Prevalence and determinants of extrapulmonary involvement in patients with pulmonary tuberculosis in a Sub-Saharan African country: a cross-sectional study.

BACKGROUND

Determinants of extrapulmonary involvement during pulmonary tuberculosis (PTB) have not been extensively investigated. We assessed the prevalence and determinants of extrapulmonary involvement during PTB in a Sub-Saharan African country with a high prevalence of both TB and human immunodeficiency virus (HIV) infection.

METHODS

The medical records of patients aged ≥ 15 y, admitted for a first episode of TB to the Pneumology Service of Yaoundé Jamot Hospital, Cameroon, between 2009 and 2010 were considered. Determinants of extrapulmonary involvement were investigated through logistic regression.

RESULTS

A total of 984 patients (58.9% male), with a median age (25(th)-75(th) percentiles) of 32 (25-41) y were admitted for a first episode of TB, including 629 (63.9%) with isolated PTB, 127 (12.9%) with isolated extrapulmonary TB (EPTB), and 228 (23.2%) with both PTB and EPTB (PTB/EPTB). Therefore, the prevalence of EPTB among those with PTB was 26.6% (228/857). The main determinants of EPTB among patients with PTB were male sex (adjusted odds ratio (OR) 2.71, 95% confidence interval (95% CI) 1.71-4.03), HIV infection (OR 2.20, 95% CI 1.36-3.55), absence of fibrotic lung lesions (OR 1.96, 95% CI 1.23-3.14), smear-negative PTB (OR 7.20, 95% CI 4.13-12.56), anaemia (OR 1.60, 95% CI 1.03-2.50), and leukopenia (OR 2.59, 95% CI 1.12-5.98).

CONCLUSIONS

About a quarter of patients with PTB in this setting also have extrapulmonary involvement. EPTB is less contagious, less frequent than PTB, and less well addressed by programs in developing countries, while its identification is important for optimizing care. The presence of determinants of EPTB among patients with PTB should motivate active investigation of extrapulmonary involvement in order to improve management.