Public understanding of toxocariasis

Knowledge of pet-related zoonotic diseases and pet care in Hong Kong, a heavily crowded urban setting

BACKGROUND

With the rapid expansion of pet animal populations worldwide, pet-related zoonotic diseases are becoming an important issue in public health. Hong Kong (HK), located in southern China, is one of the most crowded urban centres in the world. The population of pets, especially exotic pets, in HK has grown significantly in recent decades, potentially elevating the risk of pet-related zoonotic diseases. However, no studies have been conducted to explore the knowledge of HK public towards pet-related zoonotic diseases and animal husbandry practices.

OBJECTIVES

To evaluate the level of awareness among the HK public of pet-related zoonotic diseases and their understanding of proper animal husbandry practices.

METHODS

The study was carried out in HK from June-August 2019 using both online and paper versions of a questionnaire. A total of 362 completed questionnaires (74.3% return rate) were collected and the responses analysed.

RESULTS

Sixty percent of the participants were current or past pet owners or planned on becoming pet owners in the coming 2 years, irrespective of their income or size of their living space. Among the participants, pet owners (including those who planned pet ownership) had a relatively higher level of awareness of pet-related zoonotic disease. However, the overall awareness of zoonotic diseases among both pet and non-pet owners was low with a knowledge score of <50%. A similar trend was observed for knowledge about proper animal husbandry practices.

CONCLUSIONS

This study showed that the HK public was generally not familiar with pet-related zoonotic diseases and proper pet care. These knowledge gaps could potentially increase the risk of disease transmission. Further studies focusing on specific pet species and on people of different social-economic backgrounds are needed to provide future direction of efforts to reduce the risk of pet-related zoonotic diseases and to enhance pet-related animal and human welfare.

Toxocariasis in a Child with Autism Spectrum Disorder

A boy affected by autism spectrum disorder was admitted for persistent high fever, without shiver, for two weeks. The boy referred to abdominal pain, in the first week of fever, and to mild anorexia in the last days before admittance to our hospital centre. The father reported that the boy suffered by geophagia and coprophagia and he has been going to a didactical farm (where he has been exposed to several kinds of animals) to improve his neuropsychiatric condition. Blood analysis shows severe eosinophilia and high levels of total IgE, and abdominal echocardiography showed hepatic lesions. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) confirmed the suspicion of toxocariasis, linked to the habit of the boy to ingest ground or animal faeces in a didactic farm frequented by the boy. Treatment with albendazole and prednisone was administered with a rapid improvement of the symptoms and the laboratory findings and significant reduction of the hepatic lesion.

Survey of UK pet owners quantifying internal parasite infection risk and deworming recommendation implications

Background

Dogs and cats in the UK are exposed to many internal parasites which can pose risks to the health of both the pet and their owners. By understanding these endemic parasites and the risks they pose, we can assess the lifestyle of pets and recommend the correct deworming frequency. Studies identifying risk factors were discussed in the European Scientific Counsel Companion Animal Parasites (ESCCAP) guidelines. To this date, there has been very little information on how pet owners in the UK deworm their pets and if the protocols they follow align with ESCCAP recommendations. The objective of this study was to look at the current deworming protocols of UK cat and dog owners in conjunction with their lifestyle and risk.

Methods

An online survey was conducted in the UK targeting pet owners who own at least one dog and/or cat and were responsible for product purchase, the pet’s health care and veterinary visits. These survey results were analysed against the ESCCAP guidelines and each pet placed into a risk category. By comparing the current deworming frequency with that recommended for their risk category, the compliance of UK pet owners with ESCCAP recommendations was evaluated.

Results

A total of 500 dog owners and 500 cat owners completed surveys. Overall, the study found none of the pets fell into risk group A, with all pets meeting the risk level for at least deworming four times a year (risk group B and above). The majority of animals fell into the highest risk category D with 97% of dogs and 68% of cats. The average deworming per year in the UK was 3.1 for dogs and 3.1 cats, below the minimum recommended by ESCCAP.

Conclusions

For both felines and canines, the dosing frequencies are lower than recommended to both reduce zoonotic risk for reducing Toxocara spp. egg-shedding and improve pet health. This research highlights the need for improved education around dog and cat patient risk assessments and greater adherence to recommended deworming aligned with the ESCCAP guidelines.

Prevalence of Toxocara species infection in the U.S.: Results from the National Health and Nutrition Examination Survey, 2011-2014

Toxocariasis is one of the most common neglected infections of poverty in the U.S. with a reported National Health and Nutrition Examination Survey (NHANES) III (1988–1994) seroprevalence of 13.9% based on enzyme immunoassay testing. We reviewed NHANES data from 2011–2014 to assess current levels. Sera collected from NHANES 2011–2014 participants six years and older were tested for exposure using rTc-CTL-1 antigen, a more sensitive and specific recombinant antigen for IgG antibodies for Toxocara spp. These results were subdivided into children (age 6–17) and adults (age ≥ 18) and then compared between various sociodemographic characteristics. Given prior associations of Toxocara exposure with atopic disease and lead exposure, we also reviewed laboratory values including complete blood counts and blood and urine lead levels. Data from 13,509 individuals with Toxocara antibody results were examined including 3337 children (15.2%) and 10172 adults (84.8%). Overall seroprevalence was 5.1%. In adults increased antibody positivity occurred with non-White ethnicity, male gender, less than college-level education and lower income. Among children, increased antibody positivity was solely related to a lack of health insurance. Additionally, seropositivity was associated with increased blood lead and eosinophil levels in adults and both blood and urine lead levels in children. Relative to NHANES III (1988–1994), current data suggest an overall decrease in Toxocara spp. seroprevalence from 13.9% to 5.1%, however this may be artificially lowered due to difference in testing methods used. Persistent disparities appear to be associated with at-risk populations such as minority ethnicity and low socioeconomic status.

Toxocariasis is a pervasive helminth infection transmitted to humans via embryonated eggs from soil contaminated by the feces of dogs and cats (Toxocara canis and T. cati, respectively). The most recent seroprevalence study of Toxocara infection in the United States used the National Health and Nutrition Examination Survey (NHANES) III data collected from 1988 to 1994. At-risk groups identified included male gender, non-White ethnicity and low education and socioeconomic status. Since the original study, dogs and cats have increased in number and an improved testing platform has been created using rTc-CTL-1 antigen to Toxocara spp. with a sensitivity and specificity of 90% and 99%, respectively. In this study, we assessed current seroprevalence based on the NHANES data from 2011 to 2014 using the more specific testing platform. Although overall seroprevalence appears to have decreased from 13.9% to 5.1%; persistent disparities remain associated with at-risk populations including minority ethnicity and low socioeconomic status. Continued work is needed to improve awareness of disease transmission and treatment amongst the general population as well as veterinarians who may care for dogs and cats within the United States and take responsibility for education of the public.

Epidemiology of Toxocariasis in England and Wales

Toxocara infection occurs through ingestion of parasite eggs excreted by dogs and cats, and can cause severe morbidity. The burden of disease in England and Wales is not well described, and the impact of public health campaigns conducted in the mid-1990s is uncertain. This paper uses data from two extensive databases to explore the trends in this disease in England and Wales from the 1970s to 2009.

Parasite control practices and public perception of parasitic diseases: A survey of dog and cat owners

Drugs used in the control of internal and external parasites in companion animals play a crucial role in Animal and Public Health. To ensure continuing protection, these drugs should be administered regularly and in intervals, as suggested by the manufacturers. To assess parasite control practices and other related factors, including the degree of public awareness on the topic, 312 dog and cat owners were surveyed while attending the Small Animal Hospital, Faculty of Veterinary Medicine, Lisbon University. Results showed that 89.7% of the dogs were currently being treated with endoparasitic drugs. Of these, 74.3% were dewormed every four months or longer and merely 11.8% with the recommended treatment regimen (minimum quarterly). In cats, 63.6% were being treated with endoparasitic drugs and 85.7% of these were irregularly dewormed every four months or longer and merely 5.5% with the recommended treatment regimen (minimum quarterly). Combinations of praziquantel, pyrantel embonate and febantel were the most commonly used drugs in dogs, whereas macrocyclic lactones were more frequently used in cats. Regarding external parasitic control, 92.2% of the dogs were being treated, 50.5% of these at monthly intervals (all-year round or seasonally). The most common ectoparasitic drug formulation used on dogs was the spot-on imidacloprid+permethrin (89%). Only 28.4% of the dogs were uninterruptedly protected throughout the year from the main canine vector borne diseases transmitted by fleas, ticks, sandflies and mosquitoes. Merely 63.6% of the cats were being controlled with ectoparasitic drugs, most at infrequent drug intervals and imidacloprid was the most frequently used drug on cats (44.4%). Additionally, 85% of the respondents had never heard of the word "zoonosis" and 37% of them did not collect their dog's faeces in all public places. Scabies, toxoplasmosis and leishmaniasis were the most frequent parasitic diseases identified by the public in this survey. Although the majority of pet owners give antiparasitic drugs, our results show that most of them do not follow the manufacturers recommendations, deworming at irregular and consequently ineffective intervals. Therefore, it is of utmost importance for the veterinarians to educate pet owners regarding parasite cycles, methods of prevention and transmission mechanisms, as well as to follow the drug recommendations, in order, respectively, to increase their awareness and thereby improve the effectiveness of the available control measures.

Asthma and toxocariasis

BACKGROUND

Asthma is the most common chronic disease in children and a major public health problem in adults. A relation between asthma and toxocariasis has been hypothesized.

OBJECTIVE

To evaluate the strength of association between asthma and Toxocara species seropositivity by conducting a systematic review and a meta-analysis of available data.

METHODS

PubMed, EMBASE, Web of Science, and the reference lists of all relevant articles and books were screened until October 2013. Two authors independently assessed eligibility and study quality and extracted data. A common odds ratio was estimated using a random-effects meta-analysis model of aggregated published data.

RESULTS

Ten studies met the inclusion criteria, for a total of 1,530 participants (723 cases and 807 controls). This meta-analysis found a significantly higher prevalence of Toxocara canis infection in patients with asthma than in controls (odds ratio 3.36, 95% confidence interval 1.76-6.42, P < .001). Similar results were found when meta-analysis was restricted to the studies considering only children or adults.

CONCLUSION

The results support the existence of a positive association between asthma and Toxocara species seropositivity.

Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil ) by Toxocara spp. and Ancylostoma spp

The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp.) in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples were collected, between September and December 2010, and examined using the centrifugal flotation technique with sodium dichromate and zinc sulphate as well as the modified Baermann method. Notably, 35 (74.5%) of the 47 districts surveyed in Guarulhos possessed samples contaminated with Toxocara spp. and/or eggs or larvae of Ancylostoma spp. The frequency of Toxocara spp. and Ancylostoma spp. in the samples from public areas was 68.1% and 46.8%, respectively. Overall, the eastern side of Guarulhos is the region with the highest occurrence of causative agents of larva migrans. In all collection sites, the presence of feces from dogs and cats accompanied by their owners and stray animals were observed. Notably, it is important to adopt measures to control dog and cat breeding, to treat infected animals, and provide health education to the population.

Toxocariasis and epilepsy: systematic review and meta-analysis

Objective

Human toxocariasis is a zoonotic infection caused by the larval stages of Toxocara canis (T. canis) and less frequently Toxocara cati (T. cati). A relationship between toxocariasis and epilepsy has been hypothesized. We conducted a systematic review and a meta-analysis of available data to evaluate the strength of association between epilepsy and Toxocara spp. seropositivity and to propose some guidelines for future surveys.

Data Sources

Electronic databases, the database from the Institute of Neuroepidemiology and Tropical Neurology of the University of Limoges (http://www-ient.unilim.fr/) and the reference lists of all relevant papers and books were screened up to October 2011.

Methods

We performed a systematic review of literature on toxocariasis (the exposure) and epilepsy (the outcome). Two authors independently assessed eligibility and study quality and extracted data. A common odds ratio (OR) was estimated using a random-effects meta-analysis model of aggregated published data.

Results

Seven case-control studies met the inclusion criteria, for a total of 1867 participants (850 cases and 1017 controls). The percentage of seropositivity (presence of anti-Toxocara spp. antibodies) was higher among people with epilepsy (PWE) in all the included studies even if the association between epilepsy and Toxocara spp. seropositivity was statistically significant in only 4 studies, with crude ORs ranging 2.04–2.85. Another study bordered statistical significance, while in 2 of the included studies no significant association was found. A significant (p<0.001) common OR of 1.92 [95% confidence interval (CI) 1.50–2.44] was estimated. Similar results were found when meta-analysis was restricted to the studies considering an exclusively juvenile population and to surveys using Western Blot as confirmatory or diagnostic serological assay.

Conclusion

Our results support the existence of a positive association between Toxocara spp. seropositivity and epilepsy. Further studies, possibly including incident cases, should be performed to better investigate the relationship between toxocariasis and epilepsy.

Human toxocariasis is an infection caused by the larval stage of the worms Toxocara canis and less frequently Toxocara cati, common parasites of domestic and peridomestic dogs and cats. It is a cosmopolitan infection, occurring whenever the man-soil-dog relationship is particularly close, especially in tropical countries, where the humid climate favours the survival of parasite eggs in the soil, and in rural settings, where the poor hygiene increases the probability of human infection. Epilepsy affects nowadays at least 65 million of people worldwide and is particularly common in tropical areas, probably because of the presence of cases caused by infectious diseases largely absent in industrialized countries. For several decades, researchers have investigated the possible association between toxocariasis and epilepsy. In this study we conducted a statistical analysis of all the data available on the relationship between these two conditions. The combined results of the 7 studies included indicate an association between the two diseases. Further studies are necessary to demonstrate a causal relationship (i.e. toxocariasis causes epilepsy). Considering that toxocariasis is a preventable and common disease, a better understanding of the relationship between toxocariasis and epilepsy may contribute to improving prevention of epilepsy worldwide.

Pet roundworms and hookworms: a continuing need for global worming

Ascarids and ancylostomatids are the most important parasites affecting dogs and cats worldwide, in terms of diffusion and risk for animal and human health. Different misconceptions have led the general public and pet owners to minimize the importance of these intestinal worms. A low grade of interest is also registered among veterinary professions, although there is a significant merit in keeping our guard up against these parasites. This article reviews current knowledge of ascarids and ancylostomatids, with a special focus on pathogenicity, epidemiology and control methods in veterinary and human medicine.

Epidemiologic and zoonotic aspects of ascarid infections in dogs and cats

Toxocaracanis and Toxocara cati of dogs and cats, respectively, can cause significant disease in people. Human seroprevalence for Toxocara antibodies varies with factors such as geographic location, socio-economic status, and dietary habits. Risk factors for infection include geophagia and low-level education. Toxocara canis is better recognized as a cause of human toxocariasis, but Toxocara cati should not be overlooked. In addition, patent infections with Baylisascaris procyonis, the raccoon ascarid, have been increasingly recognized in dogs. Pet owners need to be properly educated about zoonotic risks, and veterinarians should institute regular parasite screening and treatment for all pets. Establishment of national surveillance programs to determine the incidence and specific etiological agent in human larva migrans patients would aid in the development of targeted intervention strategies.