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Hidden danger: Unexpected scenario in the vector-parasite dynamics of leishmaniases in the Brazil side of triple border (Argentina, Brazil and Paraguay).

ABSTRACT: Every year about 3 million tourists from around the world visit Brazil, Argentina and Paraguay´s triple border region where the Iguaçu Falls are located. Unfortunately, in recent years an increasing number of autochthonous canine and human visceral leishmaniasis (VL) cases have been reported. The parasite is Leishmania (Leishmania) infantum and it is transmitted by sand flies (Phlebotominae). To assess the risk factors favorable for the establishment and spread of potential vectors the Centers for Disease Control and Prevention light trap (CDC-light trap) collections were made in the Foz do Iguaçu (FI) and Santa Terezinha de Itaipu (STI) townships and along two transects between them. Our study determined the Phlebotominae fauna, the factors that affect the presence and abundance of Lutzomyia longipalpis and Nyssomyia whitmani, the presence of L. infantum in different sand fly species and which Leishmania species are present in this region. Lutzomyia longipalpis was the prevalent species and its distribution was related to the abundance of dogs. Leishmania infantum was found in Lu. longipalpis, Ny. whitmani, Ny. neivai and a Lutzomyia sp. All the results are discussed within the Stockholm Paradigm and focus on their importance in the elaboration of public health policies in international border areas. This region has all the properties of stable VL endemic foci that can serve as a source of the disease for neighboring municipalities, states and countries. Most of the urban areas of tropical America are propitious for Lu. longipalpis establishment and have large dog populations. Pan American Health Organization´s initiative in supporting the public health policies in the border areas of this study is crucial and laudable. However, if stakeholders do not act quickly in controlling VL in this region, the scenario will inevitable become worse. Moreover, L. (Viannia) braziliensis found in this study supports the need to develop public health policies to avoid the spread of cutaneous leishmaniasis. The consequences of socioeconomic attributes, boundaries and frontiers on the spread of diseases cannot be neglected. For an efficient control, it is essential that urban planning is articulated with the neighboring cities.

SUBMITTER: Thomaz-Soccol V

PROVIDER: S-EPMC5906028 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Hidden danger: Unexpected scenario in the vector-parasite dynamics of leishmaniases in the Brazil side of triple border (Argentina, Brazil and Paraguay).

Thomaz-Soccol Vanete V Gonçalves André Luiz AL Piechnik Claudio Adriano CA Baggio Rafael Antunes RA Boeger Walter Antônio WA Buchman Themis Leão TL Michaliszyn Mario Sergio MS Rodrigues Dos Santos Demilson D Celestino Adão A Aquino José J Leandro André de Souza AS Paz Otacílio Lopes de Souza da OLSD Limont Marcelo M Bisetto Alceu A Shaw Jeffrey Jon JJ Yadon Zaida Estela ZE Salomon Oscar Daniel OD

PLoS neglected tropical diseases 20180406 4

Every year about 3 million tourists from around the world visit Brazil, Argentina and Paraguay´s triple border region where the Iguaçu Falls are located. Unfortunately, in recent years an increasing number of autochthonous canine and human visceral leishmaniasis (VL) cases have been reported. The parasite is Leishmania (Leishmania) infantum and it is transmitted by sand flies (Phlebotominae). To assess the risk factors favorable for the establishment and spread of potential vectors the Centers f ...[more]

PMID: 29624586

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Project description:A cross-sectional epidemiological study in the extreme-west of the state of Paraná was carried out to access the prevalence, distribution, and risk variables of canine Visceral Leishmaniases (cVL). This study was conducted in three areas, two cities of far west of Parana state: Foz do Iguaçu (FI) and Santa Terezinha de Itaipu (STI), and along two transects between these two municipalities. To sample the entire urban area, the cities (FI and STI) were divided into a grid of squares of 400 m2 (patch). Among the 526 patches, 123 in FI, 40 in the transects and 33 in STI were selected according to the 'worst scenario' criterion. In the transect areas, in each 0.86 km five dogs from houses were surveyed to leishmaniasis. In each patch, blood of five dogs from houses (and from neighborhood when necessary) in the areas that seemed to be the most appropriate for the proliferation of vector were surveyed. The infection of the dogs by cVL were assessed using two serological tests were used (cELISA and TR-DPP®), and, for those seropositive for both methods, the PCR method were used. Moreover, dogs presenting clinical signs or cutaneous lesions were sampled to PCR. The identification of Leishmania species was confirmed using PCR-RFLP followed by DNA sequencing. Micro, meso and macro scale environmental variables were also surveyed and statistically analyzed. The prevalence rate Leishmania infantum was 23.8% in FI, 4.7% in STI and 9.1% in the transects areas. Among the extrinsic variables analysed, the number of vectors and the presence of infected dogs in neighbouring were positively correlated with the occurrence of infected dogs. Dog size was positively correlated with cVL infection, while the quality of the dog's nutrition affected cVL negatively. As for cutaneous leishmaniasis (CL), the first registry of dogs infected with L. braziliensis in the region shows that there is potential for transmission in peri-urban areas, since environmental conditions allow the proliferation of vectors capable of transmitting this species of parasite. cVL is widely spread in FI, with high prevalence. This supports the hypothesis that the parasite has been present in the region for longer than previously believed, despite the fact that the presence of leishmaniais in the region has only been recognized recently. It is important to control the population of dogs infected with L. infantum (parasite and non-antibodies) to prevent the spread of the disease to other dogs and also to people in the region.

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Dataset Information

Hidden danger: Unexpected scenario in the vector-parasite dynamics of leishmaniases in the Brazil side of triple border (Argentina, Brazil and Paraguay).

Publications

Hidden danger: Unexpected scenario in the vector-parasite dynamics of leishmaniases in the Brazil side of triple border (Argentina, Brazil and Paraguay).

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