HELMINTH INFECTION AND COGNITIVE IMPAIRMENT AMONG FILIPINO CHILDREN

• Published in: The American journal of tropical medicine and hygiene Vol. 72; no. 5; pp. 540 - 548
• Main Authors: EZEAMAMA, AMARA E, FRIEDMAN, JENNIFER F, ACOSTA, LUZ P, BELLINGER, DAVID C, LANGDON, GRETCHEN C, MANALO, DARIA L, OLVEDA, REMIGIO M, KURTIS, JONATHAN D, MCGARVEY, STEPHEN T
• Format: Journal Article
• Language: English
• Published: Lawrence, KS ASTMH 01.05.2005; Allen Press
• Subjects: Adolescent; Anemia - parasitology; Anemia - physiopathology; Biological and medical sciences; Child; Child Nutritional Physiological Phenomena; Diet; Female; Growth Disorders - parasitology; Helminthiasis - epidemiology; Helminthiasis - physiopathology; Humans; Infectious diseases; Learning Disorders - parasitology; Male; Medical sciences; Memory Disorders - parasitology; Philippines - epidemiology; Socioeconomic Factors; Speech Disorders - parasitology; Asia; Philippine Islands; Philippines; Human; Infection; Cognitive disorder; Tropical medicine; Parasitosis; Child; Epidemiology; Helminthiasis; Public health
• ISSN: 0002-9637; 1476-1645
• DOI: 10.4269/ajtmh.2005.72.540

The objective of this study was to examine the independent effect of infection with each of four helminths (Ascaris lumbricoides, Schistosoma japonicum, Necator americanus, and Trichuris trichiura) on cognitive function after adjusting for the potential confounders nutritional status, socioeconomic status (SES), hemoglobin, sex, and the presence of other helminthes. This cross-sectional study was carried out in a rural village in Leyte, The Philippines in 319 children 7-18 years old. Three stools were collected and read in duplicate by the Kato Katz method. Infection intensity was defined by World Health Organization criteria. Cognitive tests were culturally adapted and translated. Learning and memory cognitive domains were each defined by three subscales of the Wide Range Assessment of Memory and Learning, which had an inter-rater reliability >/= 0.92 and test-retest reliabilities ranging from 0.61 to 0.89. A household SES questionnaire was administered. A logistic regression model was used to quantify the association between performance in different cognitive domains (learning, memory, verbal fluency, and the Philippine Non-Verbal Intelligence Test) and helminth infections. After adjusting for age, sex, nutritional status, hemoglobin, and SES, S. japonicum infection was associated with poor performance on tests of learning (odds ratio [OR] = 3.04, 95% confidence interval [CI] = 1.1-6.9), A. lumbricoides infection was associated with poor performance on tests of memory (OR = 2.2, 95% CI = 1.04-4.7), and T. trichiura infection was associated with poor performance on tests of verbal fluency (OR = 4.5, 95% CI = 1.04-30). Helminth infection was associated with lower performance in three of the four cognitive domains examined in this study. These relationships remained after rigorous control for other helminths and important confounding covariates.