiency virus seroconversions in a serially tested population of young adults in the United States Army, October 1985 to October 1987. Walter Reed Retrovirus Research Group.

Direct measurement of the incidence of infection with the human immunodeficiency virus (HIV)--the rate of new HIV infection--is vital if we are to understand better the dynamics of the current epidemic of HIV infection. Because soldiers are periodically and routinely screened for antibody to HIV, it is possible to measure the incidence of HIV infection directly in this large, demographically well-characterized population of young adults. To determine the incidence of HIV infection in this population, we examined test results reported by the U.S. Army's routine antibody-screening programs. During the first two years of the screening programs, the observed incidence of HIV infection was approximately 0.77 per 1000 persons per year. This rate was higher than expected on the basis of previously published estimates of seroprevalence in the Army (approximately 1.50 per 1000). On the basis of this annual incidence, and assuming it to be stable, we estimate that approximately 600 soldiers will become infected with HIV each year. The observed rate in the Army may be lower than the incidence of HIV infection in the corresponding demographic groups within the general U.S. population.