Study on the contamination of Abadan public parks soil with Toxocara spp. eggs

Free-ranging rural dogs are highly infected with helminths, contaminating environment nine times more than urban dogs

Regardless of the highly efficient anthelmintics available and the control measures taken by dog owners and veterinarians, gastrointestinal parasites, especially zoonotic helminths, are still abundant in dogs and pose a health risk to humans. Free-ranging dogs in rural areas can be an important source of helminth infection. The aims of the present work were to collect scats of rural dogs, determine the environmental contamination caused by helminth infections among rural dogs of Western Estonia, analyse how diet affects helminth infection rate and compare the findings to a previous study focusing on dog helminths in urban areas of Estonia. To differentiate the scats of dogs from other sympatric canids, a genetic method was applied. Of 328 samples, genetic analysis identified 84 scats belonging to dogs, of which 87.0% were infected with helminths. A high proportion of rural dog scats harboured eggs of Taeniidae (65.5%), followed by Trichuris spp./Eucoleus spp. (15.5%), Uncinaria stenocephala (14.7%) and Toxocara canis (4.3%). Coinfections occurred in 34.5% of the samples, being the most common between Taeniidae and U. stenocephala (41.4%). The intensity model indicated higher helminth infection rate in rural dogs preying on rodents and game. In comparison to urban dogs, rural dogs were nine times more likely to be infected with intestinal parasites. These results emphasize the need to implement measures to reduce helminth infections in dogs living in rural areas of Western Estonia. Among a complex of measures to be taken, we suggest that it is also important to diagnose which gastrointestinal parasite species infect dogs to determine specific anthelmintic treatment against these parasites.

Comparison of the Detection of Toxocara Spp. in the Soils of Public Parks of Ahvaz (Southwest of Iran) by PCR and Loop-Mediated Isothermal Amplification (LAMP)

INTRODUCTION

The infections caused by Toxocara spp. are considered as one of the most important zoonotic diseases in the world, especially in developing countries. Human toxocariasis, particularly in children, is acquired by playing in public parks. Hence, the aim of the current study was to detect Toxocara spp. in the soils of public parks of the city of Ahvaz, southwest of Iran, using the PCR and loop-mediated isothermal amplification (LAMP) methods.

METHODS

In this descriptive cross-sectional study, 260 soil samples were randomly collected from the different public parks of the city of Ahvaz. After performing zinc sulfate (ZnSO₄) flotation technique, the DNA samples were extracted from the isolated Toxocara spp. eggs. Lastly, the extracted DNA was used for PCR and LAMP-based molecular detection.

RESULTS

Out of 260 specimens, 57 (21.9%) samples were found positive for Toxocara spp., using the PCR method, out of that 38 (14.6%) samples were positive for T. canis and 19 (7.3%) samples were positive for T. cati. Also, out of 260 specimens, 81 (31.1%) cases were positive for Toxocara species, using the LAMP method, among them 51 (19.6%) samples were found positive for T. canis and 30 (11.5%) samples were positive for T. cati. Kappa (κ) coefficient between PCR and LAMP showed a strong agreement (0.766, P-value=0.002).

CONCLUSION

The obtained data showed a relatively high outbreak of Toxocara spp. in the public parks' soils of the city, using the PCR and LAMP methods. Since the parasite can cause human toxocariasis, particularly in children; thus, the health authorities of the city of Ahvaz and other similar cities, especially in developing countries, must pay more attention to the hygiene of the public parks' soils.

High Parasitic Contamination of Soil Samples in the North of Iran: A Potential Risk of Parasitic Infection for Tourists

BACKGROUND

Soil-transmitted parasites (STPs) are significant intestinal parasites that infect humans and animals and impose considerable burdens on human society and animal husbandry industries. Therefore, the present study aimed to determine the prevalence of parasitic elements of soil samples collected from the north of Iran.

METHODS

A total of 256 soil samples were collected from public parks, public places, vegetable gardens, sand heaps, and shadow areas near houses in the north of Iran and examined using the sucrose flotation method.

RESULTS

Out of 256 examined samples, 131 (51.2%) showed parasitic contamination, including larvae (43%), oocysts (14.1%), and different eggs (6.6%). According to the results, the most and least common parasites observed in the samples were larvae (43%), as well as Toxascaris leonina, and Trichuris trichiura (0.4%), respectively. Moreover, the most and least contaminated locations were sand heaps (62.5%) and shadow areas near houses (45.6%), respectively. Regarding cities, Behshahr (68.3%) and Sari (67.5%) had the highest contaminated soil samples, whereas Chalus (37.5%) showed the lowest contamination. On the other hand, rural samples showed more contamination compared to urban areas (P< 0.05).

CONCLUSION

The findings of the present study indicate that the overall prevalence of STPs in examined areas and highly contaminated soil samples can be considered as a potential source of human contamination particularly tourists with STPs.

Spatial analysis of Toxocara spp. eggs in soil as a potential for serious human infection

Toxocara spp. cause one of the most widespread soil-transmitted helminthic infections worldwide. In both developed and developing countries, soil contamination with Toxocara eggs is considered as a major threat to public health. A total of 515 soil samples from 89 sampling sites were collected from different locations of public health such as Wastelands and Streets, public parks, and marginal areas. The soil samples were examined for Toxocara eggs using a centrifugal-floatation technique utilizing a saturated sodium nitrate solution. centralization of positive soil samples in the province was studied by Spatial Statistics Techniques such as Average Nearest Neighbors and Spatial Autocorrelation and Kernel Density Function Toxocara spp. eggs were found in 94 (18.25 %) out of 515 samples collected from the studied areas. According to the results obtained, marginal areas are often contaminated with eggs of Toxocara. Consequently, preventive measures including health education should be implemented to reduce the potential risk of this parasitic 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 and Viability of Toxocara spp. Eggs in Soil of Public Parks in Northwestern Mexico

BACKGROUND

Toxocara spp. is a zoonotic parasite that can infect human; children are the largest group at risk of infection. Therefore, this study aimed to determine the prevalence and viability of Toxocara spp. eggs in the soil of public parks.

METHODS

Overall, 1180 soil samples from 236 public parks in four sectors of the city of Culiacan were collected at random, between Jun and Dec, 2013. The presence of Toxocara spp. eggs was determined by light microscopy using a centrifugation-flotation technique and viability by trypan blue staining technique.

RESULTS

Of the 236 parks sampled, 18 were positive to Toxocara spp. resulting in a prevalence of 7.6% and viability of 94.4% with a P<0.05. Detection of Toxocara spp.in soil samples was 16.5% and viability 94.7% with a P<0.05. Parks positive to Toxocara spp., had sports fields and playgrounds (94.4%), trees and green areas (88.8%).

CONCLUSION

Although a low prevalence of Toxoxara spp. eggs in the soil of public parks was found, they exhibited high viability, suggesting that the soil from these public parks is a source of infection for pets and humans especially children.

The Study of Soil Contamination by Toxocara spp. Eggs in Different Areas of Chaharmahal and Bakhtiari Province, Southwest Iran

Background and aims: Toxocariasis caused by the larvae of Toxocara spp. is a zoonotic infection with global distribution that is considered an important health problem in the humans. The soil is regarded as the main source of the transmission of Toxocara infection to susceptible hosts. This study investigated the existence of Toxocara spp. ova in rural and urban public areas of Chaharmahal and Bakhtiari province. Methods: A total of 180 soil samples were randomly collected from 74 public places from urban and rural areas of nine counties of Chaharmahal and Bakhtiari province during May to September, 2017. The samples were examined for Toxocara spp. eggs by the modified sucrose flotation method. Results: The contamination rate of the soil samples with Toxocara spp. ova varied within 0%-18.1% in different counties. Overall, 9 (5%) out of 180 examined soil samples were found positive for Toxocara spp. ova. Of nine investigated districts, Toxocara spp. ova were observed in four counties and the highest rate of soil contamination was found in Farsan county with 18.1%. Finally, the prevalence of Toxocara spp. eggs was more in the rural areas (6.7%) compared to the urban ones (3.3%). Conclusion: This study was the first investigation regarding the contamination of Toxocara spp. eggs in the soil of public places in rural and urban areas of Chaharmahal and Bakhtiari province. According to the results, the rate of soil contamination in this region was lower compared with the other parts of Iran. Therefore, a further study is required to determine factors that may be involved in the distribution of Toxocara spp. in different areas of this province.

Molecular characterization of Toxocara spp. eggs isolated from public parks and playgrounds in Shiraz, Iran

Human toxocariasis, a worldwide parasitic disease, is caused by the larval stage of intestinal nematodes of dogs and cats, namely Toxocara canis and Toxocara cati. Human infection occurs by the accidental ingestion of embryonated eggs present in the soil, vegetables or on other contaminated surfaces, as well as via consumption of uncooked paratenic hosts, such as bird meat and giblets. The objective of this study was to evaluate the contamination of soil in public parks and playgrounds in Shiraz using microscopy and molecular methods. A total of 150 soil samples were collected from public parks and playgrounds in various areas of Shiraz, southern Iran. The samples were treated with saturated zinc sulphate solution, and Toxocara spp. eggs were detected by microscopic observation followed by nested polymerase chain reaction (PCR). To differentiate T. canis and T. cati eggs from each other, PCR restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS)-rDNA region by SalI endonuclease enzyme was used. PCR-sequencing was performed to confirm the results of the PCR-RFLP method. Based on the flotation results of the 150 soil samples, six (4%) were found to be positive for Toxocara spp. eggs, whereas nested-PCR showed 24 samples to be positive (16%). Based on the PCR-RFLP method and the sequence of the ITS-rDNA region, a total of 23 out of 24 isolates were confirmed as T. cati and one out of 24 as T. canis. The results showed a higher number of soil samples to be positive for Toxocara by the molecular method than microscopy, and higher T. cati infection in soil samples, which could have an important role in human infection with toxocariasis in this region.

Identification of Toxocara spp. eggs in dog hair and associated risk factors

AIM

The aim of the study was to identify the presence of eggs of Toxocaraspp. in dog hair and to identify any risk factors associated with this.

MATERIALS AND METHODS

A total of 96 dogs were sampled collecting hair from the head, perianal and hindquarters. Epidemiologic data from each animal were recorded to identify risk factors. The samples of hair were washed with solutions of distilled water, phosphate-buffered saline and Tween 20 detergent. Microscopic analysis was subsequently performed for the identification of eggs.

RESULTS

Out of the total dogs, 41.7% were positive for the presence of parasite egg in their hair. Toxocara eggs were found in hair from the head (14.5%), tail (20.8%), and limbs (10.4%). Dogs, younger than 12 months old, showed higher values (4.7%) of egg presence in the perianal area (p<0.05). The principal risk factors for the presence of eggs in hair were not deworming (odds ratio [OR]=3.60, p<0.004) and not brushing (OR=2.26, p<0.12).

CONCLUSION

These results show that in the state of Mexico there is a high percentage of dogs contaminated with Toxocara spp. eggs in their hair. This should be seriously considered due to the potential problems of toxocariasis and the risk to public health.

Trend of toxocariasis in Iran: a review on human and animal dimensions

One of the neglected soil and/or food-borne diseases with international public health importance is toxocariasis. Human cases are being increasingly reported from Asian, African, Oceania, European and the American countries. Hence, human toxocariasis (HT) is now considered as a major zoonosis with global and regional importance. In Iran, human and animal toxocariasis is an endemic disease with clinical and epidemiologic health problem aspects. Doubtless, understanding the epidemiology and the trend of this important parasitic disease and its affecting factors will provide the establishment of effective prevention and control programs. To better understand the trend of toxocariasis researches in Iran, this study was performed to analyze different aspects of this zoonotic disease including history, life cycle, species, human animals and environmental studies, diagnostic aspects and treatments to find out the gaps, including different aspects of clinical sings in human patients, new and specific recombinant antigens based on the native antigens, new diagnostic tools, especially rapid diagnostic tests, paratenic hosts status and new treatment procedures which is necessary to be investigated in the future studies on this important zoonotic disease.

Detection of Toxocara spp. Eggs in the Soil of Public Places in and Around of Ardabil City, Northwestern Iran

BACKGROUND

Human toxocariasis is contained in the list of neglected diseases. The infection occurs after ingestion of embryonated eggs in contaminated soil. The present study was carried out to estimate the extent of soil contamination with Toxocara spp. eggs in the public places.

METHODS

Soil samples were collected randomly from 41 public places in various parts in and around of Ardabil, Iran, between March 2013 and March 2014. Data were examined by microscopy following sodium nitrate flotation.

RESULTS

Of the 200 collected soil samples, 35 (17.5%) were positive for soil parasites. The eggs of Toxocara spp. were found in 14 (7%) soil samples.

CONCLUSION

This investigation gives baseline knowledge regarding soil contamination with Toxocara spp. eggs in Ardabil city and provides information for local control of toxocariasis.

Soil Contamination with Toxocara Spp. Eggs in Public Parks of Mashhad and Khaf, North East of Iran

BACKGROUND

Toxocariasis is an important disease caused by the larvae of parasitic worms such as Toxocara canis and T. cati. Public parks can be the source of toxocariasis for small children. This survey was conducted to determine the prevalence of Toxocara spp. ova in parks of Mashhad and Khaf northeastern Iran.

METHODS

In this descriptive cross-sectional study, performed in November 2011 to June 2012, overall, 340 soil samples were collected from 39 parks of Mashhad and 29 parks in Khaf city. Flotation method and direct smear were used, and the samples were evaluated using a light microscope. The results were analyzed using SPSS version 19 and Chi-square test.

RESULTS

In the evaluation of 195 and 145 soil samples, 18 (9.2%) and 16 cases (11.3%) of contamination with Toxocara spp. eggs were detected, respectively.

CONCLUSION

Although the prevalence of Toxocara eggs in soil samples was low, parks can be a source of Toxocara infection of children in these areas.

Human toxocariasis: current advances in diagnostics, treatment, and interventions

Toxocariasis is a neglected zoonosis caused by the nematodes Toxocara canis and Toxocara cati. This disease is widespread in many countries, reaching high prevalence independently of the economic conditions. However, the true number of cases of toxocariasis is likely to be underestimated owing to the lack of adequate surveillance programs. Although some diagnostic tests are available, their sensitivity and specificity need to be improved. In addition, treatment options for toxocariasis are limited and are non-specific. Toxocariasis is listed as one of the five most important neglected diseases by the CDC. This review presents recent advances related to the control of toxocariasis, including new immunodiagnostics, therapies, and drug formulations, as well as novel interventions using DNA vaccines, immunomodulators, and probiotics.