Temporal relationships between Staphylococcus aureus colonization, filaggrin expression, and pediatric atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is characterized by Staphylococcus aureus (S. aureus) colonization. Longitudinal early life data delineating relationships of S. aureus colonization, barrier function, and AD outcomes are lacking. We define longitudinal S. aureus endotypes and AD pathogenesis in early life. METHODS: We defined longitudinal S. aureus skin colonization phenotypes across two annual visits (non-colonized: V1- V2- , early transient: V1+ V2- , late-onset: V1- V2+ , persistent: V1+ V2+ ) in the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children cohort. We analyzed AD severity, sensitization, and skin barrier function across phenotypes, and performed mediation analyses between colonization and FLG expression. RESULTS: Persistent S. aureus colonization was associated with increased SCORAD at V1 (33.5 vs. 19.0, p = .004) and V2 (40.1 vs.16.9, p < .001), and lower non-lesional (NL) FLG at V2 (1.77 vs. 4.09, p = .029) compared to the non-colonized phenotype, with early transient and late-onset colonization as intermediate phenotypes. Children colonized at V2 demonstrated a decrease in NL-FLG expression from V1 to V2 compared to those non-colonized at V2 (p = .0012), who maintained expression. This effect remained significant even after adjusting for V1 colonization and SCORAD (p = .011). CONCLUSIONS: Our findings are the first to present longitudinal quantitative FLG expression and S. aureus skin colonization in early life and suggest that a decrease in NL-FLG drives later colonization. Hence, therapies to maintain NL-FLG expression may prevent S. aureus colonization. Further, a longitudinal AD endotype of persistent colonization is characterized by increased AD severity, sensitization, and decreasing NL-FLG.

Thymic stromal lymphopoietin rather than IL-33 drives food allergy after epicutaneous sensitization to food allergen.

BACKGROUND: A major route of sensitization to food allergen is through an impaired skin barrier. IL-33 and thymic stromal lymphopoietin (TSLP) have both been implicated in epicutaneous sensitization and food allergy, albeit in different murine models. OBJECTIVE: We assessed the respective contributions of TSLP and IL-33 to the development of atopic dermatitis (AD) and subsequent food allergy in TSLP and IL-33 receptor (ST2)-deficient mice using an AD model that does not require tape stripping. METHOD: TSLP receptor (TSLPR)-/-, ST2-/-, and BALB/cJ control mice were exposed to 3 weekly epicutaneous skin patches of one of saline, ovalbumin (OVA), or a combination of OVA and Aspergillus fumigatus (ASP), followed by repeated intragastric OVA challenges and development of food allergy. RESULTS: ASP and/or OVA patched, but not OVA-alone patched, BALB/cJ mice developed an AD-like skin phenotype. However, epicutaneous OVA sensitization occurred in OVA patched mice and was decreased in ST2-/- mice, resulting in lower intestinal mast cell degranulation and accumulation, as well as OVA-induced diarrhea occurrences on intragastric OVA challenges. In TSLPR-/- mice, intestinal mast cell accumulation was abrogated, and no diarrhea was observed. AD was significantly milder in OVA + ASP patched TSLPR-/- mice compared to wild type and ST2-/- mice. Accordingly, intestinal mast cell accumulation and degranulation were impaired in OVA + ASP patched TSLPR-/- mice compared to wild type and ST2-/- mice, protecting TSLPR-/- mice from developing allergic diarrhea. CONCLUSION: Epicutaneous sensitization to food allergen and development of food allergy can occur without skin inflammation and is partly mediated by TSLP, suggesting that prophylactic targeting of TSLP may be useful in mitigating the development of AD and food allergy early in life in at-risk infants.

Progressive accumulation of hyperinflammatory NKG2Dlow NK cells in early childhood severe atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease that often precedes the development of food allergy, asthma, and allergic rhinitis. The prevailing paradigm holds that a reduced frequency and function of natural killer (NK) cell contributes to AD pathogenesis, yet the underlying mechanisms and contributions of NK cells to allergic comorbidities remain ill-defined. Here, analysis of circulating NK cells in a longitudinal early life cohort of children with AD revealed a progressive accumulation of NK cells with low expression of the activating receptor NKG2D, which was linked to more severe AD and sensitivity to allergens. This was most notable in children co-sensitized to food and aeroallergens, a risk factor for development of asthma. Individual-level longitudinal analysis in a subset of children revealed coincident reduction of NKG2D on NK cells with acquired or persistent sensitization, and this was associated with impaired skin barrier function assessed by transepidermal water loss. Low expression of NKG2D on NK cells was paradoxically associated with depressed cytolytic function but exaggerated release of the proinflammatory cytokine tumor necrosis factor-α. These observations provide important insights into a potential mechanism underlying the development of allergic comorbidity in early life in children with AD, which involves altered NK cell functional responses, and define an endotype of severe AD.

Filaggrin loss-of-function variants are associated with atopic dermatitis phenotypes in a diverse, early-life prospective cohort.

Loss-of-function (LoF) variants in the filaggrin (FLG) gene are the strongest known genetic risk factor for atopic dermatitis (AD), but the impact of these variants on AD outcomes is poorly understood. We comprehensively identified genetic variants through targeted region sequencing of FLG in children participating in the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children cohort. Twenty FLG LoF variants were identified, including 1 novel variant and 9 variants not previously associated with AD. FLG LoF variants were found in the cohort. Among these children, the presence of 1 or more FLG LoF variants was associated with moderate/severe AD compared with those with mild AD. Children with FLG LoF variants had a higher SCORing for Atopic Dermatitis (SCORAD) and higher likelihood of food allergy within the first 2.5 years of life. LoF variants were associated with higher transepidermal water loss (TEWL) in both lesional and nonlesional skin. Collectively, our study identifies established and potentially novel AD-associated FLG LoF variants and associates FLG LoF variants with higher TEWL in lesional and nonlesional skin.

Progressive accumulation of hyperinflammatory NKG2D low NK cells in early childhood severe atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease that often precedes the development of food allergy, asthma, and allergic rhinitis. The prevailing paradigm holds that a reduced frequency and function of natural killer (NK) cell contributes to AD pathogenesis, yet the underlying mechanisms and contributions of NK cells to allergic co-morbidities remain ill-defined. Herein, analysis of circulating NK cells in a longitudinal early life cohort of children with AD revealed a progressive accumulation of NK cells with low expression of the activating receptor NKG2D, which was linked to more severe AD and sensitivity to allergens. This was most notable in children co-sensitized to food and aero allergens, a risk factor for development of asthma. Individual-level longitudinal analysis in a subset of children revealed co-incident reduction of NKG2D on NK cells with acquired or persistent sensitization, and this was associated with impaired skin barrier function assessed by transepidermal water loss. Low expression of NKG2D on NK cells was paradoxically associated with depressed cytolytic function but exaggerated release of the proinflammatory cytokine TNF-α. These observations provide important insights into a potential mechanism underlying the development of allergic co-morbidity in early life in children with AD which involves altered NK-cell functional responses, and define an endotype of severe AD.

B cell repertoire in children with skin barrier dysfunction supports altered IgE maturation associated with allergic food sensitization.

The skin is a major immune organ and skin barrier dysfunction is a major risk factor for the development of the inappropriate immune response seen in allergic disease. Skin barrier disruption alters the landscape of antigens experienced by the immune system and the downstream impacts on the antibody repertoire remain poorly characterized, particularly for the IgE isotype responsible for allergic specificity and in early life, when allergic disease is developing. In this study, we sequenced antibody gene repertoires from a large and well-characterized cohort of children with atopic dermatitis and found that food sensitization was associated with lower mutation frequencies in the IgE compartment. This trend was abrogated in children living with pets during the first year of life. These results elucidate potential molecular mechanisms underlying the protective effects of pet ownership and non-antiseptic environs reported for allergic disease, and the hygiene hypothesis more broadly. We also observed increased IgE diversity and increased isotype-switching to the IgE isotype, suggesting that B cell development, particularly isotype-switching, is heavily altered in the those with food allergen sensitizations relative to those without food allergen sensitizations. Unlike for food antigens, aeroallergen sensitization exhibited no effect on IgE mutation or diversity. Consistent patterns of antibody rearrangement were associated with food allergen sensitization in subjects with atopic dermatitis. Thus, we propose the Immune Repertoire in Atopic Disease (IRAD) score, to quantify this repertoire shift and to aid clinically in patient diagnosis and risk stratification.

A bean-free diet increases the risk of all-cause mortality among Taiwanese women: the role of the metabolic syndrome.

OBJECTIVE: To evaluate the associations with chronic disease risk and mortality of the consequences of bean-free diets in Taiwanese adults with regard to gender. DESIGN: A sub-sample of the National Health Interview Survey (NHIS) in 2001 agreed to physical examination in the subsequent year. This group then took part in the Taiwanese Survey of Hyperglycaemia, Hyperlipidaemia and Hypertension (TwSHHH) in 2002. SETTING: Individual records were linked to the eventual death files from 2002 to 2008. SUBJECTS: Up to the end of 2008, a total of 2820 men and 2950 women were tracked by death registry over the 6·8 years of follow-up. RESULTS: Among 38,077 person-years, an average follow-up 6·5 years, 225 all-cause deaths were identified. Generalized linear models showed beans to be favourable for metabolic syndrome (other than for fasting glucose) in men; in women, beans were favourable for waist circumference and HbA1c. Cumulative logistic regression models for the effect of a bean-free diet on metabolic syndrome scores according to the Taiwanese-modified National Cholesterol Education Program-Adult Treatment Panel III (NCEP-tw) gave adjusted odds ratios of 1·83 in men and 1·45 in women. Cox regression models for the bean-free diet showed an increased hazard ratio for all-cause mortality among women (1·98, 95% CI 1·03, 3·81) but not men (1·28, 95% CI 0·76, 2·16). CONCLUSIONS: A bean-free diet may play a role in developing the metabolic syndrome in both genders, and is a significant predictor of all-cause mortality in Taiwanese women but not men.

Age- and gender-specific population attributable risks of metabolic disorders on all-cause and cardiovascular mortality in Taiwan.

BACKGROUND: The extent of attributable risks of metabolic syndrome (MetS) and its components on mortality remains unclear, especially with respect to age and gender. We aimed to assess the age- and gender-specific population attributable risks (PARs) for cardiovascular disease (CVD)-related mortality and all-cause mortality for public health planning. METHODS: A total of 2,092 men and 2,197 women 30 years of age and older, who were included in the 2002 Taiwan Survey of Hypertension, Hyperglycemia, and Hyperlipidemia (TwSHHH), were linked to national death certificates acquired through December 31, 2009. Cox proportional hazard models were used to calculate adjusted hazard ratios and PARs for mortality, with a median follow-up of 7.7 years. RESULTS: The respective PAR percentages of MetS for all-cause and CVD-related mortality were 11.6 and 39.2 in men, respectively, and 18.6 and 44.4 in women, respectively. Central obesity had the highest PAR for CVD mortality in women (57.5%), whereas arterial hypertension had the highest PAR in men (57.5%). For all-cause mortality, younger men and post-menopausal women had higher PARs related to Mets and its components; for CVD mortality, post-menopausal women had higher overall PARs than their pre-menopausal counterparts. CONCLUSIONS: MetS has a limited application to the PAR for all-cause mortality, especially in men; its PAR for CVD mortality is more evident. For CVD mortality, MetS components have higher PARs than MetS itself, especially hypertension in men and waist circumference in post-menopausal women. In addition, PARs for diabetes mellitus and low HDL-cholesterol may exceed 20%. We suggest differential control of risk factors in different subpopulation as a strategy to prevent CVD-related mortality.

Dietary intake and the risk of hyperuricemia, gout and chronic kidney disease in elderly Taiwanese men.

INTRODUCTION: This study was conducted to examine the relationship between dietary intake and the risk of chronic kidney disease (CKD), treated hyperuricemia (or gout) without CKD, and untreated hyperuricemia without CKD in elderly men. METHODS: The study population comprised 752 men aged 65 or older who had been included in the Elderly Nutrition and Health Survey (1999-2000) (Elderly NAHSIT). RESULTS: Statistical analysis using a polychotomous logistic regression model revealed that compared with the individuals in the normouricemic group, the individuals in the other groups exhibited a significant association between a higher prevalence of CKD and the following factors: advanced age, drug use for hypertension, egg and shellfish consumption and consumption of poultry with the skin and meat with fat. The significant risk factors for the patients who did not have CKD and were undergoing treatment for hyperuricemia were as follows: BMI ≥ 25 kg/m(2); drug use for hypertension; intake of poultry with skin; increased daily consumption of shellfish, fried food, sugar and juice. CONCLUSIONS: Men who use anti-hypertensive drugs and who consume fewer soy products and more shellfish may be at a higher risk of developing hyperuricemia or CKD.

Differential and shared effects of eicosapentaenoic acid and docosahexaenoic acid on serum metabolome in subjects with chronic inflammation.

The omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) affect cell function and metabolism, but the differential effects of EPA and DHA are not known. In a randomized, controlled, double-blind, crossover study, we assessed the effects of 10-week supplementation with EPA-only and DHA-only (3 g/d), relative to a 4-week lead-in phase of high oleic acid sunflower oil (3 g/day, defined as baseline), on fasting serum metabolites in 21 subjects (9 men and 12 post-menopausal women) with chronic inflammation and some characteristics of metabolic syndrome. Relative to baseline, EPA significantly lowered the tricarboxylic acid (TCA) cycle intermediates fumarate and α-ketoglutarate and increased glucuronate, UDP-glucuronate, and non-esterified DHA. DHA significantly lowered the TCA cycle intermediates pyruvate, citrate, isocitrate, fumarate, α-ketoglutarate, and malate, and increased succinate and glucuronate. Pathway analysis showed that both EPA and DHA significantly affected the TCA cycle, the interconversion of pentose and glucuronate, and alanine, and aspartate and glutamate pathways (FDR < 0.05) and that DHA had a significantly greater effect on the TCA cycle than EPA. Our results indicate that EPA and DHA exhibit both common and differential effects on cell metabolism in subjects with chronic inflammation and some key aspects of metabolic syndrome.

Is impaired energy regulation the core of the metabolic syndrome in various ethnic groups of the USA and Taiwan?

BACKGROUND: The metabolic syndrome (MetS) concept is widely used in public health and clinical settings without an agreed pathophysiology. We have re-examined the MetS in terms of body fuels, so as to provide a coherent cross-cultural pathogenesis. METHODS: National Health and Nutrition Examination Survey (NHANES 2001-2) with n = 2254 and Taiwanese National Health Interview Survey (NHIS) sub-set for hypertension, hyperglycemia and hyperlipidemia assessment (TwSHHH 2002), n = 5786, were used to compare different ethnicities according to NCEP-ATPIII (NCEP-tw) criteria for METS. Exploratory factor analysis (EFA) using principal components (PC) was employed to differentiate and unify MetS components across four ethnicities, gender, age-strata, and urban-rural settings. RESULTS: The first two factors from the PC analysis (PCA) accounted for from 55.2% (non-Hispanic white) to 63.7% (Taiwanese) of the variance. Rotated factor loadings showed that the six MetS components provided three clusters: the impaired energy regulation (IER) components (waist circumference, WC, fasting triglycerides, TG, and fasting plasma glucose, FPG), systolic and diastolic blood pressures (BPs), and HDL-cholesterol, where the IER components accounted for 25-26% of total variance of MetS components. For the three US ethnic subgroups, factor 1 was mainly determined by IER and HDL-cholesterol, and factor 2 was related to the BP components. For Taiwanese, IER was determinant for both factors, and BPs and HDL-cholesterol were related to factors 1 and 2 respectively. CONCLUSIONS: There is a MetS core which unifies populations. It comprises WC, TG and FPG as a core, IER, which may be expressed and modulated in various second order ways.

Low ambient temperatures correlate with increased risk of hypoglycemia in patients with type 2 diabetes: An ecological study in Taiwan.

Little evidence is available about the relationship between ambient temperatures and hypoglycemia in Taiwan. The purpose of the present paper is to investigate whether there is an association between ambient temperatures and hypoglycemia in patients with type 2 diabetes.An ecological study was conducted to analyze the type 2 diabetes dataset of the Taiwan National Health Insurance Program. Every episode of hypoglycemia diagnosed at emergency department among subjects with type 2 diabetes was identified monthly between 2006 and 2013. Average monthly ambient temperatures in Celsius between 2006 and 2013 were measured according to the database of the Central Weather Bureau in Taiwan.The incidence rates of hypoglycemia were higher during the period of cold ambient temperatures (from December to March) than the period of warm ambient temperatures (from April to November). The peak period of hypoglycemia always occurred in winter months (January and February).Patients with type 2 diabetes in Taiwan are more susceptible to hypoglycemia during the period of cold ambient temperatures, particularly in winter months. Clinicians in Taiwan should remind patients to make a preventive strategy for hypoglycemia during the periods of cold ambient temperatures.

In addition to obesity and insulin resistance, microalbuminuria and diminished insulin secretion are linked with the metabolic syndrome in community-dwelling nondiabetic Taiwanese subjects.

Although insulin resistance and obesity are currently considered primary factors underlying development of the metabolic syndrome, microalbuminuria and inadequate insulin secretion may also be involved. The present study is the first to examine intercorrelations among these factors in a community-based Taiwanese population. An epidemiological survey of chronic diseases conducted in 1996 was utilized to evaluate 1340 community-dwelling, nondiabetic adults. Principal component factor analyses involving varimax orthogonal rotation of transformed continuously distributed variables were performed. Sex-specific factor analyses yielded four separate factors in women (obesity/insulin resistance, lipid, blood pressure and insulin resistance/secretion factors) and three in men (obesity/insulin resistance/secretion, lipid and blood pressure factors). For men the corrected insulin response clustered with obesity, and insulin resistance loaded on the same factor, explaining 31% of variance; however, microalbuminuria was closely linked with blood pressure variables, and the corrected insulin response loaded on the same factor, explaining 13.2% of variance. Obesity and insulin resistance were confirmed as central anomalies of all features of the metabolic syndrome. The observed linkage of impaired beta-cell function and microalbuminuria with the metabolic syndrome should facilitate prediction of the onset of cardio-vasculo-metabolic disorders. Inadequate beta-cell function and microalbuminuria are plausible components of the metabolic syndrome in Taiwanese subjects.

Cell-free methylation markers with diagnostic and prognostic potential in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a highly malignant tumor with poor prognosis and high mortality. There is a dearth of effective early diagnostic tools, so liver resection surgery and liver transplantation are the only effective medical treatments. The most commonly used marker for HCC detection is serum alpha fetoprotein (AFP), which has low sensitivity and specificity. Because aberrant DNA methylation of genes and miRNAs occurs early in most cancers, we explored whether circulating methylation markers could be promising clinical tools for HCC diagnosis. Using a whole-genome approach, we identified many hyper-methylated miRNAs in HCC. Furthermore, three abnormally methylated genes and one miRNA were combined to establish a methylation predictive model and tested for its diagnostic and prognostic potential in HCC. Using plasma samples, the predictive model exhibited high sensitivity and specificity (> 80%) for HBV-related HCC. Most importantly, nearly 75% of patients who could not be diagnosed with AFP at 20 ng/mL were detected by this model. Further, the predictive model exhibited an exceedingly high ability to predict 5-year overall survival in HCC patients. These data demonstrate the high diagnostic and prognostic potential of methylation markers in the plasma of HCC patients.

Clinical and Epidemiologic Features of Severe Viral Gastroenteritis in Children: A 3-Year Surveillance, Multicentered Study in Taiwan With Partial Rotavirus Immunization.

The global epidemiological landscape of childhood acute gastroenteritis (AGE) is changing after the introduction of 2 effective rotavirus vaccines in 2006. A comprehensive evaluation for viral etiology of childhood AGE in Taiwan, where rotavirus vaccination was provided by the private sector since 2006, is lacking.From 2009 to 2011, children younger than 5 years of age with AGE who were hospitalized at 3 sentinel hospitals were enrolled in this surveillance study. Stool specimens were tested for rotavirus, norovirus, enteric adenovirus, and astrovirus. The epidemiologic and clinical information was collected by questionnaire-based interviews and chart reviews.Viral agents were detected in 1055 (37.5%) of 2810 subjects, with rotavirus (21.2%) being the leading cause of disease, followed by norovirus (14.9%), enteric adenovirus (3.74%), astrovirus (2.10%), and a mixture of at least 2 of 4 above-mentioned viruses (4.06%). The majority (56%) of the viral AGE occurred in children <2 years of age. Rotavirus and norovirus were detected more frequently in cool seasons (P < 0.0001 for both), whereas no seasonal variation was observed for adenovirus and astrovirus. Adult households with diarrhea and a Vesikari score >10 were independent factors respectively associated with an increased risk of norovirus (adjusted odds ratio [aOR] 9.034, P = 0.0003) and rotavirus (aOR, 3.284, P < 0.0001) infections. Rotavirus immunization and female gender were protective factors against rotavirus (aOR, 0.198, P < 0.0001) and astrovirus (aOR, 0.382, P = 0.0299) infections, respectively.Rotavirus and norovirus are the 2 most important viral agents of childhood AGE in Taiwan with partial rotavirus immunization. In addition, different enteric viruses are associated with distinct epidemiologic and clinical features.

Effectiveness of 2 rotavirus vaccines against rotavirus disease in Taiwanese infants.

BACKGROUND: Two rotavirus (RV) vaccines (Rotarix and RotaTeq) are available on the private market in Taiwan, but are not recommended for routine use. We examined RV vaccine effectiveness (VE) against severe RV acute gastroenteritis (AGE) among Taiwanese infants to inform policymakers on the potential benefits of national RV vaccine introduction. METHODS: From May 2009 to April 2011, a case-control assessment of VE against severe RV AGE was conducted at 3 hospital-based surveillance sites in Taiwan. Case-patients included children aged 8-35 months, hospitalized with laboratory-confirmed RV AGE. Controls included children age-matched within 1 month of age of the case-patient, hospitalized with RV-negative AGE or seen for non-AGE illnesses at the same hospitals. Vaccination history was confirmed through vaccination card or hospital record review. VE was calculated as (1--odds ratio of vaccination) × 100%. RESULTS: We enrolled 184 case-patients with RV AGE, 904 RV-negative AGE and 909 non-AGE controls. Two-dose Rotarix series VE against RV gastroenteritis hospitalization was 90.4% [95% confidence interval (CI): 70.3%, 98.1%) and 92.5% (95% CI: 77.1%, 98.5%) with RV-negative AGE and non-AGE controls, respectively. Three-dose RotaTeq series VE was 96.8% (95% CI: 82.3%, 100%) and 97.1% (95% CI: 84%, 100%) with RV-negative AGE and non-AGE controls, respectively. CONCLUSIONS: Both vaccines provided excellent protection against severe RV AGE hospitalization. Addition of RV vaccination into Taiwan's National Immunization Program could substantially decrease AGE hospitalizations among children <3 years. Our findings should help inform policymakers in Taiwan and other similar Asian countries when deciding whether to include RV vaccination into their national immunization programs.

Cost-effectiveness of rotavirus vaccination programs in Taiwan.

BACKGROUND: In Taiwan, two rotavirus vaccines are available on the private market, but are not included in the National Immunization Program (NIP). To help assess whether to include rotavirus vaccines in the NIP, we examined the potential impact and cost-effectiveness of vaccination, from the health care system perspective alone. METHODS: We used a Microsoft Excel-based model to assess rotavirus vaccination impact on rotavirus disease burden and the cost-effectiveness of 2-dose and 3-dose vaccination programs among a birth cohort of Taiwanese children followed for 5 years. Principal model inputs included data on rotavirus disease burden and related healthcare costs, vaccination cost and coverage rates, and vaccine efficacy. Principal model outputs included the number of health-related events and costs averted and incremental cost per disability-adjusted life year averted. RESULTS: A national rotavirus vaccination program, regardless of number of doses per course, would prevent 4 deaths, >10,500 hospitalizations, and >64,000 outpatient visits due to rotavirus infection among children <5 years annually, resulting in ~80%, 90%, and 70% declines in these outcomes, respectively, and a ~$7 million decline in annual medical costs. A national 2- or 3-dose vaccination program would be cost-saving up to $13.30/dose ($26.60/course) or $7.98/dose ($23.94/course), respectively; very cost-effective up to $24.08 per dose ($48.16/course) or $15.18/dose ($45.54/course), respectively; and cost-effective up to $45.65/dose ($91.30/course) or $29.59/dose ($88.77/course), respectively. CONCLUSIONS: A national rotavirus vaccination program could substantially reduce rotavirus disease burden among Taiwanese children and be potentially cost-effective, depending on the vaccine price.

Risk factors for salmonella gastroenteritis in children less than five years of age in Taiwan.

BACKGROUND: Nontyphoid Salmonella spp. have been among the most common pathogens of acute gastroenteritis in children in Taiwan. However, the principal sources of transmission remain poorly defined. METHODS: A matched case-control study was conducted from January 2009 to October 2010. Cases were children aged 2-60 months who were hospitalized at 3 medical centers in Taiwan because of diarrhea and found to have culture-proven nontyphoidal Salmonella infection. Controls were healthy children or children with acute diseases other than gastroenteritis and matched to cases by age, gender, study site and enrollment date. RESULTS: A total of 396 cases and 930 matched controls were included for analysis. Multivariate analysis using conditional logistic regression identified contact with household members having diarrhea (matched odds ratio [mOR], 17.9; 95% confidence interval [CI]: 8.82-36.34; P < 0.0001), consumption of instant powdered milk (mOR, 2.04; 95% CI: 1.05-3.94; P = 0.0344), visits to health-care facilities (mOR, 1.66; 95% CI: 1.12-2.48; P = 0.0126) and consumption of purchased groundwater (mOR, 1.50; 95% CI: 1.06-2.11; P = 0.0214) within 1 week preceding enrollment as independent factors associated with increased risk of salmonellosis. Hand washing before meals (P = 0.0311), breastfeeding (P = 0.0370), consumption of chicken (P = 0.0019) and consumption of food prepared by caregivers (P = 0.0011) were protective against Salmonella infection. CONCLUSIONS: The principal transmission routes of Salmonella infection in Taiwanese children are person-to-person, waterborne and environmental contacts. The possibility of powdered milk and groundwater contamination of Salmonella cannot be excluded and requires further investigation.

Astrovirus gastroenteritis in hospitalized children of less than 5 years of age in Taiwan, 2009.

BACKGROUND/PURPOSE: Acute gastroenteritis is a common illness in children under 5 years old. Although rotavirus is a leading cause, other viruses including astrovirus are also important, but have been the subject of limited studies. This is a prospective study to investigate astrovirus gastroenteritis in hospitalized children in Taiwan. MATERIAL/METHOD: From January 2009 to December 2009, children below 5 years of age admitted to three hospitals in Taiwan due to acute gastroenteritis were eligible for this study. Stool specimens were sent for the detection of astrovirus by reverse transcriptase polymerase chain reaction; once positive for astrovirus, the sequencing and phylogenetic analysis of each strain was performed. RESULTS: A total of 989 children were enrolled during the study period. The overall positive rate of astrovirus was 1.6%, ranging from 1.03% to 2.26% in different hospitals, while rotavirus accounted for 20.2% of the patients. Six of the 16 children (37.5%) with astroviral infection had documented coinfection with rotavirus. The median age of infection was 28.2 months. The seasonal distribution of astrovirus peaked from April to June. Diarrhea alone (40% vs. 2.1%, p < 0.0001) was significantly more commonly seen than the triad of fever, vomiting and diarrhea (30% vs. 71%, p = 0.0062) in children with astroviral infection alone than in those with rotaviral infection alone. The mean duration of diarrhea was significantly longer in patients with mixed infection than those with astroviral infection alone (6.8 vs. 4.2 days, p = 0.013). Respiratory symptoms were noted in 10 children (62.5%). Serotype HAstV-1 was the most common (68.8%). CONCLUSION: Astrovirus accounted for 1.6% of infections in children under 5 years hospitalized with acute gastroenteritis in Taiwan. Compared with those caused by rotavirus, the incidence of gastroenteritis in hospitalized children caused by astrovirus was low and the disease severity was mild.