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Barriers to additional progress in preventing adolescent HIV infection were identified, and include:
Denial of risk, a problem faced by more than 80% of the prevention programs interviewed.
A lack of action in communities that still have few AIDS cases, and an opportunity to avoid the problem.
A shortage of general medical services, family planning services, and drug treatment services that are available to and appropriate for adolescents.
Difficulties in reaching out-of-school youth.
A need for funding.
A need for technical assistance, especially in program evaluation.
MILLIONS OF AMERICAN YOUTH ARE
AT RISK FOR HIV INFECTION
HIV is transmitted through sexual contact (vaginal, oral, and anal), contaminated needles or syringes, infected blood or blood products, transplanted tissue or organs from an infected donor, and from mother to fetus.
The number of adolescents currently infected with HIV is unknown. Authorities have reported relatively few cases of AIDS among teens.
However, substantial evidence indicates that thousands of adolescents are already infected with HIV and millions of youth are at risk of infection.?
The extent to which the HIV epidemic has spread in any population is estimated by a variety of methods, including AIDS case surveillance, HIV seroprevalence studies, and surveys of HIV
3 risk factors such as sexual and drug use behaviors.
This chapter discusses the findings and limitations of each of these methodologies as used with adolescents.
A. THE EPIDEMIOLOGY OF AIDS AMONG ADOLESCENTS
NEARLY 9,000 YOUNG ADULTS ALREADY DIAGNOSED WITH AIDS
AIDS case surveillance data provide a readily available method of tracking the spread of HIV. These data, collected by the Centers for Disease Control (CDC), indicate gradual changes in the spread of the HIV epidemic and the emergence of populations that are at risk of infection. It is important to note, however, that AIDS case surveillance data only track the end stage of HIV infection, thereby significantly underestimating its progression. Changes in the spread of HIV will not be reflected by patterns of AIDS cases for years.
For example, the number of teens diagnosed with AIDS is relatively small. However, nearly one-fifth of all U.S. AIDS cases have been reported in persons ages 20-29. The best estimates available indicate that the mean incubation period between HIV infection and clinical diagnosis of AIDS is eight to ten years.(a) Therefore, it is unlikely that persons infected during their teenage years would be diagnosed with AIDS as teens. As noted by the National Research Council:
Even with the assumption of a median incubation period of eight years, fewer than one-half of persons infected with HIV at age 13 would be expected to develop AIDS during their teenage years, and even fewer of those infected in the late teens would develop AIDS before age 20. Those persons who are diagnosed with AIDS during their teens will be drawn mainly from the group of persons whose incubation periods were markedly shorter than the median and who were infected during their early teens.”
Other limitations of using AIDS case data to estimate the extent of the HIV epidemic are related to problems with reporting the data. AIDS cases may be under-reported by as much as 20% in a number of states, including those with a high prevalence of HIV infection.
Further, CDC reports AIDS case data for adolescents in broad age groups (13-19 and 20-24) rather than by specific age at diagnosis. These age groupings are somewhat arbitrary and confusing. By the end of 1991, 789 cases of AIDS had been diagnosed in youth ages 13-19. However, by adding cases among youth ages 20-21, the total more than doubles to 2,552, and by adding young adults ages 22-24, the total number of AIDS cases more than triples again to 8,949.(0) Since many services are available to adolescents through age 18 or 21, many experts advocate for presenting AIDS case data by specific age at diagnosis or by narrow age groups.
The incubation period may depend on the route of transmission and the age of the individual infected. Natural history studies of hemophiliacs infected with HIV suggest that adolescents and children remain asymptomatic longer than adults. (Miller, H.G., et al. (eds.) 1990. op cit.)
For the purposes of this report, recognizing the limitations described above, AIDS case data will be presented according to the broad age groups currently reported by CDC.
In addition, without requesting a special data run by CDC, it is impossible to determine by gender, both the mode of transmission and the race/ethnicity of AIDS cases within the broad age groups. These data are particularly important because as will be illustrated in this chapter, the mode of transmission varies significantly between females and males and by race and ethnicity.
Finally, the definition of AIDS has changed several times since it was first identified more than a decade ago to more accurately reflect the opportunistic diseases that indicate advanced HIV disease in women, children and adults. CDC has recently proposed expanding the definition of AIDS for adolescents and adults to include people with severe HIV disease. This change would nearly double the number of people in the U.S. with AIDS by including an additional 160,000 persons.
AIDS Cases Among Youth Rising Quickly
As shown in Table 1 and Figure 1, the number of AIDS cases in young adults has increased dramatically in recent years, with more than half of all cases in persons ages 13-24 having been reported in the last 36 months of the decade-long epidemic. Table 1: Cumulative AIDS Cases Reported Each Year
In Persons Ages 13-24, By Age Group(c)
1 3 11 35 71 130 211 333 461 628 789
6 35 125 303 645 1,263 2,204 3,622 5,063 6,694 8,160
7 38 136 338
716 1,393 2,415 3,955 5,524 7,322 8,949
Special data request prepared by Reporting and Analysis Section, Surveillance