2017-18 年印度 5-17 岁儿童对白喉的免疫状况：一项基于人群的横断面血清学调查。

Immunity against diphtheria among children aged 5-17 years in India, 2017-18: a cross-sectional, population-based serosurvey.

机构信息

Indian Council of Medical Research (ICMR) National Institute of Epidemiology, Chennai, India.

出版信息

Lancet Infect Dis. 2021 Jun;21(6):868-875. doi: 10.1016/S1473-3099(20)30595-8. Epub 2021 Jan 21.

DOI:10.1016/S1473-3099(20)30595-8

PMID:33485469

Abstract

BACKGROUND

Diphtheria is re-emerging as a public health problem in several Indian states. Most diphtheria cases are among children older than 5 years. In this study, we aimed to estimate age-specific immunity against diphtheria in children aged 5-17 years in India.

METHODS

We used residual serum samples from a cross-sectional, population-based serosurvey for dengue infection done between June 19, 2017, and April 12, 2018, to estimate the age-group-specific seroprevalence of antibodies to diphtheria in children aged 5-17 years in India. 8309 serum samples collected from 240 clusters (122 urban and 118 rural) in 60 selected districts of 15 Indian states spread across all five geographical regions (north, northeast, east, west, and south) of India were tested for the presence of IgG antibodies against diphtheria toxoid using an ELISA. We considered children with antibody concentrations of 0·1 IU/mL or greater as immune, those with levels less than 0·01 IU/mL as non-immune (and hence susceptible to diphtheria), and those with levels in the range of 0·01 to less than 0·1 IU/mL as partially immune. We calculated the weighted proportion of children who were immune, partially immune, and non-immune, with 95% CIs, for each geographical region by age group, sex, and area of residence (urban vs rural).

FINDINGS

29·7% (95% CI 26·3-33·4) of 8309 children aged 5-17 years were immune to diphtheria, 10·5% (8·6-12·8) were non-immune, and 59·8% (56·3-63·1) were partially immune. The proportion of children aged 5-17 years who were non-immune to diphtheria ranged from 6·0% (4·2-8·3) in the south to 16·8% (11·2-24·4) in the northeast. Overall, 9·9% (7·7-12·5) of children residing in rural areas and 13·1% (10·2-16·6) residing in urban areas were non-immune to diphtheria. A higher proportion of girls than boys were non-immune to diphtheria in the northern (17·7% [12·6-24·2] vs 7·1% [4·1-11·9]; p=0·0007) and northeastern regions (20·0% [12·9-29·8] vs 12·9% [8·6-19·0]; p=0·0035).

INTERPRETATION

The findings of our serosurvey indicate that a substantial proportion of children aged 5-17 years were non-immune or partially immune to diphtheria. Transmission of diphtheria is likely to continue in India until the immunity gap is bridged through adequate coverage of primary and booster doses of diphtheria vaccine.

FUNDING

Indian Council of Medical Research.

摘要

背景

白喉在印度的几个邦再次成为公共卫生问题。大多数白喉病例发生在 5 岁以上的儿童中。在这项研究中，我们旨在估计印度 5-17 岁儿童对白喉的年龄特异性免疫力。

方法

我们使用了 2017 年 6 月 19 日至 2018 年 4 月 12 日进行的基于人群的登革热血清学横断面调查的剩余血清样本，以估计印度 5-17 岁儿童对白喉的年龄组特异性血清抗体流行率。在印度 15 个邦的 60 个选定地区的 240 个群集中（122 个城市和 118 个农村）收集了 8309 个血清样本，使用 ELISA 检测针对白喉类毒素的 IgG 抗体。我们认为抗体浓度为 0.1 IU/ml 或更高的儿童具有免疫力，浓度低于 0.01 IU/ml 的儿童无免疫力（因此易患白喉），浓度在 0.01 至低于 0.1 IU/ml 之间的儿童具有部分免疫力。我们按年龄组、性别和居住地区（城市与农村）计算了每个地理区域内免疫、部分免疫和无免疫力的儿童的加权比例（95%CI）。

结果

8309 名 5-17 岁儿童中，有 29.7%（95%CI 26.3-33.4）对白喉具有免疫力，10.5%（8.6-12.8）无免疫力，59.8%（56.3-63.1）具有部分免疫力。5-17 岁儿童对白喉无免疫力的比例在南部为 6.0%（4.2-8.3），在东北部为 16.8%（11.2-24.4）。总体而言，9.9%（7.7-12.5）的农村地区儿童和 13.1%（10.2-16.6）的城市地区儿童对白喉无免疫力。北部（17.7%[12.6-24.2]比 7.1%[4.1-11.9]；p=0.0007）和东北部（20.0%[12.9-29.8]比 12.9%[8.6-19.0]；p=0.0035）的女孩比男孩更有可能对白喉无免疫力。