If you're living with HIV, it means that: you're more likely to develop TB because of a weakened immune system. You can reduce the risk of TB by taking your HIV treatment correctly to keep your immune system strong and healthy. Antiretroviral treatment reduces the risk of developing active tuberculosis in people also infected with HIV-1, by dampening the activation of the body's immune response. These findings could help improve treatment for both conditions in the future.

TB remains to be the leading bacterial cause of death worldwide and co-infection with HIV is the biggest risk factor for developing an active infection. But it's been observed that people taking ART are less likely to have a latent TB infection become active and potentially life threatening. Infectious Diseases Research at the University of Cape Town has been researching links between the two conditions for a number of years.

This chapter describes WHO recommendations for:

• HIV testing and counselling of all patients known or suspected to have TB;
• HIV prevention for TB patients;
• Treatment of TB in people living with HIV;
• Providing co-trimoxazole preventive therapy to all HIV-positive TB patients;
• When to start antiretroviral therapy and what antiretroviral agents to use;
• Drug susceptibility testing and patient monitoring;
• Ensuring comprehensive HIV care and support services.

Firstly, the team carried out a broader analysis of blood from individuals with both latent TB infection and HIV.

• During their first six months of ART. They observed a significant drop in the inflammatory signalling activity of immune cells. This was also confirmed by further analysis of plasma samples taken after six months of ART, which showed a decrease in the presence of inflammatory markers.
• Collectively, their results show that the decreased risk of active TB can be explained by reduced inflammatory immune responses during treatment with ART.

People with HIV who also have either latent TB infection or TB disease can be treated effectively. The first step is to ensure that people with HIV are tested for TB infection. If found to have TB infection, further tests are needed to rule out TB disease. The next step is to start treatment for latent TB infection or TB disease based on test results.

The recommended treatment of TB disease in adults infected with HIV is a 6-month daily regimen consisting of:

• An intensive phase of isoniazid , a rifamycin , pyrazinamide, and ethambutol for the first 2 months.
• A continuation phase of INH and a rifamycin for the last 4 months.

Media Contact
David Paul
Managing Editor
Journal of Infectious Diseases and Diagnosis