Demographic and spatial study of visceral leishmaniasis in the state of Alagoas, Brazil, during 2007-2018

Abstract INTRODUCTION: Visceral leishmaniasis has a broad worldwide distribution and constitutes a public health problem in the Northeast of Brazil. Located in this region is the state of Alagoas, where the disease is endemic in humans and where there has been a significant increase in the number of positive dogs. The objective of this study was to describe the temporal and spatial distribution of the cases of human VL in the state of Alagoas with the aim of identifying transmission risk areas in the period from 2007 to 2018. METHODS: The data available in the National Disease Notification System (SINAN-NET) were used. The Bayesian incidence rate and the Moran's global index were calculated using the Terra View 4.2.2 program, and the maps were created using QGIS2.18.0. RESULTS: From the 102 municipalities, 68.6% (n= 70) had at least one notified case of VL in the years of study. A total of 489 cases were registered, with an average of 40.7 cases per year and an incidence rate of 1.25/100,000 inhabitants. The highest number of confirmed cases (105) occurred in 2018. Male individuals and children between 1-4 years old were the most affected, and 64% of the cases were in rural areas. Spatial dependence was detected in all the intervals except for the first triennium, and clusters were formed in the west of the state. CONCLUSIONS: Alagoas presented an accentuated geographical expansion of VL, and it is necessary to prioritize areas and increase surveillance actions and epidemiological control.

Spatial analysis of canine leishmaniasis in an area of transmission of the semi-arid region of the State of Paraíba, Brazil / Análise espacial da leishmaniose canina em uma área de transmissão do semiárido paraíbano, Brasil

Abstract Visceral leishmaniasis is a widely distributed zoonosis and canine infection is an important indicator of risk for the occurrence of the disease in humans. The goal of this analysis was to study the spatial clustering of canine leishmaniasis (CL) in the municipality of Santa Luzia, state of Paraíba. For this, 749 samples of canine plasma were tested using three serological tests. The dog was considered positive if it reacted in two serological tests. The location of the residences was performed with a Global Positioning System receiver (GPS Garmin® eTrex 30), and used to perform georeferencing and spatial analysis. The prevalence of CL was 15.49% and it was observed that most cases of the urban area were concentrated in the Frei Damião neighborhood, on the outskirts of the city, where a high-risk cluster for the occurrence of the disease was formed (p = 0.02; RR = 2.48). No statistically significant cluster was observed in rural areas. CL is widely distributed in the municipality of Santa Luzia in a heterogeneous manner and with a tendency to urbanization. The areas identified with high prevalence and highest risk should be prioritized to maximize the efficiency of the Visceral Leishmaniasis Surveillance and Control Program and minimize the chance of new canine and human cases.

Resumo A leishmaniose visceral é uma zoonose amplamente distribuída, e a infecção canina é um importante indicador de risco para a ocorrência da doença em humanos. O objetivo foi estudar o comportamento espacial da leishmaniose canina (LC) no município de Santa Luzia, estado da Paraíba. Para tal, 749 amostras de plasma canino foram testadas por meio de três técnicas sorológicas. O cão seria considerado positivo se apresentasse duas sorologias reagentes. A localização das residências foi realizado pelo receptor de Sistema de Posicionamento Global (GPS Garmin® eTrex 30) e usado para a realização do georreferenciamento e análise espacial. A prevalência da LC foi de 15,49% e observou-se que a maioria dos casos de LC da zona urbana estava concentrada no bairro Frei Damião, localizado na periferia da cidade, onde se formou um cluster de alto risco para ocorrência da doença (p = 0,02; RR = 2,48). Nenhum cluster estatisticamente significativo foi observado na zona rural. A LC está amplamente distribuída no município de Santa Luzia, porém de forma heterogênea e com tendência à urbanização. As áreas identificadas com intensa prevalência e maior risco devem ser priorizadas para maximizar a eficiência do Programa de Vigilância e Controle da Leishmaniose Visceral e minimizar a chance de novos casos caninos e humanos.

Seroprevalence and risk factors associated with canine visceral leishmaniasis in the State of Paraíba, Brazil

Abstract INTRODUCTION: The aim of this study was to determine the seroprevalence and risk factors associated with canine visceral leishmaniasis in Paraíba State. METHODS: Blood samples were collected from 411 dogs in four municipalities of Paraíba State. The seroprevalence was assessed by using ELISA. RESULTS: The seroprevalence ranged from 7.2% to 20%. The risk factors that were associated with the disease were the presence of ticks and contact with other animals. CONCLUSIONS: The seroprevalence of canine visceral leishmaniasis is high in Paraíba, indicating the need for health authorities to resume visceral leishmaniasis control activities. The ruralization of suburban areas in the region tends to homogenize the risk factors between suburban and rural areas.