Differences between Belgian and Brazilian Group A Streptococcus Epidemiologic Landscape

Pierre Robert Smeesters,Veronique Yvette Miendje Deyi,Laurence Van Melderen,Dioclécio Campos,Anne Vergison,Eurico De Aguiar,Maurizio Del Poeta

doi:10.1371/journal.pone.0000010

Abstract

BackgroundGroup A Streptococcus (GAS) clinical and molecular epidemiology varies with location and time. These differences are not or are poorly understood.Methods and FindingsWe prospectively studied the epidemiology of GAS infections among children in outpatient hospital clinics in Brussels (Belgium) and Brasília (Brazil). Clinical questionnaires were filled out and microbiological sampling was performed. GAS isolates were emm-typed according to the Center for Disease Control protocol. emm pattern was predicted for each isolate. 334 GAS isolates were recovered from 706 children. Skin infections were frequent in Brasília (48% of the GAS infections), whereas pharyngitis were predominant (88%) in Brussels. The mean age of children with GAS pharyngitis in Brussels was lower than in Brasília (65/92 months, p<0.001). emm-typing revealed striking differences between Brazilian and Belgian GAS isolates. While 20 distinct emm-types were identified among 200 Belgian isolates, 48 were found among 128 Brazilian isolates. Belgian isolates belong mainly to emm pattern A–C (55%) and E (42.5%) while emm pattern E (51.5%) and D (36%) were predominant in Brasília. In Brasília, emm pattern D isolates were recovered from 18.5% of the pharyngitis, although this emm pattern is supposed to have a skin tropism. By contrast, A–C pattern isolates were unfrequently recovered in a region where rheumatic fever is still highly prevalent.ConclusionsEpidemiologic features of GAS from a pediatric population were very different in an industrialised country and a low incomes region, not only in term of clinical presentation, but also in terms of genetic diversity and distribution of emm patterns. These differences should be taken into account for designing treatment guidelines and vaccine strategies.

Highlights

The incidence of Group A Streptococcus (GAS) diseases vary with location and time
Invasive infections in Brasılia were associated with different emmtypes (1, 49, 80, 87, st213 and st 6735), belonging to the three different emm pattern (E (n = 4), D (n = 1) and A–C (n = 1)). This comparative study illustrates how GAS epidemiology features vary greatly in clinical and molecular aspects between two cities with different history, climate and socio-economical situation, both performed in underprivileged populations attending public hospitals
No GAS was isolated in children under 3 year-old in Brasılia, while in Brussels, the GAS prevalence was similar in the 1 to 3 year-old group and in older children [14]

Summary

Introduction

The incidence of Group A Streptococcus (GAS) diseases vary with location and time. Rheumatic fever is still a major cause of cardiovascular morbidity and mortality in developing countries [1,2], while it has become uncommon in the industrialized world. Skin infections are described at a much higher rate in developing countries than in rich western nations [3,4] These epidemiological differences are not or poorly understood. Epidemiologic features of GAS from a pediatric population were very different in an industrialised country and a low incomes region, in term of clinical presentation, and in terms of genetic diversity and distribution of emm patterns. These differences should be taken into account for designing treatment guidelines and vaccine strategies

Methods

Results

Conclusion