In addition to developing strategies to deal successfully with tuberculosis (TB) among injecting drug users with HIV in drug abuse treatment programs, NIDA-supported researchers also have developed effective approaches to preventing and treating tuberculosis among out-of-treatment injecting drug users with HIV.
Out-of-treatment injecting drug users represent an even bigger threat than those in treatment for spreading infectious diseases such as HIV and TB, says Dr. David Vlahov of The Johns Hopkins University in Baltimore. "At any one time only 15 percent of drug users are in drug abuse treatment," Dr. Vlahov says. "The question is, what do you do about the other 85 percent?" he asks. Historically, most of these individuals have had little or no access to health services where treatment for infectious diseases could be provided, he points out.
Some solutions to this problem have come from a NIDA-supported study led by Dr. Vlahov that has been following 3,000 out-of-treatment drug users in Baltimore since 1988. Dubbed the AIDS Linked to the Intravenous Experiences (ALIVE) cohort, the study was originally funded by NIDA to track how HIV/AIDS progresses in this population. Slightly more than 700 of the nearly 3,000 study participants tested positive for HIV when they were first assessed. In the succeeding 10 years, another 290 participants became HIV positive.
NIDA-supported research has shown that HIV infection can activate latent TB infection, which is widespread among injecting drug users. Thus, in 1990, the ALIVE study began to conduct TB testing on 600 HIV-positive and 600 HIV-negative study participants when they visited a community-based clinic for assessment and health care every 6 months. In 1991, the study began to offer directly observed tuberculosis prevention treatment to participants with and without HIV infection who tested positive on a skin test for tuberculosis infection. With directly observed prophylaxis, study staff observed patients take twice weekly doses of isoniazid, a tuberculosis prevention medication, for at least 6 months.
Out-of-treatment drug users do not have the incentive of getting a daily methadone dose that can bring in-treatment patients back to a clinic for regular medical treatment, Dr. Vlahov points out. Initially, the ALIVE study used street outreach, word of mouth, and a small cash payment to recruit participants for initial assessment and testing, he says. To get these participants to come back for followup assessments and treatment, the ALIVE staff provided a supportive clinic environment that offered strict confidentiality, a refuge from the street, and easily accessible health care services, he says.
"The key to providing health care services for out-of-treatment drug users is one-stop shopping combining as many services as possible in one location," Dr. Vlahov says. The clinic for ALIVE participants was located in the Baltimore City Department of Health building. A health department nurse assigned to the clinic provided TB prevention medications onsite; and patients could easily be referred to other clinics in the building for specialized health services, he notes.
As a result of offering directly observed TB therapy within this comprehensive, supportive health-care environment, "the incidence of new cases of tuberculosis among the patients in the study, which had peaked at 12 cases of active disease in 1991 when we started offering TB prophylaxis, went down to nearly zero," Dr. Vlahov says. "Basically, we've eradicated TB from our cohort," he says.
Source
- Graham, N.M.H.; Galai, N.; Nelson, K.E.; Astemborski, J.; Bonds, M.; Rizzo, R.T.; Sheeley, L.; and Vlahov, D. Effect of isoniazid chemoprophylaxis on HIV-related mycobacterial disease. Archives of Internal Medicine 156:889-894, 1996.