Human fascioliasis endemic areas in Argentina: multigene characterisation of the lymnaeid vectors and climatic-environmental assessment of the transmission pattern

Abstract

BackgroundIn South America, fascioliasis stands out due to the human endemic areas in many countries. In Argentina, human endemic areas have recently been detected. Lymnaeid vectors were studied in two human endemic localities of Catamarca province: Locality A beside Taton and Rio Grande villages; Locality B close to Recreo town.MethodsLymnaeids were characterised by the complete sequences of rDNA ITS-2 and ITS-1 and fragments of the mtDNA 16S and cox1. Shell morphometry was studied with the aid of a computer image analysis system. Climate analyses were made by nearest neighbour interpolation from FAO data. Koeppen & Budyko climate classifications were used. De Martonne aridity index and Gorczynski continentality index were obtained. Lymnaeid distribution was assessed in environmental studies.ResultsDNA sequences demonstrated the presence of Lymnaea neotropica and L. viator in Locality A and of L. neotropica in Locality B. Two and four new haplotypes were found in L. neotropica and L. viator, respectively. For interspecific differentiation, ITS-1 and 16S showed the highest and lowest resolution, respectively. For intraspecific analyses, cox1 was the best marker and ITS-1 the worst. Shell intraspecific variability overlapped in both species, except maximum length which was greater in L. viator. The desertic-arid conditions surrounding Locality A, the semiaridity-aridity surrounding Locality B, and the very low yearly precipitation in both localities, are very different from the typical fascioliasis transmission foci. Lymnaeids are confined to lateral river side floodings and small man-made irrigation systems. Water availability only depends on the rivers flowing from neighbouring mountains. All disease transmission factors are concentrated in small areas where humans and animals go for water supply, vegetable cultures and livestock farming.ConclusionsThe unusually high number of DNA haplotypes and the extreme climate unsuitable for F. hepatica and lymnaeid development, demonstrate that the transmission foci are isolated. Seasonal transmission may depend on the timely overlap of appropriate temperature and river water availability. Lymnaeids and F. hepatica have probably reached these localities by livestock introduction. DNA differences regarding other populations of L. neotropica and L. viator in Argentina suggest an introduction independent from the spreading movements which allowed these two lymnaeids to expand throughout the country.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1589-z) contains supplementary material, which is available to authorized users.

Genetic uniformity, geographical spread and anthropogenic habitat modifications of lymnaeid vectors found in a One Health initiative in the highest human fascioliasis hyperendemic of the Bolivian Altiplano

“…Three species have been reported from the hyperendemic area of Cajamarca, Peru, i.e. G. truncatula, L. schirazensis and L. neotropica [80], four species, L. cousini, L. neotropica, L. cubensis and P. columella have been reported in Ecuador [29], G. truncatula, L. cubensis, L. schirazensis and P. columella have been recorded to coexist in Venezuela [28], L. neotropica and L. viator in Argentina [27], and G. truncatula and L. viator in Chile [24].…”

“…Two Fasciola species, F. hepatica and F. gigantica, cause human fascioliasis, but only F. hepatica is present in the Americas [18]. Many human fascioliasis endemic areas have been described in the Americas [8,18], from Mexico [19] to several countries in South America, such as Peru including Altiplano [12] and valleys [13,[20][21][22], Chile [23,24] and Argentina [25][26][27]. Other countries including Venezuela [28], Colombia and Ecuador [29] have also reported human infections.…”

Insights on the Presence and Economic Impact of Water Related Trematodes in Natural Environments from Patagonia, Southern Argentina

“…Upon arrival to the laboratory, snails were anesthetized with menthol [5] and they were identified at genus level by morphometric features of their shell. Snail shells were measured according to traditional malacological methods [4,6]. Moreover, the soft parts of the snails were dissected under a stereomicroscope and the anatomy of reproductive system analysed.…”

“…In Argentina this helminthiasis is caused by Fasciola hepatica (Trematoda: Digenea), with an indirect life cycle involving domestic and wild herbivorous mammals and humans as definitive hosts, and freshwater gastropods as vector [3]. In the Southern Patagonian region the status of trematodiasis in natural environments was studied in a limited number of epidemiological surveys [4]. With the aim of increasing knowledge about the parasitological situation of natural environments in the Andean region of Southern Patagonia (Argentina), the principal aim of this study was to confirm the presence of trematode species of medical and/or veterinary importance as well as to give insights into the prevalence of fascioliasis in livestock and its derived economic impact.…”

The first record of Galba cubensis (L. Pfeiffer, 1839) (Mollusca: Gastropoda: Lymnaeidae) from open fields of Europe

“…In 2007, G. neo tropica was described by barGueS et al (2007). It was found in Peru, Argentina, Venezuela, and Uruguay (PuJadaS et al 2015, barGueS et al 2017 and is also an intermediate host for Fasciola hepatica (PuJadaS et al 2015, barGueS et al 2016, 2017. There is still some uncertainty about the possible synonymy of G. cubensis, G. viator andG.…”