Evaluation of Culture-confirmed Extrapulmonary Tuberculosis Cases in a University Hospital

Abstract

Introduction: Tuberculosis (TB) is caused by Mycobacterium tuberculosis and can involve any organ, especially the lungs. In recent years, especially in developed countries, the incidence of TB has increased due to the growing number of people with acquired immunodeficiency. This has led to an increase in the incidence of extrapulmonary TB (EPTB). This study examined patients with EPTB confirmed by positive M. tuberculosis culture in İnönü University Faculty of Medicine, Department of Microbiology and Clinical Microbiology, Molecular Microbiology Laboratory. Materials and Methods: Patients with positive M. tuberculosis culture in the molecular microbiology laboratory of our hospital between January 1, 2004 and December 31, 2014 were retrospectively evaluated according to culture-confirmed site of involvement, acid-fast bacillus (AFB), polymerase chain reaction (PCR) positivity, drug resistance, and mortality. Results: The study included 132 patients; 41 (31.1%) were male and 91 (68.9%) were female. The mean age was 46.4±18.5 (17-86) years. Extrapulmonary TB types were TB lymphadenitis in 48 patients (36.4%), musculoskeletal TB in 23 (17.4%), disseminated TB in 17 (12.9%), urinary TB in 11 (8.3%), abdominal TB in 11 (8.3%), TB meningitis in eight (6.1%), pleural TB in six (4.5%), genital TB in five (3.8%), and cutaneous TB in three patients (2.3%). Acid-fast bacillus positivity rates were 21.7% in musculoskeletal samples, 16.6% in pleural samples, 12.5% in cerebrospinal fluid, 9% in urinary tract samples, and 6.2% in lymph nodes. Polymerase chain reaction positivity was not detected in cerebrospinal fluid or skin samples. The rate of resistance to at least one anti-tuberculous drug was 20%. Mortality was 16.1% (n=9) in the 56 patients (42.4%) with available data. Conclusion: Lymphatic TB was the most common form in our patients. According to national data, pleural TB is among the common forms of EPTB in Turkey. However, the rate of pleural TB was low in our study due to the lack of pleural biopsy in our hospital during the study period. In TB-endemic regions such as Turkey, it is important to consider EPTB in the differential diagnosis of patients with relevant clinical findings and to confirm the diagnosis with TB culture primarily, as well as methods such as AFB staining and PCR.

Keywords

• miliary tuberculosis
• spondylodiscitis
• osteomyelitis
• epidemiology
• multidrug resistant tuberculosis