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Invasive species constitute one of the most serious threats to biodiversity and ecosystems, and they potentially cause economic problems and impact human health. The globally invasive New Guinea flatworm, Platydemus manokwari (Platyhelminthes: Geoplanidae), has been identified as a threat to terrestrial biodiversity, particularly soil-dwelling native species (e.g. molluscs, annelids and other land planarians), and is listed among 100 of the world's worst invasive alien species. We report here, for the first time, P. manokwari occurrences in many locations throughout Thailand, using voluntary digital public participation from the social network portals associated with the Thailand Biodiversity Conservation Group and collections of living flatworm specimens. Mitochondrial cytochrome c oxidase subunit I (COI) sequences confirmed that all collected flatworms were P. manokwari and placed them in the "world haplotype" clade alongside other previously reported specimens from France, Florida (USA), Puerto Rico, Singapore, French Polynesia, New Caledonia, and the Solomon Islands. In addition, infective stage larvae (L3) of the nematode Angiostrongylus malaysiensis were found in the flatworm specimens, with a 12.4% infection rate (15/121 specimens examined). Platydemus manokwari occurrence in Thailand and its capacity to carry L3 of Angiostrongylus should be of concern to biodiversity conservation and human health practitioners, because this invasive flatworm species may be involved in the life cycle of angiostrongylid worms in Thailand. [ABSTRACT FROM AUTHOR]

As part of the international joint projects working towards the control of taeniosis/cysticercosis in Asia Pacific, epidemiological studies on Taenia solium cysticercosis have been carried out in high-incidence populations, such as minority groups in Thailand. To assess the epidemiology of cysticercotic infections in pigs in the hill-tribe minority villages (Karen) in Tak province, Thailand, we conducted serological screening and necropsies. The patterns of antibody response to T. solium antigens were then investigated using immunoblot assays. Of the 188 pig serum samples tested for antibody responses to partially purified low-molecular-weight antigens of T. solium cyst fluid, positive responses were detected in 37 samples (19.7%). Based on these results, 16 pigs (10 seropositive and 6 seronegative) were necropsied for investigation of cysticerci and intestinal parasites. All seropositive pigs were coinfected with both T. solium and Taenia hydatigena cysticerci, except one, which was infected with T. hydatigena alone. Three of the six seronegative pigs were confirmed to be infected with T. hydatigena. Pigs infected with T. solium showed much stronger antibody responses than those infected with T. hydatigena. Our results demonstrate the co-occurrence of two swine cysticercoses due to T. solium and T. hydatigena in the studied areas. This study also reveals the importance of direct confirmation of the presence of cysticerci by necropsy after serological screening. In addition to the prevalence of swine cysticercosis in these endemic areas, our findings also reveal potential implications for the development of serological diagnostic assays for swine cysticercosis. [ABSTRACT FROM AUTHOR]

Haplorchis taichui is an intestinal heterophyid fluke that is pathogenic to humans. It is widely distributed in Asia, with a particularly high prevalence in Indochina. Previous work revealed that the lack of gene flow between three distinct populations of Vietnamese H. taichui can be attributed to their geographic isolation with no interconnected river basins. To test the hypothesis that interconnected river basins allow gene flow between otherwise isolated populations of H. taichui, as previously demonstrated for another trematode, Opisthorchis viverrini, we compared the genetic structures of seven populations of H. taichui from various localities in the lower Mekong Basin, in Thailand and Laos, with those in Vietnam, using the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. To determine the gene flow between these H. taichui populations, we calculated their phylogenetic relationships, genetic distances and haplotype diversity. Each population showed very low nucleotide diversity at this locus. However, high levels of genetic differentiation between the populations indicated very little gene flow. A phylogenetic analysis divided the populations into four clusters that correlated with the country of origin. The negligible gene flow between the Thai and Laos populations, despite sharing the Mekong Basin, caused us to reject our hypothesis. Our data suggest that the distribution of H. taichui populations was incidentally associated with national borders. [ABSTRACT FROM PUBLISHER]

Angiostrongylus cantonensis is primarily considered an emerging infectious agent of eosinophilic meningitis or meningoencephalitis with a worldwide distribution. Rodents and snails are important invasive hosts for transmission and expansion of A. cantonensis. The objective of this study was to investigate infection levels of A. cantonensis in snails, the most important natural intermediate host. Our study location was Mueang Kamphaeng Phet district, Kamphaeng Phet Province, and was undertaken between October and December 2012. A total of 2228 freshwater and terrestrial snails were collected, comprising 1119 Filopaludina spp., 409 Pomacea caniculata, 275 Achatina fulica and 425 Cryptozona siamensis. Angiostrongylus larvae were isolated by artificial digestion methods following Baermann's techniques. A low prevalence and intensity of A. cantonensis were observed in A. fulica, while higher numbers were found in C. siamensis. None of the Filopaludina spp. and Pomacea caniculata were infected with A. cantonensis. Molecular characterization was performed by analysing the 264 bp of cytochrome c oxidase subunit I (COI). Three COI sequences of Angiostrongylus were identical to A. cantonensis with 91–99% identity. Cryptozona siamensis has not previously been recorded as an intermediate host for A. cantonensis in Thailand. The infection of A. cantonensis identified in the natural intermediate hosts is new and important information to assist in the prevention and control of human angiostrongyliasis. [ABSTRACT FROM AUTHOR]

The diagnostic values of immunoglobulin G subclass antibodies from patients with gnathostomiasis were assessed by immunoblot technique. Antigen was prepared from crude extracts of Gnathostoma spinigerum advanced third-stage larvae obtained from naturally infected eels. The sera were obtained from 14 parasite-confirmed gnathostomiasis cases, 63 patients with other helminthic infections and 13 healthy controls. Nine prominent IgG4 reactive bands appeared with molecular weights of 94, 51, 47, 43, 38, 24, 21, 20 and 15 kDa. The diagnostic sensitivity of each of the nine reactive bands ranged from 100% to 64.3% in 14 parasite-confirmed gnathostomiasis cases. All (100%) confirmed cases recognized the 21 kDa antigenic band, but not other helminthic infections or parasite-free control. Recognition of 21 kDa antigen in G. spinigerum advanced third-stage larvae crude extracts is the most specific diagnostic marker for human gnathostomiasis, with 100% sensitivity and specificity. The 20 and 24 kDa protein bands were additional diagnostic bands for confirming diagnosis of infection where the 21 kDa band was faint. No specific binding of IgG1, IgG2, or IgG3 antibodies was observed in any sera from confirmed gnathostomiasis cases. [ABSTRACT FROM AUTHOR]

Gnathostomiasis has rarely been described outside endemic countries. We report on a series of 5 patients (4 females, 1 male, mean age 42.2 years) who returned to France from South-East Asia and presented with cutaneous gnathostomiasis. The cutaneous lesions appeared within a mean period of 62 d (range 10–150 d) after return. They consisted of creeping eruptions in 3 patients (in addition one also had papules, one had nodules and hepatitis, and one had hepatitis; all 3 had profound asthenia) and recurring migratory swellings in 2 patients. The mean eosinophil count was 1546/mm3 (range 398–3245/mm3). Diagnosis was based on positive serological tests in 3 patients and seroconversion in 2 patients, and was confirmed by identification of Gnathostoma hispidum in a biopsy specimen from one of the seropositive patients. Albandazole (1–4 courses) was given as treatment. Recurrences may occur up to 24 months after apparent cure without reinfection. Gnathostomiasis should be considered when patients return from tropical countries and present with migratory swellings or creeping eruption that does not respond to the usual treatment for cutaneous larva migrans. Serological tests may be negative initially and thus need to be repeated to check for seroconversion. Treatment may require multiple courses of albendazole and a prolonged period of follow-up is necessary before cure can be confirmed. [Copyright &y& Elsevier]