Hookworm-related cutaneous larva migrans

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.

Gastrointestinal Parasites in Owned Dogs in Serbia: Prevalence and Risk Factors

Dogs are the most popular pets worldwide. Close contact between dogs and people increases the risk of transmission of various zoonotic parasitic infections. Given the importance of veterinary medicine in preserving the One Health concept, the aim of this research was to identify intestinal parasites that may have zoonotic potential and to evaluate risk factors (individual and environmental). The research was conducted in Serbia in 2022 and 2023 on 382 owned dogs, using qualitative methods of coprological examination with a concentration on parasitic elements. The overall prevalence of intestinal parasites was 62.6%, with the following detected: protozoa: Cystoisospora spp. (9.2%), Sarcocystis spp. (4.5%), Neospora caninum/Hammondia spp. (3.7%), Giardia intestinalis (11.8%); nematoda: Toxocara canis (11.5%), Toxascaris leonina (4.2%), family Ancylostomatidae (38.0%), Trichuris vulpis (21.5%), Capillaria spp. (10.5%); trematoda: Alaria alata (1.6%) and cestodes from the Taeniidae family (1.3%). Factors like age, size and coat length, as well as the way of living, attitude and diet were linked to a significantly higher (p < 0.05) prevalence of intestinal parasites. Based on the results of coprological diagnostics, this research indicates the importance of educating dog owners, conducting routine parasitological tests on their pets and regular deworming strategies.

Vesiculobullous Cutaneous Larva Migrans in the Absence of Domestic Dogs and Cats. Successful Treatment with Oral Ivermectin

While conducting research in a protected ecological reserve within Ecuador's subtropical rainforest, a 49-year-old biologist, residing in an Andean city, contracted hookworm-related cutaneous larva migrans (Hr-CLM) in the vesiculobullous clinical form. Since there were no domestic dogs or cats in the reserve, it is likely that wild animals carrying Ancylostoma sp. larvae infected the patient. She was effectively treated with two doses of oral ivermectin, administered 31 days after getting the infection. This case was diagnosed in a temperate city; therefore, a comprehensive travel history and clinical assessments are crucial for an accurate diagnosis and timely treatment.

Pyrantel resistance in canine hookworms in Queensland, Australia

Hookworms are the most common intestinal nematode parasites of dogs in Australia. The control of these parasites relies mostly on regular deworming with anthelmintics, with pyrantel-based dewormers being a relatively low cost and readily-available option for dog owners. Pyrantel resistance in canine hookworms in Australia was first reported in 2007, however pyrantel-based dewormers are still used against hookworm infection in dogs across Australia. The present study was conducted to evaluate the efficacy of pyrantel against hookworms infecting dogs housed in a shelter facility in Southeast Queensland which receives rescued or surrendered animals from greyhound rescue centres and dog shelters across this region. A total of 10 dogs were examined using the faecal egg count reduction test (FECRT). There was no reduction in FEC in any of the dogs following pyrantel treatment, with drug efficacies ranging from -0.9% to -283.3%. Given that these dogs originated from various sites across Southeast Queensland, the present study suggests that pyrantel resistance is widespread in this region, and hence this anthelmintic may not be a useful option for treatment of hookworm infections in dogs.

K, Baral A, Shrestha R, Shrestha R. Cutaneous larva migrans in a child: a case report and review of literature

Introduction

Cutaneous larva migrans (CLM) is a dermatitis caused by the invasion and migration of parasitic larvae of hookworms, primarily affecting tropical and subtropical regions. This report presents a case of CLM in a Nepali child and provides an overview of the literature on this condition.

Case report

A 4-year-old boy from a rural area in Nepal presented with a pruritic skin lesion on his left foot, initially misdiagnosed as fungal infection. The lesion gradually expanded, forming a serpiginous erythema, and became intensely pruritic. The patient's family had poor socioeconomic conditions, and the child frequently walked barefoot in an area with many domestic and stray dogs. Diagnosis was confirmed clinically, and treatment with oral albendazole and antihistamines resulted in complete resolution of symptoms.

Discussion

CLM is a neglected zoonotic disease, with an underestimated burden in developing countries due to underreporting and misdiagnosis. The larvae of Ancylostoma spp. are common culprits, causing a localized inflammatory reaction as they migrate through the skin. Diagnosis is mainly clinical and routine investigations usually reveal no abnormality. Complications may include secondary bacterial infections, allergies, and rare migration to internal organs. Treatment options include albendazole or ivermectin, with preventive measures emphasizing hygiene, footwear use, and pet deworming.

Conclusion

CLM is a neglected disease that primarily affects marginalized communities in tropical regions. Raising awareness among healthcare providers, conducting observational studies, and developing treatment guidelines, especially for children, are essential steps to address this public health concern. Preventive efforts, such as promoting hygiene and footwear use, should be encouraged to reduce CLM incidence.

Cutaneous larva migrans: A One Health Perspective on Familial Infection Among Tourists Returning from Southeast Asia

Cutaneous larva migrans (CLM) is a dermatosis caused by accidental infestation with animal hookworms and is widely distributed in tropical and subtropical regions. Humans become infected when their skin comes into contact with soil contaminated with dog faeces. The filariform larvae penetrate and burrow into human skin, causing a condition known as "creeping eruption". We describe a case, well-documented by photos, of CLM infection in a family of three who returned from Thailand.

Cutaneous larva migrans: A case report diagnosed using teledermatology

Teledermatology is a branch of dermatology that transmits medical data over several miles using telecommunications technologies. It involves the diagnosis of skin lesions using digital photographs and related patient data, and it can be especially helpful for patients in remote areas who might not have convenient access to dermatologists. Cutaneous larva migrans (CLM) is a zoonotic parasitic disease found in tropical and subtropical areas that are sunny and hot; however, cases of allocated resources have been disclosed in Saudi Arabia. There is little information about the frequency of CLM as a work-related illness among employees who are exposed to potentially polluted soil or have close contact with pets. In this paper, we present an ancestral case of CLM in Saudi Arabia, explaining the hazards of CLM infection. CLM may pose a challenge for physicians in non-endemic areas regarding assessment, therapeutic interventions, and protection, especially at work. The holistic strategy to CLM assessment, which includes the participation of numerous science competencies (e.g., veterinarians, dermatologists, and occupational physicians), may contribute to a better understanding of the expansion of human CLM and related risk factors, lowering the chance of infection.

Chronic Hemorrhagic Anemia Caused by Hookworm Infection: A Case Report

PURPOSE

Hookworm infection is one of the causes of long-term chronic hemorrhagic anemia in patients. This article reports a case of chronic severe anemia caused by hookworm infection.

METHODS

The capsule endoscopy showed that there were a large number of hookworms in the small intestine of a patient. At the same time, using the technique of saturated brine floatation and the automatic stool analyzer, hookworm eggs were detected.

RESULTS

The patient's anemia was caused by hookworm infection and was significantly improved after anti-hookworm treatment.

CONCLUSION

Hookworm infection cannot be ignored in the differential diagnosis of patients with chronic anemia. Capsule endoscopy combined with stool detection haves an important clinical value for the diagnosis of hookworm disease.

Molecular evidence of widespread benzimidazole drug resistance in Ancylostoma caninum from domestic dogs throughout the USA and discovery of a novel β-tubulin benzimidazole resistance mutation

Ancylostoma caninum is an important zoonotic gastrointestinal nematode of dogs worldwide and a close relative of human hookworms. We recently reported that racing greyhound dogs in the USA are infected with A. caninum that are commonly resistant to multiple anthelmintics. Benzimidazole resistance in A. caninum in greyhounds was associated with a high frequency of the canonical F167Y(TTC>TAC) isotype-1 β-tubulin mutation. In this work, we show that benzimidazole resistance is remarkably widespread in A. caninum from domestic dogs across the USA. First, we identified and showed the functional significance of a novel benzimidazole isotype-1 β-tubulin resistance mutation, Q134H(CAA>CAT). Several benzimidazole resistant A. caninum isolates from greyhounds with a low frequency of the F167Y(TTC>TAC) mutation had a high frequency of a Q134H(CAA>CAT) mutation not previously reported from any eukaryotic pathogen in the field. Structural modeling predicted that the Q134 residue is directly involved in benzimidazole drug binding and that the 134H substitution would significantly reduce binding affinity. Introduction of the Q134H substitution into the C. elegans β-tubulin gene ben-1, by CRISPR-Cas9 editing, conferred similar levels of resistance as a ben-1 null allele. Deep amplicon sequencing on A. caninum eggs from 685 hookworm positive pet dog fecal samples revealed that both mutations were widespread across the USA, with prevalences of 49.7% (overall mean frequency 54.0%) and 31.1% (overall mean frequency 16.4%) for F167Y(TTC>TAC) and Q134H(CAA>CAT), respectively. Canonical codon 198 and 200 benzimidazole resistance mutations were absent. The F167Y(TTC>TAC) mutation had a significantly higher prevalence and frequency in Western USA than in other regions, which we hypothesize is due to differences in refugia. This work has important implications for companion animal parasite control and the potential emergence of drug resistance in human hookworms.

Present and future: infectious tropical travel rashes and the impact of climate change

In this article, we discuss pertinent cutaneous findings with which patients may present after travel to tropical destinations. We address arthropod-borne infectious diseases such as cutaneous leishmaniasis, Chagas disease, cutaneous larva migrans, and myiasis. We discuss other relevant diseases with cutaneous signs such as monkey pox and severe acute respiratory syndrome coronavirus 2. We provide clinicians with information regarding the background, diagnosis, treatment, and prevention of these tropical rashes. In addition, we address the impact that climate change will have on the temporal and geographic incidence of these rashes. Viral, fungal, and vector-borne diseases have seen a geographic expansion into more northern latitudes. Among these are tick-borne Lyme disease, aquatic snail-related seabather's eruption, and atopic dermatitis. As these diseases spread, we believe that the updated information within this article is significant to the practicing physician in today's warming world.

Cutaneous larva migrans: A case report successfully treated with albendazole

Introduction

Cutaneous larva migrans (CLM) is helminthic infection that is mostly found in tropical and subtropical areas [1]. It is commonly seen with those who have contact with soil that is contaminated by cat and dog's hookworm larvae. CLM present as erythematous, serpiginous, pruritic cutaneous eruption that is caused by accidental percutaneous penetration and subsequent migration of larvae.

Case

We present a case of 45 year old male with erythematous, serpiginous, pruritic eruption over the dorsum of foot.Clinical findings and investigations: Patient had a 2-3 cm linear, erythematous, serpiginous localized lesion characteristic of a papular tip on the dorsal surface of the right foot. Total and differential blood counts, peripheral blood smear and chest x-ray were sent for investigations.

Intervention and outcome

Patient was prescribed Albendazole at a dose of 400mg, once a day for seven days. After treatment, the lesion and pruritus had regressed significantly.

Conclusion

Hookworm-related CLM is diagnosed clinically based on the typical clinical presentation (skin findings). Clinicians should be aware of the possibility of hookworm-related CLM with history of travel to tropical areas, specially walking barefoot.

Cutaneous Larvae Migrans Treated with a Single Dose of Ivermectin

Hookworm-related cutaneous larva migrans (HrCLM) is a clinical diagnosis based on a history of exposure to contaminated soil and is associated with a characteristic red serpiginous lesion that migrates within the epidermis. Our patient presented with a red, tortuous migratory rash with localized pruritus on the left plantar foot of 1-month duration. He lacked recent travel history outside the southeastern United States. Upon admission, he presented with peripheral blood eosinophilia, an uncommon feature of HrCLM. A single dose of ivermectin was sufficient for treatment, and symptoms resolved within 3 days. This case highlights the increased incidence of domestically acquired hookworm infections, explores this epidemiological shift, and emphasizes relevant differential diagnoses.

Unusual migration of cutaneous larva migrans

We report the case of a 62-year-old woman who presented with cutaneous larva migrans (CLM) of the breast after a trip to Long-Island, NY. The location of the rash is very unusual, and the region the patient was infected in NY is not known to be endemic forCLM.

Occupational risk of cutaneous larva migrans: A case report and a systematic literature review

Cutaneous larva migrans (CLM) is a parasitic zoonosis of warm tropical and subtropical areas, although autochthonous cases have been increasingly reported in Western European countries. Data on the prevalence of CLM as an occupational disease in workers exposed to potentially contaminated soil or in close contact with dogs and cats are scant. Herein, we report an autochthonous case of CLM in a dog breeder from southern Italy (Apulia region), along with a systematic literature review describing the risk of CLM infection, mainly according to job categories. The patient was referred to the dermatology unit presenting a serpiginous lesion on his hand, raising the suspected CLM diagnosis. In non-endemic areas, CLM might represent a challenge for physicians in terms of diagnosis, treatment, and prevention, particularly in workplaces. The multidisciplinary approach in the diagnosis of CLM with the involvement of different scientific competences (i.e., dermatologists, veterinarians, and occupational physicians) may contribute to further assess the distribution of human CLM and associated risk factors, toward reducing the risk for the infection.

A cluster of cutaneous larva migrans in travellers returning from Zanzibar

Beaches of East Africa are the place to relax, but when contaminated with animal faeces, they are a likely source of health problems, such as cutaneous larva migrans. Cases of CLM were diagnosed in Polish travellers returned from holidays in Zanzibar.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

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.

A Survey of Intestinal Helminths of Dogs in Slovakia with an Emphasis on Zoonotic Species

Simple Summary

Dogs are the most popular pet animals worldwide; however, frequent and close contact with people increases the risk of transmission of different zoonotic parasites. As the occurrence of intestinal parasites in the dog population is affected by several factors, understanding the epidemiology of zoonotic parasitic infections is important to minimize the risks for humans. This study presents results about the prevalence of gastrointestinal helminths in seven different groups of dogs (pet, shelter, guard, working, and hunting dogs, as well as dogs from segregated Roma settlements) in Slovakia. Out of 495 faecal samples collected between 2016 and 2021, eggs of intestinal helminths were detected in 134 (27.1%) samples. Altogether, six different species/genera/families, namely, Toxocara canis (14.7%), Toxascaris leonina (1.6%), Trichuris vulpis (6.3%), Capillaria spp. (1.4%), Ancylostoma/Uncinaria spp. (8.3%), and taeniid eggs (4.0%), were recorded. Infection with Echinococcus multilocularis was confirmed in 2.2% of dogs and 0.4% of the animals were infested with Taenia hydatigena. The results showed that the occurrence of intestinal helminths is quite frequent in the majority of analyzed dog groups, with a close correlation between the occurrence of intestinal helminths and availability of veterinary care and anthelmintic therapy.

Abstract

Dogs are the most popular pets worldwide; however, close contact with people increases the risk of transmission of different zoonotic parasites. This study aims to determine the prevalence of gastrointestinal helminths in dogs in Slovakia. A total of 495 faecal samples collected from pet, shelter, guard, working (police), and hunting dogs, as well as dogs from segregated Roma settlements between 2016 and 2021, were examined using flotation and molecular methods. Eggs of intestinal helminths were detected in 134 (27.1%) samples. Microscopically, six different species/genera/families, namely, Toxocara canis (14.7%), Toxascaris leonina (1.6%), Trichuris vulpis (6.3%), Capillaria spp. (1.4%), Ancylostoma/Uncinaria spp. (8.3%), and taeniid eggs (4.0%), were recorded. Molecular analyses revealed infection with Echinococcus multilocularis in 2.2% of dogs and 0.4% of the animals were infected with Taenia hydatigena. The results showed a correlation between the occurrence of intestinal helminths and the availability of veterinary care, as dogs from Roma settlements and shelter dogs were the most often infected (66.7% and 39.2%, respectively). On the other hand, working animals were in the best health condition, with only 2.5% being positive. The relatively frequent occurrence of zoonotic species points to the constant need for preventive measures and regular deworming of dogs.

Insights into hookworm prevalence in Asia: a systematic review and meta-analysis

INTRODUCTION

Hookworm infections are neglected tropical diseases of humans and animals worldwide. A meta-analysis and systematic review was designed to evaluate the prevalence of hookworm infection in animal and human hosts in Asia until July 2018.

METHODS

The available online articles of five English databases (PubMed, Scopus, Science Direct, Web of Science and Google Scholar) were explored.

RESULTS

The most parasitized carnivores were jackal (48%, CI: 4 to 91%), followed by dog (41%, CI: 29 to 53%), cat (26%, CI: 14 to 38%) and the red fox (19%, CI: 13 to 24%). The weighted prevalence of Ancylostoma braziliensis, A. caninum, A. ceylanicum, A. tubaeforme and Uncinaria stenocephala isolated from different canids were found to be 27% (CI: 21 to 33%), 23% (CI: 7.0 to 53%), 24% (CI: 12 to 35%), 44% (CI: 37 to 51%) and 37% (CI: 18 to 55%), respectively. In total, 98 records were obtained for human hookworms from 3209 760 examined individuals and the calculated weighted prevalence in this population was 19% (CI: 17 to 20%).

CONCLUSIONS

These findings highlight a desirable ecological milieu for parasite survival and transmission in such territories, which implicates revisiting control programs and public health infrastructures in those areas.

Clinical Profile, Risk Factors and Outcomes of Children With Cutaneous Larva Migrans Infection: A Hospital-Based Study

Background Cutaneous larva migrans (CLM) is a neglected parasitic skin disease caused by hookworm larvae such as Ancylostoma braziliense and Ancylostoma caninum. It is more common in tropical and subtropical countries. Evidence regarding clinical profiles, risk factors and outcomes of children with CLM in the Eastern province of Sri Lanka is scarce. Aim The aim of this study was to evaluate demographic profile, risk factors, clinical manifestations and outcomes associated with CLM in children who presented to paediatric and dermatological clinics of the Teaching Hospital, Batticaloa, Sri Lanka.  Method A retrospective study was conducted over three years from January 2017 to December 2019 among children who presented with CLM infection to paediatric and dermatological clinics of the Teaching Hospital, Batticaloa, Sri Lanka. Twenty-eight children who were aged between 1 and 14 years were recruited for the study. Detailed information including demographic factors such as age, sex, residence and mother's education, risk factors for infection, main reason for clinic visit, duration of illness, site of lesions, number of lesions, treatment received from out-patients department and/or general practitioner, duration of treatment, associated secondary bacterial infection, family history of similar infections and laboratory investigations were extracted from clinical records. Data were analyzed using SPSS version 19.0 (IBM Corp., Armonk, NY). Results Among 28 children recruited for this study, 19 (67.9%) were male children and 9 (32.1) were female children. The majority of children were below 6 years (n=25, 88.3%). Twenty-six (92.9%) children had residence in rural areas and also belonged to low socioeconomic class. Most cases were detected in Valaichenai (32.1%) and Kattankudy (21.4%) 'Medical Officer of Health' (MOH) regions. The majority of mothers were educated only up to ordinary level or below (n=19, 67.8%). All patients had pets either dogs or cats at home and no pets had been dewormed. Almost 92.9% of children acquired disease whilst playing on the infected soil The main reason for clinic visit had been itchiness and this presentation accounted for 60.7% (n=17). Skin infection accounted for 25% of presenting problems. Majority of them presented late to the clinic with the lesions of more than three weeks of duration (n=17, 60.7%). Single lesion was noted in the majority (n=27, 96.4%) except one child who had three lesions. Buttock lesions were observed in 35.7%, feet in 25%, and 10.7% in legs. Investigations revealed eosinophilia in 50% (n=14) of patients and neutrophil leukocytosis was seen in five patients (17.9%). All patients received treatment either from the general practitioner or outpatient department for variable duration without success before attending the specialist clinic. Fifty percent of patients needed treatment with Albendazole and antihistamine for more than three weeks to achieve complete cure. It was also observed that overall occurrence had been declining over the past three years. Conclusion CLM is a common and unreported disease in Eastern province, Sri Lanka. The majority of children presented from low socio-economic backgrounds. The common risk factors were the presence of dewormed pets at home and contamination with infected soil. The majority of children had a single lesion on presentation. Fifty percent of children needed more than three weeks of treatment to achieve a good response.

A Functional Comparison of Homopentameric Nicotinic Acetylcholine Receptors (ACR-16) Receptors From Necator americanus and Ancylostoma ceylanicum

Effective control of hookworm infections in humans and animals relies on using a small group of anthelmintics. Many of these drugs target cholinergic ligand-gated ion channels, yet the direct activity of anthelmintics has only been studied in a subset of these receptors, primarily in the non-parasitic nematode, Caenorhabditis elegans. Here we report the characterization of a homopentameric ionotropic acetylcholine receptor (AChR), ACR-16, from Necator americanus and Ancylostoma ceylanicum, the first known characterization of human hookworm ion channels. We used two-electrode voltage clamp electrophysiology in Xenopus laevis oocytes to determine the pharmacodynamics of cholinergics and anthelmintics on ACR-16 from both species of hookworm. The A. ceylanicum receptor (Ace-ACR-16) was more sensitive to acetylcholine (EC50 = 20.64 ± 0.32 μM) and nicotine (EC50 = 24.37 ± 2.89 μM) than the N. americanus receptor (Nam-ACR-16) (acetylcholine EC50 = 170.1 ± 19.23 μM; nicotine EC50 = 597.9 ± 59.12 μM), at which nicotine was a weak partial agonist (% maximal acetylcholine response = 30.4 ± 7.4%). Both receptors were inhibited by 500 μM levamisole (Ace-ACR-16 = 65.1 ± 14.3% inhibition, Nam-ACR-16 = 79.5 ± 7.7% inhibition), and responded to pyrantel, but only Ace-ACR-16 responded to oxantel. We used in silico homology modeling to investigate potential structural differences that account for the differences in agonist binding and identified a loop E isoleucine 130 of Nam-ACR-16 as possibly playing a role in oxantel insensitivity. These data indicate that key functional differences exist among ACR-16 receptors from closely related species and suggest mechanisms for differential drug sensitivity.

Unusual presentations of cutaneous larva migrans in British military personnel

Cutaneous larva migrans (CLM) is one of numerous skin diseases that occur in British military personnel on deployments to the tropics and sub-tropics. It is typically managed by military primary healthcare services, but diagnostic uncertainty or unavailability of anti-helminthic medication may prompt referral to UK Role 4 healthcare services. Cases of CLM seen at the UK Role 4 Military Infectious Diseases & Tropical Medicine Service from 2005 to 2020 were identified and their case notes were reviewed to identify learning and discussion points. There were 12 cases identified, of which five came from Brunei and three were from Belize. Causes for referral were due to diagnostic uncertainty (58%) and the unavailability of anti-helminthic medication (42%). Several cases had CLM in an unusual distribution due to specific military activities performed in endemic areas. Telemedicine was very useful in making some of the diagnoses in theatre and avoiding the need for medical evacuation. Military personnel may have unusual presentations of CLM due their unique military activities. In areas that are endemic for CLM, clinicians should maintain high clinical suspicion for CLM, carry appropriate anti-helminthic medications and consider screening cases of CLM and their colleagues for other infections with similar aetiology (eg, human hookworm infection and strongyloidiasis).

A creeping holiday souvenir: about a misleading case of hookworm folliculitis†

Hookworm-related cutaneous larva migrans occurs in endemic areas but also amongst travelers. Although this disease usually presents as a single pruritic raised erythematous track, misleading clinical presentations are not uncommon. This particularly extensive, follicular presentation of larva migrans should warn clinicians about atypical forms of this emerging tropical disease.

Exploring Tropical Infections: A Focus on Cutaneous Larva Migrans

GENERAL PURPOSE

To provide information about infection with cutaneous larva migrans (CLM).

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, NPs, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Distinguish the clinical features, diagnosis, and management of CLM.2. Explain the epidemiology of CLM.

ABSTRACT

Cutaneous larva migrans is a hookworm infection and one of the most common skin diseases of tourists in tropical countries. Most commonly, the infection is transmitted by contact with feces of dogs and cats containing hookworm eggs. This case-based review explores the epidemiology, diagnosis, clinical features, and management of cutaneous larva migrans infection.

Very High- and High-Frequency Ultrasound Features of Cutaneous Larva Migrans

Cutaneous larva migrans is a common infestation among travelers. Although the diagnosis may be suspected clinically, cases can show atypical presentations. We present the ultrasound features of 4 cases at 18 and 70 MHz. Small linear hyperechoic and hyper-refringent subepidermal and intrafollicular structures suggestive of fragments of larvae, hypoechoic dermal and hypodermal tunnels that match with dilatation of lymphatic ducts, and inflammatory dermal and hypodermal ultrasound signs can support the diagnosis. This work suggests that larvae can penetrate the cutaneous basement membrane through the ostia of the hair follicles and potentially disseminate through the dermal and hypodermal lymphatic network.

Molecular identification of zoonotic hookworms in dogs from four counties of Kenya

All canine hookworms are known to be zoonotic, causing infections ranging from transient skin irritations to prolonged ‘creeping eruptions’, eosinophilic enteritis and even patent intestinal infections. There is little information on canine hookworm species and their public health significance in sub-Saharan Africa. This study determined the prevalence and species of hookworms in dogs from different climatic zones of Kenya. Dog faecal samples were collected from the environment, and hookworm eggs were isolated by zinc chloride flotation and subjected to DNA extraction. Polymerase chain reaction (PCR) assays targeting the internal transcribed spacer (ITS) 1 and 2, 5.8S and 28S ribosomal RNA ofAncylostomaspp. andUncinaria stenocephalawere performed, and hookworm species were identified by PCR-restriction fragment length polymorphism (RFLP) or DNA sequencing. Hookworm eggs were detected by microscopy in 490/1621 (30.23%, 95% CI 28.01–32.54) faecal samples. Estimates of faecal prevalence were high in counties receiving higher rainfall (Narok 46.80%, Meru 44.88%) and low in those with a more arid climate (Isiolo 19.73%, Turkana 11.83%). In a subset of 70 faecal samples,Ancylostoma caninum(n = 59) was the most common species, followed byA. braziliense(n = 10) andA.cf.duodenale(n = 1). This study reports for the first time the detection ofA.cf.duodenalein dog faeces and zoonotic hookworm species in Kenyan dogs. These findings emphasize the need for control measures such as enforcing laws for restraining stray dogs, regular deworming of dogs, and public health awareness programmes aimed at informing communities on outdoor use of footwear.

An unusual case of extensive truncal cutaneous larva migrans in a Cameroonian baby: a case report

BACKGROUND

Cutaneous larva migrans is a neglected zoonotic helminthic disease which is paradoxically underreported in low-income and middle-income countries from where a majority of the cases emanate. It presents as migratory, raised, erythematous serpentine lesions, responsive to treatment with antihelminthics. It is common in children, but rare in babies. We report an unusual case of cutaneous larva migrans in a Cameroonian baby.

CASE PRESENTATION

We report the case of a 9-month-old Cameroonian baby girl, whose mother had the habit of drying the child's clothes on the grass in her courtyard. The child was brought to our hospital after she developed itchy, snake-like, slowly progressing lesions on her abdomen and chest. An examination revealed multiple raised serpentine and erythematous skin lesions consistent with cutaneous larva migrans which subsided on antihelminthic and antihistaminic therapy.

CONCLUSIONS

Cutaneous larva migrans is an endemic disease with predilection for poor and vulnerable persons. Preventive efforts such as wearing of slippers, usage of drying lines, and deworming of pets are crucial in preventing the occurrence of this disease and should be encouraged.

Global output of research on epidermal parasitic skin diseases from 1967 to 2017

Background

Epidermal parasitic skin diseases (EPSD) occur in most countries and cause a considerable health and economic burden, particularly in the tropics and subtropics. The aim of this study was to assess and analyse peer-reviewed literature on EPSD in humans. The results of this study serve as an indicator of the extent the scientific community, health authorities, and international health agencies interact with EPSD as a health problem that is commonly associated with poverty and poor hygiene.

Methods

A bibliometric analysis methodology was used. The Scopus database was used to retrieve documents about EPSD for the study period (1967–2017). The study focused on scabies, tungiasis, pediculosis, hookworm-related cutaneous larva migrans (HrCLM), myiasis, and cutaneous strongyloidiasis. Documents that specifically and explicitly discuss EPSD in animals, aquatic organisms, and birds were excluded.

Results

In total, 4186 documents were retrieved. A fluctuated growth of publications on EPSD in the past five decades was found. The retrieved documents received 43 301 citations, an average of 10.3 citations per article and an h-index of 74. The keywords “scabies” and was the most commonly encountered keyword followed by the keywords “head lice” and “pediculosis”. The most active journal involved in publishing articles on EPSD was the International Journal of Dermatology (164; 3.9%). Researchers from 93 different countries published the retrieved articles. The USA led with 735 (17.6%) documents, followed by the UK (274; 6.5%), and Germany (259; 6.2%). In terms of institutions, the Charité – Universitätsmedizin Berlin in Germany was the most active in this field with 78 (1.9%) publications, followed by the Universidade Federal do Ceará in Brazil with 52 (1.2%) publications.

Conclusions

Research on scabies and pediculosis dominated the field of EPSD research to the expense of tungiasis, HrCLM, myiasis, and cutaneous strongyloidiasis. There was an underrepresentation of literature from the tropics and subtropics despite EPSD being common in these areas. This could possibly be explained by the presence of limited number of non-English journals in the Scopus database. International research collaborations and research networking should be strengthened to help advance and prioritize research on EPSD.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0456-x) contains supplementary material, which is available to authorized users.

Epidemiology and morbidity of hookworm-related cutaneous larva migrans (HrCLM): Results of a cohort study over a period of six months in a resource-poor community in Manaus, Brazil

Background

Hookworm-related cutaneous larva migrans (HrCLM) is a neglected parasitic skin disease, widespread in resource-poor communities in tropical and subtropical countries. Incidence and risk factors have never been investigated in a cohort study.

Methodology/Principal findings

To understand the seasonal epidemiology of HrCLM, an open cohort of 476 children in a resource-poor community in Manaus, Brazil was examined for HrCLM monthly over a period of 6 months. Monthly prevalence and intensity of infection were correlated with the amount of monthly precipitation. Multivariable Cox regression analysis indicated male sex (hazard ratio [HR] 3.29; 95% confidence interval [CI] 1.95–5.56), walking barefoot on sandy ground (HR 2.30; 95% CI 1.03–5.16), poverty (HR 2.13; 95% CI 1.09–4.17) and age between 10 and 14 years (HR 1.87; 95% CI 1.01–3.46) as predictors of HrCLM. Monthly incidence rates ranged between 0.21 and 1.05 cases per person-year with an overall incidence of 0.52 per person-year.

Conclusions/Significance

HrCLM is a frequent parasitic skin disease in this resource-poor community. Every second child theoretically becomes infected during one year. Boys, 10 to 14 years old, belonging to the poorest households of the community, are the most vulnerable population group. Even in the tropical monsoonal climate of Amazonia there is a considerable seasonal variation with monthly incidence and number of lesions peaking in the rainy season.

Hookworm-worm related cutaneous larva migrans (HrCLM) is a parasitic skin disease caused by hookworm larvae of cats and dogs occurring in many countries with a tropical or subtropical climate. Humans are a biological impasse for these helminths as the larvae cannot pass the basal membrane of the epidermis and hence migrate haphazardly in the skin causing local inflammation and intense itching. In scientific literature HrCLM is generally described as a disease of travellers returning from endemic areas. In contrast, epidemiological data is scanty. In a previous study, we had examined an entire resource-poor neighbourhood in Manaus (Brazil) and showed, that HrCLM is an important individual and public health problem, affecting up to 8% of the population, in particular children. In this study, we followed a cohort of children for six months. We found a significant seasonal variation in incidence and morbidity between dry and rainy season. Extrapolated, every second child in this population will be affected at least once within one year. The longitudinal study design enabled us to validate previously identified risk factors. Children aged 10–14 years, in particular boys, and those walking barefoot on sandy ground had the highest infection rates. Children from the poorest families in the resource-poor community were most vulnerable to HrCLM.

Gastrointestinal Parasites in Shelter Dogs: Occurrence, Pathology, Treatment and Risk to Shelter Workers

Dogs entering shelters can carry gastrointestinal parasites that may pose serious risks to other animals, shelter staff and visitors. Shelters provide an environment that could facilitate the spread of parasitic infections between animals. Nematodes and protozoa that transmit through ingestion or skin penetration are major enteric parasites of concern in shelter settings. Ancylostoma spp., Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Trichuris vulpis and Dipylidium caninum are the major helminths while Giardia, Cryptosporidium, Isospora spp. and Sarcocystis spp. are the most prevalent protozoan parasites in shelter dogs. The prevalence of gastrointestinal parasites in shelter dogs is typically higher than in owned dogs. A range of cost-effective drugs is available for prevention and control of helminths in shelters, notably fenbendazole, pyrantel, oxantel, and praziquantel. Parasiticide options for protozoan parasites are often cost-prohibitive or limited by a lack of veterinary registration for use in dogs. Environmental control measures reliant upon hygiene and facility management are therefore a mainstay for control and prevention of protozoan parasites in shelters. This philosophy should also extend to helminth control, as integrated parasite control strategies can allow anthelmintics to be used more sparingly and judiciously. The purpose of this article is to comprehensively review the current knowledge on the prevalence of gastrointestinal parasites most commonly found in dogs in shelters, canvass recommended treatment programs in shelter dogs, and to explore the likelihood that parasiticide resistance might emerge in a shelter environment.

Cross-sectional survey of health management and prevalence of vector-borne diseases, endoparasites and ectoparasites in Samoan dogs

OBJECTIVE

To determine the prevalence of selected canine vector-borne diseases (Leishmania infantum, Anaplasma spp., Ehrlichia canis, Borrelia burgdorferi and Dirofilaria immitis) and endo- and ectoparasites in Samoan dogs presenting for surgical sterilisation and to report on the general health management of the dogs.

METHODS

This study was a prospective serological cross-sectional survey. Management data were obtained for 242 dogs by interview with their owners. Blood samples were collected from 237 dogs and screened for the canine vector-borne diseases using point-of-care qualitative ELISA assays. Anaplasma spp. positive samples were screened by PCR and sequenced for species identification. Rectal faecal samples were collected from 204 dogs for faecal flotation and immunofluorescent antibody tests were performed for Giardia and Cryptosporidium spp. on a subset of 93 faecal samples. The skin and coat of 221 dogs were examined for presence of ectoparasites.

RESULTS

The D. immitis antigen was detected in 46.8% (111/237) of dogs. Seroprevalence of Anaplasma spp. was 8.4% (20/237); A. platys was confirmed by PCR. Prevalence of hookworm was 92.6% (185/205) and Giardia was 29.0% (27/93). Ectoparasites were detected on 210/221 (95.0%) of dogs examined and 228/242 dogs (94.2%) had previously never received any preventative medication.

CONCLUSIONS

There was a very high prevalence of D. immitis, hookworm and external parasites in Samoan dogs, and prophylactic medication is rarely administered. This is the first report confirming A. platys in Samoa and the South Pacific islands. The public health implications of poor management of the dogs should be considered and investigated further.

Parasitic Infections of the Skin and Subcutaneous Tissues

A variety of arthropods, protozoa, and helminths infect the skin and subcutaneous tissues and may be identified by anatomic pathologists in standard cytology and histology preparations. The specific organisms seen vary greatly with the patient's exposure history, including travel to or residence in endemic countries. Arthropods are the most commonly encountered parasites in the skin and subcutaneous tissues and include Sarcoptes scabei, Demodex species, Tunga penetrans, and myiasis-causing fly larvae. Protozoal parasites such as Leishmania may also be common in some settings. Helminths are less often seen, and include round worms (eg, Dirofilaria spp.), tapeworms (eg, Taenia solium, Spirometra spp.), and flukes (eg, Schistosoma spp.). This review covers the epidemiologic and histopathologic features of common parasitic infections of the skin and subcutaneous tissues.

Hookworm Infection: A Neglected Cause of Overt Obscure Gastrointestinal Bleeding

Hookworm infections are widely prevalent in tropical and subtropical areas, especially in low income regions. In the body, hookworms parasitize the proximal small intestine, leading to chronic intestinal hemorrhage and iron deficiency anemia. Occasionally, hookworms can cause overt gastrointestinal bleeding, but this is often ignored in heavily burdened individuals from endemic infectious areas. A total of 424 patients with overt obscure gastrointestinal bleeding were diagnosed by numerous blood tests or stool examinations as well as esophagogastroduodenoscopy, colonoscopy, capsule endoscopy or double-balloon enteroscopy. All of the patients lived in hookworm endemic areas and were not screened for hookworm infection using sensitive tests before the final diagnosis. The patients recovered after albendazole treatment, blood transfusion, and iron replacement, and none of the patients experienced recurrent bleeding in the follow-up. All the 31 patients were diagnosed with hookworm infections without other concomitant bleeding lesions, a rate of 7.3% (31/424). Seventeen out of 227 patients were diagnosed with hookworm infections in the capsule endoscopy (CE), and 14 out of 197 patients were diagnosed with hookworm infections in the double balloon enteroscopy (DBE). Hookworm infections can cause overt gastrointestinal bleeding and should be screened in patients with overt obscure gastrointestinal bleeding (OGIB) in endemic infectious areas with sensitive methods. Specifically, the examination of stool specimens is clinically warranted for most patients, and the proper examination for stool eggs relies on staff’s communication.

Epidemiological profile of cutaneous larva migrans in travelers returning to France between 2003 and 2015

BACKGROUND

Cutaneous larva migrans (CLM) is caused by the penetration and migration of canine or feline hookworm larvae into the skin, and frequently affects travelers from high-income countries returning from tropical and sub-tropical areas. Unfortunately, this pathology is neglected due to poor understanding among both physicians and travelers. This study describes the profile of cases reported in Marseille, France.

PATIENTS AND METHODS

A retrospective study was performed in two specialized hospitals between 2003 and 2015. Data on socio-demographics, clinical aspects and treatment were collected. Diagnosis was based on travel history and symptoms.

RESULTS

Forty-three patients with a diagnosis of CLM were recorded in this study. They were aged between 14 and 70 and 51% were male. They were infected while visiting the Americas (37%), Africa (33%), Asia (28%) and (in the case of one patient) Portugal. The mean timescale for diagnosis was 41 days. Track lesions associated with pruritus in the lower limbs were the most common symptoms. Nine had a history of super-infection. Sixteen patients received treatment prior to referral including six who were administered antiparasitic drugs. A one-day treatment with ivermectin, administered at our facility, resulted, in most instances, in a favorable outcome.

CONCLUSION

This study reports 43 cases of CLM acquired mainly in Africa, Asia and the Americas but also, for the first time, CLM acquired during travel to Portugal. The data show the need for increased awareness of CLM prevention and treatment in order to optimize pre-travel advice and case management. Travelers need to understand how CLM is transmitted and the need to avoid contact with soil and sand contaminated by dogs and cats. In particular, footwear and sun chairs should be used on beaches.

[Main parasitic skin disorders]

Cutaneous parasitic skin diseases are frequent in human pathology. There are few reliable epidemiological data on the prevalence and/or incidence of such diseases. Skin parasites are cosmopolitan but their global distribution is heterogenous; prevalence is especially high in subtropical and tropical countries. They are mainly due to arthropods (insects and mites). Many species of parasites are involved, explaining the diversity of their clinical signs. The most common are caused by ectoparasites such as scabies or pediculosis (head lice, body lice and pubic lice). Clinical signs may be related to the penetration of the parasite under the skin, its development, the inoculation of venom or allergic symptoms. Diagnosis can be easy when clinical signs are pathognomonic (e.g. burrows in the interdigital web spaces in scabies) or sometimes more difficult. Some epidemiological characteristics (diurnal or nocturnal bite, seasonality) and specific clinical presentation (single or multiple bites, linear or grouped lesions) can be a great diagnostic help. Modern non-invasive tools (dermoscopy or confocal microscopy) will play an important role in the future but the eye and experience of the specialist (dermatologist, parasitologist, infectious disease specialist or entomologist) remains for the time the best way to guide or establish a diagnosis. For most skin parasites, therapeutic proposals are rarely based on studies of high level of evidence or randomized trials but more on expert recommendations or personal experience.

Prevalence and Risk Factors of Hookworm-Related Cutaneous Larva Migrans (HrCLM) in a Resource-Poor Community in Manaus, Brazil

Background

Hookworm-related cutaneous larva migrans (HrCLM) is a neglected tropical skin disease associated with significant clinical pathology. Little knowledge exists about prevalence and risk factors of HrCLM in endemic regions.

Methodology/ Principal Findings

To understand the epidemiology of HrCLM in Amazonia, we conducted a cross-sectional study in a resource-poor township in Manaus, Brazil. HrCLM was diagnosed in 8.2% (95% CI, 6.3–10.1%) of the study population (N = 806) with a peak prevalence of 18.2% (95% CI, 9.3–27.1%) in children aged 10–14. Most of the tracks (62.4%) were located on the feet, and 10.6% were superinfected. HrCLM was associated independently with age under 15, male sex, presence of animal faeces on the compound, walking barefoot on sandy ground and poverty.

Conclusions/ Significance

HrCLM is common in resource-poor communities in Amazonia and is related to poverty. To reduce the disease burden caused by HrCLM, living conditions have to be improved.

Hookworm-related cutaneous larva migrans (HrCLM) is a parasitic skin disease caused by the penetration of animal hookworm larvae into the human skin. In this compartment the larvae cannot pass the basal membrane and reproduce, but migrate in the outer skin layer for several weeks, causing skin inflammation and intense itching. Thus, humans are a biological impasse. Although HrCLM is a common skin disease in tropical and subtropical regions, studies on prevalence and risk factors are scarce. We clinically examined the population of a resource-poor neighbourhood in Manaus, capital of Amazonas State, Brazil, and investigated HrCLM-associated risk factors. HrCLM was very common with an overall prevalence of 8.2%. Children in general, and boys in particular, were most frequently infected. We could confirm that walking barefoot on sandy ground is a significant risk factor, and we identified the presence of animal faeces on the compound as another important predictive factor. Clearly, HrCLM was associated with low income and poverty-related living conditions. The poorest of the poor were identified as the most vulnerable population group.