Toxocariasis and lung function: Relevance of a neglected infection in an urban landscape

Abstract

Toxocariasis has been highlighted as a potentially important neglected infection of poverty in developed countries that experience substantive health disparities such as the United States. An association between Toxocara infection and lung function, in concert with a relatively high prevalence of infection, may mark an important mechanism by which this infection could contribute significantly to the differential morbidity across different socioeconomic groups and landscapes. To assess the potential relevance of this infection in a dense urban environment, we measured the association between forced expiratory volume in 1 second (FEV 1 ) and serology diagnosed Toxocara infection in a sample of US-born New York City residents. We identified a significant independent association between Toxocara infection and lung function, wherein those with previous Toxocara infection had a 236.9 mL reduced FEV 1 compared to those without Toxocara infection even after adjusting for age, sex, ethnicity, level of education, smoking status, body mass index, and pet ownership. These findings from New York City corroborate similar findings in a national sample and, while the cross-sectional data preclude a direct causal relationship, this study identifies a potentially important neglected infection in a dense urban landscape.

Prevalence of Toxocara species infection in the U.S.: Results from the National Health and Nutrition Examination Survey, 2011-2014

“…Similar to the previous seroprevalence study utilizing data obtained over 20 years ago, we showed a persistent elevation in odds of antibody positivity in adults among minority ethnicity, male gender and low education level [ 17 ]. These findings overall mirror those found by Congdon et al demonstrating minority ethnicity and poverty were important drivers of higher levels of Toxocara antibody positivity [ 8 , 18 ]. Conversely, with non-Hispanic white as the reference, we found Hispanic and other race/multicultural ethnicities to have a higher risk of exposure than non-Hispanic Black.…”

“…For children, no difference was found in demographic data despite looking at multiple variables including age, gender, socioeconomic status and ethnicity. Additional factors that have previously been associated such as a diagnosis of asthma and eosinophilia were also not significantly different [ 8 , 34 ]. Interestingly, a protective effect of health insurance was noted.…”

Toxocara species environmental contamination of public spaces in New York City

“…[17,18] Covert toxocariasis may also represent an important environmental cause of asthma among disadvantaged American children. [19,20] Throughout the history of the National Health and Nutrition Examination Survey (NHANES), the prevalence of Toxocara within the United States population has varied, ranging from 5%-14% during analyses from 1988-1994 and 2011-2014. [11,21] In both studies, Toxocara seropositivity was disproportionately higher in persons from lower socioeconomic status communities, particularly in Hispanic, non-Hispanic black communities, and those with less than a high-school education.…”

Electrochemical detection of Toxocara canis excretory-secretory antigens in children from rural communities in Esmeraldas Province, Ecuador: association between active infection and high eosinophilia

“…Human toxocariasis (HT) is an infection caused primarily by the roundworm Toxocara canis and to a lesser extent by T. cati [1]. It is a zoonosis with a worldwide distribution including temperate regions, although greater prevalence rates are observed in tropical areas [2][3][4]. Human infection occurs after the accidental ingestion of food or soil contaminated with eggs of the parasite.…”