Prevalence of candidiasis and oral candidiasis in 
COVID-19 patients: a cross-sectional pilot study from 
the patients’ registry in a large health center

Objective: Candida albicans in considered to be a marker of immunosuppression in serious chronic condition such as HIV and cancer patients on immunosuppresion medications. The new COVID-19 pandemic has caused acute respiratory distress syndrome in many patients, which poses a risk of super-infections including Candida strains causing oral candidiasis as well as invasive fungal infections. The aim of the study was to examine the association between COVID-19 and oral and general candidiasis.
Method and materials: The i2b2 data repository platform was used to analyze the interrelations between COVID-19, oral candidiasis, and total candidiasis in a hospital population. ICD diagnoses codes were used to generate queries on total numbers and demographic data on COVID-19, oral candidasis, total candidasis, and COVID-19 with each form of candidasis.
Results: From the 889 patients diagnosed with COVID-19, 106 (12%) were diagnosed with candidiasis at large and 14 (1.6%) had oral candidiasis. The odds ratio (OR) for COVID-19 in the presence of oral candidiasis was 2.01 (95% CI 1.1870 to 3.4143, P = .094) and the OR for COVID-19 in the presence of candidiasis was 3.73 (95% CI 3.0419 to 4.5847, P < .0001 ). African American were disproportionally affected and comprised about 40% of the COVID-19/candidiasis groups.
Conclusions: Total candidiasis was significantly associated with increased risk for COVID-19, whereas oral candidiasis showed an insignificant trend. The dental practitioner should be aware of the importance of unexplained oral and systemic candidiasis as a potential harbinger of T and B cell immunosuppression associated with viral in­fections. COVID-19 may be a risk factor for total candidiasis.