key: cord-0078840-h6ahv4yf authors: Jang, Young R.; Kim, Jeong-Min; Rhee, Jee E.; Kim, Dongju; Lee, Nam-Joo; Lee, Hyeokjin; Kim, Jong-Hun; Kim, Eun-Jin; Kim, Jin Y. title: Clinical Features and Duration of Viral Shedding Individuals with SARS-CoV-2 Omicron Variant Infection date: 2022-05-09 journal: Open Forum Infect Dis DOI: 10.1093/ofid/ofac237 sha: bece0dc3bfebe2b19041b7a543978c4c4b9c21a3 doc_id: 78840 cord_uid: h6ahv4yf We analyzed the duration of infectivity of the SARS-CoV-2 Omicron variant by the viral culture of respiratory samples collected daily from isolated patients with SARS-CoV-2 infection. The culture positivity rate of the Omicron variant was higher than that of the Delta variant within 8 days after symptom onset. Korea, all patients were isolated in IMC and treated throughout the isolation period. Nasopharyngeal and oropharyngeal swab samples were collected from the patients daily until 16 their discharge and transported in viral transport media (VTM). Eleven patients with COVID-19 17 were enrolled in this study. The median age of the patients was 38 years; 5 patients (45%) were 18 male, and 6 (55%) were female. No patients were immunocompromised, and two patients (18%) 19 received a second dose of the COVID-19 vaccine in October 2021. All patients have one or more 20 COVID-19 related symptoms at diagnosis. Five patients (45%) had pneumonia, which was 21 determined by the presence of signs of involvement of lung parenchyma on chest X-ray or high-22 resolution computed tomography. None of the patients received supplemental oxygen therapy, remdesivir, or anti-inflammatory drugs (steroids, interleukin-6 inhibitors, or Janus kinase 1 inhibitors). Two patients (18%) received monoclonal antibody therapy. All patients had mild-to-2 moderate COVID-19 (Supplementary Table S1 ). Worldwide, many guidelines on release from isolation take the resolution of fever into 13 account. However, our study results show that the duration of fever is not well correlated with 14 the time to viral culture conversion. Improvement of symptoms, including fever, is an important 15 indicator of a decrease in infectivity, but there is a lack of evidence that simply emphasizing 16 improvement in fever provides a scientific basis for release from isolation, and further studies are 17 needed to determine whether improvement in fever has a significant association with decreased 18 infectivity. Our study had some limitations. First, since the index cases were travelers and given the strict 20 hospital-based isolation procedures for this cohort, the validity of their symptom onset dates and 21 their willingness to admit, for example, that they traveled internationally while symptomatic. Second, it is important to note that the sample size of this study was small, and all the patients had a mild-to-moderate illness. Thus, these results should be verified in a larger study involving 1 different patient groups. The Omicron variant is thought to spread more easily than the original SARS-CoV-2 and 3 Delta variants 11 . The findings of this study support the high transmissibility of the Omicron 4 variant. Improvement of symptoms, including fever, is an important indicator of a decrease in 5 infectivity, but our study results show that the duration of fever might not well correlate with the 6 time to viral culture conversion. Kim 2 EJ. Increase in Viral Load in Patients With SARS-CoV-2 Delta Variant Infection in the Republic 3 of Korea. Front Microbiol Viral cultures for coronavirus disease 2019 5 infectivity assessment: a systematic review Genetic and pathogenic characterization of SARS-CoV-2: a review Epitope classification 9 and RBD binding properties of neutralizing antibodies against SARS-CoV-2 variants of concern Evaluation of the effects of the SARS-CoV-2 spike 12 mutation D614G on transmissibility and pathogenicity Loss of furin cleavage site attenuates SARS-CoV-2 14 pathogenesis Variant of concern reports Functional evaluation of the P681H mutation on 18 the proteolytic activation of the SARS-CoV-2 variant B.1.1.7 (Alpha) spike. iScience