A prospective seroepidemiological study of toxocariasis during early childhood in coastal Ecuador: potential for congenital transmission and risk factors for infection

Parasites & Vectors

Martha E. Chico¹  Aida Y. Oviedo-Vera²  Luis F. Salazar-Garcés²  Philip J. Cooper³  Neuza M. Alcantara-Neves⁴  Marcia B. Silva⁴  Irina Chis Ster⁵ 

[1] Fundacion Ecuatoriana Para Investigación en Salud, Quinindé, Ecuador;Fundacion Ecuatoriana Para Investigación en Salud, Quinindé, Ecuador;Institute of Health Sciences, Federal University of Bahia, Salvador, Bahia, Brazil;Fundacion Ecuatoriana Para Investigación en Salud, Quinindé, Ecuador;Institute of Infection and Immunity, St George’s University of London, Cranmer Terrace, SW17 0RE, London, UK;Escuela de Medicina, Universidad Internacional del Ecuador, Quito, Ecuador;Institute of Health Sciences, Federal University of Bahia, Salvador, Bahia, Brazil;Institute of Infection and Immunity, St George’s University of London, Cranmer Terrace, SW17 0RE, London, UK;

关键词: Toxocara;    Birth cohort;    Congenital transmission;    Seroprevalence;    Seroconversion;    Risk factors;    Childhood;    Ecuador;   

DOI  :  10.1186/s13071-020-04575-4

来源: Springer

【 摘 要 】

BackgroundAlthough Toxocara spp. infection has a worldwide distribution, to our knowledge, no data from birth cohorts have been reported in published studies on the potential for congenital transmission and determinants of infection in early childhood.MethodsWe followed 290 mother-infant pairs from birth to 5 years of age through periodic collection of data and samples at birth, 7 and 13 months and 2, 3 and 5 years of age. Data on potential risk factors and confounders were collected by maternal questionnaire. Blood for plasma was collected from the mother at time of birth and periodically from the child for detection of anti-Toxocara spp. immunoglobulin G (IgG) antibodies using a Toxocara canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. Stool samples were collected from the mother around the time of birth and periodically from the child for microscopic detection of soil-transmitted helminths (STH). Associations between potential risk factors and Toxocara spp. seroprevalence and seroconversion were estimated using multivariable logistic regression and generalized estimating equations.ResultsToxocara spp. seroprevalence was 80.7% in mothers and in children was 0%, 9.3%, 48.4%, 64.9%, and 80.9% at 7 months, 13 months, 2, 3 and 5 years, respectively. Risk factors significantly associated with increases in seroprevalence over the first 5 years of life in multivariable analyses were age [Odds ratio (OR) 2.06, 95% confidence interval (CI) 1.39–2.27, P < 0001], male sex (female vs. male: OR 0.66, 95% CI 0.48–0.89, P = 0.006), maternal ethnicity (non-Afro vs. Afro-Ecuadorian: OR 0.65, 95% CI 0.47–0.91, P = 0.011), lower maternal educational and socioeconomic level, and childhood STH (OR 2.29, 95% CI 1.51–3.47, P < 0.001). Seroconversion rates for infection were greatest at 2 years of age (3.8%/month). Factors associated significantly with seroconversion at 2, 3 or 5 years were childhood STH infection, male sex, and more frequent domestic cat exposure.ConclusionsOur data, from an area of high Toxocara spp. endemicity, indicate no congenital transmission but high rates of seroconversion after 13 months of age reaching maternal levels of seroprevalence by 5 years of age. Factors associated with seroprevalence and seroconversion included STH infections, domestic cats, maternal ethnicity, male sex, STH infections, and markers of greater poverty.

【 授权许可】

CC BY