Association between periodontitis and susceptibility to COVID-19 in a sample of adult Egyptian patients with respiratory infection symptoms: a case-control study

Introduction This case-control study aimed to determine the association between coronavirus-19 disease (COVID-19) and periodontitis in a sample of adult Egyptian patients with respiratory symptoms. Methods Patients with respiratory symptoms were recruited from the COVID-19 outpatient clinic of Qasr El-Aini Medical Hospital. Based on results of real-time reverse transcription polymerase chain reaction, patients were enrolled either as cases (COVID-19-positive) or controls (COVID-19-negative). After testing negative for the virus, or after recovery, a full clinical periodontal examination was performed, in addition to full-mouth periapical radiographs. Logistic regression model was conducted to determine the predictors for COVID-19. Results There was a statistically significant association between periodontitis stage III and IV and being recently positive for COVID-19 infection ( p <0.05), while both groups showed the same prevalence of periodontitis stage I and II. Also, there was no statistically significant difference between medical history presence of hypertension and diabetes mellitus, smoking, and use of oral hygiene measures in the two groups, respectively ( p >0.05). Subjects with high clinical attachment loss (CAL) measurements were 3.25-fold more prone to COVID-19 than those with low CAL values. Similarly, subjects with higher bleeding on probing (BoP)% were 1.30-fold more prone to COVID-19 than those with low BoP%. Conclusions This case-control study suggests a possible association between periodontitis severity and COVID-19 infection in a sample of adult Egyptian patients. Results of logistic regression model revealed that CAL and BoP were significant predictors of COVID-19 infection ( p <0.05).