Dental biofilm of symptomatic COVID‐19 patients harbours SARS‐CoV‐2
PORTO ALEGRE, Brazil: Since SARS-CoV-2 has been found in different sites in the human body, researchers have recently sought to examine the presence of the virus in the dental biofilm of symptomatic patients who had tested positive for COVID-19. They reported that some patients who had tested positive in nasopharyngeal and oropharyngeal samples also presented SARS-CoV-2 in the supragingival biofilm sample. The findings suggest that dental biofilm may play an important role in COVID-19 transmission as it may harbour SARS-CoV-2 in symptomatic patients.
“Measuring human health in parts is not possible anymore,” said co-author Dr Sabrina Carvalho Gomes, professor of periodontics in the Department of Conservative Dentistry at the Federal University of Rio Grande do Sul in Porto Alegre. Gomes believes that the oral cavity plays an essential role in human health. This has become even more evident during the pandemic since the oral cavity is one of the key entry and identification points for SARS-CoV-2, she noted. Since dental biofilm is polymicrobial—meaning that it is composed of bacteria, fungi and viruses—Gomes hypothesised that it may also harbour SARS-CoV-2, and her team felt obliged to investigate this, thereby joining other healthcare workers in the fight against COVID-19.
Talking about the motivation for conducting the study, Gomes told Dental Tribune International: “This study was designed and approved in March/June 2020, right at the beginning of the pandemic in Brazil. At the same time, I experienced flu-like symptoms. As a result, I was examined by the hospital’s occupational medical department, which had recommended that all staff members with symptoms show up for medical examination and laboratory analysis. Once there, I realised that it would be a great place to do the investigation.”
Aiming to better understand the link between SARS-CoV-2 and oral health, the researchers collected biofilm samples from individuals with flu-like symptoms between July and September 2020. In total, 70 participants tested positive for SARS-CoV-2 and were included in the study. Subsequently, the researchers analysed the dental biofilm samples of those who had tested positive in nasopharyngeal and oropharyngeal samples.
The findings showed that 18.6% of the patients who had had a positive polymerase chain reaction test result also presented SARS-CoV-2 in the supragingival biofilm sample. In addition, the viral load observed in the medical samples of those who tested positive in the dental biofilm was higher than that observed in the participants who tested negative. According to Gomes, these findings suggest that systemic viral load influences the presence of the virus in dental biofilm.
“Dentistry, again, is being called upon to reinforce its role in human health,” Gomes commented. “The current results put us on the alert and stimulate good oral health habits, especially the mechanical removal of the biofilm. Once inside a biofilm, no microorganism is susceptible to systemic or local drugs and host response. Therefore, mechanical disruption remains the only way to access the virus properly. So my recommendation is that we continue fighting to improve oral health by encouraging the daily mechanical removal of dental biofilm,” she concluded.
“Dentistry, again, is being called upon to reinforce its role in human health”
The researchers will continue to work on the topic and already have two studies underway at the hospital’s intensive care unit. Additionally, Gomes noted that there is a strong need to study the human microbiome closely in order to evaluate the relationship of the viruses inside the biofilm, a task Gomes is keen to undertake in the near future.
The study, titled “Dental biofilm of symptomatic COVID-19 patients harbours SARS-CoV-2,” was published online on 25 April 2021 in the Journal of Clinical Periodontology, ahead of inclusion in an issue.