Tuberculosis

Tuberculosis is an infection with the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system (meningitis), lymphatic system, circulatory system (miliary TB), genitourinary system, bones and joints.

Prevention

Prevention and control efforts include three priority strategies:

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• identifying and treating all persons who have TB disease
• finding and evaluating persons who have been in contact with TB patients to determine whether they have TB infection or disease, and treating them appropriately, and
• testing high-risk groups for TB infection to identify candidates for treatment of latent infection and to ensure the completion of treatment.

In tropical areas where the incidence of atypical mycobacteria is high, exposure to nontuberculous mycobacteria gives some protection against TB.

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BCG vaccine

Many countries use BCG vaccine as part of their TB control programs, especially for infants. The protective efficacy of BCG for preventing serious forms of TB (e.g. meningitis) in children is high (greater than 80 percent). However, the protective efficacy for preventing pulmonary TB in adolescents and adults is variable, from 0 to 80 percent. In the United Kingdom, children aged 10-14 are typically immunized during school.

Related Topics:
BCG - Meningitis - United Kingdom

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The effectiveness of BCG is much lower than in areas where mycobacteria are much less prevalent. In the USA, BCG vaccine is not routinely recommended except for selected persons who meet specific criteria:

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• Infants or children with negative skin-test result who are continually exposed to untreated or ineffectively treated patients or will be continually exposed to multidrug-resistant TB.
• Healthcare workers considered on individual basis in settings in which high percentage of MDR-TB patients has been found, transmission of MDR-TB is likely, and TB control precautions have been implemented and not successful.

Tuberculosis vaccine

The first recombinant tuberculosis vaccine entered clinical trials in the United States in 2004 sponsored by the National Institute of Allergy and Infectious Diseases (NIAID).

Related Topics:
Recombinant - Vaccine - Clinical trial - National Institute of Allergy and Infectious Diseases

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http://www2.niaid.nih.gov/newsroom/releases/corixatbvac.htm

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A 2005 study showed that a DNA TB vaccine given with conventional chemotherapy can accelerate the disappearance of bacteria as well as protecting against re-infection in mice; it may take four to five years to be available in humans. PMID 15690060.

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Because of the limitations of current vaccines, researchers and policymakers are promoting new economic models of vaccine development including prizes, tax incentives and advance market commitments.

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