H.M.CHENG1, X.H. ZHAO1, W.S. LIM2, B.J.T. TAN2, H.L. TEY1
National Skin Centre1, National University of Singapore2
Mild cases of Covid-19 in well individuals form the majority of infections and also serve as potent vectors of transmission. The factors affecting the duration of SARS-CoV-2 RNA viral shedding (DVS) in such patients remain largely unknown.
We hypothesise that in these patients, clinical, radiologic and laboratory findings may predict DVS.
In this retrospective cohort study carried out at a community care facility in Singapore, 964 consecutive male patients with mild or asymptomatic Covid-19 were included. Clinical, radiologic, laboratory investigations and their associations with DVS were analysed.
Of 964 consecutive patients included, 851 (88.3%) patients were symptomatic. 266 patients had a documented negative RT-PCR assay with a median DVS of 25 days (range: 13 to 96 days; mean = 30.7 ± 15.2 days).
Patients isolated in pairs were associated with prolonged DVS (OR: 2.7; 95% CI: 1.7 to 4.5; p<0.0001) compared to those isolated individually. Among vital signs, only tachycardia was associated with prolonged DVS (OR: 2.6; 95% CI: 1.0 to 7.1; p=0.03). Amongst investigations, only a raised CRP was associated with prolonged DVS (OR: 2.7; 95% CI: 1.1 to 6.8; p=0.02).
In young, mildly symptomatic Covid-19 patients, prolonged DVS was associated with being isolated in pairs compared to individually. In countries with sufficient testing capacity and in situations where a negative RT-PCR test result is required, retesting in patients who were not isolated individually, or who had baseline tachycardia or a raised CRP, may be delayed to increase the yield of a negative result.