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.

Ebola (subtype Reston [EBO-R]) virus infection was detected in macaques imported into the United States from the Philippines in March 1996. Studies were initiated in the Philippines to identify the source of the virus among monkey-breeding and export facilities, to establish surveillance and testing, and to assess the risk and significance of EBO-R infections in humans who work in these facilities. Over a 5-month period, acutely infected animals were found at only one facility, as determined using Ebola antigen detection. Three of 1732 monkeys and 1 of 246 animal handlers tested had detectable antibodies; all were from the same facility, which was the source of infected monkeys imported to the United States. Virus transmission, which was facilitated by poor infection-control practices, continued for several months in one facility and was stopped only when the facility was depopulated. None of the 246 employees of the facilities or 4 contacts of previously antibody-positive individuals reported an Ebola-like illness. This investigation suggests that human EBO-R infection is rare.

ObjectiveTo estimate the degree of synergism between helminth species in their combined effects on anemia.MethodsQuantitative egg counts using the Kato–Katz method were determined for Ascaris lumbricoides, hookworm, Trichuris trichiura, and Schistosoma japonicum in 507 school-age children from helminth-endemic villages in The Philippines. Infection intensity was defined in three categories: uninfected, low, or moderate/high (M+). Anemia was defined as hemoglobin <11 g/dL. Logistic regression models were used to estimate odds ratios (OR), 95% confidence intervals (CI), and synergy index for pairs of concurrent infections.ResultsM+ co-infection of hookworm and S. japonicum (OR = 13.2, 95% CI: 3.82–45.5) and of hookworm and T. trichiura (OR = 5.34, 95% CI: 1.76–16.2) were associated with higher odds of anemia relative to children without respective M+ co-infections. For co-infections of hookworm and S. japonicum and of T. trichiura and hookworm, the estimated indices of synergy were 2.9 (95% CI: 1.1–4.6) and 1.4 (95% CI: 0.9–2.0), respectively.ConclusionCo-infections of hookworm and either S. japonicum or T. trichiura were associated with higher levels of anemia than would be expected if the effects of these species had only independent effects on anemia. This suggests that integrated anti-helminthic treatment programs with simultaneous deworming for S. japonicum and some geohelminths could yield a greater than additive benefit for reducing anemia in helminth-endemic regions.