TUESDAY, July 21, 2020 (HealthDay News) -- Overall, 11.8 percent of household contacts of index COVID-19 patients in South Korea have COVID-19 compared with 1.9 percent of nonhousehold contacts, according to a study published online July 16 in Emerging Infectious Diseases, a publication of the U.S. Centers for Disease Control and Prevention.
Young Joon Park, from the Korea Centers for Disease Control and Prevention in Cheongju, South Korea, and colleagues analyzed reports for 59,073 contacts of 5,706 COVID-19 index patients from South Korea during Jan. 20 to March 27, 2020.
The researchers found that of 10,592 household contacts of index patients, 11.8 percent had COVID-19. In households with an index patient aged 10 to 19 years, 18.6 percent of contacts had COVID-19. The detection rate was 1.9 percent for 48,481 nonhousehold contacts. In nonhousehold settings, detection of COVID-19 was significantly higher for index patients aged >40 years compared with index patients aged 30 to 39 years. COVID-19 was detected in significantly more household than nonhousehold contacts for most age groups.
"We showed that household transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was high if the index patient was 10 to 19 years of age," the authors write. "In the current mitigation strategy that includes physical distancing, optimizing the likelihood of reducing individual, family, and community disease is important. Implementation of public health recommendations, including hand and respiratory hygiene, should be encouraged to reduce transmission of SARS-CoV-2 within affected households."