Martin Judith M, Green Michael, Barbadora Karen A, Wald Ellen R
Department of Pediatrics, Division of Allergy, Immunology, and Infectious Diseases, Children's Hospital of Pittsburgh, 3705 Fifth Ave, Pittsburgh, PA 15213, USA.
Pediatrics. 2004 Nov;114(5):1212-9. doi: 10.1542/peds.2004-0133.
A 4-year longitudinal study of school-aged children was conducted to describe the clinical characteristics and epidemiologic features of infections with group A streptococci (GAS).
Between 1998 and 2002, surveillance throat cultures were performed twice per month (October to May) for a cohort of elementary school children in Pittsburgh, Pennsylvania. In addition, throat cultures were obtained during any respiratory illness. Erythromycin and clindamycin susceptibility testing was performed for all isolates. Molecular typing was performed with field-inversion gel electrophoresis. Representative isolates from each field-inversion gel electrophoresis group were emm typed. Strict definitions were used to characterize each GAS infection. Children were classified into 4 categories each year, ie, single episode, recurrent episodes, carriers of GAS, and no infections.
A total of 48 to 100 children per year were studied for 4 years; 61 (49%) were male. The mean age was 9.6 years (range: 5-15 years). A total of 5658 throat cultures were performed; 878 (15.5%) were positive for GAS. Antimicrobial agents were used to treat 209 episodes of infection. Thirteen emm types were observed during the 4-year period. GAS were isolated most often from children who were carriers; isolates from single episodes were next most common. Children carried a single emm type for a mean of 10.8 weeks (range: 3-34 weeks). Carriers were likely to be classified again as carriers in subsequent years and frequently switched emm types. Sixty-two percent of the children had > or =1 year with no infections.
GAS infections are common among school-aged children. The majority of positive throat cultures observed in this longitudinal study were obtained from children who were carriers of GAS. Carriers switched emm types but tended to become carriers repeatedly during the study. Practitioners should consider treating children known to be GAS carriers when they develop a new illness that is consistent with streptococcal pharyngitis, because they may acquire new emm types and be at risk for rheumatic heart disease.
开展一项针对学龄儿童的4年纵向研究，以描述A组链球菌（GAS）感染的临床特征和流行病学特征。
1998年至2002年期间，对宾夕法尼亚州匹兹堡的一群小学生，每月（10月至5月）进行两次监测性咽拭子培养。此外，在任何呼吸道疾病期间都采集咽拭子培养。对所有分离株进行红霉素和克林霉素药敏试验。采用场反转凝胶电泳进行分子分型。对每个场反转凝胶电泳组的代表性分离株进行emm分型。使用严格的定义来描述每种GAS感染。儿童每年被分为4类，即单次发作、复发、GAS携带者和无感染。
4年中每年共研究48至100名儿童；61名（49%）为男性。平均年龄为9.6岁（范围：5至15岁）。共进行了5658次咽拭子培养；878次（15.5%）GAS检测呈阳性。209次感染发作使用了抗菌药物治疗。4年期间观察到13种emm型。GAS最常从携带者儿童中分离出来；单次发作分离株其次常见。儿童携带单一emm型的平均时间为10.8周（范围：3至34周）。携带者在随后几年中很可能再次被分类为携带者，并且经常更换emm型。62%的儿童有≥1年无感染。
GAS感染在学龄儿童中很常见。在这项纵向研究中观察到的大多数阳性咽拭子培养来自GAS携带者儿童。携带者更换了emm型，但在研究期间往往反复成为携带者。当已知为GAS携带者的儿童出现与链球菌性咽炎相符的新疾病时，从业者应考虑对其进行治疗，因为他们可能获得新的emm型并面临风湿性心脏病的风险。
