HIV Infection in Adolescents and Young Adults in the U.S.
There is a rising concern about the effects of HIV/AIDS among adolescents and young adults between ages of 13 to 24 in the United States. The Centers for Disease Control and Prevention (CDC) reported 40,049 cumulative cases of AIDS among people ages 13 to 24 through 2004. Since the epidemic began, an estimated 10,129 adolescents and young adults with AIDS have died and the proportion diagnosed with AIDS has also increased. Likewise, the proportion of adolescents and young adults with an AIDS diagnosis has increased from 3.9 percent in 1999 to 4.2 percent in 2004.
Moreover, African-American and Hispanic adolescents have been disproportionately affected by the HIV/AIDS epidemic. Between the ages of 13 and 19, African-Americans and Hispanics accounted for 66 percent and 21 percent, respectively, of the reported AIDS cases in 2003.
Because the average duration from HIV infection to the development of AIDS is 10 years, most adults with AIDS were likely infected as adolescents or young adults. In 2004, an estimated 4,883 were diagnosed with HIV/AIDS, while an estimated 18,293 were living with HIV/AIDS. However, health experts estimate the number of adolescents and adults living with HIV infection to be much higher.
Modes of Transmission
Most HIV-infected adolescents and young adults are exposed to the virus through sexual intercourse. Recent HIV surveillance data suggest that the majority of HIV-infected adolescent and young adult males are infected through sex with men. Only a small percentage of males appear to be exposed by injection drug use and/or heterosexual contact. These data also suggest that adolescent and young adult females infected with HIV were exposed through heterosexual contact, with a very small percentage through injection drug use. In addition, there is an increasing number of children who were infected as infants that are now surviving to adolescence.
Sexually Transmitted Infections (STIs) and HIV
Approximately 25 percent of cases of STIs reported in the United States each year are among teenagers. This is particularly significant because the risk of HIV transmission increases substantially if either partner is infected with an STI. Discharge of pus and mucus as a result of STIs such as gonorrhea or chlamydia also increase the risk of HIV transmission three- to five-fold. Likewise, STI-induced ulcers from syphilis or genital herpes increase the risk of HIV transmission nine-fold.
Care and Treatment
Because many adolescents and young adults tend to think they are invincible, this belief may cause them to engage in risky behavior, delay HIV testing, and if they test positive, delay or refuse treatment. The inability to link them to medical care can lead to increased transmission of HIV. Health care providers report that many young people, when they learn they are HIV-positive, take several months to accept their diagnosis and return for treatment.
Health care providers may be able to help young people understand their situation during visits by
- Ensuring confidentiality
- Explaining the information clearly
- Eliciting questions
- Emphasizing the success of newly available treatments
The U.S. Department of Health and Human Services has also developed documents that address the standard of care for the treatment of HIV, including information about how to treat HIV in adolescents. The documents Guidelines for the Use of Antiretroviral Agents in HIV-Infected Adults and Adolescents and Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection are available from AIDSinfo.
According to the Guidelines for the Use of Antiretroviral Agents in HIV-Infected Adults and Adolescents, adolescents exposed to HIV sexually or via injection drug use appear to follow a clinical course that is more similar to HIV disease in adults than in children. Most adolescents with sexually acquired HIV are in a relatively early stage of infection and are ideal candidates for early intervention that includes education and counseling, identifying high-risk behaviors, and recommended therapies and behavioral changes.
Adolescents who were infected at birth or via blood products as young children, however, follow a unique clinical course that may differ from that of other adolescents and adults. Health care providers should refer to the treatment guidelines for detailed information about treating HIV-infected adolescents.
The National Institute of Allergy and Infectious Diseases (NIAID) supports research in adolescents and young adults through studies conducted by clinical trial networks and sites within the United States. These studies help evaluate promising therapies to
- Prevent HIV infection
- Discover new therapies to improve control of viral replication in patients with HIV/AIDS
- Prevent and treat co-infections and cancers associated with AIDS
- Prevent and treat complications of HIV therapies
- Reconstitute HIV-damaged immune systems
In response to the growing epidemic among adolescents and young adults in the United States, NIAID supports the Pediatric AIDS Clinical Trials Group (PACTG), a clinical trial network co-funded with the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). The PACTG's adolescent treatment research agenda focuses on
- Studying the safety and use of new and existing drugs and treatment management to prevent perinatal transmission and pediatric infection
- Studying the effects of treatment on acute and early infection
- Increasing commitment to long-term studies of safety and clinical
- Engaging youth in treatment research opportunities
- Restoring immune function
- Promoting domestic and international collaborations, including prevention and behavioral research
- Expanding and enhancing adolescent research at all PACTG sites
effectiveness of antiretroviral therapies
In addition, the Eunice Kennedy Shriver NICHD supports the Adolescent Medicine Trials Network (ATN) for HIV/AIDS Interventions. Its mission is to conduct research, both independently and in collaboration with existing research networks supported by NIAID, on promising behavioral, microbicidal, prophylactic, therapeutic, and vaccine modalities in HIV-infected and HIV-at-risk adolescents between the ages 12 to 24 years old.
As such, recruiting adolescents and young adults into clinical trials is important to ensure that research results will be applicable to therapy for that age group. Most clinical trials are open to adolescents and young adults, but in reality very few enroll. Of the approximately 9,500 participants in studies conducted by the NIAID-supported Adult and Pediatric AIDS Clinical Trials Groups in Fiscal Year 2005, only 5.4 percent of the participants were adolescents (ages 13 to 19).