Descripción clínica y epidemiológica de un brote grave de salmonelosis en una escuela infantil urbana / Clinical and epidemiologic description of a severe outbreak of Salmonellosis in an urban nursery school

Objetivos. Se describe clínica y epidemiológicamente unbrote de infección gastrointestinal por Salmonella entéricaser. (serotipo) Enteritidis, en una escuela infantil urbana, queconllevó elevada morbilidad e importante alarma social. La comunicación inmediata, así como el estudio adecuado del brote,en ambas vertientes, permitieron identificar el patógeno y establecer medidas de control en un plazo razonable de tiempo.Se discuten aspectos controvertidos como la indicación de antibioterapia o el momento de cierre del centro.Material y métodos. Se recogió retrospectivamente información clínica, analítica y epidemiológica, y se revisó la metodología y resultados del estudio del brote.Resultados. 57 niños (3-45 meses) de 92 asistentes al centro, fueron afectados y tuvieron confirmación microbiológica.Diarrea y fiebre fueron los principales síntomas. 74% acudieronal hospital, y 37% ingresaron, (estancia media 3,3 días). Fueronfactores asociados al ingreso: deshidratación, elevación significativa de reactantes de fase aguda y coagulopatía. 12 recibieroncefotaxima parenteral. Se registraron 2 complicaciones: 1 bacteriemia y 1 reingreso. La sospecha inicial del origen del brotefueron los alimentos, pero el análisis de las muestras testigofue negativo. 5 trabajadores fueron positivos (2 sintomáticos).Vigilancia Epidemiológica concluyó que el origen probable delbrote fue un portador asintomático y la manipulación incorrectade pañales. El centro permaneció cerrado 8 días. Se realizaronmedidas de limpieza y desinfección, instrucción sobre cambio depañales y seguimiento de portadores.Conclusiones. La agrupación en tiempo y espacio de casos debe ser notificada inmediatamente para el control precozdel brote. Los niños pueden presentar formas graves de gastroenteritis por Salmonella. (AU)

Objectives. We describe clinically and epidemiologically anoutbreak of gastrointestinal infection by Salmonella entericaser. (serotype) Enteritidis in an urban infant school, which ledto high morbidity and significant social alarm. The immediatecommunication, as well as the adequate study of the outbreak, inboth aspects, allowed identifying the pathogen and establishingcontrol measures in a reasonable period of time. Controversialaspects such as the indication of antibiotherapy or the momentof closing the center are discussed.Methods. We retrospectively collected clinical, analyticaland epidemiological information and we reviewed themethodology of the outbreak study and its results.Results. A total of 57 children (3-45 months), wereaffected and had microbiological confirmation. Diarrhea andfever were the main symptoms. 74% went to the hospital and37% were admitted (mean stay 3.3 days). Factors associatedwith admission were: dehydration, significant elevation ofacute phase reactants and coagulopathy. Twelve patientsreceived parenteral cefotaxime. There were 2 complications:1 bacteremia and 1 readmission. The initial suspicion ofthe origin of the outbreak was food, but the analysis of thecontrol samples was negative. Five workers were positive (2symptomatic). Epidemiologic Surveillance concluded that theprobable origin of the outbreak was an asymptomatic carrierand improper diapers handling. The center was closed for 8days. Cleaning and disinfection measures were carried out, aswell as instruction on diaper changing, and the carriers werefollowedConclusions. Clustering in time and space of cases shouldbe reported immediately for early control of the outbreak.Children may present severe forms of Salmonella gastroenteritis (AU)

[Clinical and epidemiologic description of a severe outbreak of Salmonellosis in an urban nursery school]. / Descripción clínica y epidemiológica de un brote grave de salmonelosis en una escuela infantil urbana.

OBJECTIVE: We describe clinically and epidemiologically an outbreak of gastrointestinal infection by Salmonella enterica ser. (serotype) Enteritidis in an urban infant school, which led to high morbidity and significant social alarm. The immediate communication, as well as the adequate study of the outbreak, in both aspects, allowed identifying the pathogen and establishing control measures in a reasonable period of time. Controversial aspects such as the indication of antibiotherapy or the moment of closing the center are discussed. METHODS: We retrospectively collected clinical, analytical and epidemiological information and we reviewed the methodology of the outbreak study and its results. RESULTS: A total of 57 children (3-45 months), were affected and had microbiological confirmation. Diarrhea and fever were the main symptoms. 74% went to the hospital and 37% were admitted (mean stay 3.3 days). Factors associated with admission were: dehydration, significant elevation of acute phase reactants and coagulopathy. Twelve patients received parenteral cefotaxime. There were 2 complications: 1 bacteremia and 1 readmission. The initial suspicion of the origin of the outbreak was food, but the analysis of the control samples was negative. Five workers were positive (2 symptomatic). Epidemiologic Surveillance concluded that the probable origin of the outbreak was an asymptomatic carrier and improper diapers handling. The center was closed for 8 days. Cleaning and disinfection measures were carried out, as well as instruction on diaper changing, and the carriers were followed. CONCLUSIONS: Clustering in time and space of cases should be reported immediately for early control of the outbreak. Children may present severe forms of Salmonella gastroenteritis.

Characterization of an unusual Salmonella phage type DT7a and report of a foodborne outbreak of salmonellosis.

Salmonella enterica subsp. enterica serovar 4,[5],12,i:- is a monophasic variant of Salmonella Typhimurium and its occurrence has markedly increased in several European countries in the last ten years. In June 2011, an outbreak of Salmonella 4,[5],12,i:- was reported among attendees of a wedding reception in the North-East of Italy. The source of this outbreak was identified as a cooked pork product served during the wedding reception. All Salmonella isolates from humans and the contaminated pork products were identified as Salmonella 4,[5],12,i:- and phage typed as DT7a. Afterwards, the farm where the pigs were raised was identified and sampled, and Salmonella Typhimurium was isolated from swine fecal samples. Despite the difference in serovar, these Salmonella Typhimurium isolates were also phage typed as DT7a. In the present study, Salmonella isolates from animals, humans and pork products during the outbreak investigation were subtyped by pulsed-field gel electrophoresis (PFGE), Multiple-Locus Variable number tandem repeats Analysis (MLVA), and resistance patterns, aiming to identify the most suitable subtyping methods to characterize isolates associated with this outbreak. In addition, a collection of epidemiologically unrelated strains of Salmonella 4,[5],12,i:- and Salmonella Typhimurium sharing the same phage type (DT7a) was similarly characterized in order to investigate their genetic relationship. This study provides a first snapshot of a rare Salmonella phage type, DT7a, associated with both Salmonella 4,[5],12,i:- and Salmonella Typhimurium. Moreover, the study demonstrated that in this specific context MLVA could be a reliable tool to support outbreak investigations as well as to assess the genetic relatedness among Salmonella isolates.