Cryptic Disseminated Tuberculosis: a Secondary Analysis of Previous Hospital-Based Study

The main purpose of this study was to describe the demographic and clinical features of cryptic disseminated TB; it was also aimed to shed light on diagnostic test, procedure results, organ involvement, and outcomes of cryptic disseminated TB in patients with confirmed disseminated TB.

We performed a secondary post hoc analysis of collected data from our previous study entitled "Disseminated Tuberculosis among Adult Patients Admitted to Hamad General Hospital, Qatar: A Five-Year Hospital-Based Study" with modified objectives. This study included patients admitted from January 1, 2006 to December 31, 2010.

Twenty-three patients were recruited with non-miliary patterns on chest x-ray. Their mean age was 34.4±12.6 years and 15 (65.6%) were males. The mean duration of illness was 46.13±48.4 days and the most common presenting symptom was fever in 20 patients (87%), while 3 (13%) patients had underlying medical conditions with diabetes mellitus 2 (8.7%), being the most common. Bronchoalveolar lavage (BAL) and bronchial wash (BW) fluids were Acid-fast bacilli (AFB) positive in 1/4 (25%) of the cases and culture-positive for Mycobacterium tuberculosis (M. tuberculosis) in 4/4 (100%) of all the cases. Two patients (8.7%) had positive sputum smear, while 18 (78.3%) patients had positive culture for M. tuberculosis. All except one patient completed their treatment in Qatar. One patient died one month after the start of antituberculous treatment.

Cryptic disseminated TB should be suspected when a patient from TB-endemic countries develops unexplained fever and cough despite normal or non-miliary pattern chest radiograph. Moreover, respiratory specimen cultures should be obtained from these patients, regardless of the symptoms presented and the initial site of the involved organ.