99.1% of close contacts of Omicron-infected patients diagnosed by 10 daysLate last week in Emerging Infectious Diseases, South Korean researchers reported that average time from exposure to COVID-19 diagnosis was 3.7 days in quarantined close contacts of patients infected by the SARS-CoV-2 Omicron variant and that 99.1% of diagnoses occurred by day 10, supporting a 10-day quarantine.The study evaluated time from exposure to diagnosis among 107 close contacts from two Omicron clusters on Nov 24 and 25, 2021.
In South Korea, close contacts of Omicron patients were mandated to quarantine for 14 days amid surges, regardless of symptom and vaccination status.
Contacts were tested for COVID-19 on days 1, 9, and 13.Average time from exposure to diagnosis was 3.7 days. Of all contacts, 50% were diagnosed on day 3, while 70% were diagnosed on day 5 and 99.1% by day 10.
One diagnosis occurred on day 13 in an unvaccinated child who had previously tested negative.Half of contacts in all age-groups were diagnosed on day 3.