Background

This analysis investigated longitudinal changes in meningococcal carriage in adolescents in South Australia over 4 years.

Methods

Data from the “B Part of It” study, which included a state-wide cluster randomized controlled trial in secondary-school students (n = 34,489 in 2017 and 2018) and serial cross-sectional studies in school leavers aged 17–25 years (n = 4028 in 2019-2020). Individuals had oropharyngeal swabs collected annually. This study included two unique cohorts: (1) individuals enrolled in 2019, with three consecutive annual swabs taken in 2017, 2018 and 2019; and (2) individuals enrolled in 2020, with swabs taken in 2017, 2018, and 2020. Disease-associated N. meningitidis genogroups were identified using PCR and whole genome sequencing. Univariate analysis identified risk factors for recurrent carriage (≥2).

Results

Among school leavers, 50 (1.7%, total n = 2980) had carriage detected at successive visits. In participants with meningococcal carriage at successive visits, 38/50 (76.0%) had the same genogroup detected by porA PCR. Of those, 19 had the same MLST type and demonstrated minimal variation, indicating they most likely had sustained carriage of the same isolate (range 226 to 490 days, mean duration 352 [SD 51] days). In the 2019 school leaver cohort, 6.7% acquired carriage in their first year out of school compared to 3.3% in their final school year. Compared to single carriage detection, recurrent carriage was potentially more likely in older adolescents (16 compared to ≤15 years; OR = 1.97 (95%CI 1.0, 3.86); p = 0.048).

Conclusion

Whilst carriage is typically transient, some adolescents/young adults may have persistent carriage and are likely to be an important group in the transmission of meningococci.

中文翻译：

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2017-2020 年南澳大利亚青少年和年轻人脑膜炎球菌携带情况的纵向研究

背景

该分析调查了 4 年来南澳大利亚青少年脑膜炎球菌携带情况的纵向变化。

方法

数据来自“B Part of It”研究，其中包括一项针对中学生的全州整群随机对照试验（2017 年和 2018 年，n = 34,489 名）以及针对 17-25 岁离校生的系列横断面研究（ 2019-2020 年 n = 4028）。每年收集个人口咽拭子。这项研究包括两个独特的队列：(1) 2019 年入组的个体，在 2017 年、2018 年和 2019 年连续三年进行年度拭子采集； (2) 2020 年入组的个体，在 2017 年、2018 年和 2020 年采集了拭子。使用 PCR 和全基因组测序鉴定了与疾病相关的脑膜炎奈瑟氏球菌基因组。单变量分析确定了反复携带的危险因素（≥2）。

结果

在离校生中，有 50 人（1.7%，总数 = 2980 人）在连续访问中被检测出携带物品。在连续就诊时携带脑膜炎球菌的参与者中，38/50 (76.0%) 的porA PCR检测到相同的基因组。其中，19 个具有相同的 MLST 类型，并且表现出最小的变异，表明它们很可能持续携带相同的分离株（范围为 226 至 490 天，平均持续时间为 352 [SD 51] 天）。在 2019 年离校生群体中，6.7% 的人在离开学校的第一年获得了马车，而在最后一个学年这一比例为 3.3%。与单次携带检测相比，年龄较大的青少年中复发携带的可能性更大（16岁与≤15岁相比；OR = 1.97 (95%CI 1.0, 3.86)；p = 0.048）。

结论

虽然携带通常是短暂的，但一些青少年/年轻人可能会持续携带，并且可能是脑膜炎球菌传播的重要群体。