Factors associated with Group A Streptococcus emm type diversification in a large urban setting in Brazil: a cross-sectional study.

BACKGROUND: Group A Streptococcus (GAS) strain diversity varies across different regions of the world, according to low versus high-income countries. These differences may be related to geographic, environmental, socioeconomic, or host-related factors. However, local factors may also affect strain diversity. We compared the emm types of GAS isolates from children with and without sore throat in one large urban setting in Brazil. METHODS: Children 3-15 years of age were consecutively recruited from slum and non-slum pediatric outpatient clinics between April-October, 2008. Throat cultures were performed and data intake forms were completed. GAS isolates were typed by emm sequencing. RESULTS: From 2194 children, 254 (12%) GAS isolates were obtained. Of 238 GAS isolates that were emm-typed, 61 unique emm types were identified. Simpson's diversity index of the emm types was higher among isolates from slum children [97% (96%-98%)] than those of non-slum children [92% (89%-96%)]. Two emm types (66.0, 12.0) were more frequently isolated from children with sore throat (p < 0.05), and one emm type (27G.0) demonstrated a protective effect. CONCLUSIONS: The emm type diversity from children attending slum clinics resembled the emm diversity of low income countries rather than that of children attending a non-slum clinic in the same city. Local factors, such as crowding, may enhance the frequency of GAS transmission and horizontal gene transfers that contribute to increased strain diversity in the slums. GAS vaccine coverage and control of GAS infections will need to take these local factors and strain differences into consideration.

Apneia obstrutiva do sono em portadores da anemia falciforme / Obstructive sleep apnea in sickle cell disease carriers

A Síndrome da Apneia Obstrutiva do Sono (SAOS) é definida como episódios recorrentes de obstrução completa ou parcial das vias aéreas superiores que ocorrem durante o sono. O fluxo aéreo pode estar diminuído ou completamente interrompido, a despeito do esforço inspiratório, resultando em episódios intermitentes de hipoxemia, hipercapnia. A presença de SAOS poderá ser um fator de piora da hipoxemia noturna, da doença de base, concorrendo para ocorrência de síndrome torácica aguda. Com o objetivo de revisar dados sobre a fisiopatologia da SAOS em crianças e adolescentes portadores de anemia falciforme, foi realizada busca eletrônica de artigos no Medline e Lilacs nos últimos dez anos, bem como referências cruzadas dos artigos encontrados. Palavras-chaves: "sleep apnea, sickle cell anemia, sickle cell disease, pathophysiology ". Estudos sugerem que a SAOS pode potencializar o quadro clínico, ou seja, as crises álgicas, déficit de estatura, de peso, cognitivo e de inteligência, dessaturação arterial noturna, e acidente vascular cerebral das crianças portadoras de anemia falciforme. Rev. Bras. Hematol. Hemoter.

Obstructive Sleep Apnea Syndrome (OSAS) is defined as recurrent episodes of complete or partial obstruction of the upper airway during sleep. The airflow can be reduced or completely stopped despite of inspiratory effort, resulting in intermittent episodes of hypoxemia and hypercapnia. OSAS may be a factor in the worsening of nocturnal hypoxemia, of the underlying disease, leading to acute chest syndrome. The aim of this work was to review data on the pathophysiology of OSAS in children and adolescents with sickle cell anemia. We revisited articles published over the last ten years linked to the Medline and Lilacs databases, as well as cross-referencing using these articles. The following keywords were used: sleep apnea, obstructive sleep apnea, sickle cell anemia, sickle cell disease. Studies suggest that OSAS may increase clinical complications, such as painful crises, delayed growth, cognitive and intelligence disorders, nocturnal arterial desaturation and strokes in children with sickle cell anemia. Studies suggest that OSAS may increase the clinical complications of children with sickle cell anemia. Rev. Bras. Hematol. Hemoter.