Publications

BACKGROUND

Recognizing pulmonary involvement in tuberculosis (TB) patients is necessary to prevent TB transmission. We describe frequency and characteristics of patients with extrapulmonary TB (EPTB), normal chest radiographs, and positive sputum culture.

METHODS

We analyzed data on patients ≥15 years old with EPTB reported to the California TB registry during 2011-2017 with cultured sputum and normal chest radiographs, using generalized linear modeling to estimate prevalence ratios associated with positive sputum culture. Demographic, behavioral, clinical characteristics, and testing were compared for patients with positive and negative sputum culture.

RESULTS

Of 1,634 patients with EPTB and normal chest radiographs, 936 (57%) had sputum culture performed, and 126 (13%) patients had positive results for M. tuberculosis complex. Patients with positive results were more likely to: be male, experience homelessness, use substances, have HIV, have >1 disease site. Among 85 HIV co-infected patients, 54% had positive culture results compared to 9.5% among 852 patients without HIV co-infection. Patients with EPTB in more than one site were also more likely to have a positive sputum culture.

CONCLUSIONS

Culturing sputum from patients with EPTB identified pulmonary cases not detected by chest radiograph, particularly among patients with HIV or >1 disease site.