This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
Most people in United States do not associate tuberculosis with very dangerous and deadly disease. People tend to forget of the infections that do not cause epidemics, but in most cases exist on a low scale with low lethality rate in their own population. The purpose of an article "Tuberculosis", written by Gary Martens and Robert Wilkinson is to show the public how serious and problematic epidemic of Mycobacterium tuberculosis is in poor countries and alarm the medical field about the need of research and control of this deadly disease among the high risk populations. The first part of the article shows how widespread and deadly tuberculosis is. According to authors there were almost nine million people infected with almost two million infections with deadly outcome in 2004. The situation is the worst in Africa, especially in sub-Saharan regions, where high numbers of individuals is infected with HIV virus. Those people are highly susceptible of getting infected with tuberculosis, due to the suppression of their immune systems by the viral infection. In addition, emergence of multidrug-resistant and extensively drug-resistant strains of tuberculosis, resistant to most of the drugs on the market (like rifampicin, isoniazid, capreomycin) and possibly linked to nocosomial transmission, demonstrate the need for new drugs and treatment methods to prevent and cure the disease. Second part of the article describes the mechanisms by which the bacteria operates and evolves within the host and its macrophages for years. Tuberculosis' genome undergoes constant mutations which allows for evolution, virulence and drug resistance. Certain mutation strains like east African-Asian, east African-Indian or W/Beijin lineage correlate to specific populations. Later authors describe the mechanisms of bacteria-host cell interactions and immune system responses and possibility of tuberculosis prevention by vitamin D supplementation (p.2032). In addition, genetic basis for susceptibility to tuberculosis infection is mentioned. Third part of the article describes the ways to diagnose and treat tuberculosis. In the next paragraph authors explain that diagnosis of the disease relies largely on microscopic observation (which is not broadly available in underdeveloped countries) and analysis of the culture, the long process because bacteria grow very slow in culture. Authors mention promising and faster nucleic-amplification test, but the outcomes of this test are not consistent in every case and too expensive for routine administration. Other tests which detect tuberculosis exist (tuberculin skin test, ELISpot analysis, T-SPOT.TB), but none of them are fully effective. Treatment has not changed for years either. Although programs like DOTS (directly observed treatment short course) and DOT (direct observed therapy) are effective but authors see the need for improvement, due to the fact that those conventional treatments are long (usually several months), not very convenient for patients and expensive or not available for patients in poor countries. Some new drugs were introduced to the market, but their effectiveness is problematic and not consistent. Prevention of dormant tuberculosis infections in HIV patients is important, because it can reduce the rate of infection in this high risk group, but many drug regiments shows toxicity and therefore their use cannot be widespread. Vaccinations, although exist are not effective in 100 %. Bacille Calmette Guerin (BCG) vaccine shows some protection but does not prevent transmission; in addition the length of protection varies among individuals. In the last part of the article, authors focus on the control of tuberculosis infection in HIV positive individuals and propose combination of prevention and antiretroviral therapy.
Most of the information provided in this article is based on years of experiments and studies. The article explores various approaches on prevention, treatment, genetics and interaction of bacterial components with the host. First study emphasizes the correlation between tuberculosis epidemic and HIV status in undeveloped countries. Data shows that HIV-positive individuals from sub-Saharan Africa, most of who are not treated for HIV, are three times more likely to get infected with tuberculosis than HIV-positive individuals from industrialized parts of the world. In addition HIV infection is closely linked to reactivation of dormant tuberculosis infection and its spread. Second study shows dangerous trend in emergence of multidrug resistant strains of bacteria and the possibility of nosocomial transmission (p. 2031). In almost 5% of infected individuals, the multidrug-resistant strains were detected. In addition, M tuberculosis genomes taken from the HIV-positive patients of one of the outbreaks of extensively drug-resistant tuberculosis strains showed almost 90% similarities and have been linked to the same hospital. Third important study mentioned in the article describes how simple vitamin D supplementation might be an easy step in tuberculosis prevention (p.2032). This study shows the mechanism in which the mycobacterial cell initiates the host immune response thru the work of toll-like receptors resulting in activation of vitamin D which has numerous stimulating affects on immune system. Next study demonstrates that mutations in the pathway of some signaling molecules-cytokines make the host vulnerable to serious mycobacterial infections (p. 2023). In addition, another study examined the mechanism in which some randomly mutated bacilli can resist phagocytosis and live inside the macrophages. The results show the importance of membrane-associated proteins, small molecule transporters and K+ pump protecting the bacteria against low pH inside the macrophages. This date is important, because the knowledge of the bacterial metabolic pathways and interactions can be the first step in drug development interfering with those specific processes. Another set of data demonstrate various effectiveness of different tests used in diagnosis of tuberculosis. The nucleic-acid amplification test illustrate various sensitivity of different samples (it shows high sensitivity in positive sputum but low to moderate sensitivity in negative sputum, spinal fluid or sample taken from location other than lungs). Other test, like ELISpot analysis is shown to be more precise than conventional TST test done in vaccinated individuals and less affected by the existence of HIV infection than TST, and therefore it is used in few commercial tests available on the market with contradicting results. Next portion of the article talks about some attempts done to adjust the dosage of available antimycobial drugs like rifamycin, moxifloxacin, pyrazinamide, gatifloxacin. Some data show promise, some is concerned with multi-drug resistance, and most data confirm the need for development of new drugs. Lastly, the article discusses the data on effectiveness of BCG vaccination. Figures show that BCG is effective to some degree, and the length of protection varies among individuals. In addition, process of transmission of tuberculosis is not affected by the vaccine either Furthermore, article provide information about vaccines, created in last fifteen years that show very promising results in animals and were accepted into clinical trials. Some might be in widespread use by 2015 (p. 2026-2037).
This article's purpose is to update the public on tuberculosis; it shows the progress that was made over the years in treatment and prevention, lastly it illustrates the importance of continuing research and calls health and political agencies to work together in order to fight with tuberculosis among the people from poor countries, especially those from sub-Saharan Africa. Authors of this article show that the researches explore different avenues of how to fight with tuberculosis. Some of the researchers work on the improvement of old methods, like vaccines, others try to utilize the knowledge of bacterial genetics in order to find targets for new drugs. Data shows that the important link was found between HIV-status and the risk of tuberculosis infection and therefore strategies used to fight tuberculosis can be developed and modified accordingly. Studies show the significance of the drug-resistant strains and mechanisms of acquiring this resistance. The understanding of how to control and fight with tuberculosis exist, but there is a need to apply this knowledge to populations that are the most affected. In my opinion, prevention is always better that finding the cure, therefore researches need to work on preventive measures like finding more effective vaccines, and easier and more reliable diagnostic tests. The vitamin D potential in prevention of tuberculosis sounds very intriguing. It is definitely worth further exploration and if it happens to works, tuberculosis prevention could be as easy as adding iodine to salt in thyroid disease prevention. In addition, further research is required in order to develop better drugs, which could cure the drug resistant strains. The most important thing that the medical community has to take in account is that all of the preventive measures, as well as drugs have to be inexpensive, efficient and easy to administer. Knowing the correlation between the HIV and tuberculosis infection the tuberculosis research should overlap HIV research and vice versa. Furthermore, the health agencies have to work together will politicians and advocate groups in order to develop unified course of action against tuberculosis as well as educational campaign across the world in order to alert people of how important it is to continue to fight with Mycobacterium tuberculosis.