TB and HIV Inextricably Linked

Collegiality and cooperation among professionals involved in treating tuberculosis and AIDS are crucial in the battle against these diseases.

We knew that HIV infection or AIDS weakens the immune system and makes it at least 800 times more likely that latent tuberculosis infection will be activated. It was not realized until later that the reverse is also true: Active tuberculosis further suppresses the immune system of AIDS patients; curing tuberculosis actually improves the immune system.

The lethal combination of AIDS and TB is a worldwide problem. According to the Joint United Nations Program on HIV/AIDS (UNAIDS), at the beginning of 2000, there were 34.6 million people in the world who were infected with HIV. In the countries where most AIDS patients live, TB is the most prevalent serious infection. One third of the people who are reported as dying of AIDS actually die from TB. Worldwide, TB is the leading killer of people with HIV/AIDS. We who take care of AIDS patients know that, essentially, nobody actually dies of AIDS. AIDS weakens the immune system; people with AIDS die of diseases that are shrugged off by people with healthy immune systems.

In the early 1990s, in sub-Saharan Africa, Haiti, and Asia, the majority of adults already had latent tuberculosis infections. When AIDS came on the scene and destroyed these people’s immune systems, a waiting TB epidemic exploded.

The situation is no better today. In the countries with the largest number of people with HIV/AIDS, TB is still the most common cause of death in AIDS patients. This is particularly tragic because even in patients with AIDS, TB remains preventable and curable.

Collegiality
The coexistence and dreadful synergy between TB and HIV/AIDS are well known to health care experts and to clinicians working in affected communities. They see daily the tragic burden these dual epidemics place on young families.Therefore, I am constantly amazed that there is not more collegiality and cooperation among the legions of professionals involved with each disease, from social workers to clinicians to researchers, donors, and government officials. For some reason, over the years, major AIDS meetings only rarely have included high-profile plenary sessions on TB. This may be a symptom, reflecting, perhaps, an arrogant mind-set among some AIDS professionals, who seem to prefer to deal with AIDS while ignoring the companion epidemic of TB.

It is not entirely clear why this is so. At the beginning of the HIV/AIDS epidemic in industrialized nations, the first patients—young, gay men—were unlikely to have latent TB infection and thus usually became sick with other organisms. Furthermore, they were often considered (without any scientific basis) to be more likely to adhere to their treatment regimens. This group was considered to be very different from the other major transmission category, injecting drug users, who usually had very high latent TB infection rates and, therefore, more active TB. Injecting drug users were often considered far less adherent to treatment regimens and more difficult to deal with (again, without any scientific basis).

Perhaps the lack of cooperation and communication among these health professionals may have occurred because, historically, TB patients were usually cared for by pulmonary physicians or public health clinics, and AIDS patients were usually cared for by infectious disease physicians.

Because tuberculosis is spread through the air by breathing, rather than specific risk behavior, obviously it represents a much greater health threat to the world’s population (more in developing nations than in industrialized ones) than HIV/AIDS. Yet, paradoxically, tuberculosis still receives relatively little attention from United Nations agencies (aside from the World Health Organization) and advocacy groups, compared with HIV/AIDS.

However, it is clear to me that health experts increasingly recognize the interaction between TB and HIV/AIDS. They see that curing or preventing TB increases or preserves immune function and that TB treatments such as directly observed therapy are now frequently being studied for complex AIDS treatment regimens. Ultimately, the groups fighting each disease must cooperate more closely to prevent further loss of life. The recent global effort to consider a “Massive Effort to Fight Diseases of Poverty,” which led to the Global Fund to Fight AIDS, Tuberculosis, and Malaria and was endorsed by WHO and some (but certainly not all) nongovernmental agencies (with varying degrees of enthusiasm or funding), is encouraging, suggesting that cooperation might come sooner rather than later.

Lee B. Reichman, MD, MPH, is executive director of the New Jersey Medical School National Tuberculosis Center, Newark. He adapted this editorial from his book, Timebomb: The Global Epidemic of Multidrug Resistant Tuberculosis, published by McGraw Hill in 2002 (used with permission).