[Endemic corridors: a useful tool for the epidemiological surveillance of influenza]. / Corredores endémicos: una herramienta útil para la vigilancia epidemiológica de la influenza.

Epidemiological surveillance provides updated information about health problems which allows for the establishment of health policy guidelines. The methods for detecting the epidemic frequency of disease require the systematic collection of data on the occurrence of specific diseases. Influenza has cyclic seasonal peaks and its endemic baseline rates are useful for identifying outbreaks: the comparison between baseline and current data supplies epidemiological evidence related to an ongoing outbreak. The upper and lower incidence curves were traced for the data referring to IA detection in the nasopharyngeal aspirates from children hospitalized for acute lower respiratory tract infection from 1996 to 2002. The arithmetic mean and the 95% confidence interval for upper and lower limits of weekly incidence were calculated. The highest incidence was observed between weeks 25 and 32. When analyzing the prepared endemic corridor, it was observed that the highest detection in 2003 occurred between weeks 19 and 25, whereas two peaks occurred in 2004, the first starting at week 20, at a lower level than the normal epidemic peak, and the second at week 26.

Corredores endémicos: Una herramienta útil para la vigilancia epidemiológica de la influenza / Endemic corridors: a useful tool for the epidemiological surveillance of influenza

La vigilancia epidemiológica provee información actualizada y oportuna sobre los problemas de salud y sus condicionantes, lo que permite definir acciones de prevención y control. Para la detección de epidemias es útil disponer de corredores endémicos, que indican el número de casos esperados para un cuadro infeccioso en un momento determinado. Con datos de la sección Microbiología del Hospital de Niños "Dr. Pedro de Elizalde" acerca de pacientes internados con diagnóstico de infección respiratoria aguda baja (IRAB) entre el 1/1/96 y el 31/12/2002 se confeccionaron los corredores para influenza A (IA) por semanas epidemiológicas, correspondientes a un período de siete años. En ese período se internaron 10.473 niños con diagnóstico de IRAB y se identificó IA en 411 aspirados nasofaríngeos. Se calcularon la media y el intervalo de confianza de 95% para los límites superior e inferior de incidencia en períodos semanales, y se encontró que el pico estacional ocurre entre las semanas 25 y 32. Al analizar los datos del año 2003, se observó que el pico se produjo antes, entre las semanas 19 y 25, y con valores muy por encima de los esperados para esas semanas. En 2004 aparecen 2 picos, el primero en la semana 20 y sin superar los valores de fluctuación de la parte central de la curva, y el segundo en la semana 26.

Epidemiological surveillance provides updated information about health problems which allows for the establishment of health policy guidelines. The methods for detecting the epidemic frequency of disease require the systematic collection of data on the occurrence of specific diseases. Influenza has cyclic seasonal peaks and its endemic baseline rates are useful for identifying outbreaks: the comparison between baseline and current data supplies epidemiological evidence related to an ongoing outbreak. The upper and lower incidence curves were traced for the data referring to IA detection in the nasopharyngeal aspirates from children hospitalized for acute lower respiratory tract infection from 1996 to 2002. The arithmetic mean and the 95% confidence interval for upper and lower limits of weekly incidence were calculated. The highest incidence was observed between weeks 25 and 32. When analyzing the prepared endemic corridor, it was observed that the highest detection in 2003 occurred between weeks 19 and 25, whereas two peaks occurred in 2004 , the first starting at week 20, at a lower level than the normal epidemic peak, and the second at week 26.

[Antimicrobial resistance among species of Salmonella, Shigella, Escherichia, and aeromonas isolated from children with diarrhea in 7 Argentinian centers]. / Resistencia a los antimicrobianos de especies de Salmonella, Shigella, Escherichia y Aeromonas aisladas de niños diarreicos en siete centros de Argentina.

The increasing levels of resistance of enteropathogenic bacteria against antimicrobial agents present geographic variations. We have analysed the antimicrobial susceptibility of isolates obtained from 4,364 children under 5 years of age with acute diarrhea, in 7 cities of Argentina. Diarrheagenic E. coli exhibited 74.5% of resistance against ampicillin, 64.2% against sulfametoxazole-trimethoprim, and Shigella spp., 62% and 75.6% respectively. Salmonella sp. showed 35%, 14%, 41.8%, 65.4%, 14.5%, and 13.6% of resistance against ampicillin, chloranfenicol, sulfametoxazole-trimetoprim, sulfadiazin, gentamycin, and fosfomycin respectively. These values are higher than the ones observed in developed countries. Aeromonas showed significantly lower resistance percentage. Important differences in our country were observed, consequently, local trials should be carried out in order to apply corrective measures.

[Meningococcal meningitis:descriptive study of 76 cases in a pediatric hospital]. / Meningitis meningocócica: estudio descriptivo de 76 casos en un hospital pediátrico.

BACKGROUND: One of the principal causes of bacterial meningitis (BM) in children older than one month is Neisseria meningitidis (Nm). A quick diagnosis and an immediate treatment are considered essential for a good outcome. We propose this study with the purpose of evaluating the clinical and epidemiological characteristics of the patients with BM caused by Nm and analyzing the effect on the presentation and incidence of sequelae and/or complications of the time elapsed since the starting of symptoms and the beginning of the treatment. METHODS: We performed a retrospective analysis of the clinical registers of 76 patients diagnosed as BM caused by Nm entered in the Hospital de Pediatria Pedro de Elizalde, Buenos Aires, Argentina, during the years 1992 and 1993. We investigated age, sex, date of entrance, first symptoms, biochemistry of cerebrospinal fluid (CSF), nutritional status, convulsions and/or complications, length of internation and conditions at discharge. Processing was done with Epi-info 5.0. Differences between qualitative variables were analyzed with chi 2 and differences between means with z-test. RESULTS: Boys were majority; fever was the most frequent initial symptom; petechiae were less frequently found, specially among infants. 79% of the patients had CSF of purulent characteristics; 32.9% of the patients had complications during their evolution; its incidence raised up to 48% in infants. Lethality was 1.3%, 6.5% of the children had sequelae at the moment of discharge. The average time of internment was 13 days. There were no significant differences when different groups were compared according to their prior evolution time. CONCLUSIONS: 1) Petechiae and vomits were significantly less frequent in infants; 2) the incidence of complications was significantly higher in this last group; 3) no greater incidence of complications or sequelae was observed in patients whose previous period of evolution was longer than 48 hours; 4) in all groups of age we found insidious forms of starting, and 5) there were patients with CSF of normal biochemical characteristics in all groups considered independently of the time of evolution elapsed.

Use of a prospectively measured incidence rate of nosocomial diarrhea in an infant/toddler ward as a meaningful quality assessment tool.

OBJECTIVE: To determine the incidence of nosocomial diarrhea as a quality assessment tool, to compare such a rate with a standard rate based on results reported in the literature, and to estimate the hospital cost of narrowing the gap between both. METHODS: This was a prospective hospital-based surveillance study of patients in a 16-cradle ward of a 316-bed public-owned children's hospital in Buenos Aires, Argentina. One hundred six pediatric patients were enrolled during the 3-month surveillance period. Data were collected by a non-attending physician under the usual conditions of care. The clinical staff members were blinded to the objectives of the investigation. RESULTS: The detected incidence rate was 22.6 episodes of nosocomial diarrhea per 100 admissions. This was 6.4-fold higher than the standard rate. Each day of nosocomial diarrhea lengthened the duration of hospitalization and thereby increased the total hospital bill of each patient. The potential savings from narrowing the gap between both rates was as much as $302,400 per year. CONCLUSIONS: Nosocomial diarrhea stands out as a relevant target both for quality improvement opportunity assessment and for cost-containment-oriented efforts.

Relationship between enterotoxigenic Escherichia coli and diarrhea among children in Buenos Aires.

The incidence of enterotoxigenic Escherichia coli (ETEC) has been studied in 85 children with acute diarrhea in patients in the Hospital de Niños Pedro de Elizalde, Buenos Aires, and in 38 healthy children. All of them were up to four years old and none had received antibiotic treatment within 7 days before sampling. ETEC was recovered in 9 out of 85 (10.6%) children with diarrhea. From these positive cases, 6 were associated with heat-stable (ST), 1 with heat-labile (LT) and 2 with both LT and ST enterotoxins. Only one case (2.6%) of LT-producing ETEC was detected in the control group. In 5 out of 9 ETEC diarrhea cases (55.5%) the isolated strains expressed human colonization factor antigens (CFA); four of them were CFA/I and one CFA/II. The characteristics of the CFA, biotype, serotype and antibiotic sensitivity pattern were studied in 23 E. coli isolates from 10 ETEC positive children. Of the 12 ST only strains, 5 (41.7%) expressed CFA/I and 2 (16.7%) CFA/II (CS2 + CS3). One out of 2 LT/ST strains expressed CFA/I. CFAs were not detected in the ETEC-LT nor in the toxin negative E. coli strains. From the ETEC isolated, 82.4% were resistant to 4 or more antibiotics, whereas only 50% of simultaneously isolated toxin-negative E. coli presented this sensitivity pattern. The different ETEC strains belonged to several different serotypes, some of them rarely observed in other countries. None of these serotypes correlated either with the toxin profile or with the sugar fermentation pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between enterotoxigenic Escherichia coli and diarrhea among children in Buenos Aires.

The incidence of enterotoxigenic Escherichia coli (ETEC) has been studied in 85 children with acute diarrhea in patients in the Hospital de Niños Pedro de Elizalde, Buenos Aires, and in 38 healthy children. All of them were up to four years old and none had received antibiotic treatment within 7 days before sampling. ETEC was recovered in 9 out of 85 (10.6

) children with diarrhea. From these positive cases, 6 were associated with heat-stable (ST), 1 with heat-labile (LT) and 2 with both LT and ST enterotoxins. Only one case (2.6

) of LT-producing ETEC was detected in the control group. In 5 out of 9 ETEC diarrhea cases (55.5

) the isolated strains expressed human colonization factor antigens (CFA); four of them were CFA/I and one CFA/II. The characteristics of the CFA, biotype, serotype and antibiotic sensitivity pattern were studied in 23 E. coli isolates from 10 ETEC positive children. Of the 12 ST only strains, 5 (41.7

) expressed CFA/I and 2 (16.7

) CFA/II (CS2 + CS3). One out of 2 LT/ST strains expressed CFA/I. CFAs were not detected in the ETEC-LT nor in the toxin negative E. coli strains. From the ETEC isolated, 82.4

were resistant to 4 or more antibiotics, whereas only 50

of simultaneously isolated toxin-negative E. coli presented this sensitivity pattern. The different ETEC strains belonged to several different serotypes, some of them rarely observed in other countries. None of these serotypes correlated either with the toxin profile or with the sugar fermentation pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between enterotoxigenic Escherichia coli and diarrhea among children in Buenos Aires.

The incidence of enterotoxigenic Escherichia coli (ETEC) has been studied in 85 children with acute diarrhea in patients in the Hospital de Niños Pedro de Elizalde, Buenos Aires, and in 38 healthy children. All of them were up to four years old and none had received antibiotic treatment within 7 days before sampling. ETEC was recovered in 9 out of 85 (10.6

) children with diarrhea. From these positive cases, 6 were associated with heat-stable (ST), 1 with heat-labile (LT) and 2 with both LT and ST enterotoxins. Only one case (2.6

) of LT-producing ETEC was detected in the control group. In 5 out of 9 ETEC diarrhea cases (55.5

) the isolated strains expressed human colonization factor antigens (CFA); four of them were CFA/I and one CFA/II. The characteristics of the CFA, biotype, serotype and antibiotic sensitivity pattern were studied in 23 E. coli isolates from 10 ETEC positive children. Of the 12 ST only strains, 5 (41.7

) expressed CFA/I and 2 (16.7

) CFA/II (CS2 + CS3). One out of 2 LT/ST strains expressed CFA/I. CFAs were not detected in the ETEC-LT nor in the toxin negative E. coli strains. From the ETEC isolated, 82.4

were resistant to 4 or more antibiotics, whereas only 50

of simultaneously isolated toxin-negative E. coli presented this sensitivity pattern. The different ETEC strains belonged to several different serotypes, some of them rarely observed in other countries. None of these serotypes correlated either with the toxin profile or with the sugar fermentation pattern.(ABSTRACT TRUNCATED AT 250 WORDS)