Karumanagoundar Kolandaswamy, Raju Mohankumar, Ponnaiah Manickam, Kaur Prabhdeep, Viswanathan Vidhya, Rubeshkumar Polani, Sakthivel Manikandanesan, Shanmugiah Porchelvan, Ganeshkumar Parasuraman, Muthusamy Santhosh Kumar, Sendhilkumar Muthappan, Venkatasamy Vettrichelvan, Sambath Irene, Ilangovan Kumaravel, Murugesan Jagadeesan, Govindarajan Rameshkumar, Shanmugam Soundammal, Rajarathinam Selvakumar, Suresh Kst, Varadharajan M, Thiagarajan Manivannan, Jagadeeshkumar K, Ganesh Velmurugan, Kumar Sateesh, Venkatesan Prakash, Nallathambi Yogananth, Palani Sampath, Selvavinayagam T S, Reddy Madhusudhan, Rajesh Beela, Murhekar Manoj V
Directorate of Public Health and Preventive Medicine, Chennai, India.
ICMR - National Institute of Epidemiology, Chennai, India
BMJ Open. 2021 Nov 5;11(11):e051491. doi: 10.1136/bmjopen-2021-051491.
To describe the characteristics of contacts of patients with COVID-19 case in terms of time, place and person, to calculate the secondary attack rate (SAR) and factors associated with COVID-19 infection among contacts.
A retrospective cohort study SETTING AND PARTICIPANTS: Contacts of cases identified by the health department from 14 March 2020to 30 May 2020, in 9 of 38 administrative districts of Tamil Nadu. Significant proportion of cases attended a religious congregation.
Attack rate among the contacts and factors associated with COVID-19 positivity.
We listed 15 702 contacts of 931 primary cases. Of the contacts, 89% (n: 14 002) were tested for COVID-19. The overall SAR was 4% (599/14 002), with higher among the household contacts (13%) than the community contacts (1%). SAR among the contacts of primary cases with congregation exposure were 5 times higher than the contacts of non-congregation primary cases (10% vs 2%). Being a household contact of a primary case with congregation exposure had a fourfold increased risk of getting COVID-19 (relative risk (RR): 16.4; 95% CI: 13 to 20) than contact of primary case without congregation exposure. Among the symptomatic primary cases, household contacts of congregation primaries had higher RR than household contacts of other cases ((RR: 25.3; 95% CI: 10.2 to 63) vs (RR: 14.6; 95% CI: 5.7 to 37.7)). Among asymptomatic primary case, RR was increased among household contacts (RR: 16.5; 95% CI: 13.2 to 20.7) of congregation primaries compared with others.
Our study showed an increase in disease transmission among household contacts than community contacts. Also, symptomatic primary cases and primary cases with exposure to the congregation had more secondary cases than others.
从时间、地点和人员方面描述新型冠状病毒肺炎（COVID-19）病例密切接触者的特征，计算二代发病率（SAR）以及密切接触者中与COVID-19感染相关的因素。
一项回顾性队列研究
2020年3月14日至5月30日期间，泰米尔纳德邦38个行政区中的9个行政区内，由卫生部门确定的病例的密切接触者。相当比例的病例参加了宗教集会。
密切接触者中的发病率以及与COVID-19阳性相关的因素。
我们列出了931例原发病例的15702名密切接触者。其中，89%（n = 14002）的密切接触者接受了COVID-19检测。总体二代发病率为4%（599/14002），家庭密切接触者中的发病率（13%）高于社区密切接触者（1%）。有集会暴露史的原发病例的密切接触者的二代发病率是非集会暴露原发病例的密切接触者的5倍（10%对2%）。与无集会暴露的原发病例的密切接触者相比，有集会暴露的原发病例的家庭密切接触者感染COVID-19的风险增加了四倍（相对风险（RR）：16.4；95%置信区间：13至20）。在有症状的原发病例中，有集会暴露史的原发病例的家庭密切接触者的RR高于其他病例的家庭密切接触者（（RR：25.3；95%置信区间：10.2至63）对（RR：14.6；95%置信区间：5.7至37.7））。在无症状的原发病例中，有集会暴露史的原发病例的家庭密切接触者的RR高于其他病例（RR：16.5；95%置信区间：13.2至20.7）。
我们的研究表明，家庭密切接触者中的疾病传播比社区密切接触者中更多。此外，有症状的原发病例和有集会暴露史的原发病例的二代病例比其他病例更多。
