ORIGINAL ARTICLE http://dx.doi.org/10.1590/S1678-9946201860041 Identification of Biomphalaria sp. and other freshwater snails in the large-scale water transposition project in the Northeast of Brazil Fernando Schemelzer de Moraes Bezerra1,2,4, Marta Cristhiany Cunha Pinheiro3, José Damião da Silva Filho4, Issis Maria Nogueira de Castro1, Roberta Lima Caldeira5, Mariana Silva Sousa2, Albeniza Barbosa Cavalcante6, Alberto Novaes Ramos Júnior3 ABSTRACT The wide eco-bio-social intervention generated by the SaoFrancisco River Integration 1Universidade Federal do Ceará, Faculdade de Medicina, Programa de Pós-Graduação Project (PISF) may contribute to the dispersion or introduction of schistosomiasis intermediate em Patologia, Fortaleza, Ceará, Brazil hosts in areas without prior recording. The objective was to characterize the limnic malacofauna and its distribution along watersheds involved in the PISF. A cross-sectional 2Universidade Federal do Ceará, Faculdade study based on the collection of mollusks from 33 water bodies, from Aurora, Brejo Santo, de Medicina, Programa de Pós-Graduação em Ciências Médicas, Fortaleza, Ceará, Jaguaretama, Jaguaribara, Jati e Mauriti municipalities in the Ceara (CE) State was developed. Brazil The conchological characteristics were used to identify snails at the genus level. The snails of the genus Biomphalaria were analyzed for the presence of Schistosoma mansoni cercariae 3Universidade Federal do Ceará, Faculdade and the molecular identification (only mollusks from Brejo Santo-CE) for differentiation de Medicina, Programa de Pós-Graduação em Saúde Pública, Fortaleza, Ceará, Brazil between species. The following species were found: Biomphalaria sp.; Drepanotrema sp.; Melanoides sp.; Physa sp.; and Pomacea sp. Pomacea sp. (75.8%) and Biomphalaria 4Universidade Federal do Ceará, sp. (72.7%) were the most prevalent species. All municipalities showed Biomphalaria sp. Departamento de Análises Clínicas e Biomphalaria straminea (Porcos Stream) and Biomphalaria kuhniana was identified in the Toxicológicas, Laboratório de Pesquisa em Parasitologia e Biologia de Moluscos, Boi 1 and Cipo reservoirs (Brejo Santo). The evaluated municipalities under the influence Fortaleza, Ceará, Brazil of the PISF present areas with potential for schistosomiasis transmission. It is necessary to intensify control actions and health surveillance in these areas. 5Fundação Oswaldo Cruz-Fiocruz, Instituto René Rachou, Grupo de Pesquisa em KEYWORDS: Mollusca. Biomphalaria. Molecular biology. Schistosomiasis mansoni. Helmintologia e Malacologia Médica, Belo Horizonte, Minas Gerais, Brazil Epidemiology. Water resources. 6Governo do Estado do Ceará, Secretaria dos Recursos Hídricos, Fortaleza, Ceará, Brazil INTRODUCTION Correspondence to: Fernando Schemelzer de Moraes Bezerra Schistosomiasis mansoni is a chronic disease caused by Schistosoma mansoni Universidade Federal do Ceará (UFC), (Sambon, 1907), whose intermediate hosts are the species Biomphalaria glabrata Departamento de Análises Clínicas e Toxicológicas, Laboratório de Pesquisa em (Say, 1818), Biomphalaria straminea (Dunker, 1848) and Biomphalaria tenagophila 1 Parasitologia e Biologia de Moluscos, Rua (Orbigny, 1835) . A recent parasitological survey conducted in Brazil among Capitão Francisco Pedro, 1210, Rodolfo schoolchildren, reported a positive rate of 0.99% for S. mansoni2. The average Teófilo, CEP 60430-370, Fortaleza, CE, incidence rate of schistosomiasis in Brazil from 2001 to 2009, estimated at 22.63 Brazil cases per 100.000 inhabitants, was largely associated with transmission of S. Tel: +55 85 33668651 mansoni in Northeast and Midwest regions and in Northern Minas Gerais State. It E-mail: [email protected] should be noted that the Northeast region is characterized by a sustained pattern of endemicity for schistosomiasis3. Received: 16 April 2018 A determinant factor for the increasing dispersion of intermediate hosts and, Accepted: 6 July 2018 consequently, of schistosomiasis, is the implementation of projects that involve Rev Inst Med Trop São Paulo. 2018;60:e41 This is an open-access article distributed under the Page 1 of 10 terms of the Creative Commons Attribution License. Bezerra et al. water resources in areas of greater social vulnerability4,5. An In addition to the morbidity burden, schistosomiasis is important example of this is the water transposition project a neglected cause of death in Brazil. A population-based of the Sao Francisco River, whose objective is to guarantee study from 2000 to 2011 assessed all deaths in which water security in the Northeast of the country6. schistosomiasis was mentioned as the underlying cause The project has been carried out by the Ministry of of death or associated with it (multiple causes of death), National Integration (MI), officially known as the Sao indicating an annual average age-adjusted mortality rate of Francisco River Integration Project (PISF). The construction 0.49 deaths/ 100,000 inhabitants and proportional mortality began in 2007 and is divided into two axes (North and rate of 0.070%. The areas of greatest risk and impact of East) and comprises 477 km of channels, 27 reservoirs, 13 mortality are also located in the Northeastern region of the aqueducts, nine pumping stations, nine 230 kW substations, country, mainly in the states of Alagoas, Pernambuco and 270 km of high-voltage transmission lines and four tunnels, Sergipe12,13. including the largest tunnel for water transportation in Latin It is essential to know and monitor the spatialization America - Cuncas I, which is 15 km long. This project and population dynamics of snails, both at the level of aims to benefit 12 million people in 390 municipalities in diversity and density, in these areas affected by the PISF the Northeastern States, the most affected by the drought in the Ceara State, aiming to prevent or minimize possible periods: Pernambuco, Ceara, Paraiba and Rio Grande impacts on the distribution patterns of intermediate do Norte7. However, conflicts in affected families have hosts and, consequently, on the occurrence of cases of already been identified in all States, mainly in Ceara and schistosomiasis. Pernambuco. In fact, the Sao Francisco water transposition This study sought to identify the limnic malacofauna project exacerbates environmental conflicts involving and its distribution along the main hydrographic basins vulnerable populations living in the affected territory, which involved in the Sao Francisco River Integration Project in claim access to and use of the water8. Ceara, as well as to investigate the presence of S. mansoni These areas show intense migratory movements, larvae in the snails of the Biomphalaria genus. generated mainly by political-economic models that do not prioritize the poorest populations that migrate in MATERIAL AND METHODS search of better living conditions. This important factor, associated with the wide distribution of schistosomiasis This work was a descriptive epidemiological study of the intermediate hosts and the precarious sanitation conditions limnic malacofauna, conducted in the Ceara State, between in most municipalities, leads to the emergence of new February 2015 and September 2016, in the municipalities schistosomiasis foci9,10. of Aurora, Brejo Santo, Jaguaretama, Jaguaribara, Jati In addition, these projects can contribute to the and Mauriti. These municipalities are located in an area dissemination of waterborne diseases in areas previously defined by the Environmental Impact Report as directly unaffected by the presence of migrant construction workers influenced by PISF, and will undergo direct environmental and their families. Data from the Health Secretariat of transformations resulting from the enterprise. In the Ceara the Government of the Ceara State indicate a situation State, this area includes 21 municipalities6. of concern, with the identification of positive test results The selection of municipalities was based on the for schistosomiasis among workers at PISF construction following criteria: a registry of schistosomiasis cases based sites in the Penaforte municipality with 1.21% (3/247) of on data from the Notifiable Disease Information System positivity, Mauriti with 5.5 % (23/416) and Brejo Santo (SINAN) and/ or the Schistosomiasis Control Program with 9.1% (45/432)11. Information System (SISPCE); being located in watersheds It is noteworthy that of the 184 municipalities in with eco-epidemiological characteristics indicative the Ceara State, 71 (38.5%) are endemic areas, and the of transmission or potential risk for the occurrence of Schistosomiasis Control Program has developed systematic schistosomiasis outbreaks and having a history of the surveillance and control actions since 1977. However, in presence of intermediate hosts positive for S. mansoni. the period from 2010 to 2015, only 22.5% (16/71) of these A mapping of the water collections of epidemiological municipalities carried out malacological research and seven importance was carried out in which 33 collection points identified the presence of B. straminea snails carrying of limnic malacofauna specimens were selected within S. mansoni cercariae. The municipalities of Brejo Santo and the area directly affected by the PISF in the six study Aurora, areas of direct influence by the Sao Francisco River, municipalities (Table 1). These water collections were are among the ones that demonstrated active transmission classified according to ecological characteristics and they of schistosomiasis11. were compared regarding