Background: Toxocariasis results from infection with larval stages of a dog and cat intestinal nematode and causes human morbidity. The current United States estimate of Toxocara exposure is 13.9% (National Health and Nutrition Examination Survey [NHANES] III [1988-1994]).
Methods: We used a multiplex bead-based assay (Tc-CTL-1MBA) with purified Toxocara canis antigen to estimate Toxocara antibody seroprevalence in serum of 13 509 persons aged ≥6 years from NHANES 2011-2014 and identified seropositivity risk factors. We tested a subset of 500 samples with the T. canis enzyme immunoassay used in NHANES III to estimate prior seroprevalence had samples from NHANES III been tested by Tc-CTL-1MBA.
Results: The age-standardized estimate of Toxocara seroprevalence was 5.0% (95% confidence interval [CI], 4.2%-5.8%), lower than previously reported even after adjusting for increased Tc-CTL-1MBA specificity. Risk factors for seropositivity from multiple logistic regression were older age, non-Hispanic black/Hispanic origin, male sex, living below poverty level, households with ≥0.5 persons per room, less than college education, and birth outside of the United States.
Conclusions: Toxocara seroprevalence estimates in 2011-2014 were lower than in a study from NHANES III (1988-1994), but seropositivity risk factors remained the same and should continue to be the focus of prevention efforts.
Keywords: Toxocara canis; Toxocara cati; United States; antibodies; seroprevalence.
Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.