Association of Mycobacterium tuberculosis complex isolates of BOVIS and Central Asian (CAS) genotypic lineages with extrapulmonary disease

The association between isolate genotype, defined as in the international spoligotype database SpolDB4, and extrapulmonary tuberculosis was determined among 1009 patients in a population-based, 4-year survey performed in Tuscany, Italy. Extrapulmonary disease occurred in 24.2% of patients. A statistically significant association with extrapulmonary disease was found for the BOVIS (adjusted OR 3.2; 95% CI 1.2–8.1) and for the Central Asian (CAS) lineages (adjusted OR 2.3; 95% CI 1.0–5.1). These findings support the view that Mycobacterium tuberculosis strains within individual genotypic lineages might have evolved unique pathogenic characteristics that are capable of influencing the clinical outcome of the infection.