Tuberculosis among the elderly in Tanzania: disease presentation and initial response to treatment.

Background: Reports on tuberculosis (TB) presentation among the elderly in sub-Sahara Africa are scarce at a time when the elderly population is increasing. This dearth of information is likely to lead to an increase in the number of undetected TB cases in the region.
Objective: To describe TB presentation and response to anti-tuberculosis treatment at 2 months among elderly patients.
Methods: Consecutive patients referred to TB centres in Dar es Salaam, Tanzania, underwent clinical, microbiological and chest X-ray (CXR) evaluations at baseline and after 2 months of anti-tuberculosis treatment. Patients aged 60 years were considered elderly and those aged 18-59 years formed the comparison group.
Results: Elderly patients with TB were more likely to have smear-negative TB (76.7% vs. 49.3%, P < 0.0001) and lower-zone lesions on CXR (41% vs. 17%, P < 0.001), but less likely to have cavities on CXR (77.6% vs. 50.4%, P < 0.0001) than the comparison group. Hypertension and diabetes mellitus were more common among the elderly than among controls. Mortality at 2 months was respectively 18.6% and 8.1% among the elderly and among controls. Human immunodeficiency virus infection and smoking increased mortality, while hypertension was associated with reduced mortality.
Conclusion: TB in the elderly was associated with atypical clinical and radiological presentations. A high index of suspicion could minimise delays in diagnosis and treatment.