tetano
Editor, Senior Moderator
J Korean Med Sci
. 2020 Dec 14;35(48):e424.
doi: 10.3346/jkms.2020.35.e424.
COVID-19 Outbreak and Presymptomatic Transmission in Pilgrim Travelers Who Returned to Korea from Israel
Ji Hyuk Park[SUP] 1 2 [/SUP], Joon Ho Jang[SUP] 3 [/SUP], Kwan Lee[SUP] 1 4 [/SUP], Seok Ju Yoo[SUP] 1 [/SUP], Hyojung Shin[SUP] 5 [/SUP]
Affiliations
Abstract
Background: On February 21, 2020, 2 coronavirus disease 2019 (COVID-19) cases in pilgrim travelers from Korea to Israel were identified. We investigated the source of infection, clinical features of COVID-19, and transmission potential of presymptomatic and asymptomatic cases.
Methods: All 39 pilgrim travelers were aggressively tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Their clinical features and possible source of infection were investigated by interview and review of their medical records. Ten confirmed cases without symptoms at the first sampling dates were selected for follow-up reverse transcription polymerase chain reaction tests.
Results: Of 39 pilgrim travelers, 30 (77%) were positive for SARS-CoV-2. Among the 30 positive COVID-19 cases, 4 (13%) were asymptomatic. Available follow-up cycle threshold values from 10 cases gradually increased over time and were lower during the presymptomatic period than during the postsymptomatic period. Out of 328 contacts related to the COVID-19 cases in the pilgrim travelers, 22 additional cases (7%) were confirmed with SARS-CoV-2 infections. Three tertiary cases were identified to be transmitted by presymptomatic secondary cases.
Conclusion: To prevent transmission of COVID-19, we need to focus on presymptomatic and asymptomatic cases, and massive testing for SARS-CoV-2 is required. More research about the possibility of presymptomatic transmission over 2 days before symptom onset is required.
Keywords: COVID-19; Outbreaks; Severe Acute Respiratory Syndrome Coronavirus 2; Transmission.
. 2020 Dec 14;35(48):e424.
doi: 10.3346/jkms.2020.35.e424.
COVID-19 Outbreak and Presymptomatic Transmission in Pilgrim Travelers Who Returned to Korea from Israel
Ji Hyuk Park[SUP] 1 2 [/SUP], Joon Ho Jang[SUP] 3 [/SUP], Kwan Lee[SUP] 1 4 [/SUP], Seok Ju Yoo[SUP] 1 [/SUP], Hyojung Shin[SUP] 5 [/SUP]
Affiliations
- PMID: 33316860
- DOI: 10.3346/jkms.2020.35.e424
Abstract
Background: On February 21, 2020, 2 coronavirus disease 2019 (COVID-19) cases in pilgrim travelers from Korea to Israel were identified. We investigated the source of infection, clinical features of COVID-19, and transmission potential of presymptomatic and asymptomatic cases.
Methods: All 39 pilgrim travelers were aggressively tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Their clinical features and possible source of infection were investigated by interview and review of their medical records. Ten confirmed cases without symptoms at the first sampling dates were selected for follow-up reverse transcription polymerase chain reaction tests.
Results: Of 39 pilgrim travelers, 30 (77%) were positive for SARS-CoV-2. Among the 30 positive COVID-19 cases, 4 (13%) were asymptomatic. Available follow-up cycle threshold values from 10 cases gradually increased over time and were lower during the presymptomatic period than during the postsymptomatic period. Out of 328 contacts related to the COVID-19 cases in the pilgrim travelers, 22 additional cases (7%) were confirmed with SARS-CoV-2 infections. Three tertiary cases were identified to be transmitted by presymptomatic secondary cases.
Conclusion: To prevent transmission of COVID-19, we need to focus on presymptomatic and asymptomatic cases, and massive testing for SARS-CoV-2 is required. More research about the possibility of presymptomatic transmission over 2 days before symptom onset is required.
Keywords: COVID-19; Outbreaks; Severe Acute Respiratory Syndrome Coronavirus 2; Transmission.