Zoonotic Hookworm Research Articles

Anthroponotic and Zoonotic Hookworm DNA in an Indigenous Community in Coastal Ecuador: Potential Cross-Transmission between Dogs and Humans.

Humans can be infected with anthroponotic (Ancylostoma duodenale and Necator americanus) and with zoonotic (Ancylostoma ceylanicum, A. caninum, A. braziliense, and Uncinaria stenocephala) hookworms from dogs. Anthroponotic species are usually thought not to infect dogs. We used the internal transcribed spacer-1 (ITS1) gene in a quantitative PCR to detect anthroponotic and zoonotic hookworm species in fecal samples from 54 children and 79 dogs living in an indigenous community in tropical Northwestern Ecuador. Hookworm DNA was detected in 59.3% of children and 92.4% of dogs. Among samples from children, zoonotic hookworms were detected in 24.1% (A. ceylanicum 14.8%, A. caninum 11.1%, and A. braziliense 1.9%), whilst in dog samples, anthroponotic species were detected in 19.0% (N. americanus 12.4% and A. duodenale 6.3%). Sanger sequencing was performed successfully on 60 qPCR-positive samples (16 from children and 44 from dogs), and consensus sequences were obtained with >98% homology to GenBank references for hookworm spp. Phylogenetic analysis showed a close relationship between anthroponotic and zoonotic Ancylostoma species and no heterogeneity between A. duodenale and A. caninum; in human samples, we found A. ceylanicum but not A. braziliense sequences and we were unable to identify N. americanus in the dog samples. No infections with U. stenocephala were detected. Our data provide evidence for high rates of hookworm infections in indigenous children and dogs in a marginalized rural setting in coastal Ecuador. We also found evidence for potential cross-transmission of hookworm spp. between humans and dogs that represent a potential domestic reservoir for zoonotic and anthroponotic hookworms.

Ancylostoma ceylanicum and other zoonotic canine hookworms: neglected public and animal health risks in the Asia–Pacific region

AbstractZoonotic hookworm infections remain a significant public health problem, causing nearly 500 million cases globally and approximately four million disability-adjusted life years lost annually. More than one-fifth of these cases are attributed to Ancylostoma ceylanicum, an emerging zoonotic health issue in the Asia-Pacific region. This review presents key research gaps regarding the epidemiology, diagnosis, control, prevention and elimination of A. ceylanicum and other canine zoonotic hookworms as neglected health threats. A. ceylanicum is the second most prevalent human hookworm in the region; it is the most common hookworm among dogs and cats-reservoirs of zoonotic infections. Previous population genetic and phylogenetic analyses revealed that A. ceylanicum has three possible transmission dynamics: zoonotic, animal-only, and human-only pathways. The actual burden of zoonotic ancylostomiasis in most endemic countries remains unknown due to the use of parasitological techniques (e.g., Kato-Katz thick smear and floatation techniques) that have reduced diagnostic performance and do not allow accurate species identification in helminth surveys. The emergence of benzimidazole resistance in soil-transmitted helminths (STHs), including hookworms, is a concern due to the protracted implementation of mass drug administration (MDA). Resistance is conferred by single nucleotide polymorphisms (SNPs) that occur in the β-tubulin isotype 1 gene. These mutations have been reported in drug-resistant A. caninum but have not been found in A. ceylanicum in the field. A. ceylanicum remains understudied in the Asia-Pacific region. The zoonotic nature of the parasite warrants investigation of its occurrence in human and animal reservoir hosts to understand the dynamics of zoonotic transmission in different endemic foci. The detection of benzimidazole resistance-associated SNPs in zoonotic hookworms from Asia-Pacific countries has yet to be thoroughly explored. Considering the high level of hookworm endemicity in the region, the circulation of resistant isolates between humans and animals potentially presents a significant One Health threat that can undermine current MDA and proposed animal deworming-based control efforts.

Zoonotic hookworms and roundworms affecting dogs and cats in Europe

Ascarids and ancylostomatids are parasitic nematodes that are significant to animal and human health. Widespread misconceptions have often contributed to a tendency among the general public and pet owners to underestimate the importance of these intestinal worms. Similarly, there is a low level of concern even within the veterinary community, despite the need to remain vigilant. Understanding the epidemiology, transmission pathways and clinical implications of these infections is crucial in mitigating their impact on public health and animal wellbeing. This article provides a brief overview of zoonotic hookworms and roundworms affecting dogs and cats in Europe, with a focus on their biology, patterns of transmission, associated diseases and strategies for prevention and control. The article emphasises the need for interdisciplinary collaboration between veterinary and human health sectors and the importance of awareness, early detection and effective management of these zoonotic parasites to safeguard both animal and human health.

A rare case of neglected parasitic zoonosis.

Infections caused due to zoonotic hookworms are rare and are often under reported. Here we report a case of diarrheal disease caused by Ancylostoma ceylanicum, an important emerging zoonotic hookworm. There is limited knowledge about the epidemiology and disease burden of A. ceylanicum infections in Kerala. A 50-year-old male patient presented with complaints of loose stools for past five weeks. The laboratory investigations revealed a high total WBC count and eosinophil count. Diagnostic colonoscopy showed numerous worms which were identified as A. ceylanicum. Timely diagnosis aided in successful treatment of the patient. Improvement in diagnostic tools and awareness enable accurate and early detection of this neglected but emerging pathogen.

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.

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

BackgroundThe 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.ResultsThe 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.ConclusionsThe 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.

Comparative study of a broad qPCR panel and centrifugal flotation for detection of gastrointestinal parasites in fecal samples from dogs and cats in the United States

BackgroundFor decades, zinc sulfate centrifugal fecal flotation microscopy (ZCF) has been the mainstay technique for gastrointestinal (GI) parasite screening at veterinary clinics and laboratories. Elsewhere, PCR has replaced microscopy because of generally increased sensitivity and detection capabilities; however, until recently it has been unavailable commercially. Therefore, the primary aim of this study was to compare the performance of real-time PCR (qPCR) and ZCF for fecal parasite screening. Secondary aims included further characterization of markers for hookworm treatment resistance and Giardia spp. assemblages with zoonotic potential and qPCR optimization.MethodsA convenience sampling of 931 canine/feline fecal samples submitted to a veterinary reference laboratory for routine ZCF from the Northeast US (11/2022) was subsequently evaluated by a broad qPCR panel following retention release. Detection frequency and agreement (kappa statistics) were evaluated between ZCF and qPCR for seven GI parasites [hookworm/(Ancylostoma spp.), roundworm/(Toxocara spp.), whipworm/(Trichuris spp.), Giardiaduodenalis, Cystoisospora spp., Toxoplasmagondii, and Tritrichomonasblagburni] and detections per sample. Total detection frequencies were compared using a paired t-test; positive sample and co-infection frequencies were compared using Pearson’s chi-squared test (p ≤ 0.05 significant) and qPCR frequency for hookworm benzimidazole (BZ) resistance (F167Y) and zoonotic Giardia spp. assemblage markers calculated. Confirmatory testing, characterization, and qPCR optimization were carried out with Sanger sequencing.ResultsqPCR detected a significantly higher overall parasite frequency (n = 679) compared to ZCF (n = 437) [p = < 0.0001, t = 14.38, degrees-of-freedom (df) = 930] and 2.6 × the co-infections [qPCR (n = 172) vs. ZCF (n = 66)], which was also significant (p = < 0.0001, X2 = 279.49; df = 1). While overall agreement of parasite detection was substantial [kappa = 0.74; (0.69–0.78], ZCF-undetected parasites reduced agreement for individual and co-infected samples. qPCR detected markers for Ancylostomacaninum BZ resistance (n = 5, 16.1%) and Giardia with zoonotic potential (n = 22, 9.1%) as well as two parasites undetected by ZCF (T.gondii/T.blagburni). Sanger sequencing detected novel roundworm species, and qPCR optimization provided detection beyond ZCF.ConclusionsThese results demonstrate the statistically significant detection frequency advantage offered by qPCR compared to routine ZCF for both single and co-infections. While overall agreement was excellent, this rapid, commercially available qPCR panel offers benefits beyond ZCF with detection of markers for Giardia assemblages with zoonotic potential and hookworm (A.caninum) BZ resistance.Graphical

Modeling the effectiveness of One Health interventions against the zoonotic hookworm Ancylostoma ceylanicum.

Hookworm disease is a major global public health concern, annually affecting 500-700 million of the world's poorest people. The World Health Organization is targeting the elimination of hookworm as a public health problem by 2030 using a strategy of mass drug administration (MDA) to at-risk human populations. However, in Southeast Asia and the Pacific the zoonotic hookworm species, Ancylostoma ceylanicum, is endemic in dogs and commonly infects people. This presents a potential impediment to the effectiveness of MDA that targets only humans. Here, we develop a novel multi-host (dog and human) transmission model of A. ceylanicum and compare the effectiveness of human-only and "One Health" (human plus dog) MDA strategies under a range of eco-epidemiological assumptions. We show that One Health interventions-targeting both dogs and humans-could suppress prevalence in humans to ≤ 1% by the end of 2030, even with only modest coverage (25-50%) of the animal reservoir. With increasing coverage, One Health interventions may even interrupt transmission. We discuss key unresolved questions on the eco-epidemiology of A. ceylanicum, the challenges of delivering MDA to animal reservoirs, and the growing importance of One Health interventions to human public health.

The first study on the prevalence of gastrointestinal parasites in owned and sheltered cats in Yangon, Myanmar.

People who used to rear companion animals are healthier than others who do not. Gastrointestinal (GI) helminths are common in cats and serve as reservoirs for zoonotic diseases. However, the prevalence of GI parasites in cats in Myanmar has never been reported. This study aimed to estimate the prevalence of GI parasites in cats in Myanmar and to identify the potential risk factors associated with GI parasites. A total of 230 fecal samples were collected from seven veterinary clinics and two shelters within the Yangon region from January to May 2022. Sampled cats were classified according to age, gender, and the deworming and rearing practices. Fecal samples were analyzed by fecal wet mount, ethyl acetate centrifugal sedimentation, and zinc sulfate centrifugal flotation techniques. Descriptive data were described, and Pearson's χ2 test was used to identify associated risk factors, such as age, gender, and the deworming and rearing practices. The overall prevalence of GI parasites was 79.56%, and 57.82% of cats were infected with a diagnostic stage of more than one parasite species. Seven GI parasites were detected, including Ancylostoma spp. (55.65%), Toxocara spp. (46.08%), Trichuris spp. (20.86%), Platynosomum spp. (11.73%), Dipylidium caninum (7.39%), Taenia spp. (4.34%), and Cystoisospora spp. (32.17%). Based on statistical analysis, the deworming and rearing practices were significantly associated (p < 0.05) with GI parasitic infections. This study is the first to reveal the prevalence of GI parasites that could assist the need for effective control measures for zoonotic hookworm and roundworm infections in cats. Even with simple microscopic examination, the remarkably high prevalence of GI parasitic infections warrants regular deworming practice. Further molecular studies should also be performed to understand their genetic diversity.

Molecular Detection and Genetic Characterization of Zoonotic Hookworm in Semi-Domesticated Cats Residing in Monasteries in Bangkok, Thailand.

Hookworms are the most common parasitic nematodes in the genus of Ancylostoma that infect both humans and animals in subtropical and tropical South East Asia. The common hookworm species in cats is Ancylostoma ceylanicum which is emerging in Thailand. However, the genetic characterization of hookworms in cats is outdated and insufficiently studied in Thailand. We aimed to investigate the prevalence, risk factors and genetic characterization of hookworm infection in semi-domesticated temple cats in Bangkok, Thailand. A total of 500 temple cat fecal samples were collected from 43 monasteries in 24 districts of Bangkok, Thailand. Polymerase Chain Reaction (PCR) was performed by amplifying the internal transcribed spacer (ITS) gene and mitochondrial cytochrome oxidase c subunit I (cox 1) gene. The infection prevalence of hookworm in temple cats was 13.2% (66/500). The highest prevalence was 34.6% in the Bang Khun Thian district, which is located in a suburban area. The risk factor analysis revealed that cats older than one year (OR 2.4, 95% CI 1.1-5.5, p < 0.05), lack of veterinary attention (OR 2.9, 95% CI 1.7-4.9, p < 0.001) and Bangkok zone (suburban vs. inner city; OR 2.9, 95% CI 1.6-5.4, p < 0.001) were significantly increasing hookworm infection risk. All hookworm positive samples were identified as A. ceylanicum by ITS gene. Moreover, genetic characterization of cox 1 gene in A. ceylanicum isolates indicated a mix of isolates from humans, cats and dogs. The findings show that temple cats can act as a potential source of zoonotic hookworm parasites for the human and animal population in Bangkok, Thailand. Therefore, appropriate control measures for hookworms in semi-domesticated temple cats as well as prevention measures for hookworms in pet cats and humans should be promoted.

Excretory/Secretory Proteome of Females and Males of the Hookworm Ancylostoma ceylanicum.

The dynamic host-parasite mechanisms underlying hookworm infection establishment and maintenance in mammalian hosts remain poorly understood but are primarily mediated by hookworm's excretory/secretory products (ESPs), which have a wide spectrum of biological functions. We used ultra-high performance mass spectrometry to comprehensively profile and compare female and male ESPs from the zoonotic human hookworm Ancylostoma ceylanicum, which is a natural parasite of dogs, cats, and humans. We improved the genome annotation, decreasing the number of protein-coding genes by 49% while improving completeness from 92 to 96%. Compared to the previous genome annotation, we detected 11% and 10% more spectra in female and male ESPs, respectively, using this improved version, identifying a total of 795 ESPs (70% in both sexes, with the remaining sex-specific). Using functional databases (KEGG, GO and Interpro), common and sex-specific enriched functions were identified. Comparisons with the exclusively human-infective hookworm Necator americanus identified species-specific and conserved ESPs. This is the first study identifying ESPs from female and male A. ceylanicum. The findings provide a deeper understanding of hookworm protein functions that assure long-term host survival and facilitate future engineering of transgenic hookworms and analysis of regulatory elements mediating the high-level expression of ESPs. Furthermore, the findings expand the list of potential vaccine and diagnostic targets and identify biologics that can be explored for anti-inflammatory potential.

Zoonotic and non-zoonotic intestinal parasites in shelter dogs at admission and before discharge

Introduction: The prevalence of intestinal parasites, notably zoonotic ascarids and hookworms, is higher in shelter dogs, compared to dogs in homes, making parasite control within shelter facilities a public health priority. Objective: The objective of the study reported here was to measure and compare the frequency of dogs infected with zoonotic or non-zoonotic intestinal parasites at admission and before discharge at a shelter facility. Methods: Ninety-two dogs were tested for diagnosis of intestinal parasites at admission and before discharge. Results: At admission, 50/92 (54%) dogs were diagnosed with intestinal parasites. Most dogs (43/50) were diagnosed with mono-infections with Ancylostoma spp., or co-infections with Ancylostoma spp. and Toxocara sp. or non-zoonotic parasites. Sixty-five dogs had a complete fecal study performed, which included an intake and exit sample analyzed for presence of parasite ova. Among the 65 study dogs, the frequency of dogs with intestinal parasites was lower before discharge (23 or 35%), compared to that at admission (33 or 50%) (P = 0.02). Fifty-one of 65 (78%) dogs were adopted, transferred to an outside rescue facility, or returned to their owners. Of these 51 dogs that left the shelter during the study period, 16/51 (31%) dogs were infected with intestinal parasites, and 8 of the 16 infected dogs were diagnosed with zoonotic parasites. Finally, among 37 dogs that tested negative and 28 that tested positive to zoonotic parasites at admission and re-tested later, four (11%) and six (21%) dogs, respectively, tested positive to zoonotic parasites when tested later. Conclusion: The frequency of shelter dogs infected with intestinal parasites at admission and before discharge was high (≥35%), and most infections were caused by Ancylostoma spp., an intestinal parasite in dogs that can be transmitted to humans, particularly children. We offer health policy options that shelter veterinarians/managers and local policymakers can consider for possible implementation and evaluation.

Medicinal Plant Preparations Administered by Botswana Traditional Health Practitioners for Treatment of Worm Infections Show Anthelmintic Activities.

Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 μg/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 μg/mL.

Ancylostoma ceylanicum Hookworms in Dogs, Grenada, West Indies.

Ancylostoma ceylanicum hookworms are recognized agents of human infection in the Asia–Pacific region. We investigated prevalence of zoonotic hookworm infections in dogs in Grenada in 2021; 40.8% were infected by hookworms, including Ancylostoma ceylanicum. Surveillance of this parasite in dogs and humans is needed in tropical/subtropical countries in the Americas.

Helminth Infections in Children.

Helminth Infections in Children.

Ancylostoma ceylanicum infections in humans in Vietnam.

Ancylostoma ceylanicum is recognized as the only zoonotic hookworm species that is able to mature into adult stage in the human intestine. While human infections caused by this hookworm species have been reported from neighboring countries and this hookworm is prevalent in dogs in Vietnam, human infection has never been reported in Vietnam. The present study, therefore, aimed to identify human infections with A. ceylanicum in Vietnam. A total of 526 fecal samples from the residents in Long An Province were collected and the presence of hookworm eggs was detected by the Kato-Katz method. The results indicated that the overall prevalence of human hookworm infection was 85/526 (16.2%). After filter paper culture, 3rd stage larvae were successfully obtained from 48 egg-positive samples. The larvae were identified for their species using semi-nested PCR-RLFP on the cox1 gene. As a result, two hookworm species were confirmed; single species infections with Necator americanus or A. ceylanicum, and mixed infections with both species were found in 47.9%, 31.3%, and 20.8% of the samples, respectively.

Risk profiling and efficacy of albendazole against the hookworms Necator americanus and Ancylostoma ceylanicum in Cambodia to support control programs in Southeast Asia and the Western Pacific.

Background: Hookworm disease is endemic throughout many parts of the Asia Pacific, despite targeted control programs of at-risk populations. The success of these programs has been hindered by the limited efficacy of widely-used mebendazole, rapid re-infection rates linked to persistent reservoirs of untreated people and dogs, and the low sensitivity of conventional coprodiagnostic techniques employed.Methods: Here, we used standard faecal flotation (SFF) and a multiplex qPCR (mqPCR) assay to calculate and compare species-specific cure and egg reduction rates of single dose albendazole (400 mg) against hookworm infections at community level. Data from a cross-sectional survey in 1,232 people from Cambodia were used to inform a generalised linear mixed model to identify risk factors linked to hookworm infection(s) at baseline. Furthermore, we calculated risk factors associated to the probability of being cured after albendazole administration.Findings: Overall, 13·5% of all 1,232 people tested by SFF were positive for hookworm infection(s). Most (80·1%) infected people were >12 years of age, hence above the age targeted by the WHO control program. We estimate that as age increases, the odds of being infected increases at a faster rate for females than for males. We revealed a substantial difference in cure rate of hookworm infection(s) following albendazole treatment using the SFF (81·5%) and mqPCR (46·4%) assays, and provide the first data on the efficacy of this drug against the zoonotic hookworm Ancylostoma ceylanicum. We estimated that as age increases by one year, the odds of being cured decreases by 0·4%–3·7%. Similarly, the odds of being cured for people who boiled drinking water was estimated to be between 1·02 and 6·82.Interpretation: These findings show that the adoption of refined diagnostic techniques is central to monitoring hookworm infection(s) and the success of control strategies, which can ultimately aid in reducing associated morbidity in human populations. The approach taken is likely to be directly applicable to other parts of Southeast Asia and the Western Pacific, where specific epidemiological conditions might hamper the success of targeted treatment programs.Funding: Faculty of Veterinary and Agricultural Sciences Strategic Research Funds, The University of Melbourne.

Ancylostoma ceylanicum: The Neglected Zoonotic Parasite of Community Dogs in Thailand and Its Genetic Diversity among Asian Countries.

Simple SummaryAncylostomiasis is a zoonotic disease caused by the Ancylostoma hookworm infection of dogs, cats, and other wildlife species and is frequently found in Asia and tropical regions. The present study had confirmed the species of hookworm in dogs and soil environments collected from temple communities. In addition, we investigated the association of hookworm-contaminated soil in temple areas to increase awareness and establish a regimen to prevent zoonotic hookworm transmission. Lastly, we analyzed the genetic diversity and evolution of hookworm in dogs and soil environments among Thai A. ceylanicum and other Asian populations and disclosed insight into their fundamental genetic relationship.Ancylostoma ceylanicum is a zoonotic helminth that is commonly found in domestic dogs and cats throughout Asia but is largely neglected in many countries. This study aimed to confirm the species of hookworm in dogs and soil environments and investigate the evolutionary analyses of A. ceylanicum among Thai and Asian populations. In a total of 299 dog fecal samples and 212 soil samples from 53 temples, the prevalence rates of hookworm infection by microscopic examination were 26.4% (79/299) and 10.4% (22/212) in dog and soil samples, respectively. A PCR-RFLP targeting the ITS region was then utilized to identify the hookworm species. In dogs, A. ceylanicum was the main hookworm species, and the rates of A. ceylanicum and A. caninum infections were 96.6% and 3.5%, respectively. The genetic characterization and diversity indices of the A. ceylanicum cox1 gene among Thai and Asian populations were evaluated. Nine haplotypes were identified from Thai A. ceylanicum, in which the haplotype diversity and the nucleotide diversity were 0.4436 and 0.0036, respectively. The highest nucleotide diversity of Chinese A. ceylanicum populations suggested that it could be the ancestor of the populations. Pairwise fixation indices indicated that Thai A. ceylanicum was closely related to the Malaysian population, suggesting a gene flow between these populations. The temples with hookworm-positive dogs were associated with the presence of hookworm-contaminated soil, as these levels showed an approximately four-fold increase compared with those in temples with hookworm-negative dogs (OR = 4.38, 95% CI: 1.55–12.37). Interestingly, the genotypes of A. ceylanicum in the contaminating soil and infecting dogs were identical. Therefore, increased awareness and concern from the wider public communities with regard to the responsibility of temples and municipal offices to provide proper deworming programs to community dogs should be strongly endorsed to reduce the risk of the transmission of this zoonotic disease. In addition, parasitic examination and treatment should be strongly implemented before dogs are imported and exported worldwide.

Field application of a novel multiplex qPCR assay reveals the occurrence of the zoonotic hookworm Ancylostoma braziliense in Nigerian dogs

A number of gastrointestinal parasites have been reported to infect dogs in Nigeria, some of which have zoonotic potential. Of these, hookworms are the most prevalent, with both Ancylostoma caninum and Uncinaria stenocephala reported in the country. In this study, we subjected 203 hookworm microscopy-positive samples of the 885 individual faecal samples collected from dogs in Nigeria to a recently developed multiplex qPCR for the detection and characterisation of canine hookworm species. The qPCR demonstrated a diagnostic sensitivity of 98% (95% CI 95-99.4) allowing the detection of A. caninum and A. braziliense in 81.3% (165/203, 95% CI 75.3-86.1) and 51.2% (104/203, 95% CI 44.4-58) of the microscopy-positive faecal samples of dogs from Nigeria, respectively and 34.5% (70/203, 95% CI 28.3-41.3) of mixed infections with both hookworm species.The finding of A. braziliense is particularly worrisome given this is a well-known agent of persistent cutaneous larva migrans, commonly referred to as “creeping eruptions” in humans. Although this parasite has been diagnosed in locals and in people travelling in Nigeria suffering from dermatological illnesses, this represents the first molecular identification of A. braziliense in its canine reservoir in the country. These results update the occurrence and distribution of hookworm species affecting dogs in Nigeria highlighting the suitability of the newly developed multiplex qPCR assay as a high-throughput tool for the surveillance of zoonotic hookworms, globally.

Molecular identification of Ancylostoma ceylanicum in the Philippines.

Hookworms are some of the most widespread of the soil-transmitted helminths (STH) with an estimated 438.9 million people infected. Until relatively recently Ancylostoma ceylanicum was regarded as a rare cause of hookworm infection in humans, with little public health relevance. However, recent advances in molecular diagnostics have revealed a much higher prevalence of this zoonotic hookworm than previously thought, particularly in Asia. This study examined the prevalence of STH and A. ceylanicum in the municipalities of Palapag and Laoang in the Philippines utilizing real-time polymerase chain reaction (PCR) on stool samples previously collected as part of a cross-sectional survey of schistosomiasis japonica. Prevalence of hookworm in humans was high with 52.8% (n = 228/432) individuals positive for any hookworm, 34.5% (n = 149/432) infected with Necator americanus, and 29.6% (n = 128/432) with Ancylostoma spp; of these, 34 were PCR-positive for A. ceylanicum. Considering dogs, 12 (n = 33) were PCR-positive for A. ceylanicum. This is the first study to utilize molecular diagnostics to identify A. ceylanicum in the Philippines with both humans and dogs infected. Control and elimination of this zoonotic hookworm will require a multifaceted approach including chemotherapy of humans, identification of animal reservoirs, improvements in health infrastructure, and health education to help prevent infection.