Tuberculosis in Haiti

Haiti has the highest prevalence of TB in the Western Hemisphere. About 300 individuals per 100,000 Haitians have active TB. Humans are the only known reservoirs for M. tuberculosis. 

TB is transmitted by inhaling the tubercle bacilli. A variety of factors can increase the risk of transmission. TB can cause cavitation lesions in the lungs and these lesions have very high concentrations of the bacilli, and individuals with these lesions are more contagious. Contagion is increased in poorly ventilated situations and with prolonged exposure. Malnourished individuals have reduced cell-mediated immunity and are at higher risk. Treated individuals are much less infectious than those who have not received any treatment. 

Once the TB bacilli is established in the body, the bacteria is spread in the lymph or vascular systems to other lymph nodes, the kidney, long bones, spine, and to the brain. 

The body does fight back. A cell-mediated immune response terminates the unimpeded growth of the M. tuberculosis 2-3 weeks after initial infection. CD4 helper T cells activate macrophages to kill the intracellular bacteria with resultant epithelioid granuloma formation.

Any child with pneumonia, pleural effusion, or a cavitary or mass lesion in the lung that does not improve with standard antibacterial therapy should be evaluated for TB. Also, children with fever of unknown origin, failure to thrive, significant weight loss, or unexplained lymphadenopathy should be evaluated for TB.

Frequent sites of lymph node involvement include the neck, below the jaw, and above the clavicles. 

Multiple drug-resistant TB is a problem in Haiti. First-line agents to treat TB include rifampin, isoniazid (INH), pyrazinamide, ethambutol, and streptomycin. Hepatitis, a recognized adverse effect of isoniazid is rare in children

Recommendations for the treatment of pulmonary tuberculosis (TB) include a 6-month course of isoniazid and rifampin, supplemented during the first 2 months with pyrazinamide. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) may need to be included in the initial regimen until the results of drug susceptibility studies are available.

Because poor adherence to these regimens is a common cause of treatment failure, directly observed therapy (DOT) is recommended for treatment of TB. DOT means a health care provider or other responsible person must watch the patient ingest the medications. 

I reviewed a recent article on TB in Haiti that showed the statistically significant difference between DOT and non-DOT patients. 

2001 - There were 143 patients in the non-DOT group and 138 patients in the DOT group.

	Direct Observation  Treatment - %	Non-Direct Observation  Treatment - %
Successful	87	58
Defaulted	7	29
Died	4	12

Breastfeeding is encouraged in mothers treated for TB because the amount of drug in breast milk is very small, and no adverse effects have been documented.