For Many, TB Still a Major Health Concern

In recent class lectures, and in the news, much attention has been given to the topic of Tuberculosis (TB). TB is an infectious disease that is very common and often lethal if left untreated. As we have learned, dying from TB is evidence of inadequate health care services and pervasive social inequities. Our post will discuss several populations that are disproportionately affected by TB. These are disadvantaged populations for whom this disease is a pressing global health concern because drugs used in its treatment are rapidly becoming obsolete while drug-resistant strains are becoming more and more prevalent.

 
      
African Americans, Hispanics, and other minority groups are affected by TB at a much higher rate than non-minority populations. It has been shown that from 1985-1987, the rates of TB increased 6.3% in African Americans, 12.7% in Hispanics, and 4.8% in non-Hispanic Whites. One potential explanation for this disproportionate data could be the fact that the area between the US Border and Mexico has a higher overall TB prevalence. Surrounding states of the border: Arizona, California, Colorado, New Mexico, and Texas, make up 35% of all TB cases in the US. In addition, 31% of minority injected drug users have TB and 15% of that population uses the syringe exchange program. The relationship between minorities and injection drug users causes a problem because many lack the knowledge of TB treatments, thus causing the formation of TB strains resistant to multiple forms of drugs.

Injection drug use (IDU) is a common risk factor for the transmission of many diseases, including HIV and Hepatitis infection (both are blood-borne illness).  One can easily see how such illnesses relate to the injection of drugs. However, recent reports are indicating that TB may also be a concern for drug injectors.  Due to cramped living conditions and frequent incarcerations, this population is showing an increased rate of TB infections.  A 2009 study of drug injectors in Thailand showed that 78.2% of people who inject drugs (PWID) have been incarcerated in their lifetime.  In prisons, with little or no health care provided, the rates of TB infection is nearly 23 times higher than in the general population. These factors have led the World Health Organization to issue a bulletin about this population which includes recommendations for reducing and containing transmission, while also calling to attention the effects of punitive drug policy and of poor healthcare in prison populations.
   
TB and HIV are often closely related in terms of incidence. A CDC-produced video titled, "TB&HIV: A Deadly Duo," provides an interesting graphical representation of this trend. One third of the 33 million people infected with HIV/AIDS are co-infected with TB. The co-epidemic of HIV/TB presents difficult challenges for the typical TB diagnostic methods due to the very nature of the Human Immunodeficiency Virus. In addition to making it more difficult to diagnose TB patients, HIV is also the most powerful risk factor for progression from TB infection to TB disease.  A person with active TB disease is then able to spread the illness to others. The dangerous marriage of these two diseases, without proper treatment, results in 90% of those with HIV dying within months of contracting TB. To help treat those with HIV/TB and to prevent the spread of TB from those with the active form, the CDC recommends HIV screening for all TB patients. Globally, 50 countries tested 75% of their patients with TB for HIV in 2008. In order to curb the global health trend of increased TB incidence with HIV prevalence, there is a need for earlier identification of persons with signs and symptoms of TB and provision of TB prevention and treatment in a safe environment without risk of TB transmission.  WHO’s recommended therapy to prevent TB infection in HIV positive patients includes the three I’s: Isoniazid preventive treatment (IPT), infection control (IC) and intensified case finding (ICF).

Overall, TB is a treatable and preventable disease. The centers of infection lie mostly in developing nations with a high population density and less access to adequate health care. Its inconsistent pattern of socioeconomic influence makes TB a disease that may seem easy to ignore, but for many of the world's less fortunate populations the threat of TB infection is all too real.