Complicaciones del cateterismo vesical realizado en un servicio de urgencias para obtener una muestra de orina / Complications of bladder catheterization to obtain a urine sample in the emergency department

Introducción: El cateterismo vesical (CV) es una técnica utilizada con frecuencia para diagnosticar infecciones urinarias (ITU) (infección bacteriana invasora más frecuente de los lactantes) en los niños no continentes. El objetivo principal de este estudio es conocer el rendimiento y las complicaciones del CV transitorio para obtener una muestra de orina. Material y mé todos: Se ha realizado un estudio prospectivo de los pacientes sometidos a CV entre el 1 de noviembre de 2009 y el 15 de diciembre de 2009 en el servicio de urgencias (SU) de un hospital terciario. Además de recoger los datos epidemiológicos y el motivo de consulta que motivó el CV, se contactó por teléfono con la familia al menos un mes después, para conocer las complicaciones. Resultados: Se realizaron 126 procedimientos en 124 pacientes, 45 varones (35,7%) y 81 mujeres (64,3%). Se obtuvo muestra de orina en todos los casos. La mediana de edad fue de 7 meses (5 días-35 meses). De los 126 urocultivos recogidos, resultaron positivos 34 (26,98%), siendo el patógeno más frecuente la Escherichia coli (27; 79,41%). Se consideró contaminado 1 cultivo (0,8%). La fiebre (76,2%) fue el principal motivo de consulta que estableció la indicación del CV. Las complicaciones de los 116 pacientes con los que se contactó por teléfono fueron: dolor referido al área genital (3), hematuria no confirmada (1) e ITU 12 días después (1). Conclusiones: El CV transitorio para obtener una muestra de orina en los niños no continentes es efectivo y seguro. El CV es una técnica invasora que necesita controles de calidad (AU)

Introduction: Bladder catheterization (BC) is frequently performed to diagnose urinary tract infection (UTI) (the most common serious bacterial infection among young children). The purposes of this study were to evaluate performance and complications of BC to obtain a urine specimen. Material and methods: This was a prospective study conducted in an urban childrenŒs hospital on patients who had a urine specimen obtained in the emergency department (ED) by BC between November 1, 2009 and December 15, 2009. Epidemiological data and the medical reasons why the BC was performed were reviewed. Finally, to determine the complications we contacted the family by telephone at least one month after the BC. Results: A total of 126 BC were performed in 124 patients, 45 males (35.7%) and 81 female (64.3%). A urine sample was obtained in all cases. The median age was 7 months (5 days-35 months). Of the 126 urine cultures collected, 34 were positive (26.98%) and 1 was considered contaminated (0.8%). Escherichia coli was the most common pathogen (27, 79.41%). Fever (76.2%) was the main reason why BC was performed in children. Of the 116 patients contacted by telephone, only 5 mentioned complications: genital pain (3), unconfirmed hematuria (1) and UTI 12 days after (1). Conclusions: BC performed in ED to obtain a urine sample in non toilet-trained children is effective and safe. BC is an invasive method which needs to be quality controlled (AU)

Identification of Trypanosoma cruzi zymodemes by kinetoplast DNA probes.

Analysis of zymograms of extracts of Trypanosoma cruzi isolated from different hosts in Argentina allowed characterization of 12 zymodemes or "isozymic strains," only six of which were found in human patients. Two of these six zymodemes (Z1 and Z12) were widely distributed and found in more than 80% of human patients. These two "major natural clones" differed significantly in pathogenic activity. Because the groupings obtained by studying enzymes and kinetoplast DNA (kDNA) were similar, it is possible to identify the zymodeme by analyzing kDNA. A 290-bp fragment was amplified by PCR using primers for the sequences flanking the hypervariable regions of kDNA minicircles. Labeled probes for this fragment, prepared from Z1 and Z12 reference stocks, hybridized specifically with PCR-amplified kDNA from parasite stocks, allowing identification of zymodemes.

Characterization of Trypanosoma cruzi populations by zymodemes: correlation with clinical picture.

Trypanosoma cruzi isolated from 55 chronic chagasic patients were grouped into isozymic strains on the basis of electrophoretic patterns for a set of six enzymes. The total sample showed a distribution of asymptomatic (63.6%) and clinically ill (36.4%) patients similar to that generally reported for Chagas' disease. Six of the 12 zymodemes known to exist in Argentina have been isolated from humans. Only two (Z1 and Z12) are frequent and widely distributed in the endemic area. These two zymodemes differ significantly in their pathogenicity. The proportion of asymptomatic patients was higher with the Z1 zymodeme (81.1%) than with the Z12 zymodeme (27.3%). The incidence of heart alterations was lower in Z1 than in Z12 zymodeme patients (18.9% versus 72.7%). Clinically evident acute disease was seen in 36.3% of cases with zymodeme Z12 and in 8.1% of cases with zymodeme Z1. The differences between the two prevalent zymodemes in Argentina are statistically significant. These observations indicate that the Z1 T. cruzi is a more benign strain than Z12. Patients infected with Z1 would be more likely to be asymptomatic for a longer time than those infected with Z12. The risk of cardiac lesion would be greater for patients harboring Z12 T. cruzi than for those with Z1. The results suggest that strain identification could be a useful prognostic tool.

Genetic structure of Trypanosoma cruzi populations from Argentina estimated from enzyme polymorphism.

Isolates of Trypanosoma cruzi from human patients, domestic and sylvatic animals and vector insects were obtained in different areas of Argentina. Electrophoretic patterns of enzymes from extracts of 95 isolates were analysed. On the basis of zymograms providing information on 10 loci, 12 zymodemes are described according to their genotypes. Data presented show fixed heterozygosity, absence of segregation of genotypes, significant departures from Hardy-Weinberg equilibrium, and over-represented genotypes. This evidence supports the hypothesis that sexual reproduction is very restricted or absent in this parasite. The proportion of polymorphic loci is 80%. The expected mean heterozygosity per locus (He) is 0.43, while the observed value (Ho) is 0.24. Differences between these values may be explained by accepting a basically clonal structure for T. cruzi. The data matrix of 12 zymodemes using 28 characters was analysed using a Wagner parsimony algorithm. Two equally most parsimonious unrooted trees were generated; both have 39 steps. The results show clusters clearly separated according to the geographical origin of the stocks. There are some indications of some correlations between genetic composition of the parasite and the clinical picture of the infection in human patients.

Characterization of Trypanosoma cruzi from Argentina by electrophoretic zymograms.

Polyacrylamide gel electrophoretic patterns for six enzymes in 73 isolates and 38 clones of Trypanosoma cruzi from different areas of Argentina were classified into 12 zymodemes. The isolates were obtained from human patients with acute, chronic or congenital Chagas' disease, vector insects, domestic and sylvatic animals. Two out of 8 isolates cloned were shown to be heterogeneous. Zymodemes 1 and 12 exhibit widespread geographic distribution; isolates belonging to both zymodemes account for 55% of the total analyzed. The other zymodemes are not widely geographically dispersed. Although there is a clear predominance of zymodeme 1 among asymptomatic patients, the data do not show a clear relationship between particular zymodemes and the clinical picture. The results suggest that the sylvatic and domestic transmission cycles overlap. This remarkable heterogeneity of T. cruzi in Argentina supports the possible multiclonal origin of these parasite populations.

Establishment of a mosquito cell line from Haemagogus equinus larvae.

The establishment and characterization of a Haemagogus equinus mosquito cell line (GML-HE-12) are described. The cells are diploid (2N = 6) and seem to be free of contaminants. Their susceptibility to 13 arboviruses was tested. Eleven of the viruses multiplied in this cell line; six of these viruses still showed titers of 4 log10 plaque forming unit/ml or greater at 33 d postinoculation. No overt cytopathologic effect was observed.

Seroepidemiology of heat-labile enterotoxigenic Escherichia coli and Norwalk virus infections in Panamanians, Canal Zone residents, Apache Indians, and United States Peace Corps volunteers.

Serum antibody titrations against the heat-labile enterotoxin (LT) of Escherichia coli were carried out on Panamanians, U.S. citizens resident in the Panama Canal Zone, Apache Indians living on the reservation in Whiteriver, Arizona, and Peace Corps volunteers before they traveled overseas. Antibody titers to Norwalk virus were also carried out on serum from Panamanian and Canal Zone residents. A high prevalence of low-titer LT antibodies was found in infants and adults from Panama, the Canal Zone, and Whiteriver. Panamanian children aged 1 to 5 years had the highest LT antibody titers. Peace Corps volunteers had a low prevalence and titer of LT antibodies. Prevalence and titer of antibodies to Norwalk virus were generally higher in Panamanians compared with Canal Zone residents of the same age. In the populations we studied, various modes of transmission and mechanisms of immunity likely explain the differences which we observed in antibody prevalence and titer to these two enteric pathogens.

Venezuelan equine encephalitis virus: horse virulence of P-676 and MF-8 small and minute plaques.

The P-676 and MF-8 epizootic strains of Venezuelan equine encephalitis (VEE) virus were found to contain a minute plaque (MP), different from the predominant small plaque (SP) present in these virus strains. The MP and SP were stable after passages in Vero cells, mice, or horses. Equines were inoculated with the SP or MP of the P-676 and MF-8 strains. Inoculation of either P-676 SP or MP into horses induced high fever and viremia but no signs of encephalitis or death. Four horses infected with MF-8 SP became very ill, with high fever and viremia; three of the inoculated animals died. Four horses were infected with MF-8 MP; only showed viremia but appeared asymptomatic and afebrile. Neutralization tests with immune sera from the infected equines showed that the P-676 SP and MP appear distinct, while a clear difference cannot be observed with MF-8 SP and MP.

Presencia de anticuerpos contra la rubeola en comunidades urbanas y rurales de Panama, y evaluacion de los resultados de pruebas de neutralizacion e inhibicion de la hemaglutinacion. / Presence of rubella antibodies in urban and rural communities of Panama and evaluation of the results of neutralization and hemagglutination inhibition tests

Empleando la prueba de neutralizacion por reduccion de placas se encontro que en la poblacion de Coclesito, una comunidad rural de Panama, habia un 83% de mujeres susceptibles al virus rubeola mientras que en el area urbana de San Miguelito solo el 30% de las mujeres eran susceptibles. Una comparacion entre las pruebas de inhibicion de la hemaglutinacion y la de neutralizacion revelo que la prueba de inhibicion de la hemaglutinacion es tan sensible y confiable como la de neutralizacion, por lo cual se recomienda como metodo para la determinacion de anticuerpos en los laboratorios clinicos