(RxWiki News) People with HIV have weakened immune systems, so they are more likely to catch harmful diseases like tuberculosis. However, new research suggests that a certain prevention therapy could significantly reduce that risk.
Researchers tested this preventive therapy — called isoniazid — on a group of patients with HIV in Brazil.
Over a four-year period, they found that people who completed the therapy had a much lower chance of catching tuberculosis.
The results of this study suggest that this therapy could be effective, especially in a large-scale clinical care setting.
"If you have HIV, ask your doctor how to prevent tuberculosis."
The researchers, led by Richard Chaisson, MD, of the Department of International Health at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, conducted this study in order to find out if isoniazid therapy was effective in reducing rates of tuberculosis and death in people with HIV.
HIV, or human immunodeficiency virus, is a condition that can lead to the failure of the immune system. For individuals with HIV, infections and sickness are especially dangerous because their immune systems are weaker.
Patients with HIV are vulnerable to contracting tuberculosis, or TB, which is caused by a bacterial infection. TB causes coughing, fever, weight loss and fatigue, and can be deadly.
TB can be latent or active. Latent TB shows no symptoms, even though the patient is infected with the tuberculosis bacteria. Active TB does show symptoms.
The Centers for Disease Control and Prevention estimates that 6 percent of all TB cases occur in HIV-positive patients.
Isoniazid is a medicine that is frequently used to prevent and treat TB. Although it has been shown to be an effective preventive therapy, this study is the first to look at isoniazid's impact on an HIV-infected community.
To find out how effective isoniazid was for preventing TB in HIV patients, the researchers examined patients in 29 HIV clinics in Rio de Janeiro, Brazil. They chose patients who were HIV-positive, over the age of 15 and not already infected with active TB.
Of the 12,816 study participants, 1,186 had TB that was currently latent, meaning they showed no symptoms. The rest of the patients did not have TB.
The study participants who tested positive for TB received 300 milligrams of isoniazid daily for six months. The participants visited the clinic seven times for the doctors and nurses to collect diagnostic and treatment data.
Of the participants who completed the study, 475 were diagnosed with TB by the end of the trial.
The researchers found that the process of screening and skin-testing for TB, then offering isoniazid preventive therapy, led to a 31 percent reduction in tuberculosis and death, compared with the average rate of tuberculosis in patients with HIV.
Patients who retained in care, or continued to have consistent contact with a clinic once a year throughout the study, experienced a 58 percent reduction in TB cases and a 55-percent reduction in TB and death compared to the control.
"Providing preventive therapy on a large scale through routine HIV clinic care is an effective way to significantly reduce tuberculosis incidence and death in patients with HIV," the study concluded.
This research was published in The Lancet Infectious Diseases on August 16.
The study was funded by the Bill & Melinda Gates Foundation and the National Institutes of Health. The authors reported no conflicts of interest.