The role of mouthwash sampling in SARS-CoV-2 diagnosis.

BACKGROUND: The current practice of COVID-19 diagnosis worldwide is the use of oro-nasopharyngeal (ONP) swabs. Our study aim was to explore mouthwash (MW) as an alternative diagnostic method, in light of the disadvantages of ONP swabs. METHODS: COVID-19 outpatients molecular-confirmed by ONP swab were repeatedly examined with ONP swab and MW with normal saline (0.9%). Other types of fluids were compared to normal saline. The Cq values obtained with each method were compared. RESULTS: Among 137 pairs of ONP swabs and MW samples, 84.6% (116/137) of ONP swabs were positive by at least one of the genes (N, E, R). However MW detected 70.8% (97/137) of samples as positive, which means 83.6% (97/116) out of positive ONP swabs, missing mainly Cq value > 30. In both methods, the N gene was the most sensitive one. Therefore, MW samples targeting N gene, which was positive in 95/137 (69.3%), are comparable to ONP swabs targeting E and R genes which gave equal results-95/137 (69.3%) and 90/137 (65.7%), respectively. Comparing saline MW to distilled water gave equal results, while commercial mouth-rinsing solutions were less sensitive. CONCLUSIONS: MW with normal saline, especially when tested by N gene, can effectively detect COVID-19 patients. Furthermore, this method was not inferior when compared to R and E genes of ONP swabs, which are common targets in many laboratories around the world.

The effect of ivermectin on the viral load and culture viability in early treatment of nonhospitalized patients with mild COVID-19 - a double-blind, randomized placebo-controlled trial.

OBJECTIVES: Ivermectin, an antiparasitic agent, also has antiviral properties. In this study, we aimed to assess whether ivermectin has anti-SARS-CoV-2 activity. METHODS: In this double-blinded trial, we compared patients receiving ivermectin for 3 days versus placebo in nonhospitalized adult patients with COVID-19. A reverse transcriptase-polymerase chain reaction from a nasopharyngeal swab was obtained at recruitment and every 2 days for at least 6 days. The primary endpoint was a reduction of viral load on the sixth day as reflected by cycle threshold level >30 (noninfectious level). The primary outcome was supported by the determination of viral-culture viability. RESULTS: Of 867 patients screened, 89 were ultimately evaluated per-protocol (47 ivermectin and 42 placeboes). On day 6, the odds ratio (OR) was 2.62 (95% confidence interval [CI]: 1.09-6.31) in the ivermectin arm, reaching the endpoint. In a multivariable logistic regression model, the odds of a negative test on day 6 were 2.28 times higher in the ivermectin group but reached significance only on day 8 (OR 3.70; 95% CI: 1.19-11.49, P = 0.02). Culture viability on days 2 to 6 was positive in 13.0% (3/23) of ivermectin samples versus 48.2% (14/29) in the placebo group (P = 0.008). CONCLUSION: There were lower viral loads and less viable cultures in the ivermectin group, which shows its anti-SARS-CoV-2 activity. It could reduce transmission in these patients and encourage further studies with this drug.