BackgroundThe global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide.Methods and FindingsWe aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5–17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status.Influenza was associated with 10% (95% CI 8%–11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%–7%) among children <6 mo to 16% (95% CI 14%–20%) among children 5–17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y—of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo—and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings.ConclusionsInfluenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.

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The accuracy of the Kato-Katz technique in identifying individuals with soil-transmitted helminth (STH) infections is limited by day-to-day variation in helminth egg excretion, confusion with other parasites and the laboratory technicians' experience. We aimed to estimate the sensitivity and specificity of the Kato-Katz technique to detect infection with Ascaris lumbricoides, hookworm and Trichuris trichiura using a Bayesian approach in the absence of a 'gold standard'. Data were obtained from a longitudinal study conducted between January 2004 and December 2005 in Samar Province, the Philippines. Each participant provided between one and three stool samples over consecutive days. Stool samples were examined using the Kato-Katz technique and reported as positive or negative for STHs. In the presence of measurement error, the true status of each individual is considered as latent data. Using a Bayesian method, we calculated marginal posterior densities of sensitivity and specificity parameters from the product of the likelihood function of observed and latent data. A uniform prior distribution was used (beta distribution: α=1, β=1). A total of 5,624 individuals provided at least one stool sample. One, two and three stool samples were provided by 1,582, 1,893 and 2,149 individuals, respectively. All STHs showed variation in test results from day to day.

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.

A double-blind placebo-controlled study of the concurrent administration of albendazole and praziquantel was conducted in>1500 children with high prevalences of geohelminths and schistosomiasis. The study sites were in China and the Philippines, including 2 strains of Schistosoma japonicum, and 2 different regions of Kenya, 1 each with endemic Schistosoma mansoni or Schistosoma haematobium. Neither medication affected the cure rate of the other. There was no difference between the side effect rate from albendazole or the double placebo. Praziquantel-treated children had more nausea, abdominal pain, and headache but these side effects were statistically more common in children with schistosomiasis, suggesting a strong influence of dying parasites. The subjects were followed for 6 months for changes in infection status, growth parameters, hemoglobin, and schistosomiasis morbidity. In all 4 sites, a significant 6-month increase in serum hemoglobin was observed in children who received praziquantel, strongly supporting population-based mass treatment.

Low-intensity polyparasite infections were associated with increased odds of having anemia. In most parts of the developing world, concurrent infection with multiple parasite species is more common than single-species infections. This study suggests that concurrent low-intensity infections with multiple parasite species result in clinically significant morbidity.

The results support the hypothesis that poor nutrient intake may increase susceptibility to parasitic diseases and together they negatively affect childhood nutritional status.

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.