Pulmonary tuberculosis in HIV-infected patients presenting with normal chest radiograph and negative sputum smear

HIV-infected patients with pulmonary tuberculosis exhibit atypical radiological presentation and negative sputum smear more frequently than their HIV-negative counterparts.

We performed a retrospective study based on a chart review of 146 HIV-infected patients with pulmonary symptoms and culture-proven pulmonary tuberculosis. We compared clinical characteristics and the outcome in 71 patients (49%) with positive sputum smear (SS+), 62 patients (42%) with negative sputum smear/abnormal chest X-ray (SS-/CXR+) and 13 patients (9%) with negative sputum smear/normal chest X-ray (SS-/CXR-). Patients were enrolled from January 1987 to December 1998, and were followed up until December 1999.

On hospital admission the three groups of patients examined did not differ significantly in demographic characteristics, degree of immunosuppression or Mycobacterium tuberculosis drug-susceptibility pattern. SS-/CXR- patients were significantly Less LikeLy to present with prolonged fever and dyspnea. Median survival was shorter for SS-/CXR- patients (6.4 months vs 20.2 and 18.8 months in the other two groups). In multivariate analysis, SS-/CXR-patients had a significantly increased risk of death (hazard ratio 3.0, 95% confidence interval, 1.4 to 6.4, p = 0.004) compared to SS+ patients. This increase in risk was no longer statistically significant when initiation of antituberculous therapy within 8 weeks from the collection date of the first specimen yielding M. tuberculosis was included in the multivariate model.

Decreased survival was observed in HIV-infected patients with pulmonary tuberculosis and with both negative sputum smear and normaL chest X-ray presentation. This may primarily be a resuLt of delayed tuberculosis diagnosis and initiation of antituberculous therapy. The latter delay may also lead to a faster progression of HIV infection in SS-/CXR patients, in whom diagnostic oversight may be common.