Seroprevalence of human toxocariasis in Denmark

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.

A survey on the seroprevalence of toxocariasis and related risk factors in Eosinophilic children of Northwest Iran

Background

Toxocariasis is a serious zoonotic helminthic disease caused by the nematodes; Toxocara species.

Aim

A cross-sectional study was conducted to determine the seroprevalence of toxocariasis and related risk factors in eosinophilic children referred to the pediatrics hospital of Qazvin province northwest Iran during 2019-2020.

Methods

A total of 200 blood samples were collected from eosinophilic children referred to the Qods Pediatrics Hospital. Demographic data, clinical symptoms, and dogs- and soil-contact history were collected. The presence of anti-Toxocara IgG antibody was evaluated by T. canis IgG ELISA kit.

Results

Anti-Toxocara IgG antibodies were detected in 14 (7%) of the total eosinophilic children. The seropositive rate of toxocariasis in hyper-eosinophilic children (>1000/mm3) was 15.1%, while the seropositivity was 4.1% in children with eosinophilia status (500-999/mm3). There was a significant association between the eosinophilia rate and seropositivity (P<0.05). Also, seroprevalence in asymptomatic eosinophilic children was 4.4%, while in children with clinical symptoms it was 17.1%. Accordingly, a statistically significant difference was found between clinical symptoms and Toxocara infection (P<0.05).

Conclusion

The prevalence of toxocariasis in eosinophilic children is a serious health problem in the study area. Therefore, serologic evaluation for the diagnosis of Toxocara infection is recommended for eosinophilic children.

Detection of antigens and anti-Toxocara canis antibodies in children with different asthma severities

INTRODUCTION

Toxocara canis can produce or exacerbate asthma, and the detection of anti-T. canis immunoglobulin G (IgG) does not discriminate between recent infection or active larva migrans. In this study, we searched for T. canis third-stage larval antigens (L3 TES) and anti-T. canis antibodies in children with different severities of asthma, controlled or uncontrolled.

METHODS

A total of 145 patients with asthma who were previously diagnosed using the Global Initiative for Asthma guidelines were included. The asthma control was evaluated with the Asthma Control Questionnaire (ACQ). Enzyme-linked immunosorbent assay was performed for the detection of L3 TES; IgG was detected using sera preadsorbed with Ascaris antigens (native kit), and a commercial kit (IgG) was used as the gold standard.

RESULTS

L3 TES was found in 2 patients (1.37%). One had L3 TES and anti-T. canis IgG, suggesting active larva migrans. In the other patient, only L3 TES was detected, likely because an infection had begun. The seroprevalence with the commercial kit and native kit was 6.2% and 17.93%, respectively. There was no significant association among asthma severity, ACQ and T. canis seroprevalence (p > .05).

CONCLUSION

It is possible to detect L3 TES in patients with asthma. Two complementary techniques that can determine the infection status with T. canis and rule out cross-reactions involve the detection of L3 TES and IgG using sera preadsorbed with Ascaris antigen. There was no significant association among asthma severity, ACQ and T. canis seroprevalence.

The prevalence of intestinal nematodes among red foxes (Vulpes vulpes) in north-western Poland

Background

The red fox (Vulpes vulpes) is widely distributed in the Northern Hemisphere and Australia. The presence of nematode-infected foxes in urbanized areas increases the risk of transmission of nematodes to domestic dogs and thus, to humans. The aim of this study was to determine the prevalence and species composition of intestinal nematodiasis in red foxes in Western Pomerania, a province in north-western Poland. The intestinal contents of 620 red foxes killed during a government reduction shooting programme were examined for adult nematodes using the sedimentation and counting technique (SCT).

Results

Intestinal nematodes, including Toxocara canis, Toxascaris leonina, Uncinaria stenocephala and Trichuris vulpis, were found in 77.3% (95% CI 73.8–80.4%) of the examined foxes with a mean infection burden of 20.1 nematode per animal. Male and female foxes had similar infection burdens.

Conclusions

The nematodes are present in high prevalence and intensity among foxes in north-western Poland. Furthermore, this high prevalence of nematodes in foxes may likely constitute a health risk to humans and domestic animals due to increasing fox densities in urban and periurban areas.

Seroepidemiological Study of Toxocariasis in Children Aged 6-14 Year Old in Sanandaj, Western Iran

Background:

Toxocariasis is a disease caused by Toxocara nematodes and occurs from consuming their eggs. The main hosts of these worms are dogs and cats. The disease in humans becomes a visceral larva migrans (VLM). This descriptive cross-sectional study was conducted to determine the prevalence of toxocariasis in children aged 6–14 years.

Methods:

This cross-sectional descriptive study was conducted from Jun 1 2016 to Dec 1 2017 in Sanandaj, west of Iran. A total of 182 serum samples were collected from children age 6 to14 yr referred to medical diagnostic laboratories. Demographic data (age, sex, and parents’ literacy status), clinical signs (cough, headache, fever, abdominal pain), and the history of contact with dogs and cats was collected by a questionnaire. The presence of anti-Toxocara IgG antibody was detected by T. canis IgG ELISA (IBL, Germany) kit.

Results:

Of 182 subjects, 97 (53.3%) were male and 85 (46.7%) female. The average age was 9.2 years. Antibodies against T. canis were positive in three cases (1.65%) of all the studied subjects.

Conclusions:

The results showed a low prevalence of toxocariasis in children studied.

Seroprevalence of Toxocara Infection in Association with Different Risk Factors among Children of 4-12 Years Old Referred to Some Medical Centers in Aras Free Zone, Northwest Iran

Background:

Toxocariosis is a parasitic disease caused by the larval stage of Toxocara species from dog and cat. It has a worldwide distribution with higher prevalence in children. This study aimed to determine seroprevalence of Toxocara infection and its association with some risk factors among children of Aras Free Zone (Jolfa City) in Northwest of Iran.

Methods:

Sera were collected from 514 children aged 4–12 yr old attending to some medical centers in the study area from May 2018 to Feb 2019. Anti-Toxocara IgG antibodies assay was performed using commercial ELISA kit (Nova Tec, Germany). The seropositivity rate was determined and its association with different demographic criteria and risk factors were statistically analyzed.

Results:

The overall seroprevalence was 2.3% (12/514). Risk factors of children’s age group and contact with either pet animals (dog and cat) and/or soil were significantly associated with seropositivity. However, there was not any relationship between Toxocara infection and gender of children, place of residency (urban or rural) and their mothers’ education level.

Conclusion:

Both girls and boys are at risk of Toxocara infection in the study area. Younger age of childhood and contact with sources of infection were important associated factors. More probably, additional criteria are involved in the initiation of infection.

A Systematic Review and Meta-analysis of Toxocariasis in Iran: Is it Time to Take it Seriously?

BACKGROUND

Toxocariasis is one of the neglected zoonosis with considerable public health importance around the world. The current study aimed to elucidate the overall prevalence of Toxocara infection in human and definitive hosts and also the contamination of soil and raw vegetables with the ova of these parasites, in Iran, using systematic review and meta-analysis.

METHODS

Six English and Persian databases were explored from 2000 to 2017 using the terms toxocariasis, Toxocara spp., visceral larva migrans, Iran, epidemiology, and prevalence. This meta-analysis conducted using STATA, and for all statistical tests, a p value less than 0.05 was considered significant. The random-effects model was used to the report of the pooled prevalence with a 95% confidence interval (CI).

RESULTS

The pooled prevalence of toxocariasis in human was calculated as 11% (95% CI 8-13%). In terms of definitive hosts, the pooled prevalence of Toxocara infection in dogs and cats were calculated as 17% (95% CI 14-20%) and 37% (95% CI 26-48%), respectively. Also, the pooled prevalence of Toxocara spp. eggs in the soil and raw vegetable samples were calculated as 18% (95% CI 13-23%) and 2% (95% CI 1-3%), respectively.

CONCLUSIONS

The results of current study demonstrate that toxocariasis should be taken more seriously by health authorities. Implementing an appropriate control program is necessary to reduce the incidence of this disease in Iran.

Prevalence of toxocariasis and its related risk factors in humans, dogs and cats in northeastern Iran: a population-based study

BACKGROUND

Toxocariasis is one of the most common zoonotic infections in dogs and cats. The objectives of this study were to determine the prevalence of anti-Toxocara antibodies and identify the epidemiological and clinical features and related risk factors of toxocariasis in the general population along with the prevalence of this infection in dogs and cats in northeast Iran.

METHODS

In this cross-sectional study, anti-Toxocara antibodies from 1150 urban and rural participants were examined using a commercial enzyme-linked immunosorbent assay. In addition, the stool specimens of 538 dogs and 236 cats were tested using the formalin-ether concentration technique. Sociodemographic data and related risk factors were collected using a structured questionnaire and the data on clinical manifestations were obtained from personal health records.

RESULTS

Anti-Toxocara antibodies were detected in 7.2% (83/1150) of the study population. Risk factors for seropositivity based on multivariable analysis were younger age (p=0.019), living in rural areas (p=0.048), occupations with high exposure risk to toxocariasis (p=0.001), contact with dogs or cats (p=0.003), contact with soil (p=0.001), history of geophagy (p=0.001) and the consumption of raw or undercooked liver (p=0.001). The prevalence of symptoms such as asthma, shortness of breath, blurred vision, abdominal pain and epilepsy were significantly higher in seropositive individuals compared with seronegative ones. Toxocara eggs were found in 15.1% (81/538) of dogs and 34.7% (82/236) of cats. A significant relationship was found between infection in dogs and cats and age, type, place of residence and anthelmintic consumption.

CONCLUSIONS

Identification of anti-Toxocara antibodies in the general population and the presence of confirmed infections in dogs and cats indicates exposure to Toxocara infection as a public health problem in northeast Iran.

Seroepidemiology of human toxocariasis in selected population groups in Slovakia: A cross-sectional study

BACKGROUND

Human toxocariasis is a cosmopolitan helminthic zoonosis caused by roundworms of the genus Toxocara. The study aimed at a cross-sectional analysis of seropositivity to Toxocara spp. in selected groups of population in Slovakia and an estimate of the risk factors of infection.

METHODS

For the detection of anti-Toxocara antibodies, an enzyme-linked immunosorbent assay (ELISA) based on an excretory-secretory (E/S) antigen of Toxocara canis was used.

RESULTS

The overall seropositivity to Toxocara in 1489 evaluated sera was 3.7%. The seropositivity of Roma children/young people (40.3%) was significantly higher when compared with all other analysed groups. Among adult respondents, the positivity of farmers and hunters (5.5% and 5.1%, respectively) was significantly higher (p<0.001) than in the other analysed groups (veterinarians and veterinary assistants, soldiers, students of veterinary medicine, and students of other universities). Analysis of infection risk factors showed that living in a rural locality, everyday contact with soil, and everyday outdoor activities (12.7%, 8.8% and 8.3% positivity, respectively) can increase the risk of infection, but the observed differences were not significant.

CONCLUSION

The results underline the importance of preventive measures and the need for improving of knowledge of toxocariasis among professionals, as well as the public.

Neurocognitive and neuropsychiatric effects of toxocariasis

Caused by the neuroinvasive nematodes Toxocara canis and Toxocara cati, human toxocariasis has a worldwide distribution with seroprevalence in humans associated with low socioeconomic status and low educational attainment. Third-stage Toxocara larvae can invade human tissues, including the brain and spine, where they can result in encephalitis, meningitis, and inflammation. Toxocara infection in animal models has been associated with cognitive and behavioural changes. In humans, preliminary cross-sectional research suggests that Toxocara seropositivity is associated with worse cognitive function in children and adults. Additional preliminary cross-sectional findings suggest associations between Toxocara seropositivity and neuropsychiatric function, including schizophrenia and neurologic conditions such as epilepsy. Given the widespread distribution of human toxocariasis and early evidence suggesting that it can be associated with cognitive and neuropsychiatric function in humans, additional research regarding the effects of toxocariasis on the human brain is required.

Seroepidemiology, modifiable risk factors and clinical symptoms of Toxocara spp. infection in northern Iran

Toxocariasis is one of the most important and widespread neglected tropical infectious diseases. We designed a cross-sectional study to assess the seroepidemiological aspects of toxocariasis among the general population in northern Iran. A total of 630 rural subjects were enrolled to participate in the study. The presence of anti-Toxocara immunoglobulin G (IgG) was tested using a commercially available enzyme-linked immunosorbent assay. A structured questionnaire was also used to evaluate the potential risk factors and related clinical signs/symptoms. The presence of anti-Toxocara IgG antibodies was detected in 148 of the 630 rural subjects (23.5% [95% confidence interval {CI} 21.8 to 25.1]). By multivariate analysis, age (odds ratio [OR] 2.89 [95% CI 1 to -8.3], p=0.04), eating improperly washed vegetables (OR 4.05 [95% CI 2.47 to 6.64], p<0.001), contact with dogs (OR 3.31 [95% CI 2.13 to 5.12], p<0.001) and exposure to soil (OR 3.56 [95% CI 2.13 to 5.13], p<0.001) were significantly associated with the seroprevalence of Toxocara. The clinical study also demonstrated that the seroprevalence of Toxocara infection was significantly associated with asthma (OR 3.78 [95% CI 1.63 to 8.75], p<0.001) and ophthalmic disorder (OR 1.83 [95% CI 1.04 to 3.21], p=0.034). The findings proved that residents of rural communities in tropical regions may be heavily exposed to Toxocara spp. We highly recommend more investigations in high-risk groups.

Seroprevalence of Larval Toxocarosis in the Czech Republic

BACKGROUND

Larval toxocarosis (LT), a zoonotic disease transmitted by dogs, cats, and other carnivores, is caused by roundworms of the genus Toxocara. Humans become infected by ingesting embryonated eggs of this parasite. In this study, we present data on the seroprevalence of LT in the Czech Republic collected by the National Reference Laboratory for Tissue Helminthoses in 2012-2016.

METHODS

Using enzyme-linked immunosorbent assay, a total of 4428 adults and children with or without clinical symptoms were examined for the presence of IgG antibodies against Toxocara canis excretory-secretory antigens.

RESULTS

Of all the persons examined, specific Toxocara antibodies were detected in 160 (3.6%) individuals. There were, however, significant differences between various regions, with seropositivity rates ranging from 1.4 to 7.5%.

CONCLUSION

In comparison to studies from 1998 and 2004, our results suggest a decrease in overall Toxocara seroprevalence in the Czech population, whereby the rates are similar to or even lower than rates in some other Central European countries.

Serodiagnostic methods for diagnosing larval toxocariasis

Toxocariasis is a human infection primarily caused by larvae of Toxocara canis from dogs, and also by T. cati from cats. Children have a more significant risk of acquiring the infection due to their closer contact with pets, and greater chances of ingesting soil. Diagnosis of toxocariasis is based on clinical, epidemiological, and serological data. Indirect IgG ELISA is a widely used serodiagnostic method for toxocariasis, with native T. canis TES most commonly used as the antigen. Western blots, using the same antigen, can be used to confirm positive ELISA findings to reduce false-positive results. Improvements in Toxocara serodiagnosis include the use of recombinant TES antigens, simpler and more rapid assay formats, and IgG4 subclass detection. Also, incorporation of recombinant T. cati TES protein increases the diagnostic sensitivity. Development of antigen detection tests using polyclonal and monoclonal antibodies, nanobodies, or aptamers can complement the antibody detection assays, and enhance the effectiveness of the serodiagnosis.

Seroprevalence of human toxocarosis in Europe: A review and meta-analysis

Toxocarosis is distributed worldwide and represents the most prevalent zoonotic helminth infection in industrialized countries, thereby posing a substantial risk for public health. Thus, toxocarosis is one of CDC's Neglected Parasitic Infections that has been targeted for public health action. This systematic review and meta-analysis summarizes Toxocara seroprevalence in general populations from Europe, populations suspected of Toxocara infection and defined risk groups. Random-effects meta-analysis of proportions based on 41 publications resulted in an overall seroprevalence of 6.2% (95% CI: 4.7-8.3%) in the general population of Europe. Subgroup analysis according to decades (1970-2010s) revealed a significant increase in seroprevalence, with the highest value (12.4%; 95% CI: 6.5-22.3%) in the 2010s (χ²=17.87, df=4, P=0.001). There were no significant differences between pooled prevalence rates of European sub-regions (χ²=3.01, df=3, P=0.389). Furthermore, meta-analysis of seroprevalence according to age groups, based on data from 22 publications, indicated a significantly higher pooled seroprevalence of 14.9% (95% CI: 8.5-24.8%) in people more than 50 years of age than in younger age cohorts (χ²=8.33, df=2, P=0.016). Occupational groups exposed to contaminated soil and infected animals bear substantial risk for acquiring Toxocara infection. Due to the close link between animal infection and human Toxocara exposure, a "One Health" approach for the prevention of Toxocara infection in both humans and animals is required.

Fast One-Step Ultrasensitive Detection of Toxocara canis Antigens by a Nanobody-Based Electrochemical Magnetosensor

Human toxocariasis (HT) is a cosmopolitan zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis. Current HT diagnostic methods do not discriminate between active and past infections. Here, we present a method to quantify Toxocara excretory/secretory antigen, aiming to identify active cases of HT. High specificity is achieved by employing nanobodies (Nbs), single domain antigen binding fragments from camelid heavy chain-only antibodies. High sensitivity is obtained by the design of an electrochemical magnetosensor with an amperometric read-out. Reliable detection of TES antigen at 10 and 30 pg/mL level was demonstrated in phosphate buffered saline and serum, respectively. Moreover, the assay showed no cross-reactivity with other nematode antigens. To our knowledge, this is the most sensitive method to quantify the TES antigen so far. It also has great potential to develop point of care diagnostic systems in other conditions where high sensitivity and specificity are required.

Histopathological characterization of Toxocara canis- and T. cati-induced neurotoxocarosis in the mouse model

Infective larvae of Toxocara canis and T. cati, the common roundworms of dogs and cats, may invade the central nervous system of paratenic hosts, including humans, causing neurotoxocarosis (NT). Previous studies on NT in the model organism "mouse" have indicated distinct differences between T. canis and T. cati regarding larval migration patterns as well as the severity of clinical symptoms and behavioural alterations. The objective of the present study was to provide an extensive characterization of the underlying histopathological alterations, comparing T. canis- and T. cati-induced changes in different brain areas over the course of murine infection. Four histological sections of five brains each of T. canis- and T. cati-infected as well as uninfected C57Bl/6 mice were investigated 7, 14, 28, 42, 70 and 98 days post infection (dpi), while brains of T. cati-infected and control mice were also available 120 and 150 dpi. In addition to haematoxylin-eosin and luxol fast blue-cresyl violet staining, immunohistochemistry was employed to study microglia/macrophage cell morphology and to detect accumulation of β-amyloid precursor protein (β-APP) as an indicator of axonal damage. Haemorrhages, eosinophilic vasculitis and activated microglia/macrophages were detected in both infection groups starting 7 dpi, followed by eosinophilic meningitis in cerebra as from 14 dpi. Overall, little differences in the proportion of animals affected by these alterations were found between the two infection groups. In contrast, the proportion of animals displaying β-APP accumulation was significantly higher in the T. canis than T. cati group as from 28 dpi regarding the cerebrum as well as at 98 dpi regarding the cerebellum. In T. canis-infected mice, myelinophagic microglia/macrophages ("gitter cells") appeared as from 14 dpi, whereas these were first observed at 70 dpi in T. cati-infected animals. The proportion of animals displaying demyelination and/or gitter cells in the cerebrum was significantly higher in the T. canis than T. cati group as from 28 dpi, and at 28 and 42 dpi regarding the cerebellum. Earlier and more severe neurodegeneration during T. canis- than T. cati-induced NT, especially in the cerebrum, may explain the differences in behavioural alterations observed in previous studies. In addition to differences in larval migration preferences, immunological processes may contribute to these patterns, which warrant further investigation.

Ultrasonography for early diagnosis of Toxocara canis infection in puppies

Toxocara canis is one of the most common intestinal parasites in dogs and represents a highly infectious zoonotic parasite worldwide. Adult worms live in the bowel of dogs, and infections in puppies are commonly acquired transplacentally. The biology of the parasite and the commonly used diagnostic method, based on faecal examination, often prevent an early diagnosis of toxocariasis in puppies. Ultrasonographic diagnosis of intestinal ascariasis could be a feasible alternative method to diagnose T. canis infection in puppies during the prepatent period. The present study evaluated the diagnostic accuracy of ultrasonography for the diagnosis of intestinal toxocariasis in new-born puppies during the prepatent period. Fifty-four new-born puppies were prospectively recruited in the study. Each dog underwent intestinal ultrasonography and copro-microscopic examination every 5 days, starting from the 10th day post-birth. Intestinal ultrasonography visualized adult T. canis nematodes in the puppies' small intestine from the 10th day post-birth. On the 15th day after birth, ultrasonography showed 100% specificity and 85.4% sensitivity in diagnosing T. canis infection, despite negative results deriving from the copro-microscopic examination performed at the same time point. Our results showed that ultrasonography can be used as test for early diagnosis of T. canis infection in new-born puppies during the prepatent period. Early ultrasonographic diagnosis of T. canis infection in puppies could help control the disease in dogs and reduce the zoonotic risk for the human population.

Toxocara eggs in public places worldwide - A systematic review and meta-analysis

Toxocariasis is a neglected tropical disease of humans. Although many studies have indicated or shown that environmental contamination with Toxocara species eggs is a major risk factor for toxocariasis in humans, there has been no comprehensive analysis of published data or information. Here, we conducted the first systematic review and meta-analysis of current literature to assess the global prevalence of Toxocara eggs in public places (including beaches, parks and playgrounds). We conducted searches of the PubMed, Embase, Scopus and Science Direct databases for relevant studies published until 20 April 2018, and assessed the prevalence rates of Toxocara eggs in public places. We used the random effects model to calculate pooled prevalence estimates, with 95% confidence intervals (CIs), and analysed data in relation to WHO geographical regions. Subgroup analysis and meta-regressions regarding the geographical and environmental variables were also performed. Of 2384 publications identified, 109 studies that tested 42,797 soil samples in 40 countries were included in the meta-analysis. The pooled global prevalence of Toxocara eggs in public places was 21% (95% CI, 16-27%; 13,895/42,797). The estimated prevalence rates in the different WHO regions ranged from 13% to 35%: Western Pacific (35%; 95% CI, 15-58%), Africa (27%; 95% CI, 11-47%), South America (25%; 95% CI, 13-33%), South-East Asia (21%; 95% CI, 3-49%), Middle East and North Africa (18%; 95% CI, 11-24%), Europe (18%; 95% CI, 14-22%), and North and Central Americas (13%; 95% CI, 8-23%). A high prevalence was significantly associated with high geographical longitude (P = 0.04), low latitude (P = 0.02) and high relative environmental humidity (P = 0.04). This meta-analysis of data from published records indicates that public places are often heavily contaminated with eggs of Toxocara. This finding calls for measures to reduce the potential risk of infection and disease in humans.

Epidemiology and management of foodborne nematodiasis in the European Union, systematic review 2000-2016

BACKGROUND

Foodborne nematodiasis are caused by the ingestion of food contaminated by helminths. In Europe, these diseases are present in all countries.

OBJECTIVES

To review the available data on epidemiology and management of foodborne nematodiasis in the European Union, detect any trends and determine the possible causes of the observed changes.

METHODS

A review of available literature published between 2000 and 2016 was conducted.

RESULTS

Out of 1523 cases described in the literature, 1493 cases were autochthonous and 30 cases were imported. The detected parasites were Toxocara spp (34.7%), Ascaris lumbricoides (27.1%), Trichinella spp (21.9%), Anisakis spp (15.5%) and Angiostrongylus cantonensis (0.8%).

CONCLUSIONS

Foodborne nematodiasis remains a public health challenge for the European Union. Autochthonous cases of nematodiasis present the greatest health risk within the European Union. Foodborne nematodes due to lack of hygiene in food processing are diseases that can be avoided by increasing.

Ocular toxocariasis caused by toxocara canis in an adult woman. Case report

Introducción. La toxocariasis es una zoonosis producida por las larvas de los nematodos Toxocara canis y Toxocara cati, parásitos intestinales de los cánidos y los félidos, respectivamente.Presentación del caso. Paciente femenino de 22 años de edad, procedente de Caquetá, Colombia, con un cuadro de 3 meses de evolución con pérdida de visión en ojo izquierdo, acompañada de dolor ocular, diplopía, fotofobia y ojo rojo bilateral, quien presenta desprendimiento de retina en ojo izquierdo diagnosticado por ecografía. La mujer asiste a oftalmología, donde se hace diagnóstico diferencial con retinoblastoma y pars planitis. Se inicia manejo sintomático con corticoides orales y tópicos, con mejoría de la sintomatología, pero persistencia de pérdida de la agudeza visual.Discusión. Al revisar historial de antecedentes socioeconómicos, la paciente convive con perros y gatos, por lo que se piensa en toxocariasis ocular. En el cuadro hemático se observa ligera leucocitosis y linfocitosis, sin eosinofilia. La determinación de anticuerpos anti-Toxoplasma gondii y anti-cisticerco de Taenia solium resultaron negativas, al igual que el VDRL. El test de ELISA para T. canis fue positivo, con unos títulos IgG de 1:64 (positivo ≥1:32, especificidad >90%). Se inicia manejo con corticoide oftálmico, sistémico, albendazol y vitrectomía. Con la intervención quirúrgica se libera banda vítrea, logrando la desaparición de la diplopía, pero persiste granuloma periférico residual, el cual será intervenido por oftalmología.Conclusiones. Dada la posibilidad de ser confundida con un retinoblastoma —una neoplasia maligna que puede requerir la enucleación del ojo—, el conocimiento de esta forma de presentación de la toxocariasis es de suma importancia para los clínicos. 

Toxocara Seroprevalence and Associated Risk Factors in the United States

Caused by the parasitic nematodes Toxocara canis and cati, toxocariasis in humans can result in covert toxocariasis, ocular toxocariasis, visceral larval migrans, and neurotoxocariasis. A common infection, toxocariasis exposure varies widely within and between countries, with a previous estimate of Toxocara seroprevalence using data from 1988 to 1994 in the United States of approximately 13%. Age, poverty, sex, educational attainment, ethnicity, and region have been associated with Toxocara seroprevalence. In this study, we sought to determine the seroprevalence of and factors associated with Toxocara seropositivity in the United States using data from the National Health and Nutrition Examination Survey from 2011 to 2014 to provide a more recent estimate of Toxocara seroprevalence in the United States. We found an overall Toxocara seroprevalence of 5.1%. Increasing age, male sex, low educational attainment, low income, and immigration status each was associated with Toxocara seropositivity. Mexican Americans had reduced odds of exposure. These findings show that exposure to Toxocara continues in the United States and that several demographic factors influence the risk of exposure.

Seasonal variation in the prevalence of Toxocara eggs on children's playgrounds in the city of Hanover, Germany

BACKGROUND

Roundworms of the genus Toxocara are worldwide distributed zoonotic parasites of carnivores. Based on case numbers and the potential impact on human health, the Centers for Disease Control and Prevention (CDC) categorised toxocarosis as one of the most important neglected parasitic diseases. As contact with contaminated soil, e.g. in sandpits, is considered the primary transmission route, data on playground contamination are needed to assess infection risk for children. Here, playground contamination rates and their seasonal variation in the city of Hanover, Germany, were investigated.

METHODS

Sand samples were collected monthly over a 12-month period on 46 playgrounds in the city of Hanover, Germany. In total, 1,362 samples were examined for Toxocara eggs and analysed statistically for seasonal influences on potential infection risk.

RESULTS

Contamination rates ranged from 6.5% (3/46) Toxocara positive sandpits in September to 41.3% (19/46) in February, while contamination with infective embryonated eggs varied between 2.2% (1/46) and 23.9% (11/46). Compared to September, the month with the lowest contamination rate, significantly more sandpits were positive for Toxocara eggs from January to August and in October, while the prevalence of infective Toxocara eggs was significantly increased only in January and February. Regarding egg numbers, significantly higher total counts were observed in October and from December to June, while infective egg counts were significantly increased only in January, February and April.

CONCLUSIONS

Compared to data from 1985, contamination rates have dropped from 55.8% to an average of 23.2% in 2011. Even though the observed egg numbers indicate a moderate to low general infection risk, the potential risk to single individuals should not be underestimated, as highly contaminated spots may occur infrequently and independent of season.

Evaluation of the prevalence and clinical impact of toxocariasis in patients with eosinophilia of unknown origin

BACKGROUND/AIMS

Eosinophilia has numerous diverse causes, and in many patients, it is not possible to establish the cause of eosinophilia. Recently, toxocariasis was introduced as one cause of eosinophilia. The aims of this study were to evaluate the prevalence of toxocariasis and the clinical impact of albendazole treatment for toxocariasis in patients suspected of eosinophilia of unknown origin.

METHODS

We performed a retrospective chart review. After evaluation of cause of eosinophilia, the patients suspected of eosinophilia of unknown origin performed immunoglobulin G antibody specific assay for the Toxocara canis larval antigen by enzyme-linked immunosorbent assay.

RESULTS

This study evaluated 113 patients, 69 patients (61%) were suspected of eosinophilia of unknown origin. Among these 69 patients, the frequency of T. canis infection was very high (45 patients, 65.2%), and albendazole treatment for 45 eosinophilia with toxocariasis was highly effective for a cure of eosinophilia than no albendazole group regardless of steroid (82.3%, p = 0.007). Furthermore, among the nonsteroid treated small group (19 patients), albendazole treatment for eosinophilia were more effective than no albendazole group, too (83.3% vs. 28.6 %, p = 0.045).

CONCLUSIONS

The prevalence of toxocariasis was high among patients suspected of eosinophilia of unknown origin; therefore, evaluation for T. canis infection is recommended for patients with eosinophilia of unknown origin. Furthermore, for patients suspected of eosinophilia of unknown origin who have positive results for T. canis, albendazole treatment may be considered a valuable treatment option.

Seroprevalence and Risk Factors for Toxocara canis Infection in Serbia During 2015

We report data on the Toxocara seroprevalence evidenced in 2015 from samples of 40 children and 298 adults of the population living in different areas of Serbia, and on possible association of certain variables with infection. Detection of specific antibodies was performed using an enzyme-linked immunosorbent assay; all ambiguous results and part of the positive and negative sera were further analyzed by confirmatory Western blot test. An overall 23.5% seroprevalence was noticed, which was confirmed in 13.0% of the examined population with no significant difference regarding the age (children = 10.0%; adults = 13.4%) or by country area (East = 18.2%; North = 15.5%, Southeastern = 9.5%; p = 0.005). In contrast, the group of adult women proved more reactive than men (p = 0.001), and subjects both who spend spare time in square/parks (p = 0.041) and with positive onychophagy (p = 0.001) habit turned out more exposed to the infection. Possible reasons of these differences were analyzed, and the medical, veterinary, and economic impact of this soil-transmitted zoonosis were discussed.

Serological Evidence of Exposure to Globally Relevant Zoonotic Parasites in the Estonian Population

We investigated Estonian population and its selected subgroups for serological evidence of exposure to Ascaris lumbricoides, Echinococcus spp., Taenia solium, Toxocara canis, Toxoplasma gondii, and Trichinella spiralis. Serum samples from 999 adults representing general population, 248 children aged 14-18, 158 veterinarians, 375 animal caretakers, and 144 hunters were tested for specific immunoglobulin G antibodies against the selected parasites using commercial enzyme immunoassays (ELISA). Sera yielding positive or twice grey zone Echinococcus spp, T. solium, T. canis, and T. spiralis results were subjected to western blot (WB) analysis. In the general population, based on the ELISA results, the A. lumbricoides seroprevalence was 12.7%, Echinococcus spp. seroprevalence was 3.3%, T. solium seroprevalence was 0.7%, T. canis seroprevalence was 12.1%, T. gondii seroprevalence was 55.8%, and T. spiralis seroprevalence was 3.1%. Ascaris lumbricoides seroprevalences were higher in children and in animal caretakers than in the general population, and T. canis seroprevalence was higher in animal caretakers than in the general population. Compared with the general population, Echinococcus spp. seroprevalence was higher in children. By contrast, T. gondii seroprevalence was higher in animal caretakers, and lower in children, than in the general population. In the general population, the WB-confirmed Echinococcus spp. seroprevalence was 0.5%, T. solium cysticercosis seroprevalence was 0.0%, Toxocara spp. seroprevalence was 14.5%, and Trichinella spp. seroprevalence was 2.7%. WB-confirmed Toxocara spp. seroprevalence was higher in animal caretakers than in the general population. We found serological evidence of exposure to zoonotic parasites in all tested groups. This calls for higher awareness of zoonotic parasitic infections in Estonia.

Knowledge gaps in the epidemiology of Toxocara: the enigma remains

Toxocara species infect a wide range of companion, domestic and wild animals as definitive and paratenic hosts, via multiple routes of transmission, producing long-lived tissue-inhabiting larvae and resistant eggs that can survive in the external environment. Therefore Toxocara and the disease it causes in humans, toxocariasis, represents an ideal aetiological agent for the development of the one health approach. However, despite increasing awareness of the public health significance of toxocariasis, gaps in our understanding of certain key aspects of the parasite's biology and epidemiology remain. These gaps hinder our ability to integrate research effort within the veterinary, medical and environmental disciplines. This review will highlight key deficits in our understanding of nine dimensions of Toxocara epidemiology and discuss a potential scenario to develop a more integrated, one health approach to improve our understanding of the prevention and control of this complex and cryptic zoonosis.

Toward the formation of a Companion Animal Parasite Council for the Tropics (CAPCT)

This letter advises the imminent formation of the Companion Animal Parasites Council for the Tropics (CAPCT). The CAPCT consists of region-specific (e.g., Asia-Pacific, Latin America and Caribbean, Africa) experts comprising academics, veterinarians, parasitologists, physicians and allied industry partners that will work together to inform, guide and develop best-practice recommendations for the optimal diagnosis, treatment and control of companion animal parasites in the tropics, with the aim of protecting the health of pets and that of the public.

[Cardiovascular manifestations of human toxocariasis]

Toxocariasis is a parasitic infection produced by helminths that cannot reach their adult stage in humans. For their etiological species (Toxocara canis and Toxocara cati), man is a paratenic host. Infection by such helminths can produce a variety of clinical manifestations, such as: visceral larvae migrans syndrome, ocular larvae migrans syndrome and covert toxocariasis. In the visceral larvae migrans syndrome, the organs that are mainly involved include liver, lungs, skin, nervous system, muscles, kidneys and the heart. Regarding the latter, the importance of cardiovascular manifestations in toxocariasis, as well as its clinical relevance, has increasingly begun to be recognized. The current article is based on a systematic information search, focused mainly on the clinical and pathological aspects of cardiovascular manifestations in toxocariasis, including its pathophysiology, laboratory findings, diagnosis and therapeutical options, with the objective of highlighting its importance as a zoonosis and its relevance to the fields of cardiovascular medicine in adults and children.

Microarray gene expression analysis reveals major differences between Toxocara canis and Toxocara cati neurotoxocarosis and involvement of T. canis in lipid biosynthetic processes

Toxocara canis and Toxocara cati are globally occurring intestinal nematodes of dogs and cats with a high zoonotic potential. Migrating larvae in the CNS of paratenic hosts, including humans, may cause neurotoxocarosis resulting in a variety of neurological symptoms. Toxocara canis exhibits a stronger affinity to the CNS than T. cati, causing more severe neurological symptoms in the mouse model. Pathomechanisms of neurotoxocarosis as well as host responses towards the respective parasite are mostly unknown. Therefore, the aim of this study was to characterise the pathogenesis at a transcriptional level using whole genome microarray expression analysis and identify differences and similarities between T. canis- and T. cati-infected brains. Microarray analysis was conducted in cerebra and cerebella of infected C57Bl/6J mice 42daysp.i. revealing more differentially transcribed genes for T. canis- than T. cati-infected brains. In cerebra and cerebella of T. canis-infected mice, a total of 2304 and 1954 differentially transcribed genes, respectively, were identified whereas 113 and 760 differentially transcribed genes were determined in cerebra and cerebella of T. cati-infected mice. Functional annotation analysis revealed major differences in host responses in terms of significantly enriched biological modules. Up-regulated genes were mainly associated with the terms "immune and defence response", "sensory perception" as well as "behaviour/taxis" retrieved from the Gene Ontology database. These observations indicate a strong immune response in both infection groups with T. cati-infected brains revealing less severe reactions. Down-regulated genes in T. canis-infected cerebra and cerebella revealed a significant enrichment for the Gene Ontology term "lipid/cholesterol biosynthetic process". Cholesterol is a highly abundant and important component in the brain, representing several functions. Disturbances of synthesis as well as concentration changes may lead to dysfunction in signal transduction and neurodegenerative disease. Overall, only a minor overlap of differentially transcribed genes was observed between the two infection groups in both brain parts. Most genes are regulated individually in each infection group, supporting the evident differences of both roundworm species observed in the paratenic host in previous studies. In summary the present study underlines the differences in pathogenicity of T. canis and T. cati. It furthermore provides a comprehensive basis for future analyses over the course of infection as well as functional tests to identify gene regulatory circuits that are crucial for pathogenesis of neurotoxocarosis. The results of this study provide a promising foundation for further specific research to evaluate the particular pathogenetic mechanisms and to identify possible therapeutic targets.

Toxocariasis diagnosed in international travelers at the Institute of Tropical Medicine, Antwerp, Belgium, from 2000 to 2013

Although infection with Toxocara canis or T. catis (commonly referred as toxocariasis) appears to be highly prevalent in (sub)tropical countries, information on its frequency and presentation in returning travelers and migrants is scarce. In this study, we reviewed all cases of asymptomatic and symptomatic toxocariasis diagnosed during post-travel consultations at the reference travel clinic of the Institute of Tropical Medicine, Antwerp, Belgium. Toxocariasis was considered as highly probable if serum Toxocara-antibodies were detected in combination with symptoms of visceral larva migrans if present, elevated eosinophil count in blood or other relevant fluid and reasonable exclusion of alternative diagnosis, or definitive in case of documented seroconversion. From 2000 to 2013, 190 travelers showed Toxocara-antibodies, of a total of 3436 for whom the test was requested (5.5%). Toxocariasis was diagnosed in 28 cases (23 symptomatic and 5 asymptomatic) including 21 highly probable and 7 definitive. All but one patients were adults. Africa and Asia were the place of acquisition for 10 and 9 cases, respectively. Twelve patients (43%) were short-term travelers (< 1 month). Symptoms, when present, developed during travel or within 8 weeks maximum after return, and included abdominal complaints (11/23 symptomatic patients, 48%), respiratory symptoms and skin abnormalities (10 each, 43%) and fever (9, 39%), often in combination. Two patients were diagnosed with transverse myelitis. At presentation, the median blood eosinophil count was 1720/μL [range: 510-14160] in the 21 symptomatic cases without neurological complication and 2080/μL [range: 1100-2970] in the 5 asymptomatic individuals. All patients recovered either spontaneously or with an anti-helminthic treatment (mostly a 5-day course of albendazole), except both neurological cases who kept sequelae despite repeated treatments and prolonged corticotherapy. Toxocariasis has to be considered in travelers returning from a (sub)tropical stay with varying clinical manifestations or eosinophilia. Prognosis appears favorable with adequate treatment except in case of neurological involvement.

Seroprevalence of human Toxocara infections in the Roma and non-Roma populations of Eastern Slovakia: a cross-sectional study

Socioeconomic conditions and health of the Roma population, the most numerous minority in Europe, are worse than that of the non-Roma population. Information about the occurrence of human toxocarosis and other parasitic diseases in the Roma population is scarce or completely missing. The aim of this study was to map the seroprevalence of toxocarosis in the population living in segregated Roma settlements and to compare the data with the occurrence of antibodies in the non-Roma population of Eastern Slovakia. The seropositivity to Toxocara in 429 examined Roma inhabitants of segregated settlements reached 22·1%, while only 4/394 samples of the non-Roma population were found to be positive (odds ratio 27·7, P < 0·0001). Headache, muscle pain, influenza-like symptoms and diarrhoea occurred significantly more often in seropositive persons than in seronegative individuals. In the Roma population positivity was not influenced by gender, level of education and poverty, but age, lack of sanitary facilities and heating with wood significantly increased the risk of infection. It can be assumed that besides the high prevalence of toxocarosis, other parasitic diseases and communicable diseases will also be more prevalent in the Roma population living in segregated settlements.

Seroepidemiological Study of Toxocariasis among Volunteers Animal Husbandry Workers and Veterinary in Southern Anatolia in Turkey in 2014

BACKGROUND

Human toxocariasis is a parasitic infection caused by the larvae of Toxocara canis. We examine the Toxocara seroprevalance in veterinarians and animal husbandry workers living in the Mugla Province, Turkey to evaluate better the risk factors for Toxocara exposure.

METHODS

In 2014, 376 volunteers participated in the study in 2014. All blood specimens were tested using a commercial enzyme immunoassay kit and ELISA positive samples were confirmed by Western Blot (WB) method.

RESULTS

The seroprevalence of Toxocara, as determined by WB, was 8%. A statistically significant correlation was evident between patient age and Toxocara positivity among animal husbandry workers (P = 0.029). A strong association was also evident between sex and seropositivity in the animal husbandry group (P=0.024). Veterinarians working in pet clinics did in fact exhibit higher Toxocara seropositivities relative to those of other groups (P = 0.029). A statistically significant difference was detected between the rural geographic areas surveyed (P = 0.04).

CONCLUSION

In Mugla Province, seroprevalence of Toxocara is lower than other regions. Despite the low seroprevalence observed, especially in high risk professions toxocariasis remains an important medical concern within the region.

Ocular toxocariasis: clinical features, diagnosis, treatment, and prevention

Despite being one of the most common zoonotic infections worldwide, human toxocariasis has been one of the neglected tropical diseases. Although most human infections are asymptomatic, two main syndromes of human toxocariasis are classically recognized: systemic toxocariasis, which encompasses diseases in major organs; and ocular toxocariasis (OT), disease in the eye or optic nerve, caused by the migration of Toxocara larvae into the eye. OT is usually a unilateral disease, which typically presents as retinal granuloma, a yellowish or whitish inflammatory mass, in the posterior pole or peripheral retina. Granuloma itself or other comorbid conditions such as epiretinal membrane, macular edema, and retinal detachment can lead to permanent retinal damage and visual loss in eyes with OT. OT is diagnosed clinically by identification of clinical signs on ophthalmologic examination. Serological tests, such as enzyme-linked immunosorbent assay (ELISA) for detection of serum antibody against the Toxocara larvae, can confirm the diagnosis. In addition, serum immunoglobulin E and detection of ocular fluid antitoxocara antibody by ELISA may give additional aid to the diagnosis. Standard treatment of OT is corticosteroid in patients with active intraocular inflammation. Although the role of anthelmintic therapy is unclear, favorable outcome has been reported by combined corticosteroid and albendazole therapy in eyes with active inflammation. Prevention, by increasing public awareness and reducing the risk of infection, is also important. Recently, the association between ingestion of uncooked meat or liver and toxocariasis was reported, especially in adult patients. Future research on the potential source of infection, diagnosis, and treatment should be performed.

Transmammary infection in BALB/c mice with chronic toxocariasis

Human toxocariasis is a neglected public health problem. Infection of humans generally results from the accidental ingestion of embryonated Toxocara canis eggs, but it is important to broaden knowledge about other forms of transmission. This study aimed to demonstrate the prevalence of transmammary transmission in mice with chronic toxocariasis. BALB/c mice in groups 1 (G1) and 3 (G3) were inoculated with 1200 T. canis eggs 60days before mating, whereas those of group 2 (G2) were not infected. After delivery, the G1 neonates were transferred to G2 females to be nursed, and vice versa. Thus, the mice generated by G2 females and breastfed by G1 females could be infected only during lactation. In the G3 group, offspring were not exchanged. The search for T. canis larvae in the bodies of the lactating females and their offspring was performed after weaning and at 60days old, respectively. The frequency of transmammary infection in the mice generated by G2 uninfected females and breastfed by G1 infected females was 19.8%, which was similar to that observed (19.6%) in the mice bred and fed by G3 females. The frequency of infection in the mice generated by G1 females and breastfed by G2 females was only 4.2%, which was lower than that of G1 (p=0.0064) and G3 (p=0.0062) groups. Transmammary infection by mice with chronic toxocariasis was found to be more prevalent than congenital infection.

Comparison of six simple methods for extracting ribosomal and mitochondrial DNA from Toxocara and Toxascaris nematodes

Six simple methods for extraction of ribosomal and mitochondrial DNA from Toxocara canis, Toxocara cati and Toxascaris leonina were compared by evaluating the presence, appearance and intensity of PCR products visualized on agarose gels and amplified from DNA extracted by each of the methods. For each species, two isolates were obtained from the intestines of their respective hosts: T. canis and T. leonina from dogs, and T. cati from cats. For all isolates, total DNA was extracted using six different methods, including grinding, boiling, crushing, beating, freeze-thawing and the use of a commercial kit. To evaluate the efficacy of each method, the internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit 1 (cox1) gene were chosen as representative markers for ribosomal and mitochondrial DNA, respectively. Among the six DNA extraction methods, the beating method was the most cost effective for all three species, followed by the commercial kit. Both methods produced high intensity bands on agarose gels and were characterized by no or minimal smear formation, depending on gene target; however, beating was less expensive. We therefore recommend the beating method for studies where costs need to be kept at low levels.