Mycobacterial infections in the elderly

In 2008, elderly subjects accounted for more than 262,000 cases of smear-positive tuberculosis worldwide, reaching the highest age-adjusted rates in some regions. Elders are at a greater risk for reactivation of latent tuberculosis or acquisition of new infection, especially if they live in long-term care facilities or are smokers. Once overt clinical tuberculosis appears, they are at increased risk of hospitalization and death. Pulmonary tuberculosis presentation may be atypical in elderly people, as they tend to have lower prevalence of fever, sweating, or hemoptysis, and their chest x-rays show less cavities and more lower lung field involvement. Compared with younger patients, tuberculous elders seem to have lower frequency of positive PPD, but differences in sputum smear positivity are not clear. Regimen recommended for treating new cases of pulmonary tuberculosis is not different from other age groups: a two-month bactericidal phase with daily oral administration of isoniazid, rifampin, pyrazinamide, and ethambutol, and a continuation phase with isoniazid and rifampin daily during four months, though some variations are allowed. Directly observed strategy is highly recommended in the initial phase. Elders with pulmonary tuberculosis may require longer time to become smear negative and seem to have worse outcomes than younger patients.