Changes in reverse transcription polymerase chain reaction cycle threshold values of SARS-CoV-2 with topical povidone...

Repurposed povidone iodine (PVP-I) has been suggested as an effective adjuvant against coronavirus disease-2019 (COVID-19).

The aim of this study was to assess the changes in RT-PCR cycle threshold (Ct) values of severe acute respiratory Syndrome Coronavirus-2 (SARS-CoV-2) genes with PVP-I intranasal and oral application.

A longitudinal (repeated measures) single-arm open-label interventional study was conducted for 200 samples of ten COVID-19 patients in South India.

Demographic and clinical information were collected. Intranasal application and oral gargle with 1% PVP-I solution was done four times a day for seven days. Nasopharyngeal and oropharyngeal samples were taken for RT-PCR test at hour-0, hour-2, hour-4 on Day-0, Day-3, Day-6, and hour-0 on Day-9.

STATA analysis software version 14.2 was used. McNemar Test was applied for paired samples. Skilling Mack Test was used to assess the association between PVP-I use (intra-day and inter-day) and E gene/N gene Ct values. Pearson correlation coefficients and Bland-Altman plots were used for further analyses.

Mean (SD) age of the patients was 41.5 (±8.82) years. A total of 100 pairs of nasopharyngeal and oropharyngeal samples were analysed. No significant difference was observed in the Ct values of asymptomatic and symptomatic patients. E gene Ct values (nasopharyngeal) at Hour-0 increased from Day-0 to Day-9 (P = 0.005). Ct value was higher at Hour-2 for most of the samples.

RT-PCR results (qualitative) differed at various testing points in the same patients. Lower Ct values were found in the nasopharyngeal samples. Successive increase in E gene Ct values indicates reduced viral load with natural course of COVID-19. PVP-I may have an optimal impact within 2 h of usage.

CTRI/2020/05/024962.