Dynamics of transmission of COVID-19 cases and household contacts

Abstract

Objective: To study the transmission dynamics of coronavirus disease 2019 (COVID-19) among 101 confirmed cases and their 387 household contacts and to determine risk factors associated with secondary attack among the household contacts. Methods: A prospective cohort study was conducted from January 1st 2021 to February 28th 2021, among 101 SARS-CoV-2 cases and 387 household contacts who were followed up for 14 days from the last day of contact with the index case of COVID-19. The dynamics of disease transmission was estimated, and factors affecting transmission risk were analyzed. Besides, the association between various factors and household secondary attack rate was determined. Results: The median incubation period was found to be 5 days, and the observed reproductive number (R) was found to be 1.63 (95% CI: 1.28-1.98). The mean household secondary attack rate was 40.7%. Contacts with comorbidities like diabetes mellitus, hypertension, dyslipidemia, and hypothyroidism had significantly higher attack rates (P<0.05). Conclusions: As new variants of SARS-CoV-2 emerges, it is crucial to know the trasmission dynamics. This study shows a high secondary attack rate of COVID-19 among household contacts that must be closely monitored.

The role of children in transmission of SARS-CoV-2 variants of concern within households: an updated systematic review and meta-analysis, as at 30 June 2022

“…Specifically, 29 studies from 16 countries (Australia [17], Bosnia and Herzegovina [18], Brazil [19], Canada [20], China [21][22][23][24][25][26][27][28], Greece [29,30], India [31], Israel [32], Japan [33,34], Malaysia [35], the Netherlands [36], Norway [37], Singapore [38], Spain [39], the United Kingdom (UK) [40,41] and the US [42][43][44][45]) were subjected to analysis for SAR in the period defined as pre-VOC. Twenty-three studies involving 12 countries (Denmark [46][47][48][49], Germany [50], India [51], Israel [52], Japan [53], the Netherlands [54,55], Norway [56,57], Singapore [6], South Africa [58], Thailand [59], the UK [60,61] and the US…”

Household Secondary Attack Rates of SARS-CoV-2 by Variant and Vaccination Status

“…We identified 2097 records (1791 from PubMed, 306 from medRxiv, and 2 from reference lists of eligible articles) published between June 18, 2021, and March 8, 2022 (eFigure 1 in the Supplement). Fifty-eight new studies (eTable 2 in the Supplement) were combined with 77 studies from our previous review (see eTable 3 in the Supplement for references included from our previous review), with Figure 1 showing household SAR by study period, resulting in 135 total studies representing 1 375 806 contacts from 36 countries. Four of the new studies were preprints in our previous review that were subsequently published.…”

Risk factors of infection among close contacts of COVID-19: A systematic review and meta-analysis

“…The sensitivity analysis method was used to exclude and analyze the indicators of the groups included in the study, and the final results did not change much. So we Bi Q [19] 2020 China 2020-01-01/2020-02-12 1286 7.62% ABF 8 Liu R [20] 2020 China 2020-01-22/2020-02-14 4880 38.42 C 7 Liu T [21] 2020 China 2020-01-15/2020-03-15 11686 3.84% ACD 8 Wu Y [22] 2020 China 2020-01-23/2020-02-08 2994 4.81% ACE 9 Xin H [23] 2020 China 2020-01-20/2020-03-27 17.92% ACD 8 Burke RM [24] 2020 China 2020-01-01/2020-02-26 445 10.50% AB 8 Li W [25] 2020 China 2020-01-01/2020-02-20 392 16.30% A 7 Karumanagoundar [26] 2021 India 2020-03-14/2020-05-30 15702 3.81% AB 9 Luo L [27] 2020 China 2020-01-13/2020-03-06 3410 3.73% AEF 7 P Rajmohan [28] 2021 India 2021-01-01/2021-03-31 387 42.64% A 8 Jing COVID-19 = coronavirus disease-2019, QL [29] 2020 China 2020-01-07/2020-02-18 103 12.4% AC 9…”