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  • Infection with Mycobacterium tuberculosis or other very closely related strains, as well as the inflammatory reaction of the host define, the disease (tuberculosis [TB]).

  • One-third of the world’s population is infected with TB.

  • TB is the main cause of death of patients infected with HIV.

  • TB usually affects the lung, but virtually all other organ systems may be involved.

  • TB of the skin is a relatively rare manifestation with a wide spectrum of clinical findings depending on the source of infection and the immune status of the host.

  • Diagnosis is based on clinical manifestations, histopathologic analysis, demonstration of the relevant mycobacteria in tissue or in culture and host reaction to M. tuberculosis antigen.

  • Treatment is with standard multidrug regimens; cases of multidrug-resistant TB or extensively multidrug-resistant TB require special attention.

  • Course and prognosis depend on the immune status of the host. Treatment is curative except for patients with a severely compromised immune system.

Tuberculosis (TB) is still an important worldwide disease. TB is currently the ninth leading cause of death worldwide and the leading cause from an infectious agent, ranking higher than HIV/AIDS. In 2016, 6.3 million new cases of TB were reported, which was up from 6.1 million in 2015. There were 476,774 reported cases of HIV-positive TB, of whom 85% were on antiretroviral therapy.1 In 2016, there were an estimated 1.3 million TB deaths among HIV-negative people. An additional 374,000 deaths were reported among HIV-positive people. An estimated 10.4 million people fell ill with TB in 2016: The highest burden of disease was in 5 countries: India, Indonesia, China, the Philippines, and Pakistan.

In 2008, a total of 12,898 incident TB cases were reported in the United States; the TB rate declined 3.8% from 2007 to 4.2 cases per 100,000 population, the lowest rate recorded since national reporting began in 1953. In 2008, the TB rate in foreign-born persons in the United States was 10 times higher than in U.S.-born persons. TB rates among Hispanics and blacks were nearly 8 times higher than among non-Hispanic whites, and rates among Asians were nearly 23 times higher than among non-Hispanic whites. To ensure that TB rates decline further in the United States, especially among foreign-born persons and minority populations, TB prevention and control capacity should be increased. Additional capacity should be used to (a) improve case management and contact investigations; (b) intensify outreach, testing, and treatment of high-risk and hard-to-reach populations; (c) enhance treatment and diagnostic tools; (d) increase scientific research to better understand TB transmission; and (e) continue collaboration with other nations to reduce TB globally.2

HIV-positive people are approximately 20 times more likely than HIV-negative people to develop TB in countries with a generalized HIV epidemic, and between 26 and 37 times more likely to develop TB in countries where HIV prevalence is lower.

The so-called atypical mycobacteria (mycobacteria other than Mycobacterium tuberculosis [MOTT]) ...

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