Public Health Department, Greater Chennai Corporation, Chennai, Tamil Nadu, India.
Division of Noncommunicable Diseases, ICMR-National Institute of Epidemiology, Chennai, Tamil Nadu, India.
PLoS One. 2021 Sep 24;16(9):e0257739. doi: 10.1371/journal.pone.0257739. eCollection 2021.
Government of Tamil Nadu, India, mandated the face mask wearing in public places as one of the mitigation measures of COVID-19. We established a surveillance system for monitoring the face mask usage. This study aimed to estimate the proportion of the population who wear face masks appropriately (covering nose, mouth, and chin) in the slums and non-slums of Chennai at different time points.
We conducted cross-sectional surveys among the residents of Chennai at two-time points of October and December 2020. The sample size for outdoor mask compliance for the first and second rounds of the survey was 1800 and 1600, respectively, for each of the two subgroups-slums and non-slums. In the second round, we included 640 individuals each in the slums and non-slums indoor public places and 1650 individuals in eleven shopping malls. We calculated the proportions and 95% confidence interval (95%CI) for the mask compliance outdoors and indoors by age, gender, region, and setting (slum and non-slum).
We observed 3600 and 3200 individuals in the first and second surveys, respectively, for outdoor mask compliance. In both rounds, the prevalence of appropriate mask use outdoors was significantly lower in the slums (28%-29%) than non-slum areas (36%-35%) of Chennai (p<0.01). Outdoor mask compliance was similar within slum and non-slum subgroups across the two surveys. Lack of mask use was higher in the non-slums in the second round (50%) than in the first round of the survey (43%) (p<0.05). In the indoor settings in the 2nd survey, 10%-11% among 1280 individuals wore masks appropriately. Of the 1650 observed in the malls, 947 (57%) wore masks appropriately.
Nearly one-third of residents of Chennai, India, correctly wore masks in public places. We recommend periodic surveys, enforcement of mask compliance in public places, and mass media campaigns to promote appropriate mask use.
印度泰米尔纳德邦政府规定在公共场所佩戴口罩是 COVID-19 缓解措施之一。我们建立了一个监测系统来监测口罩使用情况。本研究旨在不同时间点估计钦奈贫民窟和非贫民窟居民正确佩戴口罩（覆盖鼻子、嘴巴和下巴）的人口比例。
我们在 2020 年 10 月和 12 月两个时间点对钦奈居民进行了横断面调查。第一轮和第二轮调查中，户外口罩合规性的样本量分别为贫民窟和非贫民窟亚组各 1800 人和 1600 人。在第二轮中，我们在贫民窟和非贫民窟的室内公共场所各纳入 640 人，在 11 家购物中心纳入 1650 人。我们按年龄、性别、地区和地点（贫民窟和非贫民窟）计算了户外和室内口罩佩戴情况的比例和 95%置信区间（95%CI）。
我们分别在第一轮和第二轮调查中观察到 3600 人和 3200 人户外口罩合规性。两轮调查中，贫民窟户外口罩正确使用率（28%-29%）均明显低于非贫民窟地区（36%-35%）（p<0.01）。两轮调查中，贫民窟和非贫民窟亚组的户外口罩佩戴情况相似。第二轮非贫民窟地区未佩戴口罩的比例（50%）高于第一轮（43%）（p<0.05）。第二轮室内调查中，1280 名参与者中有 10%-11%的人正确佩戴了口罩。在观察到的 1650 名购物中心顾客中，947 人（57%）正确佩戴了口罩。
印度钦奈近三分之一的居民在公共场所正确佩戴了口罩。我们建议定期进行调查、加强公共场所的口罩佩戴监管，并通过大众媒体宣传活动来推广正确佩戴口罩。
