Aspectos epidemiológicos da leishmaniose visceral no Estado da Bahia no período de 2007 a 2017

Abstract

COSTA, L. B. Epidemiology of visceral leishmaniasis in Bahia. 2018.Tese (Doutorado Ciência Animal nos Trópicos) - Escola de Medicina Veterinária e Zootecnia – Universidade Federal da Bahia, 2018. Visceral leishmaniasis (VL) is caused by the protozoan Leishmania infantum. It is a zoonosis that is still poorly studied in terms of its incidence and lethality in children. In Brazil, the State of Bahia, Northeast Region, is one of the most prevalent in the recording of human cases of infection and deaths from VL. The present study analyzed, in the State of Bahia, the spatio temporal distribution of cases and deaths due to VL, from 2007 to 2017, evaluating the possible involvement of socioeconomic and environmental determinants. A case-control study was also carried out, covering the period from 2012 to 2017, in which the sample of children under 10 years of age with VL who progressed to cure or died was evaluated. Socioeconomic and environmental information relating to the respective children's homes, in addition to serological and entomological data associated with the case series, were analyzed. During the period studied, 3.847 new confirmed cases in humans and 227 deaths were recorded. The average incidence of VL was 1.73/100.000 inhabitants, ranging from 2.54 (2014) to 0.86 (2016), with a predominance in urban areas (54.1%), in males (60.7%) and in children under ten years of age (48.2%). Of the variables analyzed regarding the distribution of cases and deaths due to VL, after model adjustments for logistic regression, it was observed that age and the Gini Index (Index that measures inequality in income distribution between municipalities) are significant (p- value=0.000 and p-value=0.000) to explain the occurrence of deaths. The spatial distribution of both cases and deaths predominates in the Central-North region of the State, with a dry to semi-arid climate. The results of the case control study, regarding the children who died, showed a seroprevalence of VL in family members of 1.9% (1/52), in household dogs 26.6% (4/15), and in neighborhood dogs 18.7% (53/282), and the presence of the L. longipalpis vector was identified in 71.4% of these residences. The seroprevalence of VL in family members, dogs in the household and neighborhood of the children who progressed to cure was zero, 15.62% (5/32) and 10.19% (16/157), respectively, with the presence of L. longipalpis identified in 70% of these residences. The interval between the appearance of symptoms and the diagnosis of VL in children who died or was cured was 34.63 and 26.87 days. The average number of times that children who died or were cured were taken to the health service was 6.4 and 4.25, respectively. The study shows that VL remains endemic in Bahia, mainly affecting children, with the occurrence of cases and deaths associated with socioeconomic factors. Furthermore, the results demonstrate that VL foci remain active and the time spent until the start of treatment and the high frequency of visits to the health service point to the urgent need for professional requalification and prevention and control actions for this zoonosis, as well as the modernization of patient care infrastructure and most importantly: accepting the fact that a more equitable income distribution is a fundamental condition for health promotion.