key: cord-0934038-1585stal
authors: nan
title: Coronavirus Disease-19: Summary of 2,370 Contact Investigations of the First 30 Cases in the Republic of Korea
date: 2020-04-03
journal: Osong Public Health Res Perspect
DOI: 10.24171/j.phrp.2020.11.2.04
sha: e9eb97b0610b3fcbcd8b42eaeeeb5af2f7f15b07
doc_id: 934038
cord_uid: 1585stal

Between January 24(th) and March 10(th), a total of 2,370 individuals had contact with the first 30 cases of COVID-19. There were 13 individuals who contracted COVID-19 resulting in a secondary attack rate of 0.55% (95% CI 0.31–0.96). There were 119 household contacts, of which 9 individuals developed COVID-19 resulting in a secondary attack rate of 7.56% (95% CI 3.7–14.26).

Since the first reported cases of coronavirus disease 2019 in the Republic of Korea, there have been 30 confirmed cases as of February 17 th , 2020. The epidemiological and clinical characteristics of 28 cases have been previously reported [1] .

Contact tracing is essential for containing COVID-19 within the community. In Korea, an established system exists where public health centers conduct epidemiological investigations and instigate the quarantine/isolation of suspected cases, thus interrupting the line of transmission. This approach has been particularly successful in containing COVID-19 in the early phase of the outbreak.

Here, we summarize the investigation into the first 30 cases of COVID-19, and the 2,370 individuals who came into contact with these original 30 cases in Korea. The study includes calculation of secondary attack rates among different age groups and modes of transmission of COVID-19.

Demographic, epidemiological, and early clinical information were retrieved from COVID-19 reporting and surveillance data from Korea Centers for Disease Control and Prevention (KCDC).

As in the previous report, the patient's age was provided on the date of diagnosis, and key indicators were identified by an epidemiological investigator who participated in the field investigation and the epidemiological investigation team [1] . Data presented in this study may change depending on further epidemiological investigations.

The working definition for "close contact (or high risk exposure)" was being within 2 meters of a COVID-19 case and "daily contact (or low risk exposure)" was defined as having proximity with a person who was a confirmed COVID-19 case, without having had close contact. The classification was then repealed and was integrated into "contact (regardless of level of exposure)." All contacts who were asymptomatic were mandated to self-quarantine for 14 days and were put under active surveillance by public health workers who called twice a day to check presence of fever or respiratory symptoms. A smartphone-based, "self-assessment app," was introduced as an additional tool to track symptoms of COVID-19. and CCTV have been used to complete the contact tracing of COVID-19 cases [7] .

There are certain limitations that should be considered in 

There was no conflicts of interest to declare. to control a new outbreak of COVID-19 in most scenarios [6] .

In Korea, various tracking measures such as the history of clinic visits, GPS of cell phones, credit card transaction logs,

Epidemiology and Case Management Team, Korea Centers for Disease Control and Prevention. Early Epidemiological and Clinical Characteristics of 28 Cases of Coronavirus Disease in South Korea

A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: A study of a family cluster

A familial cluster of infection associated with the 2019 novel coronavirus indicating potential person-to-person transmission during the incubation period

Characteristics of COVID-19 infection in Beijing

Active Monitoring of Persons Exposed to Patients with Confirmed COVID-19 -United States

Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts

Epidemiology & Case Management Team, Korea Centers for Disease Control & Prevention. Contact Transmission of COVID-19 in South Korea: Novel Investigation Techniques for Tracing Contacts