Beyond Parasite Detection: Association between Intestinal Parasitic Infections, Hematological Profiles, and Gastrointestinal Symptoms among Children: A Cross-Sectional Study

Abstract

Background: Intestinal parasites are frequently detected in children living in endemic settings, but pathogen detection does not necessarily correspond to gastrointestinal illness or measurable systemic disturbance. This study examined whether parasite-centered infection phenotypes were associated with gastrointestinal symptoms and routine hematological profiles among children in rural Madagascar.

Methods: A secondary cross-sectional analysis included 242 children younger than 15 years from three rural communities. Infection status was classified as pathogen-negative, parasite-only, bacterial-only, or mixed/complex. Firth bias-reduced logistic regression estimated adjusted associations with gastrointestinal symptoms, and multivariable linear models with HC3 robust standard errors evaluated six hematological outcomes. Age group, sex, and study site were included as covariates, and false-discovery-rate correction was applied to hematological tests.

Results: Eighty-six children (35.5%) were pathogen-negative, 68 (28.1%) had parasite-only infection, 42 (17.4%) had bacterial-only infection, and 46 (19.0%) had mixed/complex infection. Gastrointestinal symptoms were recorded in 68 children (28.1%). Parasite-only infection was not associated with symptom status after adjustment (adjusted OR 1.01, 95% CI 0.42–2.44). Infection phenotype was not associated with white blood cell count, lymphocytes, granulocytes, hemoglobin, hematocrit, or platelets after multiplicity correction (all q≥0.552). None of the six hematological markers independently predicted gastrointestinal symptoms (all q≥0.460).

Conclusion: In this endemic pediatric population, parasite detection alone did not identify children with gastrointestinal symptoms or a distinct routine hematological profile. Gastrointestinal symptoms and standard blood-count indices therefore appear to be poor proxies for intestinal parasitic carriage, supporting laboratory-based diagnosis and more species- and intensity-specific assessment of parasite-related morbidity.