Aim: Droplets and aerosols are the main source of transmission and rapid spread of COVID-19 worldwide. Topical mouthwashes and oronasal irrigation are recommended as ways of preventing airborne transmission to health care professionals. This meta-analysis aimed to assess the changes of COVID 19 viral load after administration of different mouthwashes.
Methods: An electronic search was undertaken including the following databases: Medline/PubMed, Web of Science, Scopus, and Embase. Search for grey literature, and hand search for relevant studies was also performed. The quality of included randomized clinical trials (RCTs) were assessed using the Cochrane Collaborations. Afterward, the relevant data from the included studies was extracted. Inverse-variance random-effects meta-analysis was performed to compare the effects of different types of mouthwashes on COVID viral presence.
Results: After screening 1437 studies, 10 randomized clinical trials were finally selected. A total of 884 patients were assessed in these studies. The meta-analysis revealed the Cyclic Threshold (CT) values increased after the use of mouthwashes (MD=2.00, 95%CI= 0.51, 3.49, P<0.05). Considering the CT values are inversely correlated to the viral load, the result means the use of mouthwashes decreases the viral load in the saliva. This study also showed that increase of CT values was statistically significant for Povidone Iodine mouthwash (MD=4.08, 95%CI= 0.13, 8.02, P<0.05); however, Cetylpyridinium Chloride and Chlorhexidine Gluconate mouthwashes non-significantly (P value>0.05) reduced viral load in the saliva of patients with COVID 19.
Conclusion: According to the result of this study, the use of mouthwashes reduces the viral load of saliva in patients with COVID 19. In addition to basic precautions for preventing the transmission of COVID 19, using mouthwashes may be a reasonable way to decrease the risk of disease transmission to medical staff.