Spatial exploration of Streptococcus pneumoniae clonal clustering in São Paulo, Brazil

OBJECTIVES: To examine the spatial distribution of Streptococcus pneumoniae and its clonal patterns collected between 2002 and 2006 in São Paulo, Brazil. METHODS: As part of an observational study in São Paulo city, Brazil, S. pneumoniae isolates routinely cultured from blood, respiratory specimens, or cerebrospinal and other profound fluids were selected. Additionally, only isolates with either penicillin (PEN) intermediate (I) or resistant (R) status on routine antibiogram were included, in order to obtain a higher probability of clonal isolates. A single I/R S. pneumoniae isolate per patient was included and submitted to genotypic determination by pulsed field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) were determined for the isolates by Etest® to PEN and other antimicrobials. Each isolate was geocoded in a digital map. The Kernel function and ratio methods between total isolates vs. clones were used in order to explore possible cluster formations. RESULTS: Seventy-eight (78) S. pneumoniae community isolates from two major outpatient centers in São Paulo, Brazil, were selected from the databank according to their penicillin susceptibility profile, i.e. R or I to penicillin assessed by oxacillin disc diffusion. Of these, 69 were submitted to PFGE, 65 to MIC determination, and 48 to spatial analytical procedures. Preliminary spatial analysis method showed two possible cluster formation located in southwest and southeast regions of the city. CONCLUSION: Further analyses are required for precisely determining the existence of S. pneumoniae clusters and their related risk factors. Apparently there is a specific transmission pattern of S. pneumoniae clones within certain regions and populations. GIS and spatial methods can be applied to better understand epidemiological patterns and to identify target areas for public health interventions.

Prevalence of upper respiratory tract infections at a tertiary care hospital in the city of São Paulo / Prevalência das infecções de vias aéreas superiores em um hospital terciário na cidade de São Paulo

Objective: To evaluate the prevalence of pathogens in the upper respiratory tract according to age at a tertiary care hospital in the city of São Paulo. Methods: A total of 6,144 biological material tests from upper respiratory airways were analyzed: 740 bacterial cultures, 726 virus screenings and 4,678 rapid tests for S. pyogenes. Results: The most frequently found etiological agent was respiratory syncytial virus (29.6%; 215/726). The main agents detected per age groups were: respiratory syncytial virus (25.34%; 184/726) in patients aged 28 days-3 years; S. pyogenes (9.5%; 70/740) in 3-12 year-old children; influenza virus (8.8%; 64/726) in adults (18-59 years). Conclusions: The etiologic agents of upper respiratory infections vary according to age and imply diverse clinical and therapeutic management.

Objetivo: Avaliar a prevalência de patógenos das vias aéreas superiores em relação à faixa etária de pacientes atendidos em um hospital terciário da cidade de São Paulo. Métodos: Foram analisados 6.144 exames de materiais biológicos provenientes das vias aéreas superiores, sendo 740 de cultura bacteriana, 726 de triagem de vírus e 4.678 provas rápidas para S. pyogenes. Resultados: O agente etiológico com maior frequência nas infecções de vias aérea superiores foi o vírus sincicial respiratório, com 29,6% (215/726). Os principais agentes detectados por faixa etária foram: vírus sincicial respiratório em 25,34% (184/726) dos exames de pacientes com faixa etária entre 28 dias a 3 anos; S. pyogenes, com 9,5% (70/740) na fase da infância (3 a 12 anos); vírus influenza, com 8,8% (64/726) detectados na fase adulta (18 a 59 anos). Conclusões: Os agentes etiológicos das infecções de vias aéreas superiores variam de acordo com a faixa etária do paciente, o que resulta em uma conduta clínica e laboratorial diferenciada.