Infecção por Mycobacterium leprae em menores de 15 anos contatos de casos de Hanseníase

Abstract

leprosy in people under 15 years of age indicates an early exposure to the causative agent of the disease. It is a high-potential disabling disorder that has been considered hyperendemic in the state of Mato Grosso. Contacts of patients diagnosed with

leprosy constitute a high-risk population for infection and disease. Anti-NDO-LID and anti- PGL-I serological tests are ancillary tools for detecting individuals with the infection and at a

higher risk of developing the disease. Objective: to analyze the Mycobacterium leprae infection in people under 15 years of age, contacts of leprosy cases, through anti-NID-LID and anti-PGL-I serological tests, in the city of Cuiabá-MT, from 2014 to 2016. Method: this is a cross-sectional study with 250 people under 15 years of age, where 50 were household contacts, 160 were neighborhood contacts and 40 were case-contacts. The information was obtained through notification/investigation records of the disorder, the Information System for Notifiable Diseases in Mato Grosso, interviews by means of a standardized instrument and collection of blood samples, from February to July 2016. In order to analyze data, we

employed the following tests: Prevalence Ratio, Kolmogorov-Smirnov, Kruskal-Wallis one- way ANOVA, Spearman correlation coefficient and Poisson and Quantile regressions.

Results: among the 250 individuals, 127 (50.8%) were male and 123 (49.2%) were female, with a mean age of 8.3 years. The proportion of anti-NDO-LID positivity in neighborhood contacts was 6.9%; in household contacts, it was 4%; and in contact-cases, it corresponded to 7.5%. The general prevalence of infection in the household and neighborhood contacts was 6.2% with anti-NDO-LID and 2.8% with anti-PGL-I. The western region of the city of Cuiabá showed a higher proportion of seropositivity in the household and neighborhood contacts, while the rural region showed a higher rate of detection of leprosy cases in the child population from 2014 to 2015. We detected a percentage of 1.9% of new cases among the 210 household and neighborhood contacts. As for the factors associated with the seropositivity of the anti-NDO-LID test in neighborhood contacts, we found the variables “race/color” and “number of people in the residence”. We found a positive correlation between the titration of anti-PGL-I antibodies and the variables “number of people aged less than 15 years in the residence” and “overnight time in the same house of a person with leprosy”. The serological tests used in the study showed a reasonable agreement among themselves. Conclusion: the rapid anti-NDO-LID test was more suitable for detecting infection in the investigated population, when compared to the anti-PGL-I. We found a higher percentage of contacts infected in the western region. The accomplishment of a screening with employment of clinical evaluation and serological tests has proved to be a useful strategy to control leprosy. The factors associated with the positive result of the rapid test and the variables correlated with the titration of anti-PGL-I antibodies are linked to sociodemographic and co-housing aspects.