Does the Misuse of Oral Hygiene Facilitate the Spread of COVID-19 Among Cohabiting Individuals? A Cross-Sectional Study

Background: Despite all the available guidelines for coronavirus disease 2019 (COVID-19), less emphasis has been placed on oral care to reduce the viral load in the mouth and saliva. Objectives: This study aimed to investigate oral hygiene habits and infection control behaviors and their relationship with household transmission rates in patients with COVID-19. Methods: In this analytical cross-sectional study, 179 patients with COVID-19 were investigated through continuous sampling in 2021 - 2022. The data collection tool was a 3-section questionnaire, including (1) social and clinical information about the individual infected with COVID-19, preliminary information about family members and transfer to another person in the family, (2) oral hygiene habits during quarantine, and (3) infection control behaviors. The collected data were analyzed using independent t-test, ANOVA, Spearman's correlation, and chi-square test in SPSS version 24. Results: The rate of household disease transmission was 61.5%. There was no significant relationship between oral hygiene habits and the household transmission of COVID-19 (P = 0.108); however, the use of a shared toothbrush container and a toothpaste tube among family members was significantly related to the rate of household transmission (P = 0.042 and P > 0.001, respectively). Conclusions: No relationship was found between oral hygiene habits and the intra-familial transmission of COVID-19; however, oral hygiene habits were influential in contracting a more severe type of disease and hospitalization rate. Using shared toothbrush containers and toothpaste tubes by the family members increased the probability of household transmission of COVID-19.