BCG vaccine and leprosy household contacts: Protective effect and probability to becoming sick during follow-up.

BACKGROUND: Immunoprophylaxis with Bacillus Calmette-Guérin (BCG) vaccine is still the most effective intervention in the prevention of leprosy among household contacts (HHCs) of leprosy patients. METHODS: A retrospective cohort study using data of 5.061 HHCs for a period of 16 years (follow-up of 7 years per leprosy HHCs), evaluating the occurrence of disease as the main outcome and the presence or absence of BCG scars verified at the first evaluation. Statistical analyzes were performed using the relative risk, hazard ratio and survival curves by Kaplan-Meier test. RESULTS: A total of 92 contacts sickened, of which 41.3% (38/92) in the first year and 58.7% (54/92) in the course of the other years of follow-up. Of those who became sick, 62% (57/92) developed borderline tuberculoid (BT). The additional protective effect occurred for those who had 2 BCG scars at the first follow-up assessment (Relative Risk: 0.41; p = 0.007) when compared to those not previously exposed to the vaccine. The number of BCG scars examined at the first assessment (t0 = time zero) affected the occurrence of the outcome evidenced by the difference in survival curves throughout the follow-up (Log Rank, p = 0.041; Breslow, p = 0.012; Tarone-Ware, p = 0.020). Leprosy HHCs with 0 BCG scar at time zero (t0) have a shorter survival time (average time of 22 months between t0 and outcome) when compared to those with 2 BCG scars (average time of 36 months between t0 and outcome). CONCLUSIONS: Vaccination of healthy individuals without signs and symptoms of leprosy is extremely important because BCG vaccine has an additional protective effect in those cases with 2 BCG scars throughout follow-up. Reducing the risk of leprosy HHCs becoming sick depends on preventive actions such as immunoprophylaxis and index cases treatment.

Number of leprosy reactions during treatment: clinical correlations and laboratory diagnosis.

INTRODUCTION:: The occurrence of leprosy reactions, a common event during treatment, may be mostly related to the action of multidrug therapy on Mycobacterium leprae. The clinical and laboratory monitoring of patients with reactions is important, since collecting data that assists in predicting the risk of reactions may help to prevent disability. METHODS:: This was a sectional study, in order to correlate clinical and laboratory diagnosis with the number of reactions during treatment. Spearman's correlation was used to verify the degree of association between the assessed variables. RESULTS:: This study was conducted with 211 patients with leprosy reactions during treatment of M. leprae. The borderline tuberculoid group was the most prevalent clinical form (74/211; 35.1%) and the type one reaction showed the highest frequency (136/211; 64.5%). It was observed that 73.5% (155/211) of reactions occurred within 3 months of the initiation of multidrug therapy. The diagnostic values, including the bacterial indices (BIs) of dermal smears (r = 0.21, p < 0.05) and skin biopsies (r = 0.20; p < 0.05), showed a positive correlation with the number of reactions during treatment. CONCLUSIONS:: This research showed a positive correlation between bacillary load markers and the number of leprosy reactions. This study provided scientific support to future research aiming to elucidate the influence of antigenic load on the number of leprosy reactions during treatment.

Number of leprosy reactions during treatment: clinical correlations and laboratory diagnosis

Abstract INTRODUCTION: The occurrence of leprosy reactions, a common event during treatment, may be mostly related to the action of multidrug therapy on Mycobacterium leprae. The clinical and laboratory monitoring of patients with reactions is important, since collecting data that assists in predicting the risk of reactions may help to prevent disability. METHODS: This was a sectional study, in order to correlate clinical and laboratory diagnosis with the number of reactions during treatment. Spearman's correlation was used to verify the degree of association between the assessed variables. RESULTS: This study was conducted with 211 patients with leprosy reactions during treatment of M. leprae. The borderline tuberculoid group was the most prevalent clinical form (74/211; 35.1%) and the type one reaction showed the highest frequency (136/211; 64.5%). It was observed that 73.5% (155/211) of reactions occurred within 3 months of the initiation of multidrug therapy. The diagnostic values, including the bacterial indices (BIs) of dermal smears (r = 0.21, p < 0.05) and skin biopsies (r = 0.20; p < 0.05), showed a positive correlation with the number of reactions during treatment. CONCLUSIONS: This research showed a positive correlation between bacillary load markers and the number of leprosy reactions. This study provided scientific support to future research aiming to elucidate the influence of antigenic load on the number of leprosy reactions during treatment.