An Article Review On Tuberculosis Biology Essay

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The article Tuberculosis is written by Gary Maartens and Robert J Wilkinson to show the readers problems of tuberculosis disease. Tuberculosis is the leading cause of death in developing countries especially in sub-Saharan Africa. Many people in this region are infected to HIV therefore it increases susceptibility of tuberculosis, which is an opportunistic disease that infects immunosuppressed people. Incident of tuberculosis declined in high-income countries, however still remain high in resource-poor countries due to lack of advances. The key to the control of the tuberculosis disease is development of new diagnostic method, treatment, and vaccination. Health agencies are trying to support low-income countries that are in risk, but effort, political will, and high amount of resources are needed for this plan.

According to the article, the risk of tuberculosis infection is higher in HIV infected patients, thus the incidence rate is increased in sub-Saharan Africa due to HIV epidemic. Some patients have multidrug-resistant tuberculosis, which have resistance to antimycobacterial drugs such as rifampicin and isoniazid. If the resistance level is high, the disease is untreatable, so the patients die in about 16 days. Multidrug-resistant tuberculosis is found more in patients who has been treated previously than newly infected patients. Since existing drugs have no effect on multidrug resistant tuberculosis, new antimycobacterial drugs are needed for treatment. Researchers examined the interaction of immune system to mycobacterium tuberculosis and they found that lack of vitamin D is associated with tuberculosis infection. This suggests that prevention of tuberculosis is possible by vitamin D supplementation. Also many studies show that membrane-associated protein mce operon, and small-molecule transporters have important role in virulence and replication of mycobacterium tuberculosis. The studies also found that a K+ efflux channel called kefB prevent mycobacterium tuberculosis from electrophile toxic effects. These proteins are potential targets of novel antimycobacterial drugs. Diagnosis of tuberculosis is done by detecting acid fast bacilli on microscopy and on culture. There are several diagnosis methods for tuberculosis available. Conventional smear diagnosis is seldom used technique because it is time-consuming and has low yield. In-house nucleic-acid amplification tests have high specificity and sensitivity in smear-positive sputum, and can be used to identify if the acid-fast bacilli are mycobacterium tuberculosis. However, this method show moderate sensitivity in smear-negative sputum and the cost is very expensive, thus it cannot be continuously used in developing countries. TST (Tuberculosis Skin Test) is another method of detecting mycobacterium tuberculosis but it is not the most accurate test because it has limitations that may lead to false positive and false negative results. Studies of Lalvani and colleagues state that ESAT-6-based and CFP-10-based enzyme-linked immunospot analysis is more specific than the TST. However, it cannot differentiate active infection from latent infection. T-SPOT.TB test and other similar tests, QFG and QFGIT, are developed from previous tests. Studies suggest that these tests may be able to detect the risk of developing active tuberculosis in people infected with HIV. Researchers are still testing to see if these techniques are more accurate and valid than TST. For treatment of tuberculosis, DOTS (directly observed treatment short course) is recommended. It is a simple treatment that is cost-effective in developing countries and successfully reduced tuberculosis incidence. However, many patients stop taking the treatment when their symptoms improve, as a result, tuberculosis can become drug resistance. Rifampicin is used for treatment of tuberculosis, but resistance of rifampicin is increased in people with HIV. African pharmacokinetic studies reported that outcome is better when higher doses of rifampicin are taken. New antitubercular drugs such as moxifloxacin and gatifloxacin are developed and licensed. Moxifloxacin is very effective against mycobacterium tuberculosis that can be substituted for isoniazid to reduce the time for treatment. The only problem with this drug is that resistance of moxifloxacin can develop rapidly within the patient especially when this drug is used alone for treatment. Moreover gatifloxacin has toxic effects, thus it has not been used. Several clinical trials show that rifampicin and pyrazinamide are effective against latent tuberculosis, therefore successfully prevent tuberculosis infection in HIV-positive people. However these drugs cause severe hepatotoxicity to HIV-negative people. BCG vaccination is known to have some protection against tuberculosis although it does not reduce transmission of the disease. According to researches, vaccines have possibility to reduce reactivation of disease when vaccinated after infection. Vaccinologists has been developing new vaccines that have same or better efficacy than BCG when tested in animals. Vaccine research is not an easy process because a lot of volunteers are needed and data must be collected from them for a long time period. It is reasonable to apply available therapies altogether for prevention and treatment of tuberculosis but it requires a lot of resources that developing countries lack of. Nevertheless, other data mention that co-administration of antitubercular and antiretroviral therapies cause increased risk of harmful side effect such as immune reconstitution inflammatory syndrome. Under this syndrome, tuberculosis can become worse due to appearance of non-apparent tuberculosis. There are drugs attempt to improve the condition of immune reconstitution inflammatory syndrome, however these drugs cannot be used on HIV-infected patients for the reason that safety issue still remains.

Tuberculosis has been a leading cause of death and still is dreadful when associated with HIV-infection. People in sub-Saharan Africa are highly exposed to HIV-infection; therefore they have increased susceptibility to tuberculosis. These people living in Africa or other low-income countries are in need of advances for diagnosis, treatment, and prevention. Previously developed therapies are becoming incapable because strains of mycobacterium tuberculosis in many patients are resistance to drugs available for treatment. Moreover, multidrug treatment is not cost-effective due to its long-lasting time needed for the treatment. Authors of this article indicate the need for developing cost-effective novel therapies that are better at treating and preventing tuberculosis. The research activities to provide new therapies are rapidly increasing and progressing. Nonetheless, developing countries have limited resources for the advances. Authors suggest development of global plan to help and stop tuberculosis not only in high-income countries but also in middle and low-income countries. It is very challenging to apply advances to developing countries because effort, political will, and abundant resources are needed to support the global plan. This article clearly explains severity of tuberculosis in developing countries and informs why they are in need of advances. Although the cost of generating new drugs and supporting poor countries is very expensive, it should be done as soon as possible to save people dying from tuberculosis. Researchers need to find a way to treat HIV as well, since tuberculosis occurs more frequently in HIV-infected patients. Incidence rate of tuberculosis in worldwide will eventually drop if novel therapies are able to cure HIV, then people in sub-Saharan Africa will suffer lesser from tuberculosis.