ORACLE ver 1 [COVID-19]
Research type
Research Study
Full title
Oral health, microbial burden and COVID-19 (ORACLE)
IRAS ID
283766
Contact name
Francesco D’Aiuto
Contact email
Sponsor organisation
University College London, Joint Research Office, (part of the Research Support Centre)
Clinicaltrials.gov Identifier
Z6364106/2020/05/82 , UCL Data Protection Registration
Duration of Study in the UK
0 years, 11 months, 31 days
Research summary
The currently ongoing world-crippling pandemic with the new SARS-CoV2 virus shows the desperate and urgent need for a better understanding of the biological pathways activated by the virus inducing Coronavirus disease 2019 (COVID-19) in infected patients. A subset of COVID-19 patients develop very severe respiratory symptoms requiring hospital admission with or without the need for mechanical ventilation, whereas others experience mild flu-like symptoms. The biological mechanisms underlying this striking difference in clinical outcome and the long term consequences are unknown.
Whilst COVID-19 has a viral origin, it is suspected that in severe forms of the infection, bacteria play a part, increasing the chance of complications such as pneumonia, acute respiratory distress syndrome, sepsis, septic shock and death (World Health Organization, 2020).
The development and severity of complications following a COVID-19 infection depends on numerous host and viral factors that will affect a patient’s immune response. Whilst 80% of patients with COVID-19 infections have mild symptoms, 20% progress to have a severe form of infection associated with higher levels of inflammatory markers (Interleukin 2, 6, 10) (Gong, 2020) and bacteria.
They also exhibit a remarkably higher neutrophil count and lower lymphocyte count than in mild patients (Zheng, 2020). A high neutrophil count is abnormal for a viral infection, but common for a bacterial infection, suggesting that in severe cases of COVID-19, bacterial superinfection is common.
The four main comorbidities associated with an increased risk of complications from COVID-19 are diabetes, hypertension, obesity and cardiovascular disease (Zhou, 2020). These comorbidities are also associated with altered oral biofilms and periodontitis. Periodontopathic bacteria are implicated in systemic inflammation, bacteraemia, and pneumonia (Nagaoka, 2014). Bacteria present in the metagenome of patients severely infected with COVID-19 included high reads for Prevotella, Staphylococcus, and Fusobacterium, all usually commensal organisms of the mouth (Chakraborty, 2020). Over 80% of patients in ICU exhibited an exceptionally high bacterial load (Liu, 2020). Furthermore oral epithelial cells express ACE-2 receptors which could facilitate COVID-19 infection (8).
The main aim of this study was to characterize the oral microbiome of patients with various degrees of severity of Covid19 disease and compare them to controls.
REC name
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee
REC reference
20/YH/0227
Date of REC Opinion
9 Sep 2020
REC opinion
Further Information Favourable Opinion