Loading…

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

AbstractBackgroundImmunoprophylaxis with Bacillus Calmette–Guérin (BCG) vaccine is still the most effective intervention in the prevention of leprosy among household contacts (HHCs) of leprosy patients. MethodsA retrospective cohort study using data of 5.061 HHCs for a period of 16 years (follow-up...

Full description

Saved in:
Bibliographic Details
Published in:Vaccine 2019-10, Vol.37 (43), p.6510-6517
Main Authors: Gomes, Rafaela Resende, Antunes, Douglas Eulálio, dos Santos, Diogo Fernandes, Sabino, Elaine Fávaro Pípi, Oliveira, Dulcinéia Bernardes, Goulart, Isabela Maria Bernardes
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:AbstractBackgroundImmunoprophylaxis with Bacillus Calmette–Guérin (BCG) vaccine is still the most effective intervention in the prevention of leprosy among household contacts (HHCs) of leprosy patients. MethodsA 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. ResultsA 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 (t 0 = 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 (t 0) have a shorter survival time (average time of 22 months between t 0 and outcome) when compared to those with 2 BCG scars (average time of 36 months between t 0 and outcome). ConclusionsVaccination 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 .
ISSN:0264-410X
1873-2518
DOI:10.1016/j.vaccine.2019.08.067