RESUMO
OBJECTIVES: To develop an exposure and risk assessment model to estimate listeriosis infection risks for Peruvian women. METHODS: A simulation model was developed utilising Listeria monocytogenes concentrations on kitchen and latrine surfaces in Peruvian homes, hand trace data from Peruvian women and behavioural data from literature. Scenarios involving varying proportions of uncontaminated, or 'clean', surfaces and non-porous surfaces were simulated. Infection risks were estimated for 4, 6 and 8 h of behaviours and interactions with surfaces. RESULTS: Although infection risks were estimated across scenarios for various time points (e.g. 4, 6, 8 h), overall mean estimated infection risks for all scenarios were ≥ 0.31. Infection risks increased as the proportions of clean surfaces decreased. Hand-to-general surface contacts accounted for the most cumulative change in L. monocytogenes concentration on hands. CONCLUSIONS: In addition to gaining insights on how human behaviours affect exposure and infection risk, this model addressed uncertainties regarding the influence of household surface contamination levels. Understanding the influence of surface contamination in preventing pathogen transmission in households could help to develop intervention strategies to reduce L. monocytogenes infection and associated health risks.
OBJECTIFS: Développer un modèle d'exposition et d'évaluation des risques pour estimer les risques d'infection par la listériose chez les femmes péruviennes. MÉTHODES: Un modèle de simulation a été développé en utilisant des concentrations de Listeria monocytogenes sur la surface des cuisines et des latrines dans des foyers péruviens, des données de traces de mains de femmes péruviennes et des données comportementales de la littérature. Des scénarios impliquant différentes proportions de surfaces non contaminées ou «propres¼ et de surfaces non poreuses ont été simulés. Les risques d'infection ont été estimés pour 4, 6 et 8 heures de comportements et d'interactions avec les surfaces. RÉSULTATS: Bien que les risques d'infection aient été estimés pour tous les scénarios à différents moments (par ex. à 4, 6 ou 8 heures), les risques d'infection globaux moyens estimés pour tous les scénarios étaient ≥ 0,31. Les risques d'infection augmentaient à mesure que les proportions de surfaces propres diminuaient. Les contacts entre la main et les surfaces générales contribuent pour le plus de changement cumulatif de la concentration de L. monocytogenes sur les mains. CONCLUSIONS: En plus de comprendre comment les comportements humains affectent l'exposition et le risque d'infection, ce modèle a traité des incertitudes quant à l'influence des niveaux de contamination des surfaces ménagers. Comprendre l'influence de la contamination de surface dans la prévention de la transmission d'agents pathogènes dans les ménages pourrait aider à développer des stratégies d'intervention pour réduire l'infection à L. monocytogenes et les risques associés pour la santé.
Assuntos
Higiene , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Contagem de Colônia Microbiana/métodos , Contagem de Colônia Microbiana/estatística & dados numéricos , Feminino , Humanos , Peru/epidemiologia , Medição de RiscoRESUMO
The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.
Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Quinolonas/farmacologia , Estudos Transversais , Farmacorresistência Bacteriana , Humanos , Lactente , Testes de Sensibilidade Microbiana , Peru , Saúde da População UrbanaRESUMO
El objetivo principal del estudio fue establecer el nivel de resistencia a antimicrobianos en un total de 222 cepas comensales de E. coli de origen fecal, en Perú. Las frecuencias de resistencia encontrados, frente los antimicrobianos evaluados, fueron: ampicilina (62,6 por ciento), cotrimoxazol (48,6 por ciento), tetraciclina (43,0 por ciento) y cloranfenicol (15,8 por ciento). Destacan los elevados niveles de resistencia a quinolonas: 32 por ciento al ácido nalidíxico (NAL) y 12 por ciento a ciprofloxacino (CIP). Estos elevados niveles hacia las quinolonas en cepas comensales aisladas en niños de esta franja de edad, realzan el uso extendido y el impacto de consumo de este tipo de antimicrobianos en la comunidad, mostrando el riesgo potencial de su pérdidade utilidad en el área
Assuntos
Humanos , Lactente , Coliformes , Escherichia coli , Quinolonas , Testes de Sensibilidade Microbiana , Estudos Transversais , PeruRESUMO
The purpose of this study was to determine the presence and quantity of fecal leukocytes in children infected with diarrheagenic Escherichia coli and to compare these levels between diarrhea and control cases. We analyzed 1,474 stool samples from 935 diarrhea episodes and 539 from healthy controls of a cohort study of children younger than 2 years of age in Lima, Peru. Stools were analyzed for common enteric pathogens, and diarrheagenic E. coli isolates were studied by a multiplex real-time PCR. Stool smears were stained with methylene blue and read by a blinded observer to determine the number of polymorphonuclear leukocytes per high-power field (L/hpf). Fecal leukocytes at >10 L/hpf were present in 11.8% (110/935) of all diarrheal episodes versus 1.1% (6/539) in controls (P < 0.001). Among stool samples with diarrheagenic E. coli as the only pathogen isolated (excluding coinfection), fecal leukocytes at >10 L/hpf were present in 8.5% (18/212) of diarrhea versus 1.3% (2/157) of control samples (P < 0.01). Ninety-five percent of 99 diarrheagenic E. coli diarrhea samples were positive for fecal lactoferrin. Adjusting for the presence of blood in stools, age, sex, undernutrition, and breastfeeding, enterotoxigenic E. coli (ETEC) isolation as a single pathogen, excluding coinfections, was highly associated with the presence of fecal leukocytes (>10 L/hpf) with an odds ratio (OR) of 4.1 (95% confidence interval [CI], 1.08 to 15.51; P < 0.05). Although diarrheagenic E. coli was isolated with similar frequencies in diarrhea and control samples, clearly it was associated with a more inflammatory response during symptomatic infection; however, in general, these pathogens elicited a mild inflammatory response.
Assuntos
Diarreia/imunologia , Diarreia/patologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/patologia , Escherichia coli/imunologia , Fezes/citologia , Neutrófilos/imunologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , PeruRESUMO
BACKGROUND: Diarrheagenic Escherichia coli strains are being recognized as important pediatric enteropathogens worldwide. However, it is unclear whether there are differences in age-related susceptibility to specific strains, especially among infants. METHODS: We conducted a passive surveillance cohort study of diarrhea that involved 1034 children aged 2-12 months in Lima, Peru. Control stool samples were collected from randomly selected children without diarrhea. All samples were analyzed for common enteric pathogens and for diarrheagenic E. coli with use of multiplex real-time polymerase chain reaction. RESULTS: The most frequently isolated pathogens in 1065 diarrheal episodes were diarrheagenic E. coli strains (31%), including enteroaggregative (15.1%) and enteropathogenic E. coli (7.6%). Diarrheagenic E. coli, Campylobacter species, and rotavirus were more frequently isolated from infants aged >or=6 months. Among older infants, diffusely adherent E. coli and enterotoxigenic E. coli were more frequently isolated from diarrheal samples than from control samples (P <.05). Children aged >or=6 months who were infected with enterotoxigenic E. coli had a 4.56-fold increased risk of diarrhea (95% confidence interval, 1.20-17.28), compared with younger children. Persistent diarrhea was more common in infants aged <6 months (13.5% vs 3.6%; P <.001). Among children with diarrheagenic E. coli-positive samples, coinfections with other pathogens were more common in children with diarrhea than in control children (40.1% vs 15.6%; P <.001). CONCLUSIONS: Diarrheagenic E. coli strains were more frequently isolated in samples from older infants. In this setting with high frequency of pathogen exposure and high frequency of breastfeeding, we hypothesize that the major age-related differences result from decreased exposure to milk-related protective factors and from increased exposure to contaminated food and water.
Assuntos
Diarreia Infantil/epidemiologia , Diarreia Infantil/microbiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/fisiologia , Fatores Etários , Escherichia coli/genética , Feminino , Humanos , Lactente , Masculino , Peru/epidemiologia , Vigilância da População , PrevalênciaRESUMO
In a prospective passive diarrhea surveillance cohort study of 1,034 infants of low socioeconomic communities in Lima, Peru, we determined the prevalence and antimicrobial drug susceptibility of the diarrheagenic Escherichia coli . The prevalence of diarrheagenic E. coli was 29% (161 of 557) in children with gastroenteritis and 30% (58 of 195) in the control group without diarrhea. The most common E. coli pathogens in diarrhea were enteroaggregative E. coli (EAEC) (14%), enteropathogenic E. coli (EPEC) (7%), diffusely adherent E. coli (DAEC) (4%), and enterotoxigenic E. coli (ETEC) (4%). Diarrheagenic E. coli as a group exhibited high levels of antimicrobial drug resistance in diarrheal cases to ampicillin (85%), cotrimoxazole (79%), tetracycline (65%), and nalidixic acid (28%). Among individual E. coli groups in patients with diarrhea, DAEC and EAEC exhibited significant higher frequencies of resistance to ampicillin, cotrimoxazole, tetracycline and nalidixic acid than EPEC and ETEC. Antimicrobial drug resistance to ampicillin and cotrimoxazole were more frequent in E. coli isolated from diarrheal samples than controls, which reflected greater antibiotic exposure in patients with gastroenteritis.