Investigation on Toxocara spp. eggs in hair coat of dogs in YSR Kadapa district of Andhra Pradesh, India

Systematic review and meta-analysis on the risk potential of zoonotic toxocariasis from soil contamination of public places in India

Parasitic zoonoses despite of their potential threats to human health remain neglected especially in developing countries. Toxocara canis and Toxocara cati worms are considered important zoonotic parasites and the ability of their infective ova to sustain longer in suitable edaphic environments poses constant risk of infection to humans. This systematic review and meta-analysis aims to highlight the burden and importance of soil borne toxocariasis in India. A total of 14 primary prevalence studies spanned over a period from 1985 to 2017 were included in this study. Due to expected variation between studies, a random-effects model was applied by using MetaXL add-on. The apparent prevalence based on the soil samples tested positive was found in the range of 2.11 to 31.0% while the weighted pooled prevalence was estimated as 11.26 (95% CI 07.59 - 15.54%). A high heterogeneity between studies (I² = 93.39 and Q = 227.024, p = 0.00) confirmed the diversity of the populations under study. This meta-analysis highlights the need of more studies on soil transmission of zoonotic toxocariasis in India.

Canine Toxocariosis: Its prevalence, incidence and occurrence in the Indian subcontinent

Toxocariosis is an important neglected tropical helminth disease of zoonotic significance for which canids are the definitive hosts. Dogs are also considered the sentinel host for the occurrence of T. canis infections in humans. Therefore, understanding its prevalence in canine population is imperative for any effective disease control in humans. A comprehensive review of literature on the prevalence of T. canis in canids was lacking from the Indian subcontinent which necessitated our efforts to compile available data published on this topic. Data on prevalence, incidence and occurrence of this helminths in canids were presented in this review as tabular format for easy comprehension. Moreover, the data were categorized based on the region where the studies were conducted with an aim to understand the spatial distribution of this parasite in the subcontinent. Factors influencing the regional prevalence/occurrence of T. canis such as type of canids (stray or pet), age, sex, breed, season and the choice of analytical methods were also discussed. In addition, data on the prevalence of T. canis in environmental samples and in zoo canids were also compiled and presented. We anticipate such an exhaustive review of literature available mostly in the journals published from the subcontinent would become a point source of information necessary for prioritizing future surveillance efforts in this region and for making informed policy decision to control this zoonotic helminth infection.

A systematic review and meta-analysis of canine, feline and human Toxocara infections in sub-Saharan Africa

Toxocariasis is an emerging zoonotic disease caused by Toxocara canis and T. cati. Toxocariasis and its etiological agents are of global public health importance, whose burden appears underestimated, especially in sub-Saharan Africa (SSA). The diversity in the transmission routes of these parasites contributes to disease prevalence and often hinders disease control measures. This study aimed to review the epidemiological distribution of Toxocara infections in SSA region. A systematic review and meta-analysis were performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). We identified 94 relevant, peer-reviewed articles, out of which, 75 articles were found eligible based on Toxocara infections in dogs, cats and humans. Overall, 27,102 samples were examined for T. canis in dogs, T. cati in cats and Toxocara serology in humans, out of which 6142 were positive for Toxocara infection: 3717 (13.7%) in dogs (faecal, 3487; necropsy, 180; hair, 50); 266 (1%) in cats (faecal, 101; necropsy, 165); and 2159 (8%) in humans (serology). Overall mean prevalences of 19% (95% confidence interval (CI): 14-23%), 9% (95% CI: 0-28%) and 36% (95% CI: 24-49%) were recorded in dogs, cats and humans, respectively. Substantial heterogeneity was observed between studies and subgroups (I2 = 99%, P < 0.01). Findings from the review showed that studies on the epidemiology of Toxocara infections in the SSA region are limited. We strongly recommend focused, collaborative and coordinated studies to determine Toxocara spp. prevalence in various hosts, including food animals and the environment, through a 'One Health' approach across SSA countries.

The Presence of Toxocara Eggs on Dog's Fur as Potential Zoonotic Risk in Animal-Assisted Interventions: A Systematic Review

Animal-assisted interventions (AAIs) usually contribute to the well-being and health of users/patients, but it is essential that the animals involved in these activities do not represent a source of zoonoses. This systematic review focused on the evaluation of the potential risk of the transmission of Toxocara by dogs' fur, considering their involvement as the main animal species in AAIs. Three databases were considered: MEDLINE/PubMed, Scopus, and Web of Science, and the PRISMA guidelines were used. Out of 162 articles found, 14 papers were identified as eligible for inclusion in the review. Although the findings were very heterogeneous, they showed that regular parasitological surveillance to plan effective control programs is strongly needed to guarantee the health of pets and consequently the public health, according to the concept of One Health. Since AAIs involve patients and/or users potentially susceptible, it is very important to appropriately treat dogs enrolled in these interventions after an accurate diagnosis of parasitic zoonoses.