Department of Medicine, University of Cambridge, Cambridge, United Kingdom.
Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
PLoS Negl Trop Dis. 2023 Oct 30;17(10):e0011728. doi: 10.1371/journal.pntd.0011728. eCollection 2023 Oct.
Shigella sonnei is a pathogen of growing global importance as a cause of diarrhoeal illness in childhood, particularly in transitional low-middle income countries (LMICs). Here, we sought to determine the incidence of childhood exposure to S. sonnei infection in a contemporary transitional LMIC population, where it represents the dominant Shigella species.
Participants were enrolled between the age of 12-36 months between June and December 2014. Baseline characteristics were obtained through standardized electronic questionnaires, and serum samples were collected at 6-month intervals over two years of follow-up. IgG antibody against S. sonnei O-antigen (anti-O) was measured using an enzyme-linked immunosorbent assay (ELISA). A four-fold increase in ELISA units (EU) with convalescent IgG titre >10.3 EU was taken as evidence of seroconversion between timepoints.
A total of 3,498 serum samples were collected from 748 participants; 3,170 from the 634 participants that completed follow-up. Measures of anti-O IgG varied significantly by calendar month (p = 0.03). Estimated S. sonnei seroincidence was 21,451 infections per 100,000 population per year (95% CI 19,307-23,834), with peak incidence occurring at 12-18 months of age. Three baseline factors were independently associated with the likelihood of seroconversion; ever having breastfed (aOR 2.54, CI 1.22-5.26), history of prior hospital admission (aOR 0.57, CI 0.34-0.95), and use of a toilet spray-wash in the household (aOR 0.42, CI 0.20-0.89).
Incidence of S. sonnei exposure in Ho Chi Minh City is substantial, with significant reduction in the likelihood of exposure as age increases beyond 2 years.
宋内志贺菌作为导致儿童腹泻病的病原体，其重要性日益增加，尤其是在转型期中低收入国家（LMICs）。在此，我们旨在确定在一个代表性的转型期 LMIC 人群中，宋内志贺菌感染的儿童暴露率，该人群中宋内志贺菌是主要的志贺菌属物种。
参与者在 2014 年 6 月至 12 月之间，年龄在 12-36 个月之间，通过标准化电子问卷获得基线特征，并在两年的随访中每 6 个月收集一次血清样本。采用酶联免疫吸附试验（ELISA）检测血清针对宋内志贺菌 O 抗原（anti-O）的 IgG 抗体。采用 ELISA 单位（EU）的 4 倍增加和恢复期 IgG 滴度 >10.3 EU 作为时间点之间血清转换的证据。
共从 748 名参与者中采集了 3498 份血清样本；3170 份来自完成随访的 634 名参与者。anti-O IgG 的测定值随日历月份显著变化（p = 0.03）。估计宋内志贺菌血清发病率为每年每 10 万人 21451 例感染（95%CI 19307-23834），发病率峰值出现在 12-18 个月龄。三个基线因素与血清转化率独立相关：母乳喂养史（aOR 2.54，CI 1.22-5.26）、既往住院史（aOR 0.57，CI 0.34-0.95）和家庭使用厕所冲洗器（aOR 0.42，CI 0.20-0.89）。
胡志明市宋内志贺菌的暴露率相当高，随着年龄超过 2 岁，暴露的可能性显著降低。
