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Anais Da Academia Brasileira de Ciencias 2024Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of...
Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of biodiversity. However, they may offer risk parasitic infections, such as schistosomiasis and fascioliasis, which are both transmitted by freshwater snails. The present study investigated the occurrence of freshwater gastropods in urban parks of the Brazilian city of Rio de Janeiro, and their possible infection by helminths of medical-veterinary importance. Gastropods were collected from six parks (2021 - 2022) and examined for the presence of larval helminths. In all, 12 gastropod species from different families were collected: Ampullariidae, Assimineidae, Burnupidae, Lymnaeidae, Physidae, Planorbidae, Succineidae, and Thiaridae. The parasitological examination revealed cercaria of three types in five snail species, with the Pleurolophocerca cercariae type in Melanoides tuberculata (the most abundant species), Echinostoma cercariae in Physella acuta and Pomacea maculata, and Virgulate cercariae, in Pomacea sp. and Pomacea maculata. None of the Biomphalaria tenagophila and Pseudosuccinea columella (the most frequent species) specimens were parasitized by Schistosoma mansoni or Fasciola hepatica, respectively. Even so, some parks may represent a considerable potential risk for transmission of both Schistosoma mansoni and Fasciola hepatica, given the presence of these gastropod vectors and the frequent contact of visitors with the waterbodies.
Topics: Animals; Brazil; Fresh Water; Gastropoda; Parks, Recreational; Humans; Snails
PubMed: 38747790
DOI: 10.1590/0001-3765202420230707 -
BMC Veterinary Research May 2024The occurrence of trematodes among ruminants and their snail vectors is a major concern across various agro-ecological regions of Ethiopia. Trematodes pose significant...
The occurrence of trematodes among ruminants and their snail vectors is a major concern across various agro-ecological regions of Ethiopia. Trematodes pose significant threats to animals, causing considerable economic losses and impacting public health. In this study, we have investigated 784 ruminant fecal samples, and 520 abattoir samples, alongside the collection and identification of snail vectors from various agro-ecological regions. Fecal examinations revealed Fasciola, Paramphistomum and Schistosoma species infected 20.5% (95% CI: 17.6, 23.8), 11.7% (95% CI: 9.6, 14.2), and 6.3% (95% CI: 4.1, 9.1) of the animals, respectively. The overall prevalence of trematodes among ruminants was 28.8% (95% CI: 25.7, 32.1%), with 6.0% (95% CI: 4.3, 7.7) showing mixed infections. Fasciola was more prevalent in Asela (26%) compared to Batu (19%) and Hawassa (11.5%), while a higher proportion of animals in Batu were infected with Paramphistomum. Schistosoma eggs were detected only in Batu (12.5%), but not in other areas. Sheep and cattle exhibited higher infection rates with Fasciola, Paramphistoma, and Schistosoma compared to goats. Significant associations were observed between trematode infections and risk factors including agro-ecology, animal species, body condition score, and deworming practices. About 20.8% and 22.7% of the slaughtered animals harbored Fasciola and Paramphistomum flukes, respectively, with a higher prevalence in Asela and Hawassa abattoirs compared to Batu abattoir. Additionally, a total of 278 snails were collected from the study areas and identified as lymnae natalensis, lymnae trancatula, Biomphalaria pffiferi, Biomphlaria sudanica, and Bulinus globosus. In conclusion, the study highlights the widespread occurrence of trematode infections, emphasizing the need for feasible control measures to mitigate their economic and public health impacts.
Topics: Animals; Ethiopia; Trematode Infections; Feces; Prevalence; Snails; Sheep; Sheep Diseases; Goat Diseases; Goats; Cattle Diseases; Cattle; Trematoda; Abattoirs; Fasciola; Paramphistomatidae; Ruminants
PubMed: 38741097
DOI: 10.1186/s12917-024-04049-0 -
Infectious Diseases of Poverty May 2024The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly... (Review)
Review
The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly related families, includes species that act as the intermediate host for one of the three most widespread schistosome species infecting humans, Schistosoma haematobium, S. mansoni and S. japonicum, respectively. An important step in the fight against schistosomiasis in Asia has been taken with the publication of the article "Chromosome-level genome assembly of Oncomelania hupensis: the intermediate snail host of Schistosoma japonicum", which means that genomes for all three major genera, including species across three continents, are now available in the public domain. This includes the first genomes of African snail vectors, namely Biomphalaria sudanica, Bi. pfeifferi and Bulinus truncatus, as well as high-quality chromosome level assemblies for South American Bi. glabrata. Most importantly, the wealth of new genomic and transcriptomic data is helping to establish the specific molecular mechanisms that underly compatibility between snails and their schistosomes, which although diverse and complex, may help to identify potential targets dictating host parasite interactions that can be utilised in future transmission control strategies. This new work on Oncomelania hupensis and indeed studies on other snail vectors, which provide deep insights into the genome, will stimulate research that may well lead to new and much needed control interventions.
Topics: Animals; Genomics; Snails; Disease Vectors; Humans; Schistosomiasis; Host-Parasite Interactions
PubMed: 38711151
DOI: 10.1186/s40249-024-01199-z -
Current Research in Parasitology &... 2024Schistosomiasis is a neglected tropical disease (NTD) caused by infection with parasitic trematodes of the genus that can lead to debilitating morbidity and mortality....
Schistosomiasis is a neglected tropical disease (NTD) caused by infection with parasitic trematodes of the genus that can lead to debilitating morbidity and mortality. The World Health Organization recommend molecular xenomonitoring of spp. freshwater snail intermediate hosts of to identify highly focal intestinal schistosomiasis transmission sites and monitor disease transmission, particularly in low-endemicity areas. A standardised protocol to do this, however, is needed. Here, two previously published primer sets were selected to develop and validate a multiplex molecular xenomonitoring end-point PCR assay capable of detecting infections within individual spp. missed by cercarial shedding. The assay proved highly sensitive and highly specific in detecting and amplifying DNA and also proved highly sensitive in detecting and amplifying non- trematode DNA. The optimised assay was then used to screen spp. collected from a endemic area for infection and successfully detected infections missed by cercarial shedding as well as infections with non- trematodes. The continued development and use of molecular xenomonitoring assays such as this will aid in improving disease control efforts, significantly reducing disease-related morbidities experienced by those in schistosomiasis-endemic areas.
PubMed: 38618156
DOI: 10.1016/j.crpvbd.2024.100174 -
Heliyon Apr 2024Mass drug administration of praziquantel is expected to reduce carriage in treated children in endemic communities. However, the effectiveness of this annual exercise...
Point-of-care circulating cathodic antigen positivity and associated factors in school children one year after mass praziquantel administration in an endemic district in Ghana.
BACKGROUND
Mass drug administration of praziquantel is expected to reduce carriage in treated children in endemic communities. However, the effectiveness of this annual exercise has not been assessed in Ghana. Therefore, this study aimed to detect viable infection using point-of-care circulating cathodic antigen (POC-CCA) positivity as proxy and associated factors in children previously treated with praziquantel in an endemic municipality in Ghana.
MATERIALS AND METHODS
This cross-sectional study was done in the Assin Central municipality in the Central Region of Ghana. School children, less than 16 years of age, treated with 40 mg/kg of praziquantel (treatment period: February-March 2019), provided early morning urine (∼40 mL) and stool (∼4 g) samples. Immediately, POC-CCA (ICT International, South Africa) was done, while ova were detected in formalin fixed samples using microscopy later. Additionally, participant's socio-demographic information and factors associated with infection transmission were collected from each child.
RESULTS
A total of 520 children participated in the study (males-51.9%, majority age range [9-11 years, 34.4%]). Overall, 244 (46.9%) were positive for urinary CCA with no detected by microscopy. POC-CCA positivity was higher in females (48.4%), children with 2-3 siblings (49.3%), children aged 6-8-year range (55.4%) and residents of Brofoyedur (52%). However, age ( = 16.1, p = 0.0003) and town of residence ( = 11.7, p = 0.019) associated with CCA positivity. Further, location of water body ( = 16.4, p = 0.008), frequency of water contact ( = 12.3, p = 0.015) and handling of the intermediate host ( = 5.1, p = 0.024) associated with POC-CCA outcome.
CONCLUSION
About 47% of the school children were positive for CCA, one year after mass praziquantel administration in the Assin Central municipality. Varied factors associated with the post-praziquantel administration POC-CCA positivity. This study should be replicated in other endemic areas to identify groups at risk of parasite persistence or reinfection to inform modification of control and preventive measures.
PubMed: 38596068
DOI: 10.1016/j.heliyon.2024.e28529 -
Frontiers in Immunology 2024
Topics: Animals; Gastropoda; Host-Pathogen Interactions; Genome, Mitochondrial
PubMed: 38585274
DOI: 10.3389/fimmu.2024.1385106 -
Parasites & Vectors Apr 2024ABSTRACT: BACKGROUND: Intestinal schistosomiasis remains a worrying health problem, particularly in western Côte d'Ivoire, despite control efforts. It is therefore...
UNLABELLED
ABSTRACT: BACKGROUND: Intestinal schistosomiasis remains a worrying health problem, particularly in western Côte d'Ivoire, despite control efforts. It is therefore necessary to understand all the factors involved in the development of the disease, including biotic and abiotic factors. The aim of this study was to examine the factors that could support the maintenance of the intermediate host and its vectorial capacity in western Côte d'Ivoire.
METHODS
Data on river physicochemical, microbiological, and climatic parameters, the presence or absence of snails with Schistosoma mansoni, and human infections were collected between January 2020 and February 2021. Spearman rank correlation tests, Mann-Whitney, analysis of variance (ANOVA), and an appropriate model selection procedure were used to analyze the data.
RESULTS
The overall prevalence of infected snails was 56.05%, with infection reaching 100% in some collection sites and localities. Of 26 sites examined, 25 contained thermophilic coliforms and 22 contained Escherichia coli. Biomphalaria pfeifferi was observed in environments with lower land surface temperature (LST) and higher relative air humidity (RAH), and B. pfeifferi infection predominated in more acidic environments. Thermal coliforms and E. coli preferred higher pH levels. Lower maximum LST (LST_Max) and higher RAH and minimum LST (LST_Min) were favorable to E. coli, and lower LST_Max favored coliforms. The presence of B. pfeifferi was positively influenced by water temperature (T °C), LST_Min, RAH, and precipitation (Pp) (P < 0.05) and negatively influenced by pH, total dissolved solids (TDS), electrical conductivity (EC), LST_Max, and mean land surface temperature (LST). The parameters pH, TDS, EC, LST_Min, LST, and Pp had a positive impact on snail infection, while LST_Max had a negative impact on infection. Only pH had a positive effect on coliform and E. coli abundance. Of the 701 people examined for human schistosomiasis, 73.13% were positive for the point-of-care circulating cathodic antigen (POC-CCA) test and 12.01% for the Kato-Katz (KK) test. A positive correlation was established between human infections and the abundance of Biomphalaria (r = 0.879, P = 0.04959).
CONCLUSIONS
The results obtained reflect the environmental conditions that are conducive to the maintenance of S. mansoni infection in this part of the country. To combat this infection as effectively as possible, it will be necessary not only to redouble efforts but also to prioritize control according to the level of endemicity at the village level.
Topics: Animals; Humans; Schistosoma mansoni; Biomphalaria; Cote d'Ivoire; Escherichia coli; Schistosomiasis mansoni
PubMed: 38581062
DOI: 10.1186/s13071-024-06163-2 -
PLoS Neglected Tropical Diseases Apr 2024Schistosomiasis and fasciolosis are snail-borne diseases of great medical and veterinary health importance. The World Health Organization recommends complementing drug...
INTRODUCTION
Schistosomiasis and fasciolosis are snail-borne diseases of great medical and veterinary health importance. The World Health Organization recommends complementing drug treatment with snail control and community involvement for disease elimination, but there is a general lack of snail experts and hence snail distribution data. Therefore, we adopted a citizen science approach and involved citizens in the monitoring of medically and veterinary important snail taxa.
MATERIALS AND METHODS
Snail data was collected weekly by 25 trained citizen scientists (CSs) at 76 sites around southern Lake Albert (Uganda) for 20 months. At each site, snails were searched for 30 minutes, sorted, target snail hosts identified to genus level, counted and data submitted through a smartphone application. The quality of this data was assessed by comparing it to monthly data collected by an 'expert' malacologist using the same sampling protocol. Generalised binomial logistic and linear mixed-effects models were used to analyse the variables for agreement between the CSs and expert.
FINDINGS
The binary agreement in presence/absence of Biomphalaria, Bulinus and Radix snails reported by the expert and CSs ranged between 70% and 86% (900 reports) with an average of 17% false negatives (sites wrongly defined as snail-free). The agreement for Biomphalaria and Radix increased with snail abundance, and false negatives decreased when the number of snails collected by citizens was aggregated per month. Site type significantly predicted binary agreement, which was lowest at lake sites (55%) and highest at spring sites (99%) with variations across genera. Similar temporal trends in snail abundance were recorded despite the expert reporting higher abundance. However, the relative abundance was consistent across site types. The match between the sites with highest Biomphalaria spp. abundance identified by CSs and expert was consistently high (~84.1%) and increased over time.
CONCLUSIONS AND RECOMMENDATIONS
Our results demonstrate the potential of citizen science to map putative schistosomiasis transmission sites. We therefore argue that this inclusive, powerful and cost-effective approach can be more sustainable than top-down monitoring and intervention campaigns.
Topics: Animals; Humans; Schistosomiasis; Biomphalaria; Bulinus; Seasons; Disease Vectors
PubMed: 38574112
DOI: 10.1371/journal.pntd.0012062 -
PLoS Neglected Tropical Diseases Feb 2024Schistosomiasis is one of the world's most devastating parasitic diseases, afflicting 251 million people globally. The Neotropical snail Biomphalaria glabrata is an...
A haplotype-like, chromosome-level assembled and annotated genome of Biomphalaria glabrata, an important intermediate host of schistosomiasis and the best studied model of schistosomiasis vector snails.
Schistosomiasis is one of the world's most devastating parasitic diseases, afflicting 251 million people globally. The Neotropical snail Biomphalaria glabrata is an important intermediate host of the human blood fluke Schistosoma mansoni and a predominant model for schistosomiasis research. To fully exploit this model snail for biomedical research, here we report a haplotype-like, chromosome-level assembled and annotated genome of the homozygous iM line of B. glabrata that we developed at the University of New Mexico. Using multiple sequencing platforms, including Illumina, PacBio, and Omni-C sequencing, 18 sequence contact matrices representing 18 haploid chromosomes (2n = 36) were generated (337x genome coverage), and 96.5% of the scaffold sequences were anchored to the 18 chromosomes. Protein-coding genes (n = 34,559), non-coding RNAs (n = 2,406), and repetitive elements (42.52% of the genome) were predicted for the whole genome, and detailed annotations for individual chromosomes were also provided. Using this genomic resource, we have investigated the genomic structure and organization of the Toll-like receptor (TLR) and fibrinogen-domain containing protein (FReD) genes, the two important immune-related gene families. Notably, TLR-like genes are scattered on 13 chromosomes. In contrast, almost all (39 of 40) fibrinogen-related genes (FREPs) (immunoglobulin superfamily (IgSF) + fibrinogen (FBG)) are clustered within a 5-million nucleotide region on chromosome 13, yielding insight into mechanisms involved in the diversification of FREPs. This is the first genome of schistosomiasis vector snails that has been assembled at the chromosome level, annotated, and analyzed. It serves as a valuable resource for a deeper understanding of the biology of vector snails, especially Biomphalaria snails.
Topics: Humans; Animals; Biomphalaria; Haplotypes; Schistosomiasis; Fibrinogen; Hemostatics; Chromosomes
PubMed: 38421953
DOI: 10.1371/journal.pntd.0011983 -
International Journal of Molecular... Feb 2024Ramshorn snails from the family are important freshwater snails due to their low trophic level, and some of them act as intermediate hosts for zoonotic trematodes....
Ramshorn snails from the family are important freshwater snails due to their low trophic level, and some of them act as intermediate hosts for zoonotic trematodes. There are about 250 species from 40 genera of , but only 14 species from 5 genera (, , , , and ) have sequenced complete mitochondrial genomes (mitogenomes). In this study, we sequenced and assembled a high-quality mitogenome of a ramshorn snail, sp. TS-2018, which represented the first mitogenome of the genus. The mitogenome of sp. TS-2018 is 13,749 bp in length, which is shorter than that of most gastropods. It contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and 2 ribosomal RNA (rRNA). We compared mitogenome characteristics, selection pressure, and gene rearrangement among all of the available mitogenomes of ramshorn snails. We found that the nonsynonymous and synonymous substitution rates (Ka/Ks) of most PCGs indicated purifying and negative selection, except for of , , and , which indicated positive selection. We observed that transpositions and reverse transpositions occurred on 10 tRNAs and , which resulted in six gene arrangement types. We reconstructed the phylogenetic trees using the sequences of PCGs and rRNAs and strongly supported the monophyly of each genus, as well as three tribes in . Both the gene rearrangement and phylogenetic results suggested that had a close relationship with and , while was the sister group to all of the other genera. Our results provide useful data for further investigation of species identification, population genetics, and phylogenetics among ramshorn snails.
Topics: Animals; Phylogeny; Genome, Mitochondrial; Acanthaceae; Snails; RNA, Ribosomal; RNA, Transfer
PubMed: 38396956
DOI: 10.3390/ijms25042279