Surveillance of Ancylostoma caninum in naturally infected dogs in Quebec, Canada, and assessment of benzimidazole anthelmintics reveal a variable efficacy with the presence of a resistant isolate in imported dogs.

Ancylostoma caninum is a widely prevalent parasitic nematode in dogs across the world. There has been a notable increase in reports of anthelmintic resistance in A. caninum within the United States of America in recent years, which has led us to investigate the potential of this scenario in Canada. The study objectives were to assess the prevalence of A. caninum in two different groups, including a colony of rescued dogs in Canada and three imported Greyhound dogs from USA, and to evaluate the efficacy of two benzimidazole (BZ) anthelmintics against A. caninum, complemented with a molecular genetic analysis adapted to low prevalence. Fecal samples were collected at pre- and post-treatment with fenbendazole for the native shelters-origin group, and a combination of anthelmintic formulations, including the pro-BZ febantel for the USA-origin group. The coprology analyses found several genera of internal parasites. Canine ancylostomiasis was the most prevalent parasitosis with 30.77% in the native group and 100% in the USA group, but with overall low average of A. caninum eggs per gram. Through the fecal egg count reduction test (FECRT), applying a cut-off at 90% as baseline of egg reduction for successful efficacy, BZ showed variable efficacy. Furthermore, molecular analysis confirmed the presence of A. caninum in both groups of dogs and found differences in the genetics linked to BZ resistance on the A. caninum ß-tubulin isotype 1 gene. In the isolate from the native group, both codons 167 and 200 were homozygous without the presence of single nucleotide polymorphism (SNP). In contrast, the selected isolate from the USA group, showed a homozygous allele at position 200 and a heterozygous SNP at position 167. The latter was congruent with the low efficacy in FECRT and agrees with the recent findings of USA A. caninum isolate resistant phenotype to the BZ anthelmintics. The limitations of the study include an overall low eggs-per-gram in both canine groups, and the shortage of additional fecal samples from the USA group, restraining the molecular analysis only to one out of the three Greyhounds. This study provided some insights on the efficacy of BZs against A. caninum and revealed the presence of BZ resistant isolates in imported dogs in Quebec, Canada. All this information should be considered, for choosing the best strategy in the control of A. caninum using anthelmintic drugs.

Evaluation of Parasight All-in-One system for the automated enumeration of helminth ova in canine and feline feces.

BACKGROUND:  Digital imaging combined with deep-learning-based computational image analysis is a growing area in medical diagnostics, including parasitology, where a number of automated analytical devices have been developed and are available for use in clinical practice. METHODS: The performance of Parasight All-in-One (AIO), a second-generation device, was evaluated by comparing it to a well-accepted research method (mini-FLOTAC) and to another commercially available test (Imagyst). Fifty-nine canine and feline infected fecal specimens were quantitatively analyzed by all three methods. Since some samples were positive for more than one parasite, the dataset consisted of 48 specimens positive for Ancylostoma spp., 13 for Toxocara spp. and 23 for Trichuris spp. RESULTS: The magnitude of Parasight AIO counts correlated well with those of mini-FLOTAC but not with those of Imagyst. Parasight AIO counted approximately 3.5-fold more ova of Ancylostoma spp. and Trichuris spp. and 4.6-fold more ova of Toxocara spp. than the mini-FLOTAC, and counted 27.9-, 17.1- and 10.2-fold more of these same ova than Imagyst, respectively. These differences translated into differences between the test sensitivities at low egg count levels (< 50 eggs/g), with Parasight AIO > mini-FLOTAC > Imagyst. At higher egg counts Parasight AIO and mini-FLOTAC performed with comparable precision (which was significantly higher that than Imagyst), whereas at lower counts (> 30 eggs/g) Parasight was more precise than both mini-FLOTAC and Imagyst, while the latter two methods did not significantly differ from each other. CONCLUSIONS: In general, Parasight AIO analyses were both more precise and sensitive than mini-FLOTAC and Imagyst and quantitatively correlated well with mini-FLOTAC. While Parasight AIO produced lower raw counts in eggs-per-gram than mini-FLOTAC, these could be corrected using the data generated from these correlations.

Evaluation of heating and liming treatments in sand samples artificially contaminated with Ancylostoma spp. eggs.

Ancylostoma spp. are found worldwide. Infected dog and cat feces can contaminate soil in public places. Despite prophylactic measures being available, studies on direct remediation of Ancylostoma-contaminated soils are scarce. This study aimed to determine the impact of heat treatment and liming on the viability of Ancylostoma spp. eggs in artificially contaminated sandy soil. Sterilized sand samples were contaminated with Ancylostoma spp. eggs extracted from infected dogs' feces. Samples were heated (trial I) to 70 °C or 80 °C, then sieved after 24 hours (212, 90, 38, and 25 µm). Larval cultures were assessed for larval development following heat treatment. Five quicklime concentrations (trial II; 50, 30, 20, 10 and 5%) were used to treat sand. The effect of liming on larval cultures was assessed by measuring embryonic development. Filariform larvae were exposed to 20% quicklime (25 °C and 37 °C, 20 min). Heat treatment destroys Ancylostoma spp. eggs and prevents in vitro larval development. Liming at 50, 30, and 20% concentrations made embryonic development impossible. However, filariform larvae treated with 20% lime solution retained their motility. Heating at 70 °C and liming at 20% were sufficient to make Ancylostoma spp. egg embryogenesis impossible in experimentally contaminated sand samples.

Retrospective analysis of canine fecal flotation and coproantigen immunoassay hookworm positive results in Greyhounds and other dog breeds.

Recent studies demonstrated that Greyhounds are commonly infected with Ancylostoma caninum and these infections have been shown to be resistant to anthelmintics. This study evaluated samples submitted to a commercial reference laboratory (IDEXX Laboratories) for canine fecal flotation zinc sulfate centrifugation and coproantigen immunoassay between January 1, 2019, and July 30, 2023 for evidence that Greyhounds were more often positive for Ancylostoma spp. (hookworms) compared to other breeds. The purpose of the study was to determine if Greyhounds were more likely to be hookworm-positive compared to other breeds, if Greyhounds on preventives with efficacy against hookworm infections are more likely to test positive than other breeds, if their infections take longer to resolve, to estimate how long this takes and to assess whether the proportion of hookworm positive tests for all breeds is increasing over time. Records of 25,440,055 fecal results were obtained representing 17,671,724 unique dogs. Of these, 49,795 (∼0.3%) were Greyhounds. The overall odds ratio (OR) of 15.3 (p < 0.001) suggests that Greyhounds are at significantly higher risk than other breeds for hookworm positive float findings, and the OR of 14.3 (p < 0.001) suggests significantly higher risk for hookworm antigen positive results. The median time to negative testing event from the Turnbull distribution estimate was in the interval of 1-2 days for other breeds and 71-72 days for Greyhounds. These results provide evidence that anthelmintic resistant A. caninum strains may be having population-level impacts on the frequency and duration of infections in Greyhounds. The findings have broader health implications beyond Greyhounds as MADR A. caninum strains could spread to other breeds and even pet owners.

Zoonotic Ancylostoma ceylanicum Infection in Coyotes from Guanacaste Conservation Area, Costa Rica, 2021.

Ancylostoma ceylanicum is the second most common hookworm infecting humans in the Asia-Pacific region. Recent reports suggest presence of the parasite in the Americas. We report A. ceylanicum infections in coyotes from the Guanacaste Conservation Area, Costa Rica. Our findings call for active surveillance in humans and animals.

Management of paediatric soil-transmitted helminthiasis in a non-endemic area: experience in a reference international health unit.

Soil-transmitted helminth (STH) infections inflict disability worldwide, especially in the poorest communities. Current therapeutic options against STHs show limited efficacy, particularly against Trichuris trichiura. The empirical management of patients coming from high-prevalence areas has been suggested for non-endemic areas. This study aimed to describe the management of STH infections in a non-endemic setting using an individualised approach. We performed a retrospective, descriptive study of all patients up to 16 years of age with STH infections attended at an international health unit in a non-endemic area (2014-2018), including all T. trichiura, Necator americanus, Ancylostoma duodenale, and Ascaris lumbricoides infections diagnosed using a formol-ether concentration technique and direct visualisation. Patients were treated according to current international guidelines. Sixty-one stool samples from 48 patients testing positive for STHs were collected, with 96% (46/48) reporting a previous long-term stay in endemic areas. Cure rates with 3-day benzimidazole regimens were 72% for T. trichiura, 40% for hookworms, and 83% for A. lumbricoides. The results were not influenced by any reinfection risk due to the study being performed in a non-endemic area. Patients coming from STH-endemic areas should be evaluated with appropriate diagnostic tools and followed up until cure control results. Cure rates in our cohort were moderate to low, similar to those published in studies in endemic areas. The efficacy of current treatment options is insufficient to recommend a specific empirical approach in high-income countries' healthcare systems.

In vitro immunoregulatory role of recombinant Ancylostoma ceylanicum calreticulin.

Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and iron-deficiency anemia. Helminth parasites secrete calreticulin (CRT), which regulates or blocks the host's immune response. However, no data on A. ceylanicum calreticulin (Ace-CRT) are available. We investigated the biological function of recombinant Ace-CRT (rAce-CRT). rAce-CRT showed reliable antigenicity and stimulated the proliferation of mouse splenocytes and canine peripheral blood mononuclear cells. Quantitative reverse-transcription PCR assays revealed that rAce-CRT primarily promoted the expression of T helper 2 cytokines, particularly IL-13, in canine peripheral blood lymphocytes. rAce-CRT inhibited complement-mediated sheep erythrocyte hemolysis in vitro. Our findings indicate that Ace-CRT plays an immunomodulatory role and may be a promising candidate molecule for a hookworm vaccine.

Ecoepidemiology of Ancylostoma spp. in Urban-Marginal and Rural Sectors of the Ecuadorian Coast and Prevalence of Cutaneous Larvae Migrans.

BACKGROUND Ancylostoma spp., including A. duodenale, A. braziliense, A. caninum, and A. ceylanicum, are hookworms that are transmitted from infected soil and by contact with domestic animals and rodent hosts, and can cause systemic disease and cutaneous larva migrans. The objective of this study was to describe the ecoepidemiology of Ancylostoma caninum and Ancylostoma spp. in urban-marginal sectors and in rural sectors located in Ecuador. MATERIAL AND METHODS Through addressed sampling, a total of 498 domestic dogs and 40 synanthropic rodents were analyzed via the following coproparasitic methods: direct, flotation, sedimentation with centrifugation using saline (egg identification), modified Baermann (larval identification), and morphometric methods (confirmation). A total of 236 people were surveyed, and a clinical analysis was performed via physical examination. The environmental variables were obtained through reports from the INAMHI of Ecuador and the use of online environmental programs. Through surveys, data related to social determinants were obtained. Epidemiological indicators (prevalence, morbidity, and mortality) were obtained through microbial analysis and surveys. RESULTS A total of 250 domestic dogs were diagnosed with Ancylostoma caninum (50, 20%), and 41 were diagnosed with Ancylostoma spp. (8.23%). One synanthropic rodent (2.5%) was positive for A. caninum. In the clinical analysis, 3 patients were identified as positive (1.27%) for cutaneous larva migrans (CLM). Likewise, environmental variables and social determinants influence the transmission, prevalence, and nature of parasitism by hookworm. CONCLUSIONS People, domestic dogs, and rodents were infected with these parasites. Consequently, there is a risk of ancylostomiasis and cutaneous larvae migrans spreading.

Effect of Soil Temperature on Canine Soil-Transmitted Nematodes in Kandy District with the First Record of Hookworm, Ancylostoma tubaeforme from Sri Lanka.

PURPOSE: Soil-transmitted nematodes (STNs) are widespread in tropical and subtropical regions, particularly where the communities are socio-economically challenged. We investigated the effect of soil temperature on the prevalence and intensity of STN infection in free-roaming dogs. METHODS: Fresh faecal samples collected from free-roaming dogs in Digana and Pussellawa town areas in the Kandy District, Sri Lanka, were microscopically analysed for canine STNs. Soil temperature was measured at each sampling site. Highly prevalent canine hookworm Ancylostoma, was further studied using PCR and sequencing, followed by phylogenetic analysis. RESULTS: The soil temperature ranged between 28 and 31 °C (mean = 29.79 °C) and 18-21 °C (mean = 19.52 °C) in Digana and Pussellawa, respectively, showing a significant difference in the two sites (Students t-test t = 1.68, p < 0.0001). Of the total 44 dogs sampled, 41 (93.2%) were positive for STNs. During microscopic analysis, five nematodes: Ancylostoma spp., Capillaria sp., Strongyloides sp., Toxocara canis, and Trichuris sp., were identified. Ancylostoma species (93.2%) were the most prevalent, followed by Strongyloides sp. (22.7%) and Toxocara canis (15.9%). Infection prevalence of Strongyloides sp. was higher in Digana (40.9%) compared to that in Pussellawa (4.5%; Chi-square test, χ2 = 8.28, p = 0.004) and also the infection intensity from Digana (EPG = 8.02 ± 20.2) compared to that from Pussellawa (0.45 ± 2.1; Mann Whitney U test, p = 0.006). Amplicons (ITS1-5.8S-ITS2) of the expected size for A. caninum, and A. tubaeforme were produced. An A. caninum sequence reported here (OQ101719) illustrated the highest similarity of 99.2% to one of the local sequences (MZ707153) upon pairwise comparison. CONCLUSION: Digana, with a higher soil temperature than Pussellawa, had a significantly higher prevalence and infection intensity, particularly Strongyloides sp. This study also signifies the first molecular identification of hookworm species A. tubaeforme in Sri Lanka.

Hookworm Anthelmintic Resistance: Novel Fecal Polymerase Chain Reaction Ancylostoma caninum Benzimidazole Resistance Marker Detection in a Dog.

A 4 yr old castrated male greyhound presented with a history of chronic (>3 wk) intermittent diarrhea. Initial fecal analysis identified infection with Ancylostoma caninum. Despite treatment with routine anthelmintics, the dog remained persistently A caninum positive for several months. A novel fecal gastrointestinal real-time polymerase chain reaction (qPCR) parasite panel detected A caninum and the genetic benzimidazole (BZ) F167Y resistance marker in multiple samplings over 48 hr. This finding, together with the dog's clinical signs (diarrhea) and lack of response to routine anthelmintics, prompted treatment with cyclooctadepsipeptide emodepside, a drug currently not registered for dogs in the United States. The dog's clinical signs resolved and post-treatment fecal qPCR testing was negative. However, 5 mo later, retesting with fecal qPCR detected A caninum and concurrent BZ resistance marker, as well as Giardia. A presumptive diagnosis of re-infection was made and the emodepside treatment was continued. The dog again reverted to undetected (A caninum and the 167 resistance marker) on reassessment fecal qPCR. This case report describes the use of a novel fecal qPCR panel for gastrointestinal parasites, persistent hookworm and BZ F167Y resistance marker detection in a dog, and highlights the importance of a stepwise approach to clinical management, treatment, and retesting.

Geographic Distribution of Human Infections with Zoonotic Ancylostoma ceylanicum and Anthropophilic Hookworms in Ecuador: A Retrospective Analysis of Archived Stool Samples.

Zoonotic human infections with Ancylostoma ceylanicum have recently been reported in the Americas. We used archived human stool samples to study the geographic distribution of human infections with A. ceylanicum and anthropophilic hookworms in different geoclimatic regions (coastal, Andean, and Amazon) of Ecuador. We analyzed retrospectively archived human stool samples from five studies previously screened for hookworm infection by microscopy, of which four included hookworm-positive samples only and one involved hookworm-negative samples to increase geographic distribution of sampling. Stools were analyzed using multi-parallel quantitative polymerase chain reaction (qPCR) assays to detect Necator americanus, Ancylostoma duodenale, A. ceylanicum, Ascaris lumbricoides, Trichuris trichiura, and Strongyloides stercoralis. Sequencing was done for the A. ceylanicum cox1 gene. A total of 132 samples were analyzed, of which 69 (52.3%) were from hookworm-positive and 63 (47.7%) from hookworm-negative individuals by microscopy. Overall, 82.6% of microscopy-positive samples and 33.3% of microscopy-negative samples were positive for hookworm by qPCR. Of microscopy-positive samples, 36.2% were A. ceylanicum, 37.7% A. duodenale, and 33.3% N. americanus, whereas equivalent proportions for microscopy-negative samples were 1.6%, 31.7%, and 1.6%, respectively. Ancylostoma duodenale was the most widely dispersed geographically, followed by N. americanus. Ancylostoma ceylanicum was least dispersed but was detected in coastal and Amazon regions. In conclusion, human infections with A. ceylanicum, A. duodenale, and N. americanus were detected in different geoclimatic regions of Ecuador. Additional studies are required to further define the epidemiology of human A. ceylanicum infections, but the potentially widespread presence of this helminth in human populations in Ecuador has implications for hookworm control strategies.

Nationwide USA re-analysis of amplicon metabarcoding targeting ß-tubulin isoform-1 reveals absence of benzimidazole resistant SNPs in Ancylostoma braziliense, Ancylostoma tubaeforme and Uncinaria stenocephala.

Nationwide sampling by Venkatesan and colleagues (2023) described the resistance status of the canine hookworm, Ancylostoma caninum, to benzimidazoles across the USA via ß-tubulin isotype-1 amplicon metabarcoding. In this study, we aimed to use the existing public amplicon metabarcoding data and mine it for the presence of ß-tubulin isotype-1 sequences that belong to hookworm species other than A. caninum. Through bioinformatics analysis we assigned species to A. caninum, Ancylostoma braziliense, Ancylostoma tubaeforme and Uncinaria stenocephala. All non-A. caninum sequences contained only the benzimidazole susceptible residues of ß-tubulin isotype-1. Using two ß-tubulin isotype-1 metabarcoding sequence data (assay targeting 134 and 167 codons, and assay targeting 198 and 200 codons), 2.0% (6/307) and 2.9% (9/310) individual samples had hookworms other than A. caninum (A. braziliense n = 5, A. tubaeforme n = 4 and U. stenocephala n = 2), respectively. We identified one sample containing A. braziliense in each of the Northeastern region and Midwestern region, and in three samples from the Southern region. Presence of A. tubaeforme in dog faeces is considered as pseudoparasitism. There were no statistically significant regional differences for the distribution of each species, for either of the two assays independently or combined (χ2 tests, P > 0.05). Our work demonstrates the utility of the amplicon metabarcoding for the identification of species through antemortem assays, thus resolving the dilemma of assigning hookworm species based on either post-mortem or egg sizes for the identification of hookworms.

Molecular identification and genetic diversity of zoonotic hookworm infections in domestic dogs from northeastern, Thailand.

Hookworm infections remain a significant public health concern in tropical and subtropical regions, including Thailand. This study investigated the species and genetic diversity of hookworm infections in domestic dogs from northeastern Thailand. The molecular analysis focused on amplifying and sequencing specific regions of ribosomal RNA genes (ITS1-5.8S-ITS2 region) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene in hookworm larvae recovered from 21 domestic dog stool samples. Among 21 larvae (one larva per infected dog) analyzed, 14 had sequences identical to Ancylostoma caninum, and 7 showed sequences almost identical to Ancylostoma ceylanicum. Phylogenetic analysis of cox1 sequences placed A. caninum and A. ceylanicum in separate clades. The median-joining network of A. caninum cox1 sequences from Thailand showed high haplotype diversity and belonged to the same cluster as sequences from Australia while forming separate clusters from those of A. caninum samples from the USA. The available published A. ceylanicum cox1 sequences (n = 33), in combination with seven sequences in the present study, represented 15 haplotypes distributed among three clusters. Interestingly, A. ceylanicum sequences from dogs and humans shared the same haplotypes. These findings are crucial for recognizing the potential for zoonotic transmission, highlighting the necessity for targeted control measures, and increasing awareness among pet owners and healthcare professionals to mitigate the risk of hookworm transmission to humans.

Benzimidazole F167Y polymorphism in the canine hookworm, Ancylostoma caninum: Widespread geographic, seasonal, age, and breed distribution in United States and Canada dogs.

Surveillance data for Ancylostoma spp. and the A. caninum benzimidazole treatment resistance associated F167Y polymorphism using molecular diagnostics was obtained in a large population of dogs from the United States and Canada. Real-time PCR (qPCR) for Ancylostoma spp. and allele-specific qPCR detecting a single nucleotide polymorphism (SNP) F167Y was used in 262,872 canine stool samples collected between March and December of 2022. Ancylostoma spp. was found at an overall prevalence of 2.5% (6538/262,872), with the highest prevalence in the Southern US, 4.4% (4490/103,095), and the lowest prevalence in Canada 0.6% (101/15,829). The A. caninum F167Y polymorphism was found with the highest prevalence (13.4%, n = 46/343) in the Western US and the lowest in Canada at 4.1% (4/97). The F167Y polymorphism was detected every month over the 10-month collection period. Seasonal distribution showed a peak in June for both Ancylostoma spp. (3.08%, 547/17,775) and A. caninum F167Y (12.25%, 67/547). However, the A. caninum F167Y polymorphism prevalence was highest in September (13.9%, 119/856). Age analysis indicates a higher prevalence of both hookworm infections and occurrence of resistant isolates in puppies. The breeds with the highest F167Y polymorphism prevalence in Ancylostoma spp. detected samples were poodles (28.9%), followed by Bernese Mountain dogs (25%), Cocker spaniels (23.1%), and greyhounds (22.4%). Our data set describes widespread geographic distribution of the A. caninum benzimidazole resistance associated F167Y polymorphism in the United States and Canada, with no clear seasonality compared to the Ancylostoma spp. prevalence patterns. The F167 polymorphism was present in all geographic areas with detected hookworms, including Canada. Our study highlights that the F167Y polymorphism is represented in many dog breeds, including greyhounds.

Altered larval activation response associated with multidrug resistance in the canine hookworm Ancylostoma caninum.

Parasitic gastrointestinal nematodes pose significant health risks to humans, livestock, and companion animals, and their control relies heavily on the use of anthelmintic drugs. Overuse of these drugs has led to the emergence of resistant nematode populations. Herein, a naturally occurring isolate (referred to as BCR) of the dog hookworm, Ancylostoma caninum, that is resistant to 3 major classes of anthelmintics is characterized. Various drug assays were used to determine the resistance of BCR to thiabendazole, ivermectin, moxidectin and pyrantel pamoate. When compared to a drug-susceptible isolate of A. caninum, BCR was shown to be significantly resistant to all 4 of the drugs tested. Multiple single nucleotide polymorphisms have been shown to impart benzimidazole resistance, including the F167Y mutation in the ß-tubulin isotype 1 gene, which was confirmed to be present in BCR through molecular analysis. The frequency of the resistant allele in BCR was 76.3% following its first passage in the lab, which represented an increase from approximately 50% in the founding hookworm population. A second, recently described mutation in codon 134 (Q134H) was also detected at lower frequency in the BCR population. Additionally, BCR exhibits an altered larval activation phenotype compared to the susceptible isolate, suggesting differences in the signalling pathways involved in the activation process which may be associated with resistance. Further characterization of this isolate will provide insights into the mechanisms of resistance to macrocyclic lactones and tetrahydropyrimidine anthelmintics.

Influence of tides on the dissemination and related health risks of intestinal helminths along the Kribi beaches (Atlantic Coast, Southern Cameroon).

Kribi is a seaside town that welcomes thousands of tourists each year. However, the poor sanitation condition of its beaches along the Atlantic coast is not without risk for visitors. In this study, we used the formol-ether concentration technique to identify and quantify larvae or eggs of intestinal helminths in waters of three regularly visited Kribi beaches (Mpalla, Ngoyè, and Mboamanga). Results revealed that all identified larvae and eggs were cestodes (Hymenolepis nana) and nematodes (Strongyloides sp., Ascaris sp., Ancylostoma duodenale and Trichuris trichiura). All the helminth eggs and larvae showed high abundance at low tide during rainy seasons. Ancylostoma duodenale eggs, totally absent at Mpalla, were densely present at low tide at Ngoyè (301 ± 15 eggs/L). Trichuris trichiura eggs showed the lowest abundance (0 to 62 eggs/L) at all sites. Abiotic variables indicated that waters at the various beaches were basic (pH: 8.75-9.77), generally warmer (32.44°C at Mpalla in the Short Rainy Season), more oxygenated at low tide, and moderately mineralized at high tide. Positive and significant correlations were observed at Ngoyè at low tide between Strongyloides sp. larvae and dissolved oxygen (P ˂ 0.05); and between Ancylostoma duodenale eggs and temperature (P ˂ 0.05). The overall results indicated that the beaches studied are subjected to fecal pollution. This pollution is more accentuated during low tides than during high tides. Depending on tidal movements, swimmers risk exposure to helminth eggs and larvae known to be responsible for gastroenteritis.

Dermoscopic characteristics of cutaneous larva migrans in dark skin: a study from Banjul, The Gambia.

Cutaneous larva migrans (CLM) results from hookworm larvae infestation, mainly Ancylostoma braziliense or Ancylostoma caninum. It is common in Sub-Saharan Africa, often acquired through soil contact, especially in sandy beaches, manifesting as serpiginous, erythematous and intensely pruritic tracts within the epidermis, and presenting with diverse clinical appearances. Diagnosis is mostly clinical; however, dermoscopy can enhance diagnostic accuracy and distinction from mimics. The current body of literature is deficient in its representation of dermoscopic data for CLM in Black patients. This study explores dermoscopy in nine dark-skinned patients with 16 CLM lesions. Distinctive serpiginous structureless areas displaying a range of colours, peripheral scales surrounding brown areas and brown dots were predominant features, whereas vascular characteristics were less evident. This article highlights the presence of distinct reaction patterns, including brown dots, scales, and accentuated, often disrupted brown reticular lines in addition to the characteristic winding tracts in darker skin.

Immunity mediates host specificity in the human hookworm Ancylostoma ceylanicum.

Hookworm infection affects millions globally, leading to chronic conditions like malnutrition and anaemia. Among the hookworm species, Ancylostoma ceylanicum stands out as a generalist, capable of infecting various hosts, including humans, cats, dogs and hamsters. Surprisingly, it cannot establish in mice, despite their close phylogenetic relationship to hamsters. The present study investigated the development of A. ceylanicum in immunodeficient NSG mice to determine the contribution of the immune system to host restriction. The infections became patent on day 19 post-infection (PI) and exhibited elevated egg production which lasted for at least 160 days PI. Infective A. ceylanicum larvae reared from eggs released by infected NSG mice were infectious to hamsters and capable of reproduction, indicating that the adults in the NSG mice were producing viable offspring. In contrast, A. ceylanicum showed limited development in outbred Swiss Webster mice. Furthermore, the closely related canine hookworm Ancylostoma caninum was unable to infect and develop in NSG mice, indicating that different mechanisms may determine host specificity even in closely related species. This is the first report of any hookworm species completing its life cycle in a mouse and implicate the immune system in determining host specificity in A. ceylanicum.

New insight into genetic diversity of zoonotic-potential Ancylostoma ceylanicum in stray cats living in Bangkok, Thailand, based on deep amplicon sequencing.

AIMS: This study aimed to characterize feline hookworms from stray cats living in Bangkok. METHODS AND RESULTS: A total of 56 hookworm-positive faecal samples were identified for hookworm species by using PCR targeting the ITS1, 5.8S, and ITS2 fragment and qPCR targeting ITS2. Of 56 samples, 96.4% (54/56) were identified as Ancylostoma ceylanicum and 1.8% (1/56) as Ancylostoma caninum. With qPCR, 89.3% (50/56) were identified as single A. ceylanicum infection and 5.4% (3/56) as coinfection of A. ceylanicum and A. caninum. For genetic characterization of A. ceylanicum, 10 samples were pooled, and the partial COI gene was amplified, followed by deep amplicon sequencing. Five pooled samples were analysed, and 99.73% were identified with A. ceylanicum sequences, which were allocated into 19 haplotypes (AC01-AC19). Genetic diversity findings for A. ceylanicum in Asia revealed that three of eight haplotypes considered of zoonotic significance occurred in humans, dogs, and cats, including haplotypes H01, H20, and H21. The predominant haplotype in this study, AC01, was clustered with H01-a zoonotic haplotype. CONCLUSIONS: The diversity obtained by deep amplicon sequencing supported that the A. ceylanicum community had high genetic variation. Deep amplicon sequencing was a useful method to determine source, zoonotic potential, and host-parasite relationship.

Epidemiological and molecular updates on hookworm species in dogs from southern Italy.

BACKGROUND: The zoonotic hookworms Ancylostoma caninum and Uncinaria stenocephala are widespread soil-transmitted helminths in dogs in Europe. Given the veterinary and public health importance of hookworms in dogs and the recent changes in the molecular epidemiology of some species, there is a need to continuously monitor the epidemiological and molecular prevalence of these parasites also at the "local" level. The present study aimed to update the epidemiological scenario of hookworm infections in both owned and stray dogs in southern Italy and to discriminate between different hookworm species (A. caninum and U. stenocephala) through molecular analyses. For this purpose, a retrospective analysis was performed over 10 years (2011-2021), including a total of 7008 owned dogs and 5642 stray dogs referred to our laboratory for copromicroscopic examinations. Moreover, 72 faecal samples, from dogs naturally infected by hookworms, were used to discriminate between A. caninum and U. stenocephala using two PCR protocols. Prior to molecular analyses, a subsample of 40/72 positive faecal samples was used for morphometric investigations on hookworm eggs. RESULTS: The results of the ten-year retrospective analysis (2011-2021) showed an overall prevalence of hookworm infection of 9.16%, specifically 5.1% in owned dogs and 14.2% in stray dogs. Logistic regression showed a significant association between positivity to hookworms and the variable "puppies" both in stray (13.84%; OR = 2.4) and owned (7.07%; OR = 2.2) dogs. The results of molecular analyses showed that positivity was confirmed only in 21/72 samples, specifically, 6 samples using protocol A and 19 with protocol B. Sequencing revealed 15 samples positive to U. stenocephala and 6 to A. caninum. CONCLUSIONS: The findings of this study showed a high prevalence of hookworm infections in dogs in southern Italy, updating the epidemiological scenario of the last decade. Moreover, the results of the study revealed the first identification of hookworm species in dogs in Italy by molecular studies, highlighting that U. stenocephala is more prevalent than A. caninum.