[Antimicrobial resistance characteristics of clinical isolates of Streptococcus pyogenes]. / Características de la resistencia antimicrobiana de una colección clínica de Streptococcus pyogenes.

OBJECTIVE: To determine the antibiotic susceptibility of recent isolates of Streptococcus pyogenes and to evaluate the prevalence of macrolide-resistant phenotypes. MATERIAL AND METHODS: In 1999, we conducted a cross-sectional study at Mexico Children's Hospital "Federico Gomez", to analyze one hundred strains of S. pyogenes isolated from 1992 to 1998, in children with uncomplicated pharyngotonsillitis. Strains were frozen at the bacteriology lab until they were analyzed. Strains were tested for susceptibility against some beta-lactams, macrolides and clindamycin. Double-disk testing was carried out to evaluate erythromycin-resistant phenotypes. Data are presented using central tendency measures. RESULTS: All tested strains were not resistant to beta-lactams and clindamycin; 16% of the strains were resistant to macrolides and all of them belonged to phenotype M. CONCLUSIONS: Susceptibility testing is recommended to identify possible changes in antibiotic resistance to streptococci.

Clinical outcome of invasive infections in children caused by highly penicillin-resistant Streptococcus pneumoniae compared with infections caused by penicillin-susceptible strains.

BACKGROUND: In this report based on data from the Institutional Surveillance System during 1994-1998, we document the continuing emergence of drug-resistant Streptococcus pneumoniae strains at the Hospital Infantil de Mexico Federico Gómez in Mexico City. METHODS: We evaluate the clinical course of 49 invasive pneumococcal infection outside the central nervous system (CNS) by a number of factors including the site, severity, and place where the infection was acquired, the underlying health of the patient, and the adequacy of antimicrobial therapy. RESULTS: An underlying illness was present in 21 of 49 (43%) patients, 37 (75%) patients had taken previous antimicrobial therapy, and 25% of the infections were nosocomially acquired. Overall, 25 of 49 (51%) of the pneumococcal strains tested were pencillin-resistant; strains with the highest resistance to penicillin were also resistant to cephalosporins. Twenty-two percent of all strains were considered to be multidrug-resistant. Eleven of 25 penicillin-resistant strains were identified as multidrug-resistant, i.e., to erythromycin, TMP/SMX, and chloramphenicol. Ten serotypes accounted for 88% of the isolates, the most frequent serotypes being 23F, 14, 19V, 6A, and 6B. The overall case-fatality rate was 37% (18 of 49), with most deaths occurring within 3-5 days after antibiotic therapy was initiated. There was no difference in the case fatality rate between children with penicillin-nonsusceptible and penicillin-susceptible pneumococcal infections; instead; case-fatality rate correlated with severity of illness on admission and presence of underlying disease. CONCLUSIONS: Characterizing groups at risk for invasive pneumococcal disease could aid in the development of preventive programs and increase the benefits from wide use of future conjugated vaccines.

[Clinico-microbiological characteristics of meningitis caused by penicillin-resistant Streptococcus pneumoniae]]. / Características clínico-microbiológicas de la meningitis por Streptococcus pneumoniae resistente a la penicilina.

OBJECTIVE: To evaluate the susceptibility to antibiotics of Streptococcus pneumoniae isolated from cerebrospinal fluid of children with meningitis. To describe and compare the clinical and microbiological characteristics, treatment and outcome among children infected with strains either susceptible or resistant to penicillin and cephalosporin. MATERIAL AND METHODS: A total of 38 children with pneumococcal meningitis were prospectively enrolled in the Institutional Surveillance Program for Pneumococcal Infections during 1994-1998. Clinical and laboratory data were collected by chart review. RESULTS: Of the 38 children, 24 (63%) were less than 2 years of age, 11 (28.9%) had drug-resistant S. pneumoniae, 18.4% had intermediate resistance, 10.5% high level resistance and 2.6% also showed high level resistance to cefotaxime. The only associated factors (by Fisher's exact test) associated to resistance were: previous use of antibiotics (p = 0.2), underlying disease (p < 0.001). Course of illness and clinical course were similar for children infected with penicillin or cefotaxime susceptible, vs. non-susceptible strains. CONCLUSIONS: Current levels of S. pneumoniae resistance to penicillin and cephalosporin are not associated to an increase in mortality in children with meningitis.

Determination of zinc in serum, blood, and ultrafiltrate fluid from patients on hemofiltration by graphite furnace/atomic absorption spectroscopy or flow injection analysis/atomic absorption spectroscopy.

Two methods were optimized for the determination of zinc in samples of blood, serum, and ultrafiltrate fluid from patients with chronic renal impairment undergoing hemofiltration. In the first procedure, after acid digestion of the samples, Zn in blood and serum is determined by a system coupled to flow injection analysis and atomic absorption spectroscopy. The method is rapid, automated, simple, needs small amounts of sample, and has acceptable analytical characteristics. The analytical characteristics obtained were as follows: determination range of method, 0.05-2.0 ppm of Zn; precision as coefficient of variation (CV), 5.3%; recovery, 95-105%; and detection limit (DL), 0.02 ppm. The second method is optimized for ultrafiltrate fluid because the sensitivity of the first procedure is not suitable for the levels of Zn (ppb or ng/mL) in these samples. The technique chosen was atomic absorption spectroscopy with electrothermal atomization in a graphite furnace. The analytical characteristics obtained were as follows: determination range of method, 0.3-2.0 ppb Zn; CV, 5.7%; recovery, 93-107%; and DL, 0.12 ppb. The methods were used to determine zinc in samples of blood, serum, and ultrafiltrate fluid from 5 patients with chronic renal impairment undergoing hemofiltration to discover whether there were significant differences in the zinc contents of blood, serum, and ultrafiltrate fluid after the hemofiltration process. An analysis of variance of the experimental data obtained from a randomly selected group of 5 patients showed that zinc concentrations in the ultrafiltrate fluid, venous blood, and venous serum do not vary during hemofiltration (p < 0.05), whereas in arterial blood and serum, the time factor has a significant effect.

[Sudden death syndrome in childhood. Current recommendations for its possible prevention]. / Síndrome de muerte súbita en la infancia. Recomendaciones actuales para su posible prevención.

The sudden infant death syndrome (SIDS) has a prevalence of 0.31 to 3.5 per 1000 live newborns. It has its peak between two and four months with a greater incidence in the winter season. This syndrome should be diagnosed only after a careful post-mortem examination and a review of the death scene. The babies with SIDS have physiologic differences in their autonomic nervous system when compared with control groups. These babies have a history of excessive room heating and infant bedding. In addition the position most commonly used to put these infants to bed is the prone position. Changes in the way these infants are put to bed, changing from prone to supine position, have led to a significative reduction in SIDS. In order to decrease accidental death by asphyxia, pillows filled with polysterene beads should be avoided.

[Epidemic outbreak of viral meningitis caused by type 30 ECHO virus]. / Brote epidémico de meningitis viral causado por virus ECHO tipo 30.

The clinical records of 15 children admitted to Hospital Infantile de México Federico Gómez with diagnosis of viral meningitis were reviewed. They were part of 19 patients admitted with this diagnosis during a 5 week period (March 22 to April 30, 1992) and represent a significant increase of aseptic meningitis compared with the same periods of previous years at Hospital Infantile de Mexico and in Mexico City where there is an ongoing epidemic outbreak of this entity. All the patients studied had spinal fluid findings consistent with viral meningitis and in 4 of them on ECHO virus type 30 was isolated at the Enterovirus Section of the CDC, Atlanta Georgia USA.

[Presence of a non-HLA antigen in B-lymphocytes from patients with rheumatic fever and their relatives defined using monoclonal antibodies]. / Presencia de un antígeno no-HLA en los linfocitos B de pacientes con fiebre reumática y sus familiares definido mediante anticuerpos monoclonales.

Numerous investigators have suspected that there is a genetic predisposition to rheumatic fever (RF). In this context a group of investigators at Rockefeller University have produced a monoclonal antibody that identifies an antigen present in 100% of all RF studied at that center. Using this antibody, labeled D8/17, we studied 47 patients with acute rheumatic fever and rheumatic heart disease. Of these, 39 were not receiving steroids at the of the test and 35 were positive for the marker (89.7%). The highest percentage of positive cells was seen in the probands with 34.6 +/- 13.16%, while unaffected mothers, fathers and siblings gave 24.9, 5.2 and 7.3% respectively. The control group had an average of 7.5% of positive cells. This study and previous ones, performed by the Rockefeller University group in which HLA typing was included, suggest an autosomal recessive mode of inheritance, not associated with the MHC system, for the D8/17 antigen. Rheumatic fever; non-HLA antigen in; genetic predisposition in.

[The prognosis of thrombocytopenic purpura using predictive criteria evaluation by multivariate analysis methods]. / El pronóstico de la púrpura trombocitopénica con criterios predictivos valorados con métodos de análisis multivariado.

The development of predictive systems with the resources of multivariate analysis let us to do gradually a more objective medicine. In this study we correlate a set of characteristics observed in 39 patients with thrombocytopenic purpura during the first week of medical treatment against the score of severity of the whole purpuric disorder, evaluated a the 25 week of evolution. It was accomplished with a model of multiple logistic regression of successive steps which let us to get the weights of each one of the indicants in order to predict the severity of the whole hemorrhagic diathesis. Probably the more significative indicants of severity are intracranial bleeding, profuse nasal and vaginal bleeding, profuse petechial bleeding and the presence of hematomas.

A randomized, controlled, single-blind study comparing furazolidone with trimethoprim-sulfamethoxazole in the empirical treatment of acute invasive diarrhea.

An outpatient study of 125 children with acute invasive diarrhea was conducted at the Hospital Infantil de Mexico Federico Gomez. Through a single-blind randomization, we compared the efficacy of furazolidone, 7.5 mg/kg/day (49 patients), with trimethoprim-sulfamethoxazole (TMP-SMX), 8 mg/40 mg/kg/day (52 patients), each given for 5 days. A control group of 24 patients received no antimicrobials. Stool samples were collected from all patients at the time of admission, and active drugs were administered before the stool culture results were available. At baseline, 48 of 125 patients (38.5%) had negative stool cultures. In the other patients, the most frequently isolated pathogens were Shigella sp and enteropathogenic Escherichia coli. Of the total population who completed the study 43 of 49 (87.8%) of the patients in the furazolidone group and 43 of 52 (82.7%) of the patients in the TMP-SMX group achieved clinical cure by day 3, compared with 10 of 22 (45.5%) of the patients in the control group. Day 3 cure rates were similar between groups, independent of baseline stool culture results. Of those patients who had positive stool cultures on day 1, 20 of 34 (58.8%) in the furazolidone group and 19 of 29 (65.5%) in the TMP-SMX group had negative culture results on day 6, compared with 4 of 12 (33.3%) in the control group. Overall, clinical and bacteriologic success was achieved in 31 of 49 (63%) patients treated with furazolidone and in 36 of 52 (69%) patients treated with TMP-SMX, compared with 5 of 22 (23%) patients in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial-induced diarrhoea.

In diverse parts of the world, many bacterial strains have been recognised as the causative agents of diarrhoea. Great achievements have been made in perceiving the varied mechanisms which explain their intestinal pathogenicity. These achievements include the elucidation of the 5 mechanisms of disease production by Escherichia coli, the mechanisms of action of Shigella, Salmonella, Campylobacter and Yersinia, new information about antimicrobial-associated colitis caused by Clostridium difficile and the recognition of microbes such as Aeromonas hydrophila and Pleisomonas shigelloides. Information is available on the use and indications of antimicrobial treatment in children with diarrhoea of bacterial aetiology which is proven or suspected by clinical symptomatology or simple laboratory procedures. Finally, the usefulness of oral rehydrating solutions has been appreciated in the prevention as well as in the correction of diarrhoeal dehydration.

Estudios de educacion para la salud en el ambito escolar. I. Ausentismo en 1,010 escolares y sus causas.Estudio en dos escuelas primarias del Distrito Federal / Health education studies in schools. I. Absenteeism in 1,010 schoolchildren and motives.Study in two elementary schools of the Distrito Federal

Se llevo al cabo un estudio sobre las razones de ausentismo en 1,010 escolares de dos escuelas primarias del Distrito Federal. Las enfermedades respiratorias superiores, las gastrointestinales y las exantematicas fueron las causas principales de ausentismo por enfermedad. Se analizan la utilizacion de los recursos de salud y las razones de su no utilizacion; asi como las causas de ausentismo no relacionadas con enfermedad. Se deduce que en estudio y tipo de poblacion el ausentismo no es un buen indicador de enfermedad