Tuberculosis and Global Health, Research Paper Example

Defining Tuberculosis

Disease caused by TB: Tuberculosis is a disease caused by Mycobacterium tuberculosis. Tuberculosis is first and foremost a disease of the lungs, although it is also capable of spreading to affect other parts of the body, including the kidneys, bones, and brain (Myers, Neighbors, & Tannehill-Jones, 2002, p. 117). The pathogenic bacteria are spread thanks to the coughing and sneezing reactions they stimulate in their hosts. Infected persons emit droplets containing bacteria, providing potential opportunities for the bacteria to colonize new hosts. Thanks to the thick coating of proteins that makes up their cell walls, tuberculosis bacteria can survive for extended periods of time outside of a host. However, tuberculosis bacteria are vulnerable to both bactericidal solutions and direct sunlight (p. 117).

Today, roughly one-third of the global population, about two billion people, are infected with tuberculosis bacteria. However, this does not mean that all of those people have the disease as such. Thereare something on the order of nine million new cases of tuberculosis and two million deaths from the disease every year. While considerable, these numbers are still a very small fraction of the one out of every three people who carry an infection. The reason for this is that in about 80 percent of cases, the immune system eliminates the bacteria. In a small minority of cases, the immune system fails to kill the bacteria, but succeeds in building a defensive barrier around them. Such a case is known as latent tuberculosis. It is only when the immune system is not able to contain or defeat the tuberculosis bacteria that the infected person develops a case of “active” tuberculosis (Royal College of Physicians, 2006, p. 3; Moise, McMurry, & DeGroot, 2009, pp. 1219-1221). Active tuberculosis within the lungs, the most common form of active tuberculosis, is known as pulmonary tuberculosis. If the disease becomes active in the lymph glands within the chest, it is known as intrathoracic respiratory tuberculosis. If it becomes active within other parts of the body it is known as extrapulmonary tuberculosis (Royal College of Physicians, 2006, p. 3).

Treating TB: The development of antibiotic drugs in the 20^th century precipitated a watershed in the long-standing battle between tuberculosis and human medicine. In 1944, streptomycin was first used to combat tuberculosis. However, because bacteria evolve quickly and exchange genes through lateral gene transfer, it did not take long for Mycobacterium tuberculosis to develop resistance to streptomycin. The answer to this problem proved to be administering multiple antibacterial drugs over a protracted period of time, leading to a dramatic decrease in rates of tuberculosis (Gantz, Brown, Berk, & Myers, 2006, p. 418). The prevalence of tuberculosis declined from a rate of 53 cases per 100,000 in 1953 to 5.2 cases per 100,000 in 2002 (p. 418).

HIV comorbidity and drug-resistant TB: For a time, the success of multi-drug treatment in the 1950s and 1960s was a cause for optimism regarding the outcome of humanity’s long-standing battle with tuberculosis. Tuberculosis was on the retreat, beaten back by powerful pharmacological advances. The 1980s, however, punctured this illusion. The rise of the global HIV/AIDS pandemic in that decade led to an ongoing health crisis. Since HIV weakens the immune system, causing AIDS, the patient is left vulnerable to opportunistic infections by other diseases. Tuberculosis soon proved to be a major beneficiary of the HIV epidemic, and rates of active tuberculosis rose quickly in the wake of HIV (Cegielski et al., 2007, p. 8). Many patients infected with both pathogens have experienced a progression from latent to active tuberculosis. Populations with high rates of tuberculosis, including the latent form, experienced many more cases of active tuberculosis after the HIV epidemic hit (p. 8). In addition to the opportunities opened up by HIV, strains of Mycobacterium tuberculosis began to emerge that were resistant to multiple anti-tuberculosis drugs (Dyer, 2010, pp 89-90). Thus, between the spread of HIV and the evolution of drug resistance in tuberculosis bacteria, the disease has made a dramatic comeback.

Assessing the TB epidemic: Since the 1980s, rates of tuberculosis have surged throughout the world. The burden has disproportionately fallen on lower-income nations, chiefly due to the impacts of population growth, economic woes, and ineffectual national public health programs to control tuberculosis (Dyer, 2010, pp. 91-92). Although the spread of HIV fueled the resurgence of tuberculosis throughout the world in the 1980s, the decline of HIV in recent decades has not consistently produced a commensurate decline in the prevalence of tuberculosis. For example, HIV has been declining in Thailand since 1993, but tuberculosis rates have continued to rise (Cegielski et al., 2007, p. 9).

In developed countries such as the United States tuberculosis has also made a comeback. Rates of tuberculosis began to rise steeply in New York starting in 1979 (Dyer, 2010, p. 95). Thanks to neglect from the city’s government, by 1990 tuberculosis was well-established as an epidemic. The disease took root in traditionally poor New York neighborhoods, and spread thanks to the concentration of people living in impoverished neighborhoods that did not receive adequate public health support. Coupled with the impact of HIV, drug abuse, and homelessness, tuberculosis proliferated in New York City. However, after years of official neglect of the problem, the disease finally drew the attention of policymakers at the local, state, and national levels. The result was a public health campaign that aimed to combat the spread of the disease. The effort involved early identification, treatment for people who had latent tuberculosis and were at risk of developing active cases, and better therapies for active cases (p. 95). The result was a 44 percent decline in the prevalence of tuberculosis in the United States from 1993 to 2003. Today, the prevalence of tuberculosis in the United States stands at a historic low. However, immigration has resulted in an ongoing stream of cases, complicating efforts to eliminate the disease from the United States entirely (p. 95).

The Republic of Moldova presents a very different case. The Republic of Moldova is one of 16 countries in Europe and Central Asia deemed by the WHO to have a “critical” tuberculosis problem (World Bank, 2003, p. 19). Like other post-Soviet nations, Moldova has suffered high rates of tuberculosis for reasons that have everything to do with poverty and lack of a robust public health program to ameliorate the impact of the epidemic. In fact, Moldova is Europe’s poorest country, and this has contributed to the spread of both HIV/AIDS and tuberculosis since the middle of the 1990s. HIV/AIDS prevalence accelerated during the middle of the 1990s, reaching rates of 0.2 percent for adults aged 15-49. In part because of this tuberculosis spread 53 percent over the course of the 1990s, and the trend has continued to accelerate (p. 124).

In 2008, rates of mortality due to tuberculosis fell from 20.2 cases per 100,000 to 17.4 cases per 100,000, the first time in three years that this happened (IMF, 2011, p. 16). However, in 2009 the rates of tuberculosis-related mortality rose again, to 18 per 100,000. There is a significant urban-rural divide in the prevalence of tuberculosis in Moldova, with cases in the cities declining significantly even as cases in the country increase (OECD, 2011, p. 217).

Financing TB treatment

Although progress has sometimes been slow, the Republic of Moldova is working to combat the spread of tuberculosis. The Moldovan government approved a package of strategies to combat the spread of HIV/AIDS and tuberculosis, and launched a major public health effort to implement them (World Bank, 2003, p. 124). In order to implement this Moldovan tuberculosis/AIDS program, the Republic of Moldova sought assistance from the World Bank, “the WHO, UNAIDS, UNICEF, the Dutch government, and the Swedish International Development Agency” (p. 124). The Moldovan effort focuses on vulnerable populations, identifying groups that are most at risk for developing tuberculosis and then working to target interventions designed to contain the spread of the disease and help those afflicted. Intravenous drug users are case in point, as are sex workers, men who have same-sex sexual encounters, prison inmates, members of the Moldovan military, and patients at clinics that treat sexually transmitted infections (p. 124).

Under advisement from WHO Moldova has also adopted the strategy of directly observed treatment, short course (DOTS), as of 2001, and the country has worked to reform its healthcare system (Soltan, Henry, Crudu, &Zatusevski, 2008, p. 71). Chief among these reforms are a new focus on primary health care (PHC) and a new program of national health insurance. In order to diagnose tuberculosis, PHC practitioners are contracted by the national insurance system, which is responsible for covering laboratory tests and personnel (p. 72). International donors, as seen, have played a key role in supporting these efforts. In particular, the Global Drug Facility (GDF) and the Global Fund to Fight AIDS, Tuberculosis and Malaria grants provided most of the funding for anti-tuberculosis drugs during the period from 2001-2005 (p. 72).

Addressing and Controlling TB from a global perspective

From a global-historical perspective, tuberculosis was long a great scourge of humanity, a deadly disease that periodically swept across entire societies. For a time in the mid-to-late twentieth century, it looked as if modern medical science had struck a decisive and victorious blow to the disease with the development of anti-tuberculosis drugs. From about the 1950s to about the middle of the 1980s, the developed world at least largely forgot about the disease, and even some of the more solidly middle-income countries were able to achieve significant progress in combating it. For a considerable cross-section of the world’s population, then, tuberculosis became a distant memory for the most part, a foe that had been defeated by the advances of medical science (Cegielski et al., 2007, p. 2).

However, since about the middle of the 1980s, the world has had a rude awakening. Tuberculosis staged a spectacular comeback throughout the developing world, both by traveling in the wake of the HIV/AIDS pandemic and by virtue of having evolved resistance to most antibiotic drugs hitherto used to treat it (Cegielski et al., 2007, p. 2). Tuberculosis has made inroads even into the high-income, developed world, but it remains overwhelmingly a disease of poverty, with the highest rates of the disease in impoverished African and Asian countries. There are very important reasons for this. Today, treatment for tuberculosis typically takes at least six months, and it requires strict adherence (Barrett & Stanberry, 2009, p. 1220). This is much harder to achieve in impoverished countries where few resources have been allocated to the treatment of the disease, meaning that equipment and drugs are quite often in short supply. The spread of multidrug-resistant tuberculosis has, not surprisingly, greatly complicated the global fight against tuberculosis (p. 1220). Thanks to the aid of international donors, the prevalence of tuberculosis in poor countries like the Republic of Moldova has been curbed to some degree, but it remains unlikely that the problem can be solved even by widespread access to current methods of treatment. However, there is one tantalizing possibility, an intervention that could obviate the need for expensive and time-consuming tuberculosis treatment: a vaccine (p. 1220)

Research and Development

An effective tuberculosis vaccine would fundamentally solve the problem of tuberculosis in a way that current methods of pharmacological treatment never could (Barrett & Stanberry, 2009, p. 1220). Currently, there is no vaccine that is effective for adults, although a vaccine using a similar species of bacteria has some efficacy for children. This is the major research frontier in tuberculosis treatment currently, and the top priority for the future.

References

Barrett, A. D. T., & Stanberry, L. R. (Eds.). (2009). Vaccines for biodefense and emerging and neglected diseases. San Diego, CA: Elsevier.

Cegielski, J. P., et al. (2007). The global epidemiology and control of tuberculosis. In D. D. Spiegelburg (Ed.), New topics in tuberculosis research (pp. 1-70). New York: Nova Science Publishers, Inc.

Dyer, C. A. (2010). Tuberculosis. Santa Barbara, CA: ABC-CLIO, LLC.

Gantz, N. M., Brown, R. B., Berk, S. L., & Myers, J. W. (2006). Manual of clinical problems in infectious diseases (5^th ed.).Philadelphia, PA: Lippincott Williams & Wilkins.

IMF. (2011). Republic of Moldova: Poverty reduction strategy paper—progress report. Washington, D.C.: IMF.

Myers, J. W., Neighbors, M., & Tannehill-Jones, R. (2002). Principles of pathophysiology and emergency medical care. New York: Delmar.

OECD. (2011). Development in Eastern Europe and the South Caucasus: Armenia, Azerbaijan, Georgia, Republic of Moldova and Ukraine. Paris: OECD.

Royal College of Physicians. (2006). Tuberculosis: Clinical diagnosis and management of tuberculosis, and measures for its prevention and control. London: Royal College of Physicians.

Soltan, V., Henry, A. K., Crudu, V., &Zatusevski, I. (2008). Increasing tuberculosis case detection: Lessons from the Republic of Moldova. Bulletin of the World Health Organization, 86(1), pp. 71-76. Retrieved from http://search.ebscohost.com/

World Bank. (2003). Averting AIDS crises in Eastern Europe and Central Asia: A Regional Support Strategy. Washington, D.C.: World Bank.