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1.
Clin Infect Dis ; 75(8): 1334-1341, 2022 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-36094137

RESUMEN

BACKGROUND: Sapovirus is one of the principal agents of acute viral enteritis in children. Because it has not been routinely included in diagnostic evaluations, the epidemiology and natural history remain poorly described. METHODS: A birth cohort of 1715 children from 8 countries contributed surveillance samples (n = 35 620) and diarrheal specimens (n = 6868) from 0 to 24 months of age. Sapovirus was detected by quantitative polymerase chain reaction concurrently to other enteropathogens using multiarray cards. Logistic regression was used to identify risk factors, and longitudinal models were employed to estimate incidence rates and evaluate evidence of protective immunity. RESULTS: Sapovirus was detected in 24.7% (n = 1665) of diarrheal stools and 12.8% (n = 4429) of monthly surveillance samples. More than 90% of children were infected and 60% experienced sapovirus diarrhea in the first 2 years of life. Breastfeeding and higher socioeconomic status were associated with reduced incidence of infection and illness. Specimens with sapovirus detected had an increased odds of coinfection with rotavirus (odds ratio [OR], 1.6 [95% confidence interval {CI}, 1.3-2.0]), astrovirus (OR, 1.5 [95% CI, 1.3-1.7]), adenovirus (OR, 1.3 [95% CI, 1.1-1.5]), and Shigella (OR, 1.4 [95% CI, 1.3-1.6]). Prior infection with sapovirus conferred a risk reduction of 22% for subsequent infection (hazard ratio [HR], 0.78 [95% CI, .74-.85]) and 24% for subsequent diarrhea (95% CI, 11.0%-35.0%; HR, 0.76). CONCLUSIONS: Sapovirus is a common cause of early childhood diarrhea. Further research on coinfections is warranted. Evidence of acquired immunity was observed even in the absence of genotype-specific analysis for this pathogen of known genetic diversity.


Asunto(s)
Coinfección , Desnutrición , Sapovirus , Niño , Salud Infantil , Preescolar , Coinfección/complicaciones , Coinfección/epidemiología , Diarrea , Heces , Femenino , Humanos , Lactante , Factores de Riesgo , Sapovirus/genética
2.
Clin Infect Dis ; 67(1): 120-127, 2018 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-29351583

RESUMEN

Background: Travelers' diarrhea (TD) is a common illness experienced by travelers from developed countries who visit developing countries. Recent questionnaire-based surveillance studies showed that approximately 6%-16% of travelers experienced TD while visiting Thailand; however, a majority of TD information was limited mainly to US military populations. Methods: A TD surveillance study was conducted at Bumrungrad International Hospital in 2012-2014 in Bangkok, Thailand. Enteropathogens were identified using conventional methods and the TaqMan® array card (TAC), which uses real-time polymerase chain reaction for the simultaneous detection of multiple pathogens. Analyses to determine pathogen-disease and symptoms association were performed to elucidate the clinical relevance of each enteropathogen. Results: TAC identified more pathogens per sample than conventional methods. Campylobacter spp. were the most prevalent, followed by the diarrheagenic Escherichia coli and norovirus GII. These agents had significant pathogen-disease associations as well as high attributable fractions among diarrheal cases. A wide range of pathogen loads for Campylobacter spp. was associated with TD, while heat-labile toxin enterotoxigenic Escherichia coli was associated with an increased pathogen load. Most cases were associated with inflammatory diarrhea, while Campylobacter spp. and Shigella spp. were associated with dysentery. Conclusions: A pan-molecular diagnostic method such as TAC produces quantifiable and comparable results of all tested pathogens, thereby reducing the variability associated with multiple conventional methods. This allows better determination of the clinical relevance of each diarrhea etiologic agent, as well as their geographical relevance in Thailand.


Asunto(s)
Diarrea/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Enfermedad Relacionada con los Viajes , Adolescente , Adulto , Anciano , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/epidemiología , Campylobacter/aislamiento & purificación , Diarrea/epidemiología , Escherichia coli Enterotoxigénica/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Femenino , Humanos , Vigilancia Inmunológica , Masculino , Persona de Mediana Edad , Norovirus/aislamiento & purificación , Análisis de Secuencia por Matrices de Oligonucleótidos , Tailandia/epidemiología , Viaje , Virosis/diagnóstico , Virosis/epidemiología , Adulto Joven
3.
J Pediatr Gastroenterol Nutr ; 66(2): 325-333, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29356769

RESUMEN

OBJECTIVE: We evaluated the impact of subclinical enteroaggregative Escherichia coli (EAEC) infection alone and in combination with other pathogens in the first 6 months of life on child growth. METHODS: Nondiarrheal samples from 1684 children across 8 Multisite Birth Cohort Study, Malnutrition and Enteric Diseases (MAL-ED) sites in Asia, Africa, and Latin America were tested monthly; more than 90% of children were followed-up twice weekly for the first 6 months of life. RESULTS: Children with subclinical EAEC infection did not show altered growth between enrollment and 6 months. Conversely, EAEC coinfection with any other pathogen was negatively associated with delta weight-for-length (P < 0.05) and weight-for-age (P > 0.05) z scores between 0 and 6 months. The presence of 2 or more pathogens without EAEC was not significantly associated with delta weight-for-length and weight-for-age. The most frequent EAEC coinfections included Campylobacter spp, heat-labile toxin-producing enterotoxigenic E coli, Cryptosporidium spp, and atypical enteropathogenic E coli. Myeloperoxidase levels were increased with EAEC coinfection (P < 0.05). EAEC pathogen codetection was associated with lower neopterin levels compared to those of no-pathogen control children (P < 0.05). Mothers of children with EAEC coinfections had lower levels of education, poorer hygiene and sanitation, lower socioeconomic status, and lower breast-feeding rates compared to mothers of children in whom no pathogen was detected (P < 0.05). CONCLUSIONS: These data emphasize the public health importance of subclinical EAEC infection in early infancy in association with other pathogens and the need for improved maternal and child care, hygiene, sanitation, and socioeconomic factors.


Asunto(s)
Escherichia coli Enteropatógena/aislamiento & purificación , Infecciones por Escherichia coli/complicaciones , Trastornos del Crecimiento/microbiología , Antropometría/métodos , Desarrollo Infantil , Estudios de Cohortes , Coinfección/complicaciones , Coinfección/epidemiología , Heces/microbiología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Intestinos/inmunología , Intestinos/microbiología , Masculino , Factores de Riesgo
4.
J Pediatr ; 182: 127-132.e1, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27974166

RESUMEN

OBJECTIVE: To estimate the abilities of weight and length velocities vs attained growth measures to predict stunting, wasting, and underweight at age 2 years. STUDY DESIGN: We analyzed data from a community-based cohort study (The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development study [MAL-ED] study) in Bhaktapur, Nepal. A total of 240 randomly selected children were enrolled at birth and followed up monthly up to age 24 months. Linear and logistic regression models were used to predict malnutrition at 2 years of age with growth velocity z scores at 0-3, 0-6, 3-6, 6-9, 6-12, and 9-12 months (using the World Health Organization Growth Standards) or attained growth at 0, 3, 6, and 12 months as predictors. RESULTS: At age 2 years, 4% of the children were wasted, 13% underweight, and 21% stunted. Children who were malnourished at age 2 years had lower mean growth z scores already at birth and throughout the study period. Anthropometric indicators in infancy were significant predictors for growth at the age of 2 years during most periods and at most ages in infancy. Weight-for-age z score, length-for-age z score, and weight-for-length z score at age 12 months had excellent areas under the curve (91-95) to predict the value of the same indicator at age 24 months. Maximum area under the curve values for weight and length velocity were somewhat lower (70-84). CONCLUSIONS: Growth measured at one time point in infancy was better correlated with undernutrition at age 2 years than growth velocity.


Asunto(s)
Antropometría/métodos , Estatura , Peso Corporal , Desnutrición/diagnóstico , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Nepal , Análisis de Regresión
5.
J Immunol ; 195(9): 4378-86, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26408671

RESUMEN

Studies of influenza-specific immune responses in humans have largely assessed systemic responses involving serum Ab and peripheral blood T cell responses. However, recent evidence indicates that tissue-resident memory T (TRM) cells play an important role in local murine intrapulmonary immunity. Rhesus monkeys were pulmonary exposed to 2009 pandemic H1N1 virus at days 0 and 28 and immune responses in different tissue compartments were measured. All animals were asymptomatic postinfection. Although only minimal memory immune responses were detected in peripheral blood, a high frequency of influenza nucleoprotein-specific memory T cells was detected in the lung at the "contraction phase," 49-58 d after second virus inoculation. A substantial proportion of lung nucleoprotein-specific memory CD8(+) T cells expressed CD103 and CD69, phenotypic markers of TRM cells. Lung CD103(+) and CD103(-) memory CD8(+) T cells expressed similar levels of IFN-γ and IL-2. Unlike memory T cells, spontaneous Ab secreting cells and memory B cells specific to influenza hemagglutinin were primarily observed in the mediastinal lymph nodes. Little difference in systemic and local immune responses against influenza was observed between young adult (6-8 y) and old animals (18-28 y). Using a nonhuman primate model, we revealed substantial induction of local T and B cell responses following 2009 pandemic H1N1 infection. Our study identified a subset of influenza-specific lung memory T cells characterized as TRM cells in rhesus monkeys. The rhesus monkey model may be useful to explore the role of TRM cells in local tissue protective immunity after rechallenge and vaccination.


Asunto(s)
Linfocitos B/inmunología , Memoria Inmunológica/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Macaca mulatta/inmunología , Infecciones por Orthomyxoviridae/inmunología , Linfocitos T/inmunología , Factores de Edad , Animales , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/inmunología , Antígenos de Diferenciación de Linfocitos T/metabolismo , Linfocitos B/metabolismo , Linfocitos B/virología , Médula Ósea/inmunología , Médula Ósea/metabolismo , Médula Ósea/virología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/virología , Células Cultivadas , Interacciones Huésped-Patógeno/inmunología , Humanos , Subtipo H1N1 del Virus de la Influenza A/fisiología , Cadenas alfa de Integrinas/inmunología , Cadenas alfa de Integrinas/metabolismo , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-2/inmunología , Interleucina-2/metabolismo , Lectinas Tipo C/inmunología , Lectinas Tipo C/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/virología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/virología , Macaca mulatta/metabolismo , Macaca mulatta/virología , Mediastino/virología , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Bazo/inmunología , Bazo/metabolismo , Bazo/virología , Linfocitos T/metabolismo , Linfocitos T/virología , Factores de Tiempo
6.
J Pediatr Gastroenterol Nutr ; 65(1): 31-39, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28644347

RESUMEN

OBJECTIVES: The aim of the study was to describe changes in intestinal permeability in early childhood in diverse epidemiologic settings. METHODS: In a birth cohort study, the lactulose:mannitol (L:M) test was administered to 1980 children at 4 time points in the first 24 months of life in 8 countries. Data from the Brazil site with an incidence of diarrhea similar to that seen in the United States and no growth faltering was used as an internal study reference to derive age- and sex-specific z scores for mannitol and lactulose recoveries and the L:M ratio. RESULTS: A total of 6602 tests demonstrated mannitol recovery, lactulose recovery, and the L:M ratio were associated with country, sex, and age. There was heterogeneity in the recovery of both probes between sites with mean mannitol recovery ranging for 1.34% to 5.88%, lactulose recovery of 0.19% to 0.58%, and L:M ratios 0.10 to 0.17 in boys of 3 months of age across different sites. We observed strong sex-specific differences in both mannitol and lactulose recovery, with boys having higher recovery of both probes. Alterations in intestinal barrier function increased in most sites from 3 to 9 months of age and plateaued or diminished from 9 to 15 months of age. CONCLUSIONS: Alterations in recovery of the probes differ markedly in different epidemiologic contexts in children living in the developing world. The rate of change in the L:M-z ratio was most rapid and consistently disparate from the reference standard in the period between 6 and 9 months of age, suggesting that this is a critical period of physiologic impact of enteropathy in these populations.


Asunto(s)
Enfermedades Intestinales/diagnóstico , Mucosa Intestinal/metabolismo , Lactulosa/metabolismo , Manitol/metabolismo , África del Sur del Sahara/epidemiología , Factores de Edad , Asia Occidental/epidemiología , Biomarcadores/metabolismo , Femenino , Humanos , Lactante , Enfermedades Intestinales/epidemiología , Enfermedades Intestinales/metabolismo , Estudios Longitudinales , Masculino , Permeabilidad , Valores de Referencia , Factores Sexuales , América del Sur/epidemiología
7.
Clin Infect Dis ; 62(10): 1210-7, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27013692

RESUMEN

BACKGROUND: Norovirus is an important cause of childhood diarrhea. We present data from a longitudinal, multicountry study describing norovirus epidemiology during the first 2 years of life. METHODS: A birth cohort of 1457 children across 8 countries contributed 7077 diarrheal stools for norovirus testing. A subset of 199 children contributed additional asymptomatic samples (2307) and diarrheal stools (770), which were used to derive incidence rates and evaluate evidence for acquired immunity. RESULTS: Across sites, 89% of children experienced at least 1 norovirus infection before 24 months, and 22.7% of all diarrheal stools were norovirus positive. Severity of norovirus-positive diarrhea was comparable to other enteropathogens, with the exception of rotavirus. Incidence of genogroup II (GII) infection was higher than genogroup I and peaked at 6-11 months across sites. Undernutrition was a risk factor for symptomatic norovirus infection, with an increase in 1 standard deviation of length-for-age z score associated with a 17% reduction (odds ratio, 0.83 [95% confidence interval, .72-.97]; P = .011) in the odds of experiencing diarrhea when norovirus was present, after accounting for genogroup, rotavirus vaccine, and age. Evidence of acquired immunity was observed among GII infections only: Children with prior GII infection were found to have a 27% reduction in the hazard of subsequent infection (hazard ratio, 0.727; P = .010). CONCLUSIONS: The high prevalence of norovirus across 8 sites in highly variable epidemiologic settings and demonstration of protective immunity for GII infections provide support for investment in vaccine development.


Asunto(s)
Infecciones por Caliciviridae , Diarrea , Norovirus/genética , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/inmunología , Infecciones por Caliciviridae/virología , Preescolar , Estudios de Cohortes , Diarrea/epidemiología , Diarrea/inmunología , Diarrea/virología , Heces/virología , Humanos , Incidencia , Lactante , Recién Nacido
8.
Immunology ; 147(2): 178-89, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26496144

RESUMEN

Shigella dysenteriae causes the most severe of all infectious diarrhoeas and colitis. We infected rhesus macaques orally and also treated them orally with a small and non-absorbable polypropyletherimine dendrimer glucosamine that is a Toll-like receptor-4 (TLR4) antagonist. Antibiotics were not given for this life-threatening infection. Six days later, the clinical score for diarrhoea, mucus and blood was 54% lower, colon interleukin-8 and interleukin-6 were both 77% lower, and colon neutrophil infiltration was 75% less. Strikingly, vasculitis did not occur and tissue fibrin thrombi were reduced by 67%. There was no clinical toxicity or adverse effect of dendrimer glucosamine on systemic immunity. This is the first report in non-human primates of the therapeutic efficacy of a small and orally bioavailable TLR antagonist in severe infection. Our results show that an oral TLR4 antagonist can enable controlled resolution of the infection-related-inflammatory response and can also prevent neutrophil-mediated gut wall necrosis in severe infectious diarrhoeas.


Asunto(s)
Antidiarreicos/administración & dosificación , Colon/efectos de los fármacos , Citocinas/metabolismo , Dendrímeros/administración & dosificación , Disentería Bacilar/tratamiento farmacológico , Glucosamina/análogos & derivados , Shigella dysenteriae/efectos de los fármacos , Receptor Toll-Like 4/antagonistas & inhibidores , Administración Oral , Animales , Colon/inmunología , Colon/metabolismo , Colon/microbiología , Colon/patología , Citocinas/inmunología , Modelos Animales de Enfermedad , Disentería Bacilar/inmunología , Disentería Bacilar/metabolismo , Disentería Bacilar/microbiología , Disentería Bacilar/patología , Femenino , Glucosamina/administración & dosificación , Interacciones Huésped-Patógeno , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/microbiología , Macaca mulatta , Masculino , Necrosis , Infiltración Neutrófila/efectos de los fármacos , Índice de Severidad de la Enfermedad , Shigella dysenteriae/inmunología , Shigella dysenteriae/patogenicidad , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Receptor Toll-Like 4/inmunología , Receptor Toll-Like 4/metabolismo
9.
PLoS Med ; 13(8): e1002055, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27483136

RESUMEN

BACKGROUND: Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR) lineage of Shigella sonnei (lineage III) is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei. METHODS AND FINDINGS: We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1) and two outside of Asia (Australia, n = 19; Ireland, n = 16). We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei. CONCLUSIONS: This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing endemic transmission in new locations. Despite being limited in geographical scope, our work has major implications for understanding the international transfer of antimicrobial-resistant pathogens, with S. sonnei acting as a tractable model for studying how antimicrobial-resistant Gram-negative bacteria spread globally.


Asunto(s)
Antibacterianos/uso terapéutico , Ciprofloxacina/uso terapéutico , Disentería Bacilar/tratamiento farmacológico , Shigella sonnei/efectos de los fármacos , Australia/epidemiología , Bután/epidemiología , Cambodia/epidemiología , Preescolar , Estudios Transversales , Farmacorresistencia Bacteriana/genética , Farmacorresistencia Bacteriana Múltiple/genética , Disentería Bacilar/epidemiología , Disentería Bacilar/microbiología , Genoma Bacteriano/genética , Humanos , Irlanda/epidemiología , Filogenia , Shigella sonnei/genética , Tailandia/epidemiología , Vietnam/epidemiología
10.
BMC Public Health ; 16: 309, 2016 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-27067256

RESUMEN

BACKGROUND: Measles remains a major public health concern in Thailand despite the introduction of vaccination since 1984. Similar to other countries, Thailand has experienced numerous measles outbreaks including adult communities such as university student dormitories, prisons, refugee camps, and military recruit camps. These outbreaks raise questions on the seroprotective antibody level in Thai adults. METHODS: To better understand measles susceptibility in young Thai adults, a retrospective measles seroprevalence study on repository serum specimens obtained with informed consent from young Thai men entering the Royal Thai Army (RTA) during 2007-2008 was conducted. A total of 7760 stratified randomized samples were chosen by residence province. Measles IgG titer was measured using a commercial IgG quantitative ELISA kit following the manufacturer's instructions. An antibody level ≥ 250 International Units per Liter (IU/L) was interpreted as seropositive. RESULTS: The overall measles seroprevalence was 78.5 % (95 % Confidence Interval: 77.6-79.4 %) with geometric mean titer of 738 IU/L (95 % Confidence Interval: 716-760 IU/L). The measles seroprevalence by province ranged from 59.6 % to 93.1 %. A trend of decreasing seroprevalence in the younger cohorts despite increasing immunization coverage was found. Lower seroprevalence than vaccination coverage was observed in the youngest age group. CONCLUSIONS: To achieve long term measles control and elimination, an integrated two doses vaccination strategy has been implemented in children in Thailand. This nationwide measles seroprevalence study in young adult RTA recruits found a measles seroprevalence lower than WHO's recommendation for measles outbreak prevention and elimination. These results raise concerns for measles control in Thailand. Supplementary immunization in young adults is essential especially in high-risk and densely populated communities to establish herd immunity for outbreak prevention and elimination.


Asunto(s)
Brotes de Enfermedades/prevención & control , Susceptibilidad a Enfermedades , Necesidades y Demandas de Servicios de Salud , Vacuna Antisarampión/administración & dosificación , Sarampión/epidemiología , Sarampión/prevención & control , Adolescente , Adulto , Estudios Transversales , Humanos , Masculino , Personal Militar/estadística & datos numéricos , Estudios Retrospectivos , Riesgo , Estudios Seroepidemiológicos , Tailandia/epidemiología , Vacunación/estadística & datos numéricos , Adulto Joven
11.
J Med Virol ; 87(4): 664-74, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25649836

RESUMEN

This study identified norovirus in children presenting with acute gastroenteritis and determined the capsid genotypes of the circulating norovirus strains in multiple regions in Thailand during October 2004 to December 2006 and March 2008 to August 2010. A total of 7,420 stool samples were collected from both cases (3621) and controls (3799). The stool samples were screened by two real-time RT-PCR assays to detect genogroup I and genogroup II noroviruses. Norovirus-positive samples were identified in 516 cases (14.3%) and 181 controls (4.8%) with more than half of norovirus positive samples from 7-24 months old children. Positive samples were sequenced and genotyped for the capsid gene. GII.4 was the genotype observed most frequently (56.4%) followed by GII.3 (28.2%). Five peaks of infection were observed, with predominant capsid genotypes that alternated during the surveillance periods between GII.4 and GII.3. Analyses of positive samples showed variation in genotype from each region as well as from different study periods. This emphasizes the importance of multi-site studies to investigate norovirus epidemiology. Additionally, the observed regional and temporal variations suggest that a systematic nation-wide surveillance effort in Thailand is needed to track the continually changing norovirus epidemiology.


Asunto(s)
Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Norovirus/clasificación , Norovirus/aislamiento & purificación , Proteínas de la Cápside/genética , Preescolar , Análisis por Conglomerados , Heces/virología , Femenino , Genotipo , Humanos , Lactante , Masculino , Epidemiología Molecular , Datos de Secuencia Molecular , Norovirus/genética , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Tailandia/epidemiología
12.
Clin Infect Dis ; 59 Suppl 4: S273-9, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305297

RESUMEN

Most vaccine assessments have occurred in well-nourished populations of higher socioeconomic status. However, vaccines are often used in populations with high incidences of malnutrition and infections, in whom the effectiveness of some vaccines is inferior for unknown reasons. The degree and extent of vaccine underperformance have not been systematically studied for most vaccines across differing epidemiologic settings. This paper outlines the methods used and challenges associated with measuring immunological responses to oral vaccines against poliovirus and rotavirus, and parenteral vaccines against pertussis, tetanus, and measles in an observational study that monitored daily illness, monthly growth, intestinal inflammation and permeability, pathogen burden, dietary intake, and micronutrient status in children in 8 countries. This evaluation of vaccine response in the context of low- and middle-income countries is intended to address the gaps in knowledge of the heterogeneity in vaccine response in diverse epidemiological settings and the interplay between infections, nutrition, and immune response.


Asunto(s)
Diseño de Investigaciones Epidemiológicas , Enfermedades Intestinales/epidemiología , Estudios Longitudinales , Desnutrición/epidemiología , Vacunas/inmunología , Trastornos de la Nutrición del Niño/epidemiología , Preescolar , Diarrea/epidemiología , Humanos , Lactante
13.
Clin Infect Dis ; 59 Suppl 4: S300-3, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305301

RESUMEN

The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study site in Nepal is located in the Bhaktapur municipality, 15 km east of Kathmandu, the capital city of Nepal. Bhaktapur, an ancient city famous for its traditional temples and buildings, is included on UNESCO's World Heritage List and is a major tourist attraction in Nepal. Nepal is a land-locked country located in South Asia between China and India with an area of 147 181 km(2), ranging from sea-level plains to Mount Everest, the world's highest peak. The total population as of the 2011 census was 26.6 million, with an average annual population growth rate of 1.4. Nepal is one of the world's least developed countries and is ranked 157 of 186 in the 2013 Human Development Report; one-third of the Nepali population lives below the poverty line. The current under-5 mortality rate is 54 per 1000 live births, the infant mortality rate is 46 per 1000 live births, and the neonatal mortality rate is 33 per 1000 live births. Vaccine coverage for all Expanded Program on Immunization vaccines is >80%. Among children, the most common diseases contributing to significant morbidity and mortality are acute respiratory infection and dehydration from severe diarrhea. In this article, we report on the geographic, demographic, and socioeconomic features of the Bhaktapur MAL-ED site and describe the data that informed our cohort recruitment strategy.


Asunto(s)
Diseño de Investigaciones Epidemiológicas , Estudios Longitudinales , Desarrollo Infantil , Preescolar , Conducta Cooperativa , Diarrea , Infecciones por Enterobacteriaceae , Femenino , Humanos , Masculino , Desnutrición , Nepal/epidemiología , Embarazo , Factores Socioeconómicos
14.
Clin Infect Dis ; 59 Suppl 4: S225-32, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305291

RESUMEN

A central hypothesis of The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study is that enteropathogens contribute to growth faltering. To examine this question, the MAL-ED network of investigators set out to achieve 3 goals: (1) develop harmonized protocols to test for a diverse range of enteropathogens, (2) provide quality-assured and comparable results from 8 global sites, and (3) achieve maximum laboratory throughput and minimum cost. This paper describes the rationale for the microbiologic assays chosen and methodologies used to accomplish the 3 goals.


Asunto(s)
Diseño de Investigaciones Epidemiológicas , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/normas , Preescolar , Infecciones por Enterobacteriaceae/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Humanos , Lactante , Recién Nacido , Enfermedades Intestinales/diagnóstico , Parasitosis Intestinales/diagnóstico , Estudios Longitudinales , Microscopía , Reacción en Cadena de la Polimerasa , Garantía de la Calidad de Atención de Salud
15.
Clin Infect Dis ; 59 Suppl 4: S239-47, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305293

RESUMEN

Individuals in the developing world live in conditions of intense exposure to enteric pathogens due to suboptimal water and sanitation. These environmental conditions lead to alterations in intestinal structure, function, and local and systemic immune activation that are collectively referred to as environmental enteropathy (EE). This condition, although poorly defined, is likely to be exacerbated by undernutrition as well as being responsible for permanent growth deficits acquired in early childhood, vaccine failure, and loss of human potential. This article addresses the underlying theoretical and analytical frameworks informing the methodology proposed by the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study to define and quantify the burden of disease caused by EE within a multisite cohort. Additionally, we will discuss efforts to improve, standardize, and harmonize laboratory practices within the MAL-ED Network. These efforts will address current limitations in the understanding of EE and its burden on children in the developing world.


Asunto(s)
Enfermedades Transmisibles , Medicina Ambiental , Diseño de Investigaciones Epidemiológicas , Enfermedades Intestinales , Desnutrición , Preescolar , Costo de Enfermedad , Humanos , Lactante , Recién Nacido , Estudios Longitudinales
16.
Emerg Infect Dis ; 20(9): 1531-4, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25148245

RESUMEN

The nationwide seroprevalence of hepatitis E IgG was determined among young men in Thailand. Overall seroprevalence was 14% (95% CI 13%-15%); range by province was 3%-26%. Seroprevalence was lowest in the south, an area predominantly occupied by persons of the Islam religion, whose dietary laws proscribe pork.


Asunto(s)
Microbiología de Alimentos , Virus de la Hepatitis E/inmunología , Hepatitis E/epidemiología , Hepatitis E/transmisión , Productos de la Carne/efectos adversos , Productos de la Carne/virología , Porcinos , Adolescente , Adulto , Animales , Femenino , Geografía Médica , Anticuerpos Antihepatitis/sangre , Hepatitis E/historia , Historia del Siglo XXI , Humanos , Inmunoglobulina G/sangre , Masculino , Vigilancia en Salud Pública , Factores de Riesgo , Población Rural , Estudios Seroepidemiológicos , Tailandia/epidemiología , Población Urbana , Adulto Joven
17.
Prev Med ; 64: 8-13, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24657549

RESUMEN

OBJECTIVE: To assess the net impact on U.S. longevity of the decision to commute by bicycle rather than automobile. METHODS: We construct fatality rates per distance traveled using official statistics and denominators from the 2009 National Household Travel Survey. We model the life-table impact of switching from auto to bicycle commuting. Key factors are increased risks from road accidents and reduced risks from enhanced cardiovascular health. RESULTS: Bicycling fatality rates in the U.S. are an order of magnitude higher than in Western Europe. Risks punish both young and old, while the health benefits guard against causes of mortality that rise rapidly with age. Although the protective effects of bicycling appear significant, it may be optimal to wait until later ages to initiate regular bicycle commuting in the current U.S. risk environment, especially if individuals discount future life years. CONCLUSIONS: The lifetime health benefits of bicycle commuting appear to outweigh the risks in the U.S., but individuals who sufficiently discount or disbelieve the health benefits may delay or avoid bicycling. Bicycling in middle age avoids much fatality risk while capturing health benefits. Significant cross-state variations in bicycling mortality suggest that improvements in the built environment might spur changes in transit mode.


Asunto(s)
Accidentes de Tránsito/estadística & datos numéricos , Conducción de Automóvil/estadística & datos numéricos , Ciclismo/estadística & datos numéricos , Esperanza de Vida/tendencias , Accidentes de Tránsito/mortalidad , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Ciclismo/lesiones , Ciclismo/fisiología , Causas de Muerte , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Tablas de Vida , Longevidad/fisiología , Masculino , Persona de Mediana Edad , Medición de Riesgo , Transportes/métodos , Estados Unidos/epidemiología , Adulto Joven
18.
Artículo en Inglés | MEDLINE | ID: mdl-23691636

RESUMEN

To better understand the epidemiology of bacterial food borne pathogens in children, in relation to pathogens in meats from a market in rural Thailand, we collected 73 cultures samples from raw chicken, pork and fish at a local market where diarrheal disease surveillance was conducted. Standard methods were employed to isolate, identify and serotype enteric pathogens from children and food samples. Antibiotic susceptibility testing was performed. Ninety-seven percent of food samples were contaminated with at least one enteric pathogen. The pathogens most commonly isolated from food were Salmonella spp (84%), Arcobacter butzleri (74%) and Campylobacter spp (51%). The most common serovars of Salmonella obtained from humans with diarrhea were S. Risen, S. Stanley and S. Anatum. Most common serovars of Salmonella isolated from food were S. Anatum, S. Stanley, and S. Corvallis. Fifty-one percent and 25% of children infected with Salmonella and Campylobacter, respectively, infected with the same serotypes isolated from food samples, suggesting these pathogens are widespread in food and humans. Pulsed-field gel analysis of Salmonella spp revealed 65 pulsotypes, but no point-sources of salmonellosis were identified. Joint epidemiologic/laboratory studies are useful to describe the epidemiology of enteric pathogens in rural populations.


Asunto(s)
Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Carne/microbiología , Población Rural , Animales , Técnicas Bacteriológicas , Pollos/microbiología , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Heces/microbiología , Peces/microbiología , Humanos , Porcinos/microbiología , Tailandia/epidemiología
19.
Am J Trop Med Hyg ; 108(1): 174-180, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36509064

RESUMEN

Diarrhea is a common cause of morbidity and mortality among children younger than 5 years in developing countries. Children from 3 to 60 months of age were recruited from two hospitals in Nepal- Bharatpur Hospital, Bharatpur, and Kanti Children's Hospital, Kathmandu-in 2006 to 2009. Stool specimens collected from 1,200 children with acute diarrhea (cases) and 1,200 children without diarrhea (control subjects) were examined for a broad range of enteropathogens by standard microbiology, including microscopy, enzyme immunoassay for viral pathogens (adenovirus, astrovirus, and rotavirus) and protozoa (Giardia, Cryptosporidium, and Entamoeba histolytica), as well as by using reverse transcription real-time polymerase for norovirus. Antimicrobial susceptibility testing was performed using the disk diffusion method. Overall, rotavirus (22% versus 2%), norovirus (13% versus 7%), adenovirus (3% versus 0%), Shigella (6% versus 1%), enterotoxigenic Escherichia coli (8% versus 4%), Vibrio (7% versus 0%), and Aeromonas (9% versus 3%) were identified significantly more frequently in cases than control subjects. Campylobacter, Plesiomonas, Salmonella, and diarrheagenic E. coli (enteropathogenic, enteroinvasive, enteroaggregative) were identified in similar proportions in diarrheal and non-diarrheal stools. Campylobacter was resistant to second-generation quinolone drugs (ciprofloxacin and norfloxacin), whereas Vibrio and Shigella were resistant to nalidixic acid and trimethoprim/sulfamethoxazole. This study documents the important role of rotavirus and norovirus in acute diarrhea in children younger than 5 years, followed by the bacteria Shigella, enterotoxigenic E. coli, Vibrio cholera, and Aeromonas. Data on the prevalence and epidemiology of enteropathogens identify potential pathogens for public health interventions, whereas pathogen antibiotic resistance pattern data may provide guidance on choice of therapy in clinical settings.


Asunto(s)
Infecciones por Adenoviridae , Antiinfecciosos , Campylobacter , Criptosporidiosis , Cryptosporidium , Escherichia coli Enterotoxigénica , Norovirus , Rotavirus , Shigella , Humanos , Lactante , Preescolar , Nepal/epidemiología , Diarrea/microbiología , Adenoviridae , Enfermedad Aguda
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