A Cross-sectional Study of Patients With Extrapulmonary Tuberculosis and Normal Chest Radiographs - What...

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Public Health

Background:

• Recognizing pulmonary involvement in tuberculosis (TB) patients is crucial for preventing disease transmission.
• Extrapulmonary TB (EPTB) with normal chest radiographs presents diagnostic challenges.

Purpose of the Study:

• To determine the frequency and characteristics of patients with EPTB who have normal chest radiographs but positive sputum cultures.
• To identify patient factors associated with positive sputum cultures in this population.

Main Methods:

• Analysis of data from the California TB registry (2011-2017) for patients aged ≥15 with EPTB, cultured sputum, and normal chest radiographs.
• Generalized linear modeling was used to estimate prevalence ratios for positive sputum cultures.
• Demographic, behavioral, clinical characteristics, and testing data were compared between patients with positive and negative sputum cultures.

Main Results:

• Of 1635 patients with EPTB and normal chest radiographs, 13% had positive sputum cultures for Mycobacterium tuberculosis complex.
• Patients with positive cultures were more likely to be male, homeless, substance users, have HIV, or have multiple disease sites.
• HIV co-infection was associated with a significantly higher likelihood of positive sputum culture (54% vs. 9.5%).

Conclusions:

• Sputum culture is valuable for detecting pulmonary TB in EPTB patients with normal chest radiographs.
• This diagnostic approach is particularly important for individuals with HIV co-infection or multiple sites of EPTB.