Preliminary results of city-wide geo-surveillance study of Toxocara sp in parks and playgrounds of NYC

Abstract

Background. Toxocara species are common pet parasites that can be found in the stool of dogs and cats. The infective larvae released in the stool survive in soil for many years and can subsequently be ingested by children who encounter them in sandboxes or on playgrounds. The CDC lists Toxocariasis as one of five neglected parasitic infections in the US and states that 'we urgently need to know more about who is at risk and how they are affected'. It is considered a neglected disease of poverty in the US, posing a significant disease burden in certain groups, remaining largely underdiagnosed. Infection in humans, paratenic hosts, can lead to visceral or ocular larva migrans, blindness, and silent brain infection that can diminish neurological cognition. New York City is pet-friendly, well-known for its sprawling parks and play areas. It has been suggested that certain NYC neighborhoods may pose a higher risk for Toxocara infection, particularly in lower socioeconomic and predominately immigrant communities, although no study of actual Toxocara burden in NYC has been reported. The goals of this study are to: 1)determine the burden of Toxocara in parks by examining sand/soil in playgrounds, 2) to determine if a disparity exists in neighborhood distribution, and 3) to explore which species of Toxocara is more prevalent. Methods. To accomplish these objectives multiple samples are being obtained from a representative sample of the more than 100 parks and playgrounds in NYC. These are being analyzed by standard flotation and microscopy methods. Speciation is carried out by multi-parallel quantitative real-time PCR (qPCR) using specific primers to T. cati and cani. Results. Preliminary results from 21 sites spanning Manhattan and the Bronx have identified Toxocara eggs in 43% of samples/sites. Variation between boroughs and specific areas exists. Toxocara was present in 66% of samples from Bronx parks compared to 33% of Manhattan parks. 75% of the toxocara in Bronx samples were noted be in larval stages compared to none of the Manhattan sites. Conclusion. We can conclude from this preliminary data that Toxocara is common in many play areas in NYC particularly in poorer neighborhoods which poses a health risk particularly to young children with pica.