Patients with recurrent tuberculosis in Istanbul: reactivation?, reinfection?

Introduction: A recurrence of tuberculosis (TB) is a second episode of tuberculosis occuring after a first episode had been treated successfully. Activation of the old lesion (reactivation) suggests the inadequacy of the quality of treatment, while disease development due to a new TB infection (re-infection and disease) informs about the risk of infection in the community. This study investigated the rate of reactivation and the rate of infection during recurrence in Istanbul. Method: Of 99 cases who were followed up as recurrent disease in 12 disricts of Istanbul in between 2002 and 2015, 55 cases which had cultures of both episodes in Istanbul University Aziz Sancar Institute Of Experimental Medicine Tuberculosis Unit were included in the study.. Fingerprints of strains obtained during the first and recurrent disease episodes were determined by spoligotyping method. Clinical demographic data of the cases were obtained from the dispensary files. Results: A total of 55 cases with mean age 35,45±13,607 years (range 13 to 61); 44 male, 11 female were culture positive lung tuberculosis. Forty one cases (74.5 % ) were smear positives tuberculosis in the first episode. Twenty nine (67,4 %) cases were smoking. In addition to tuberculosis;2 (4,1 %) cases had DM, 3 (6 %) cases had COPD/asthma an one patient had silicosis . Twelve cases tested for HIV, the test results were negative. All cases treated with standard rifampisin-containing regimen for at least 6 months (mean duration: 7,49±3,89 months). Five (9,2 % ) cases had INH resistance , one (1.8% ) case had RIF resistance , 2 (%3,7) cases had ETM resistance ,7 (13%)cases had SM resistance in the first episode. Only one of the cases was MDR-TB. Directly observed treatment (DOT) was applied to 27 (56%) cases. All of the cases were treated successfully in the first episode of disease ,33 (60%) were cured, 22(40%) completed treatment. Forty one (75,9 %) cases were smear positive in recurrent period. Fingerprint analysis revealed 34 different strains. Of the 55 recurrent cultere-pozitive tuberculosis cases, 49 (89,1%) were reactivation and 6 (10,9 %) reinfection tuberculosis case. The median time to recurrence due to reactivation is 2,82 years and duo to reinfection is 3,67 years..Whether, smoking and smoking cessation; being successfully treated as completion of treatment or cure didn't make a meaningful difference in cause of recurrence 3 Conclusion: The cause of recurrence in lung TB was reactivation in Istanbul. This may be attributed to relatively low incidence of smear-positive TB disease in Istanbul, as well as the lack of therapeutic treatment quality.