High-throughput multiplex qPCRs for the surveillance of zoonotic species of canine hookworms

Comparison of different molecular protocols for the detection of Uncinaria stenocephala infection in dogs

The present study aims to assess the performance of different molecular targets using various matrices of samples for the detection of Uncinaria stenocephala (US) in hookworm infected dogs. To this end, the DNA extraction was performed on the following matrices of samples: (i) larvae of US obtained from experimentally infected dogs with US with different larvae counts per microliter (µl); (ii) pure US eggs suspension in distilled water with different egg counts per µl; (iii) spiked dog fecal samples with different US eggs per gram (EPG) of feces; (iv) feces from dogs naturally infected with hookworm eggs; (v) fecal suspension with hookworm eggs recovered from the FLOTAC apparatus. All the samples were tested with four different PCR protocols targeting specific regions for the detection of both hookworms US and AC as follows: Protocol A (ITS1, 5.8 S, ITS2) and Protocol B (18 S) for the detection of both species, Protocol C (ITS1) for the detection of AC and Protocol D (ITS1) for the detection of US. The best results were obtained with DNA extracted from US larvae matrix obtained from experimentally infected dogs, showing a detection limit of 3.5 larvae/ml for the protocols A, B and D. A moderate correlation was found between the FLOTAC technique and PCR protocols B and D with respect to fecal samples from dogs naturally infected with hookworms. Indeed, PCR protocols B (18 S) and D (ITS1) gave the best results for feces and fecal suspension from naturally infected dogs. However, all the PCR protocols used showed lower sensitivity than FLOTAC technique. Perhaps, isolating US eggs in advance could help to obtain better quality and quantity of DNA, avoiding some notable factors such as inhibitors present in faecal samples. However, a further study is needed to evaluate and standardise a protocol for the recovery of parasitic elements, that could be applied prior to DNA extraction. Therefore, this could lead to a better amplification of US eggs DNA. In conclusion, our results showed that the type of sample (sample-matrix) used for the DNA extraction samples is crucial, as this affects the diagnostic sensitivity of the technique.

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.

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.

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.

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.

A Taq-Man-based multiplex quantitative PCR for the simultaneous detection and quantification of Angiostrongylus vasorum, Crenosoma vulpis, and species of respiratory capillarids in canids

In recent years, Angiostrongylus vasorum, Crenosoma vulpis, Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi), commonly referred to as canine lungworms, have gained a growing interest worldwide as the result of their geographical expansion. Each of these nematode species differs considerably in its biology and pathogenicity. Despite their impact on dogs' health, these parasites are often underdiagnosed owing to diagnostic challenges. Here, we describe the development and validation of a Taq-Man-based multiplex quantitative PCR (qPCR) for the simultaneous detection of the main species of canine lungworms in faeces of infected dogs. Using 10-fold serial dilutions of synthetic gene block fragments containing individual sequence targets of each lungworm species, the analytical sensitivity of the assay ascertained was 1.84 ng/μl for A. vasorum, 3.08 ng/μl for C. vulpis and 0.79 ng/μl for Eucoleus spp. The sensitivity of the assays and their ability to detect mixed species infections were compared with microscopy-based techniques (faecal floatation and Baermann technique) applied to faecal samples submitted for lungworm testing through an accredited diagnostic laboratory at the Institute of Parasitology, University of Zurich, Switzerland, and from community dogs as part of a research project on canine endoparasites in Cambodia. The multiplex qPCR displayed high diagnostic sensitivity (42/46, 91.3%; 95% Confidence Interval (CI): 79.1-97.1%) and a diagnostic specificity of 100% (45/45, 95% CI: 90.6-100%), and was able to detect 42.9% additional mixed lungworm species infections compared with microscopy-based methods. Kappa statistics showed substantial agreement between the qPCRs and microscopy for mixed infections (κ = 0.72, 95% CI: 0.4-1) and Eucoleus spp. (κ = 0.65, 95% CI: 0.45-0.85) and almost perfect agreement for C. vulpis (κ = 0.85, 95% CI: 0.63-1) and A. vasorum (κ = 0.92, 95% CI: 0.84-1). This multiplex qPCR enables timely, accurate, and sensitive diagnosis of canine lungworm species in faecal samples and can be used to monitor the geographical distribution and emergence of these parasitic species, globally.

Risk Factors Associated with Soil-Transmitted Helminths in Dog Feces That Contaminate Public Areas of Warsaw, Poland

A constant increase in dog numbers, especially in large towns, has been observed recently. The presence of dogs in urban spaces increases the risk of pollution by dogs' feces, which may contain growth forms of parasites including canine, soil-transmitted helminths (cSTHs), most of which have a proven zoonotic potential. This study assessed the frequency of occurrence and estimated the potential risk associated with the presence of cSTHs in dogs' feces left uncollected in urban areas. The study material consisted of 200 fecal samples obtained from city and dog parks situated in selected Warsaw districts. Each fecal sample was processed using the flotation technique. Eggs of cSTHs, including Toxocara canis, Toxascaris leonina, Trichuris vulpis, and hookworms from the Ancylostomatidae family were found in 23 (11.5%) of the examined fecal samples. The most prevalent species were hookworms from the family Ancylostomatidae (8%). The presence of parasites was confirmed in 14 out of 20 studied locations (70%), including eight city parks (72.7%) and six dog parks (66.7%). City and dog parks did not differ significantly in the frequency of parasite occurrence. This study indicated that dogs' feces, left uncollected, may cause environmental contamination with cSTHs. It also indicated that the presence of dogs' feces in public areas and the associated presence of parasites is still a problem.

Anthelmintic resistance in soil-transmitted helminths: One-Health considerations

The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.

Unambiguous identification of Ancylostoma caninum and Uncinaria stenocephala in Australian and New Zealand dogs from faecal samples

Hookworms (Ancylostomatidae) are well-known parasites in dogs due to their health impacts and zoonotic potential. While faecal analysis is the traditional method for detection, improvements in husbandry and deworming have decreased their prevalence in urban owned dogs. Drug resistance in Ancylostoma caninum is becoming a discussion point in small animal practices across the region. This study aimed to identify hookworm species present in Australian and New Zealand dogs using molecular techniques. The ITS-2 and isotype-1 β-tubulin assays were used to identify and quantify hookworm species. Results showed absence of coinfection in Australian samples from Greater Sydney region belonging either to A. caninum or Uncinaria stenocephala, while New Zealand samples were a mixture of A. caninum and U. stenocephala. The amplified isotype-1 β-tubulin sequences exhibited susceptibility to benzimidazole drugs. Rare mutations were identified in A. caninum and U. stenocephala sequences, representing a small percentage of reads. This study highlights the importance of molecular techniques in accurately identifying and quantifying hookworm species in dog populations.

Associations between canine hookworm infection and dog owners' awareness, perception, and behaviour: A cross-sectional study in Brisbane, Queensland, 2019-2020

Canine hookworms are found globally, and infections have been recorded in domestic dogs visiting dog parks in Queensland, Australia. Some canine hookworms also present a risk of zoonotic transmission to humans. Potential transmission of hookworms can occur in the household and at public places because of lack of owner awareness and poor coverage of canine deworming. Between April 2019 and March 2020, faecal samples from owned dogs were collected from 39 dog parks in metropolitan Brisbane, Queensland, and tested for the presence of hookworm eggs using faecal floatation technique. Dog owners who provided samples were requested to complete a survey on their awareness, perceptions and behaviour regarding the risks and consequences of canine parasitic infection. Associations between dog owner demographics and responses to the survey were measured using Goodman and Kruskal's gamma. Statistical associations between canine hookworm infection in dogs and their owner's responses were quantified using a two-sample Wilcoxon rank-sum test. A total of five canine faecal samples from 175 respondents were found positive for hookworm eggs, corresponding to a sample- and park-level prevalence of 2.86% and 12.82%, respectively. Female dog owners were found to be more aware of the importance of regular deworming of their dogs (|γ| = 0.405). Our results indicate that hookworm infection was associated with a lower awareness of the importance of deworming (p = 0.007), less diligence in administration of deworming (p = 0.004), lower awareness of the risk of acquiring parasites from raw meat (p = 0.010), less likelihood of cooking meat before feeding it to their dogs (p = 0.028), and less likelihood to properly dispose their dog's faeces (p = 0.027). This study not only indicates a need for improving owner education towards the importance of deworming but also a need for changing owner's behaviours to reduce potential environmental contamination with infective hookworms. The latter in particular indicates a broader public health risk of disease transmission in public places due to improper disposal of dog faeces, especially in areas with higher canine hookworm infections.

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

BACKGROUND

For 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.

METHODS

A 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.), Giardia duodenalis, Cystoisospora spp., Toxoplasma gondii, and Tritrichomonas blagburni] 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.

RESULTS

qPCR 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 Ancylostoma caninum 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.

CONCLUSIONS

These 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.

Zoonotic helminths of dogs and risk factors associated with polyparasitism in Grenada, West Indies

Canine soil-transmitted helminths (STHs) cause important zoonoses in the tropics, with varying degrees of intensity of infection in humans and dogs. This study aimed to investigate the prevalence and associated risk factors for STHs in community dogs residing in Grenada, West Indies. In May 2021, 232 canine fecal samples were examined for zoonotic helminths by microscopy (following flotation), and genomic DNA from a subset of 211 of these samples were subjected to multiplex qPCR for the detection and specific identification of hookworms, Toxocara spp. and Strongyloides. Microscopic examination revealed that 46.5% (108/232, 95% CI 40–52.9), 9% (21/232, 95% CI 5.35–12.7) and 5.2% (12/232, 95% CI 2.3–8) of the samples contained eggs of Ancylostoma spp., Toxocara spp. and Trichuris vulpis, respectively. Multiplex qPCR revealed that, 42.2% (89/211, 95% CI 35.5–48.8) were positive for at least 1 zoonotic parasite. Of these, 40.8% (86/211, 95% CI 34.1–47.3) of samples tested positive for Ancylostoma spp., 36% (76/211, 95% CI 29.5–42.9) were positive for A. caninum, 13.3% (28/211, 95% CI 9–18.6) for A. ceylanicum, 5.7% for T. canis (12/211, 95% CI 2.97–8.81) and 1% (2/211, 95% CI 0–2.26) for Strongyloides spp. (identified as S. stercoralis and S. papillosus by conventional PCR-based Sanger sequencing). Using a multiple logistic regression model, a low body score and free-roaming behaviour were significant predictors of test-positivity for these parasitic nematodes in dogs (P < 0.05). Further studies of zoonotic STHs in humans should help elucidate the public health relevance of these parasites in Grenada.

Diversity and prevalence of gastrointestinal helminths of free-roaming dogs on coastal beaches in Ecuador: Potential for zoonotic transmission

Free-roaming dogs are highly exposed to a range of zoonotic parasites, including helminths, which can be transmitted to humans, particularly in rural tropical settings of developing countries. To evidence the diversity and prevalence of gastrointestinal helminths in the stools of free-roaming dogs on the public Pacific coastal beaches of Ecuador, a cross-sectional study was conducted from August 2021 to August 2022. The sampling beaches are located along the tropical Pacific coastal region. Stools were collected from the ground in containers with 10% formalin and processed using the Ritchie method; eggs were identified under a microscope. A total of 573 stools were examined from 20 beaches; the overall prevalence was 157 (27.4%) for one or more helminths. Ten parasites were identified, nine of which are potentially zoonotic. Ancylostoma spp. was the most prevalent (19.4%), followed by Toxocara spp. (7.2%). Trichuris spp., Dipylidium caninum, Diphyllobothrium spp., Capillaria spp., Dicrocoelium spp., Heterobilharzia americana, Hymenolepis spp. and Spirocerca spp. were also observed. Five of them are reported for the first-time infecting dogs in Ecuador. Hence, we evidenced that Ecuadorian beaches are highly contaminated with the dogs' zoonotic gastrointestinal helminths, posing a great risk to public health. Differences in the presence and prevalence were found in samples of tropical humid and dry climate zones. Therefore, based on our findings, we encourage the implementation of broad antiparasitic treatment and prevention strategies to reduce the zoonotic risk.

Emergence of Ancylostoma caninum parasites with the benzimidazole resistance F167Y polymorphism in the US dog population

BACKGROUND

Anthelmintic resistance to benzimidazole has been detected in the canine hookworm, Ancylostoma caninum. Benzimidazole resistance is believed to have developed originally in greyhounds, but has also been detected in non-greyhound pet dogs. The aim of this study was to validate a probe-based allele-specific real-time PCR tests for the F167Y polymorphism on the β-tubulin isotype-1 gene and to determine the geographic distribution.

METHODS

Allele-specific real-time PCR tests were established and validated to detect the codon 167 polymorphism in the Ancylostoma caninum β-tubulin isotype-1gene. Additionally, real-time PCR tests were validated for Ancylostoma spp. and Uncinaria stenocephala. Two nucleic acid extraction protocols were validated including mechanical disruption of parasite structures in stool. The frequency of the F167Y single nucleotide polymorphism (SNP) was determined in hookworm confirmed stool samples. Samples with the resistant 167Y genotype were confirmed by β-tubulin gene sequencing and allele frequencies were determined.

RESULTS

The Ancylostoma spp. and A. caninum F167Y allele-specific real-time PCR tests were highly sensitive and specific when tested against synthetic DNA, spiked samples, and characterized parasites. Using an optimized total nucleic acid extraction protocol, 54 of 511 (10.6%) were found to contain the benzimidazole resistance allele. All 55 samples containing hookworms with the resistance mutation were confirmed by β-tubulin gene sequencing. The majority of resistant hookworms (44 resistant, 183 tested; 24.4%) originated from Florida, five from California (103 tested, 4.9%), three from Idaho (40 tested, 7.5%), two from Nevada (22 tested, 9.1%), and one sample from Hawaii (13 tested, 7.7%). Resistant genotypes were found in 14 different dog breeds including eight in Greyhounds. Allele-frequency determination revealed resistance allele frequencies between 1 and 100% with 58% above 50%.

CONCLUSIONS

This data strongly supports recent findings of benzimidazole resistant canine hookworms present throughout the general US pet dog population.

Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond

Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.

Human social conditions predict the risk of exposure to zoonotic parasites in companion animals in East and Southeast Asia

Background

A recent dramatic surge in pet ownership has been observed across metropolitan areas in Asia. To date, there is a dearth of information on the risk associated with pet ownership for the transmission of parasites on a large scale in Asia, despite this continent giving rise to the largest burden of zoonotic infections worldwide.

Methods

We explored the nature and extent of zoonotic internal (endo-) and external (ecto-) parasites and arthropod-borne pathogens in 2381 client-owned dogs and cats living in metropolitan areas of eight countries in East and Southeast Asia using reliable diagnostic tests and then undertook extensive statistical analyses to define predictors of exposure to zoonotic pathogens.

Results

The estimated ORs for overall parasite infections are 1.35 [95% CIs 1.07;1.71] in young animals and 4.10 [1.50;11.2] in the animal group older than 15 years as compared with adult animals, 0.61 [0.48;0.77] in neutered animals as compared to unneutered animals, 0.36 [0.26;0.50] in animals living in urban areas as compared with rural areas, 1.14 [1.08;1.21] for each 1 °C increase of annual mean temperature which varies from 12.0 to 28.0 °C, and 0.86 [0.78;0.95] for each year of life expectancy which varies from 70.9 to 83.3 years.

Conclusions

Here we highlight the influence of human life expectancy and the neutering status of the animals, which reflect increased living standards through access to education and human and veterinary health care, to be both strongly associated with exposure to zoonotic parasites. An integrated approach of local and international authorities to implement and manage educational programs will be crucial for the control of zoonotic infections of companion animals in Asia.

Parasites live on or inside animals or humans and can cause disease. Companion animals (pets) with parasites present a potential risk to the health of their owners, as certain kinds of parasites (known as zoonotic parasites) can affect both animal and human health. Here, we investigated whether human social conditions are associated with zoonotic parasite infections in companion animals in East and Southeast Asia. We found that higher human life expectancy and neutering of the companion animals were associated with fewer zoonotic parasite infections in the animals. These findings highlight the need for an enhanced commitment of local authorities to establish prevention campaigns, including education programs, against zoonotic pathogens. These measures will play a crucial role in alleviating the impact of these diseases in companion animals and humans in Asia.

Colella, Wongnak et al. test pet dogs and cats from metropolitan areas of eight countries in East and Southeast Asia for zoonotic parasites. The authors identify factors associated with potential exposure to zoonotic parasites, including animal characteristics and human living conditions.

A systematic review and meta-analysis of human and zoonotic dog soil-transmitted helminth infections in Australian Indigenous communities

Soil-transmitted helminths (STH) infect 1.5 billion people and countless animals worldwide. In Australian Indigenous communities, STH infections have largely remained endemic despite control efforts, suggesting reservoirs of infection may exist. Dogs fulfil various important cultural, social and occupational roles in Australian Indigenous communities and are populous in these settings. Dogs may also harbour zoonotic STHs capable of producing morbidity and mortality in dogs and humans. This review provides an overview of human and zoonotic STH infections, identifies the Australian Indigenous locations affected and the parasite species and hosts involved. The meta-analysis provides estimates of individual study and pooled true prevalence of STH infections in Australian Indigenous communities and identifies knowledge gaps for further research on zoonotic or anthroponotic potential. A systematic literature search identified 45 eligible studies documenting the presence of Strongyloides stercoralis, Trichuris trichiura, Ancylostoma caninum, Ancylostoma duodenale, Ancylostoma ceylanicum, undifferentiated hookworm, and Ascaris lumbricoides. Of these studies, 26 were also eligible for inclusion in meta-analysis to establish true prevalence in the light of imperfect diagnostic test sensitivity and specificity by Rogan-Gladen and Bayesian methods. These studies revealed pooled true prevalence estimates of 18.9% (95% CI 15.8–22.1) for human and canine S. stercoralis infections and 77.3% (95% CI 63.7–91.0) for canine A. caninum infections indicating continued endemicity, but considerably more heterogenous pooled estimates for canine A. ceylanicum infections, and A. duodenale, undifferentiated hookworm and T. trichiura in humans. This review suggests that the prevalence of STHs in Australian Indigenous communities has likely been underestimated, principally based on imperfect diagnostic tests. Potential misclassification of hookworm species in humans and dogs due to outdated methodology, also obscures this picture. High-quality contemporary studies are required to establish current true prevalence of parasite species in all relevant hosts to guide future policy development and control decisions under a culturally sound One Health framework.

Soil-transmitted helminths include hookworms, threadworms, whipworms and roundworms. These worms may infect different hosts including humans and dogs, and some species are zoonotic, meaning that they are able to transmit between animals and humans. In many Australian Indigenous communities, people remain infected with these worms at high rates compared to other parts of the country despite various control strategies. Resource and health literacy inequalities are primary drivers for these differences. However, the potential for dogs to act as reservoirs for zoonotic worm infections in humans must also be considered. For this reason, it’s important to create a clear picture of the level of infection by location and host. Given that tests used to establish prevalence can produce false positive or negative results, we performed a meta-analysis allowing comparison of true prevalence estimates by location and host, regardless of the test used. This review suggests that threadworm and dog hookworm remain endemic in Australian Indigenous communities, though a gap exists to accurately inform the prevalence of the other worms. It also highlights the need for One Health strategies in research, policy and control where humans, all animal hosts and the environment are considered in a culturally relevant way.

Advances in diagnosis of gastrointestinal nematodes in livestock and companion animals

Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.

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.

Faecal prevalence, distribution and risk factors associated with canine soil-transmitted helminths contaminating urban parks across Australia

Dog parks provide an ideal urban space where dogs and their owners can exercise, play, and socialize in a safe environment. However, these parks can also increase the risk of exposure to a series of infectious agents including canine soil-transmitted helminths (cSTHs) such as hookworms, roundworms, Strongyloides stercoralis, and Trichuris vulpis, which are endemic to Australia. In this study, we collected 1581 canine faecal samples in 190 urban parks across Australia and subjected these to faecal floatation and multiplex real-time PCRs (qPCR) to detect a range of cSTHs. In total, 44.2% of the parks sampled were contaminated with at least one species of cSTH, with hookworms being the most prevalent parasites (10.2%) followed by Trichuris spp. (1.3%) and Strongyloides spp. (1.2%). This is the first large-scale study investigating the contamination of urban parks with cSTHs in Australia, and the first nation-wide study to demonstrate the occurrence of Strongyloides spp. in canine faecal samples from urban areas in the country. This study reveals a high rate of contamination with cSTHs in dog parks in urban Australia, most of which having proven zoonotic potential. Preventive measures, including awareness-raising educational programs promoting responsible pet ownership, should be encouraged to minimise the health risks associated with cSTHs for both dogs and humans.

Occurrence of Hookworm and the First Molecular and Morphometric Identification of Uncinaria stenocephala in Dogs in Central Europe

PURPOSE

Hookworms are hematophagous parasitic nematodes that occur in the intestinal tract of various mammals, including humans. The objective of this work was to develop a two-step morphology-molecular analysis-based strategy to identify the genus and the species of eggs and larvae of the Ancylostomatidae family in dogs, which were kept in various living conditions in Slovakia.

METHODS

Faecal samples were collected from 270 dogs kept in two different shelters (160 samples) and in a marginalised Roma community (110 samples). Faecal samples were processed using the flotation method. Microscopically positive faecal samples with hookworm eggs were subjected to a coproculture and the hatched larvae were identified morphometrically, prior to molecular testing. The faecal samples with hookworm´s eggs and individual larvae were identified by a molecular assay based on the amplification of the 18S ribosomal RNA gene fragment. Further, species-specific primer sets were designed for the internal transcribed spacer (ITS 1 region) and the mitochondrial cytochrome c oxidase subunit I (COX1) gene section.

RESULTS

Hookworm eggs were microscopically detected in 9.6% (26/270) of the total number of faecal samples. The prevalence in the Roma settlement was higher, 14.5% (16/110), than in shelters, 6.3% (10/160). Using PCR and subsequent Sanger sequencing, we identified the canine hookworm species Uncinaria stenocephala in all positive samples.

CONCLUSION

Our results have provided new data on the molecular identification of the neglected species U. stenocephala affecting dogs in Slovakia and supplemented the missing information on the prevalence and incidence of hookworms in dogs in Europe.

Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics

Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut. Stool-based diagnostics are likely to serve as an important tool well into the future; improved diagnostics of helminths and their environment in the gut may assist the identification of biomarkers with the potential to define the health/disease status of individuals and populations, and to identify existing or emerging anthelmintic resistance.

Development of a New LAMP Assay for the Detection of Ancylostoma caninum DNA (Copro-LAMPAc) in Dog Fecal Samples

Ancylostoma caninum is a zoonotic nematode which is able to affect animals and humans. Diagnosis in the definitive host and environmental detection are key to prevent its dissemination and achieve control. Herein, a new coprological LAMP method for the detection of A. caninum (Copro-LAMPAc) DNA was developed. DNA extraction was performed using a low-cost method and a fragment of the cox-1 gene was used for primer design. The analytical sensitivity, evaluated with serial dilutions of genomic DNA from A. caninum adult worms, was 100 fg. A specificity of 100% was obtained using genomic DNA from the host and other pathogens. The Copro-LAMPAc was evaluated using environmental canine fecal samples. When compared with gold standard optical microscopy in epidemiological studies, it proved to be more sensitive. This new LAMP assay can provide an alternative protocol for screening and identification of A. caninum for epidemiological studies in endemic areas.

Zoonotic hookworms of dogs and cats - lessons from the past to inform current knowledge and future directions of research

The early-to-mid 1900s was an era that marked the first published reports of clinical cases and experimental human infections that provided valuable evidence to inform our current knowledge on the zoonotic nature of the canid and felid hookworms. To this day, descriptions of the pathognomonic syndromes produced in humans by these early pioneers provide vital information on the putative geographical distribution of these hookworm species, even before their discovery in dogs and cats. Cases of hookworm-related cutaneous larvae migrans and Ancylostoma caninum-induced eosinophilic enteritis continue to be reported in the medical literature, most commonly in recent migrants or returned travellers who have spent time in regions in which these canine and feline hookworms remain highly endemic. Ancylostoma ceylanicum, now recognised as the second most common hookworm infecting humans in the Asia Pacific region, is also being reported in regions of Africa and South America previously assumed free of this parasite. Despite the substantial technological progress made in the field of parasite diagnostics, our knowledge on the epidemiology and population-level morbidity impacts of these zoonotic hookworms in humans has remained relatively stagnant over the last few decades, with 'covert' infections continuing to remain undetected by currently available forms of routine diagnostics. Improved diagnostic tools that enable accurate and rapid species-specific diagnosis of zoonotic hookworm infections in humans are required to provide the necessary evidence to advocate for future investments in One Health-based intervention strategies.

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.

Validation and maintaining laboratory developed molecular tests compliant with ISO15189 for diagnosis of intestinal parasitic infections

INTRODUCTION

Although, in the past few decades molecular diagnostics of parasitic infections have been accepted as first-line diagnostics, laboratories tend to be reluctant of introducing nucleic acid based tests as they dread the validation of laboratory developed tests (LDTs) compliant with ISO1589.

AREAS COVERED

This paper describes how to set tailor-made performance characteristics for the validation of laboratory developed tests (LDTs) for the molecular diagnosis of intestinal parasitic infections complying with the ISO 15189 guidelines. Then, just as important, maintaining these tests by daily monitoring, external quality assessment schemes, and reassessment of the test set-up.

EXPERT OPINION

Tailoring performance characteristics for the validation of LDTs defining criteria that make sense and actually leading to a process of continuous quality improvement in the day-to-day practice of a diagnostic laboratory. It is essential or even obligatory to modify these characteristics, skip, or to add additional characteristics based on personal or changing insights fitted for a specific setting.

Ancylostoma ceylanicum as the second most frequent hookworm species isolated in France in travellers returning from tropical areas

Ancylostoma ceylanicum is the second most common hookworm species infecting humans in Southeast Asia and Oceania. We performed a 3 years multicenter study to assess its frequency in hookworm infecting patients returning from tropical areas to France and found that A. ceylanicum was the second most frequent hookworm species isolated.

Zoonotic Soil-Transmitted Helminths in Free-Roaming Dogs, Kiribati

Soil-transmitted helminths are highly prevalent in the Asia-Pacific region. We report a 96.5% prevalence of zoonotic soil-transmitted helminths in dogs in Kiribati. We advocate for urgent implementation of treatment and prevention programs for these zoonotic pathogens, in line with the Kiribati-World Health Organization Cooperation Strategy 2018-2022.

Comparison of the egg recovery rates and limit of detection for soil-transmitted helminths using the Kato-Katz thick smear, faecal flotation and quantitative real-time PCR in human stool

Background

Monitoring the success of soil-transmitted helminth (STH) control programs relies on accurate diagnosis and quantitative assessment of infection prevalence and intensity. As preventative chemotherapeutic program coverage for STH expands, the necessity of gaining insights into the relative or comparative sensitivities, in terms of limits of detection (LOD) and egg-recovery-rates (ERR) for microscopy and quantitative polymerase chain reaction qPCR-based diagnostic techniques becomes imperative to inform suitability for their intended use for large scale STH monitoring and treatment efficacy studies.

Methodology/Principal findings

The diagnostic performance in terms of ERR and LOD of the Kato-Katz (KK) thick smear technique, sodium nitrate (NaNO₃) faecal floatation (FF) and qPCR for the accurate detection and enumeration of STH eggs were calculated and expressed in eggs per gram (EPG), by experimentally seeding parasite-free human faeces with Ascaris spp., Trichuris spp. and Necator americanus eggs representing low, medium and high intensity infections. The efficiency of NaNO₃ flotation was also calculated over a range of specific gravities (SpGr) for the optimum recovery of STH eggs. FF of SpGr 1.30 recovered 62.7%, 11% and 8.7% more Trichuris spp., Necator americanus and Ascaris spp. eggs respectively, than the recommended SpGr of 1.20. All diagnostic methods demonstrated strong direct correlation to the intensity of seeded EPG. KK and FF (SpGr 1.30) resulted in significant lower ERRs compared to qPCR (p <0.05). qPCR demonstrated significantly (p <0.05) greater sensitivity with an ability to detect as little as 5 EPG for all three STH, compared to 50 EPG by KK and FF (SpGr 1.30).

Conclusions/Significance

This study compares the diagnostic parameters in terms of LOD and ERRs of STHs for the KK, FF and qPCR. These results indicate that the diagnostic performance of qPCR assays should be considered by control programs in the phase that aims to seek confirmation of transmission break and cessation of preventive chemotherapy in low-transmission settings, in line with the control targets of the WHO neglected tropical diseases 2030 Roadmap.

STH infections predominately affect resource-poor communities and negatively impact on child and maternal health. Diagnostics play a critical role in guiding and informing existing STH control programs and the implementation and evaluation of intervention strategies. The KK technique is most commonly used as per WHO guidelines and is the basis for determining quantitative thresholds for low, moderate and heavy infections. More recently, FF and laboratory-based quantitative PCR techniques have provided alternative options of diagnosing STH infections. A number of studies correlating the relative sensitivity, diagnostic agreement, and egg enumeration of these techniques by comparing field-generated diagnostic data have attempted to correlate quantitative outputs to those defined by the WHO, with little resolution. Moreover, as large-scale deworming programs levels scale up, the necessity to apply techniques that can precisely detect light infections is of outmost importance to establish preventive chemotherapy end-points using more accurate means. In this study we compared the LOD and ERR of seeded non-infected human faecal samples with Ascaris, Trichuris and Necator spp. eggs using KK, FF and qPCR. When compared to copro-microscopy methods, qPCR showed the highest sensitivity for the detection of light-intensity infections and was more accurate in enumerating the original number of eggs per gram of seeded faeces. In addition to this, the results indicated that the diagnostic performance of both KK and FF (using solution at a SpGr of 1.30) were equally efficient and should be considered with their diagnostic limitations in mind, when aiming to monitor STH infections in low-transmission settings.

Novel High-Throughput Multiplex qPCRs for the Detection of Canine Vector-Borne Pathogens in the Asia-Pacific

The Asia-Pacific hosts a large diversity of canine vector-borne pathogens (VBPs) with some of the most common and most pathogenic, generating significant mortality as well as a spectrum of health impacts on local dog populations. The VBPs Anaplasma platys, Babesia gibsoni, Babesia vogeli, Ehrlichia canis, Hepatozoon canis and haemotropic Mycoplasma spp. are all endemic throughout the region, with many exhibiting shifting geographical distributions that warrant urgent attention. Moreover, many of these species cause similar clinical signs when parasitising canine hosts, whilst knowledge of the exact pathogen is critical to ensure treatment is effective. This is complicated by frequent coinfection that can exacerbate pathology. Here, we describe the development, optimisation and validation of two novel quadruplex Taq-Man based real-time PCRs (qPCRs) for the specific and sensitive detection of the aforementioned VBPs. To ensure accurate evaluation of diagnostic performance, results of our qPCRs were evaluated on field samples from Thai dogs and compared with both conventional PCR (cPCR) results and next-generation sequencing (NGS) metabarcoding. Our qPCRs were found to be more sensitive at detecting canine VBP than cPCR and generated results similar to those achieved by NGS. These qPCRs will provide a valuable high-throughput diagnostic tool available to epidemiologists, researchers and clinicians for the diagnosis of key canine VBPs in the Asia-Pacific and further afield.

Canine gastrointestinal parasites as a potential source of zoonotic infections in Nigeria: A nationwide survey

Dog feces may contain zoonotic parasites that contaminate the environment and serve as a potential source of infection to animals and humans. In this study, microscopic and molecular analyses were used to estimate the prevalence and intensity of gastrointestinal (GI) parasites and assess the risk factors for infection in 948 dogs in three climatically distinct zones of Nigeria. Zoonotic helminths including Strongyloides stercoralis, Ancylostoma braziliense, A. caninum and Toxocara canis were detected either as single or multiple infections in 377 (39.8 %) of dogs examined. At multiple logistic regression analyses, association was found between GI parasite infection and deworming practices and dog management. Regarding A. braziliense, A. caninum and T. canis infections, intensity of egg shedding was statistically associated with the age of the dogs and not with their sex or breed. The majority of GI parasite-positive dogs did not receive regular deworming treatment (59 %) and roamed freely (56 %) thereby constituting public health risk. This is the first nationwide survey and analyses of risk factors of GI parasites of dogs using molecular methods as confirmation of their identity. The zoonotic potential of these parasites is exacerbated by the lack of both operational national policies to control the population of free-roaming dogs and to promote responsible dog ownership, and veterinary public health programs for dogs.

Urban public squares as potential hotspots of dog-human contact: A spatial analysis of zoonotic parasites detection in Gran Santiago, Chile

Zoonotic parasites are a major public health problem globally, representing a hazard to human health. The infections occur through contact with different parasite forms. Public squares are a common meeting place for people and dogs, becoming a risk area for transmission to other dogs and humans. A spatial analysis of zoonotic parasite distribution in urban public squares in Gran Santiago, Chile was performed to elucidate its importance, exploring spatial aggregation on positivity rates at commune level. A total of 170 stool samples were analysed; 54 (31.7%) were positive for gastrointestinal-zoonotic parasites. Positivity was detected in 27 (79.4%) squares. Diversity of parasite species was variable across sites. Toxocara canis was the most frequently detected (27 samples, 21/34 squares), followed by Toxascaris leonina (13 samples, 10/34 squares), cestode eggs (10 samples, 9/34 squares), Giardia sp. (6 samples, 5/34 squares), Ancylostomatidae-like eggs (4 samples, 4/34 squares), Cryptosporidium spp. (2 samples, 2/34 squares) and Entamoeba spp. (1 sample, 1/34 square). Spatial autocorrelation (SA) was observed at commune level. The local indicators of the spatial association test showed statistical significance for cestode eggs (p < 0.001) with a negative SA (Moran's I Index = -0.2929, CI-95% = -0.3869--0.1989) and Ancylostomatidae (p = 0.046) with a positive SA (Moran's I Index = 0.1404, CI-95% = 0.0499-0.2309). Toxocara canis is the most prevalent geo-helminth in public places of Santiago, Chile. Spatial autocorrelation was detected for cestode eggs and Ancylostomatidae. Diagnosis and detection of parasites is key for the establishment of control/eradication of environmental dissemination following One Health guidelines.

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.

Opportunistic Mapping of Strongyloides stercoralis and Hookworm in Dogs in Remote Australian Communities

Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, S. stercoralis and some species of hookworms infect canids and therefore present both environmental and zoonotic sources of transmission to humans. Currently, there is limited information available on the prevalence of hookworms and S. stercoralis infections in dogs living in communities across the Northern Territory in Australia. In this study, 274 dog faecal samples and 11 faecal samples of unknown origin were collected from the environment and directly from animals across 27 remote communities in Northern and Central Australia. Samples were examined using real-time polymerase chain reaction (PCR) analysis for the presence of S. stercoralis and four hookworm species: Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma braziliense and Uncinaria stenocephala. The prevalence of S. stercoralis in dogs was found to be 21.9% (60/274). A. caninum was the only hookworm detected in the dog samples, with a prevalence of 31.4% (86/274). This study provides an insight into the prevalence of S. stercoralis and hookworms in dogs and informs future intervention and prevention strategies aimed at controlling these parasites in both dogs and humans. A "One Health" approach is crucial for the prevention of these diseases in Australia.