Abstract
Background: The risk of transmission of Coronavirus Disease 2019 (COVID-19) is increasingly understood to be greatest early after symptom onset, however, factors associated with prolonged and increased risk of transmission remain unclear. In settings where COVID-19 prevalence is low, there may be a benefit of extending the period that patients are isolated to decrease the risk of transmission. This study explored the duration of viral shedding in such a location, in patients with mild-moderate COVID-19 disease in Ballarat, Australia.
Methods: Patients diagnosed with COVID-19 disease using a real-time reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay from oropharyngeal and bilateral deep nasopharyngeal sampling and managed through Ballarat Health Services between March 1 and May 1, 2020 were included. Patients were retested if they were afebrile for >72 hours, asymptomatic and >14days since symptom onset. If positive on retesting, patients were tested every 3 to 7days thereafter.
Results: Patients underwent testing a median of 4days (range 1-12) after initial symptom onset. Duration of symptoms ranged from 1 to 36days. Positive tests were recorded up to a median of day 21 (range 6-38). Cycle thresholds were inversely correlated with time since symptom onset (P < .0001). Median time to the first negative test was 25days (range 12-32). Two patients who had remained asymptomatic for >7days after initial symptom onset had recrudescence of mild symptoms on day 13 and 14; both tested positive on follow-up tests at this time.
Conclusions: This study demonstrates prolonged shedding of COVID-19 in patients with mild-moderate disease. It suggests that some patients with mild disease may have recrudescence of symptoms a week or more after their initial symptoms resolved.
Methods: Patients diagnosed with COVID-19 disease using a real-time reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay from oropharyngeal and bilateral deep nasopharyngeal sampling and managed through Ballarat Health Services between March 1 and May 1, 2020 were included. Patients were retested if they were afebrile for >72 hours, asymptomatic and >14days since symptom onset. If positive on retesting, patients were tested every 3 to 7days thereafter.
Results: Patients underwent testing a median of 4days (range 1-12) after initial symptom onset. Duration of symptoms ranged from 1 to 36days. Positive tests were recorded up to a median of day 21 (range 6-38). Cycle thresholds were inversely correlated with time since symptom onset (P < .0001). Median time to the first negative test was 25days (range 12-32). Two patients who had remained asymptomatic for >7days after initial symptom onset had recrudescence of mild symptoms on day 13 and 14; both tested positive on follow-up tests at this time.
Conclusions: This study demonstrates prolonged shedding of COVID-19 in patients with mild-moderate disease. It suggests that some patients with mild disease may have recrudescence of symptoms a week or more after their initial symptoms resolved.
| Original language | English |
|---|---|
| Pages (from-to) | 1-3 |
| Number of pages | 3 |
| Journal | Infectious Diseases: Research and Treatment |
| Volume | 14 |
| DOIs | |
| Publication status | Published - 13 Apr 2021 |