WormWatch: Park soil surveillance reveals extensive Toxocara contamination across the UK and Ireland

Paul M. Airs*, Claire Brown, Erica Gardiner, Liz Maciag, Jamie P. Adams, Eric R. Morgan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

45 Downloads (Pure)


Toxocarosis is a globally distributed zoonotic disease, but sources of infection are not well documented over large geographical scales. To determine levels of environmental contamination, soil from 142 parks and recreational areas across the UK and Ireland was assessed for the presence of Toxocara.

Toxocara ova (eggs) were isolated from soil samples by sieving and flotation and then enumerated. Individual eggs were isolated and imaged, and a subset was characterised by species-specific PCR and Sanger sequencing.

Characteristic Toxocara-type eggs were found in 86.6% of parks, with an average of 2.1 eggs per 50 g of topsoil. Representative eggs were confirmed as Toxocara canis by Sanger sequencing, with many eggs containing developed larvae, hence being viable and potentially infective. Positive samples were more common, and egg density was higher, in parks with greater perceived levels of dog fouling.

Samples were collected at a single timepoint and with limited spatial mapping within parks. Further study is needed to discern spatiotemporal differences within parks and recreational areas.

Toxocara is widespread in soil in public parks, indicating a need for further efforts to reduce egg shedding from pet dogs. Standardised methods and large-scale surveys are required to evaluate risk factors for egg presence and the impact of interventions.

Original languageEnglish
Article numbere2341
Number of pages11
JournalVeterinary Record
Issue number1
Early online date09 Nov 2022
Publication statusPublished - Jan 2023


  • eggs
  • molecular biology
  • public health
  • Toxocara canis
  • toxocarosis
  • zoonoses


Dive into the research topics of 'WormWatch: Park soil surveillance reveals extensive Toxocara contamination across the UK and Ireland'. Together they form a unique fingerprint.

Cite this