Epidemiology of visceral leishmaniasis through spatial analysis, in Belo Horizonte municipality, state of Minas Gerais, Brazil

Abstract

The geographic information system approach has permitted integration between demographic, socio-economic and environmental data, providing In the 1990s, an increasing capacity of data analysis and ease of information accessibility through cheap and simple computational systems was remarkable. Such technology represents a breakthrough in data bank organization, mainly regarding health.Geoprocessing is a broad term that is applied to several technologies of manipulation and processing of geographical data through computational programs. System of geographical information (SGI) is one of the geoprocessing techniques, the most widely used, once it gathers organized data at the stages of data capture by remote sensing, GPS or organization of digital cartographic basis, and organizes systems, which are able to obtain new information and improve knowledge. SGI comprises computational systems used for understanding facts and phenomena that occur in the geographical space. Its capacity of gathering data sets of conventional spatial expression, structuring and integrating them adequately, makes it an essential tool for manipulating geographical information (Pina 1994).Applications of SGI in the field of health have been reported in studies on epidemiological surveys, health service assessment, urbanization, and environment. Moreover, evaluation of endemic diseases from the perspective of several elements involved in the transmission cycle, such as historical, environmental, and social determinants of disease foci, became easier with Geoprocessing techniques (Sabroza et al. 1992, Albuquerque 1993, Thomson & Connor 2000.Geoprocessing technology has enabled scientists to map vectors and analyze environmental factors that affect spatial and temporal distribution of insects. Such techniques have been used to monitor diseases such as malaria, trypanosomiasis, and leishmaniases (Elnaiem et al. 1998, Thomson & Connor 2000.American cutaneous leishmaniasis (ACL) and visceral leishmaniasis (VL) have been studied through geoprocessing techniques by several investigators: Cross et al. (1996), by gathering data from 136 scientific papers, have generated a distribution model of Phlebotomus papatasi in Southeast Asia throughout the year. By using satellite images and field-collected data in Sudan, Elnaiem et al. (1998Elnaiem et al. ( , 2003 and Thomson et al. (1999) observed that several ecological factors are crucial for the presence of Phlebotomus orientalis, the vector of VL in that country. Kawa and Sabroza (2002) and Werneck and Maguire (2002) have analyzed historical and spatial determinants, in the city of Rio de Janeiro, Brazil, and Teresina, state of Piauí, Brazil, respectively, for implementation, maintenance, and spread of ACL and their correlation with urban organization and occupation in the periphery of those cities. Hay et al. (1997), Connor et al. (1998), andKing et al. (2004) Therefore, data collection through geoprocessing techniques has contributed to monitor and specially to identify effective and priority contro...

Distribuição temporal e espacial da leishmaniose visceral em humanos e cães em Belo Horizonte-MG, 1993 a 2007

“…Este achado foi confirmado pelo modelo de dessazonalização de séries temporais. Estudos demonstram que a maior densidade de flebotomíneos coincide com o período de chuvas, de outubro a março, mas o vetor da LV é encontrado durante todo o ano (Monteiro et al, 2005;Margonari et al, 2006), mantendo o ciclo de transmissão.…”

“…Pelo Box-plot, observou-se que os anos diferem em patamar e não obedecem a um perfil O município enfrenta dificuldades no desenvolvimento das ações de controle, não só por problemas técnico-operacionais do próprio serviço, mas também pela crescente resistência dos proprietários em permitir o acesso dos agentes de saúde às suas residências para controle químico e coleta de sangue animal, pela recusa para entrega do cão positivo para eutanásia, e, ainda, pelo crescente número de cães sendo tratados por médicos veterinários, apesar da proibição pelo MS. A maioria dos cães não apresenta sinais clínicos da doença (Marzochi et al, 1985), mas pode participar como fonte de infecção em seu ciclo de transmissão. Ações educativas para melhorar a abordagem da população quanto ao conhecimento e às formas de prevenção da LV são de fundamental importância para o êxito do Programa de Controle da doença (Magalhães et al, 2009).…”

“…A grande capacidade de adaptação do vetor Lutzomyia longipalpis a ambientes urbanos, tanto no intra como no peridomicílio, e a diferentes temperaturas tem influenciado a dinâmica de transmissão da LV, caracterizando áreas endêmicas pela presença elevada do vetor e pelo grande número de casos caninos da doença (França-Silva et al, 2005;Margonari et al, 2006). A presença de outros animais no imóvel pode representar risco diferenciado para o homem (Borges et al, 2009), e estudos vêm sendo feitos com outros possíveis reservatórios e vetores incriminados na transmissão da doença Paz et al, 2010).…”

How effective is dog culling in controlling zoonotic visceral leishmaniasis? a critical evaluation of the science, politics and ethics behind this public health policy

“…However, the evidence suggests that infections in humans and dogs are interdependent, although transmission between dogs may be independent of the presence of sand flies and not associated with human infection 49 . As a general rule, where transmission of L. infantum among humans occurs, it also occurs among dogs 19,23,50 . In one study, the highest prevalence of infection among dogs was not associated with the highest incidence among humans 51 , but in two other studies in Brazil and in a third in Iran, this association was shown [52][53][54] .…”

Phlebotomine sand flies (Diptera: Psychodidae) of the state of Minas Gerais, Brazil

“…intermedia has been recorded in 74 or so municipalities of Minas Gerais. Nyssomyia whitmani is also widely spread in this state; it is known to occur in at least 76 municipalities (Hermeto et al 1998, Margonari et al 2006. An average of 1,793 cases of cutaneous leishmaniasis has been notified in Minas Gerais (Ministério da Saúde 2007b).…”