One Health for fascioliasis control in human endemic areas

One-health approach on the future application of snails: a focus on snail-transmitted parasitic diseases

Snails are fascinating molluscs with unique morphological and physiological adaptive features to cope with various environments. They have traditionally been utilized as food and feed sources in many regions of the world. The future exploitation of alternative nutrient sources, like snails, is likely to increase further. Snails, however, also serve as an intermediate host for several zoonotic parasites. A category of parasitic infections, known as snail-transmitted parasitic diseases (STPDs), is harmful to humans and animals and is mainly driven by various trematodes, cestodes, and nematodes. The environment plays a crucial role in transmitting these parasites, as suitable habitats and conditions can facilitate their growth and proliferation in snails. In light of diverse environmental settings and biologically categorized snail species, this review evaluates the dynamics of significant STPDs of zoological importance. Additionally, possible diagnostic approaches for the prevention of STPDs are highlighted. One-health measures must be considered when employing snails as an alternative food or feed source to ensure the safety of snail-based products and prevent any adverse effects on humans, animals, and the environment.

Wide variation of heterozygotic genotypes of recent fasciolid hybrids from livestock in Bangladesh assessed by rDNA internal transcribed spacer region sequencing and cloning

Fascioliasis causes high economic losses in livestock and underlies public health problems in rural areas, mainly of low-income countries. The increasing animal infection rates in Bangladesh were assessed, by focusing on host species, different parts of the country, and rDNA sequences. Fasciolid flukes were collected from buffaloes, cattle, goats and sheep from many localities to assess prevalences and intensities of infection. The nuclear rDNA internal transcribed spacer (ITS) region including ITS-1 and ITS-2 spacers was analyzed by direct sequencing and cloning, given the detection of intermediate phenotypic forms in Bangladesh. The 35.4% prevalence in goats and 55.5% in buffaloes are the highest recorded in these animals in Bangladesh. In cattle (29.3%) and sheep (26.8%) prevalences are also high for these species. These prevalences are very high when compared to lowlands at similar latitudes in neighboring India. The high prevalences and intensities appear in western Bangladesh where cross-border importation of animals from India occur. The combined haplotype CH3A of Fasciola gigantica widely found in all livestock species throughout Bangladesh fits its historical connections with the western Grand Trunk Road and the eastern Tea-Horse Road. The "pure" F. hepatica sequences only in clones from specimens showing heterozygotic positions indicate recent hybridization events with local "pure" F. gigantica, since concerted evolution did not yet have sufficient time to homogenize the rDNA operon. The detection of up to six different sequences coexisting in the cloned specimens evidences crossbreeding between hybrid parents, indicating repeated, superimposed and rapidly evolving hybridization events. The high proportion of hybrids highlights an increasing animal infection trend and human infection risk, and the need for control measures, mainly concerning goats in household farming management. ITS-1 and ITS-2 markers prove to be useful for detecting recent hybrid fasciolids. The introduction of a Fasciola species with imported livestock into a highly prevalent area of the other Fasciola species may lead to a high nucleotide variation in the species-differing positions in the extremely conserved fasciolid spacers. Results suggest that, in ancient times, frequent crossbreeding inside the same Fasciola species gave rise to the very peculiar characteristics of the present-day nuclear genome of both fasciolids.

Fasciola Infection Unexpectedly Found During Cholecystectomy: Review on How to Avoid Increasing Surgery Interventions in Non-human Endemic Areas

PURPOSE

Fascioliasis is caused by Fasciola hepatica of almost worldwide distribution and F. gigantica in wide regions of Asia and Africa. Their adult stage develops in the biliary canals and gallbladder. Infection follows an initial, 3-4 month long invasive, migratory or acute phase, and a several year-long biliary, chronic or obstructive phase.

METHODS

The unexpected finding of a fasciolid inside the gallbladder during a cholecystectomy for obstructive lithiasis suspicion in a patient is reported from an area of Iran where human infection had been never reported before and studies on fascioliasis in livestock are absent.

RESULTS

The fluke obtained was phenotypically classified as F. hepatica by morphometry and genotypically as F. gigantica by mtDNA cox1 fragment sequencing, although with F. hepatica scattered mutations in species-differing nucleotide positions. The clinical, radiological, and biological signs observed at the acute and chronic phases often lead to some misdiagnosis. Serological methods may be useful in cases of negative coprology. Diagnostic techniques with insufficient resolution leading to unnecessary invasive interventions are analyzed. The way to avoid unnecessary surgery is described, including analyses to be made, diagnostic tools to be used, and aspects to be considered.

CONCLUSION

Reaching a correct diagnosis in the confusing presentations avoids procedure delays and unnecessary surgery. A correct drug treatment may be sufficient. Except in extreme pathological presentations, lesions decrease in number and size and finally disappear or calcify after a successful treatment. Finally, the need to increase awareness of physicians about fascioliasis is highlighted, mainly in non-human endemic areas.