Date of Award
Doctor of Philosophy in Nursing (PhD)
Cathy L. Rozmus, PhD
Geri LoBiondo-Wood, PhD
Peter J. Hotez, M.D.
Rojelio Mejia, M.D.
Background: Gastrointestinal (GI) parasites may have important influences on growth outcomes during early childhood. Previous studies investigating the effects of GI parasites on growth have predominantly used microscopy-based diagnostic methods with low sensitivity. Few accurate epidemiologic data are available on GI parasitic infections among rural Ecuadorian children. To investigate the impact of single and multiple GI parasite infections on growth during early childhood data from a longitudinal birth cohort in Ecuador were analyzed.
Purpose: The aims of this study were to determine the prevalence of GI parasites (soil-transmitted helminths and intestinal protozoa) and to describe associations between GI parasitic infections and growth among rural Ecuadorian children at 36 and at 60 months of age.
Methods: A retrospective longitudinal study was conducted using matched data from 177 children. A rapid, high-throughput, multi-parallel qPCR assay was used to detect GI parasites. Data on parasite infection prevalence, parasite burden, growth measures, and sociodemographic factors were examined. Univariate analyses were carried out to describe the study population. Bivariate analyses including Spearman's correlation, Chi-square test and Mann-Whitney U test were used to examine differences between categorical and continuous variables. McNemar's test was used to examine the change in prevalence, while the Wilcoxon signed-rank test was used to examine the change in parasite burden and growth changes. Multivariate analysis was used to predict growth at 60 months from parasite infection at 36 months.
Results: Over half of the study population was infected with GI parasites at 36 and 60 months with 66.7% and 58.2%, respectively. Overall, Giardia lamblia was most prevalent followed by Trichuris trichiura, and Ascaris lumbricoides. Prevalence decrease with age except for Trichuris trichiura with a significant change for Ascaris lumbricoides (p = .014), Strongyloides stercoralis (p = .039), and Giardia lamblia (p = .039). Parasite burden also tended to decrease with age, however, statistically significant increases were found for Giardia lamblia (z = -2.204, r = .20, p = .027) and Strongyloides stercoralis (z = -2.312, r = .20, p = .021). While single parasite infections were more prevalent, polyparasitim was associated with reduced measured for height (cm) (z = -2.120, r = .20, p = .034) and HAZ (z = -2.233, r = .20, p = .026) at 36 months. Also, at 36 months, Trichuris trichiura was associated with reduced HAZ (z = -2.787, r = .21, p = .005) and WAZ (z = -2.324, r = .20, p = .020). No growth deficits were found at 60 months.
Conclusion: The true prevalence of GI parasites was determined using multi-parallel qPCR with high sensitivity and specificity contributing accurate epidemiologic data on the distribution of soil-transmitted helminths and protozoa among children in rural Ecuador. GI parasitic infections were associated with deficits in growth indicators among children at 36 months of age. Findings indicate that GI parasites are highly prevalent and have an important influence on growth during early childhood in rural Ecuador.
Bryan, Patricia, "Molecular Diagnosis of Intestinal Parasites: Impact on Growth among Preschool-Age Children in Rural Ecuador" (2020). UT SON Dissertations (Open Access). 50.
GI parasites, soil-transmitted helminths, protozoa, early childhood, rural Ecuador