SARS-CoV-2 RT-PCR profile in 298 Indian COVID-19 patients: a retrospective observational study

Abstract

Background Despite being in the 5th month of pandemic, knowledge with respect to viral dynamics, infectivity and RT-PCR positivity continues to evolve. Aim To analyse the SARS CoV-2 nucleic acid RT-PCR profiles in COVID-19 patients. Design It was a retrospective, observational study conducted at COVID facilities under AIIMS, New Delhi. Methods Patients admitted with laboratory confirmed COVID-19 were eligible for enrolment. Patients with incomplete details, or only single PCR tests were excluded. Data regarding demographic details, comorbidities, treatment received and results of SARS-CoV-2 RT-PCR performed on nasopharyngeal and oropharyngeal swabs, collected at different time points, was retrieved from the hospital records. Results 298 patients were included, majority were males (75·8%) with mean age of 39·07 years (0·6–88 years). The mean duration from symptom onset to first positive RT-PCR was 4·7 days (SD 3·67), while that of symptom onset to last positive test was 17·83 days (SD 6·22). Proportions of positive RT-PCR tests were 100%, 49%, 24%, 8·7% and 20·6% in the 1st, 2nd, 3rd, 4th & >4 weeks of illness. 12 symptomatic patients had prolonged positive test results even after 3 weeks of symptom onset. Age > = 60 years was associated with prolonged RT-PCR positivity (statistically significant). Conclusion This study showed that the average period of PCR positivity is more than 2 weeks in COVID-19 patients; elderly patients have prolonged duration of RT-PCR positivity and requires further follow up.

COVID-19 patient characteristics and time to viral clearance: A retrospective observational study in a multiethnic population (United Arab Emirates)

“…Our study revealed that advanced age was associated with an increased risk of prolonged time to viral clearance, which is consistent with previous studies [ 19 , 22 , 23 ]. This could be attributed to the decline of T cell functions and proliferation with increasing age resulting in decreased control of viral replication and viral clearance.…”

“…Diabetic patients also showed a significantly longer duration for viral clearance when compared with nondiabetic patients. However, Li et al [12,p.506–512] and Bhattacharya et al [23] showed a non-significant correlation between diabetes and viral shedding. And Hirai et al [19,p.864–868] showed a significant association between diabetes and a shorter time till viral clearance.…”

Understanding the Demographic, Clinical, and Real-Time Polymerase Chain Reaction Profiles of COVID-19 Patients in a Tertiary Care Hospital in Northeast India

“…In the present study, males predominated the symptomatic cases. Similar findings were reported by Xiao et al (2020) [10], Bhattacharya et al (2020) [11], and Alshukry et al (2020) [12]. The biological differences in the immune systems existing between males and females may influence the ability to fight infection including SARS-CoV-2, and that may be the reason for the male predominance in the study.…”

Cycle threshold values in RT‐PCR to determine dynamics of SARS‐CoV‐2 viral load: An approach to reduce the isolation period for COVID‐19 patients

“…A period of 14 days' isolation is generally recommended throughout the world to prevent the spread of SARS‐CoV‐2. Increased age was positively associated with prolonged RT‐PCR positivity 8 . Although SARS‐CoV‐2 RNA shedding can be detected for an extended period, the duration of a live virus is relatively short‐lived 9 .…”

“…Increased age was positively associated with prolonged RT‐PCR positivity. 8 Although SARS‐CoV‐2 RNA shedding can be detected for an extended period, the duration of a live virus is relatively short‐lived. 9 In this study, we compared the duration of SARS‐CoV‐2 viral RNA in individuals with different Ct values and evaluated the dynamics of viral load in cases that required 15–30 days to clear SARS‐CoV‐2 viral RNA.…”