Background Group A Streptococcus (GAS) causes an estimated 5.2 million outpatient visits for pharyngitis annually in the United States (U.S.) with incidence peaking in winter, but the annual spatiotemporal pattern of GAS pharyngitis across the U.S. is poorly characterized. Methods We used outpatient claims data from individuals with private medical insurance between 2010-2018 to quantify GAS pharyngitis visit rates across U.S. census regions, subregions, and states. We evaluated seasonal and age-based patterns of geographic spread and the association between school start dates and the summertime upward inflection in GAS visits. Results The South had the most visits per person (yearly average 39.11 visits per 1000 people, 95% CI: 36.21-42.01), and the West had the fewest (yearly average 17.63 visits per 1000 people, 95% CI: 16.76-18.49). Visits increased earliest in the South and in school-age children. Differences in visits between the South and other regions were most pronounced in the late summer through early winter. Visits peaked earliest in central southern states, in December to January, and latest on the coasts, in March. The onset of the rise in GAS pharyngitis visits correlated with, but preceded, average school start times. Conclusions The burden and timing of GAS pharyngitis varied across the continental U.S., with the South experiencing the highest overall rates and earliest onset and peak in outpatient visits. Understanding the drivers of these regional differences in GAS pharyngitis will help in identifying and targeting prevention measures.

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美国 A 组链球菌性咽炎的时空趋势

背景 在美国，A 组链球菌 (GAS) 每年导致约 520 万人次咽炎门诊就诊，发病率在冬季达到高峰，但美国各地 GAS 咽炎的年度时空模式尚不清楚。方法 我们使用 2010 年至 2018 年间拥有私人医疗保险的个人的门诊索赔数据来量化美国人口普查区域、次区域和州的 GAS 咽炎就诊率。我们评估了地理分布的季节性和年龄模式，以及开学日期和夏季 GAS 访问量上升趋势之间的关联。结果 南方人均访问次数最多（年均每千人 39.11 次访问，95% CI：36.21-42.01），西部人均访问次数最少（年均每千人 17.63 次访问，95% CI：16.76-18.49） 。南部地区和学龄儿童的就诊次数增加最早。南方和其他地区的访问量差异在夏末至初冬期间最为明显。中南部各州的旅游高峰最早出现在 12 月至 1 月，沿海地区最晚出现在 3 月。GAS 咽炎就诊次数的增加与平均开学时间相关，但先于平均开学时间。结论 美国大陆各地 GAS 咽炎的负担和发生时间各不相同，南部地区的总体发病率最高，发病最早，门诊就诊高峰。了解气体性咽炎这些区域差异的驱动因素将有助于确定和制定预防措施。