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Updated: Nov 8, 2025
Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
Published on: December 31, 2017
Dental biofilm of symptomatic COVID-19 patients harbours SARS-CoV-2
Sabrina Carvalho Gomes1,2, Sabrina Fachin3, Juliane Gonçalves da Fonseca3
1Department of Conservative Dentistry, Dentistry School, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Aims:
SARS-CoV-2 RNA has been recovered from different sites in the human body, including the mouth. The present study aimed to investigate the presence of SARS-CoV-2 RNA in the dental biofilm of symptomatic patients who tested positive in nasopharyngeal and oropharyngeal (NASO/ORO) samples.
Materials & Methods:
An observational clinical study of individuals with flu-like symptoms was conducted between July and September 2020. Dental biofilm (BIO) samples were collected and analysed using real-time quantitative polymerase chain reaction (RT-qPCR) to determine the virus's presence.
Results:
Seventy participants (40 ± 9.8 years of age, 71.4% female) tested positive for SARS-CoV-2 RNA in NASO/ORO samples and were included in the study. Among them, 13 tested positive in BIO samples (18.6%; 95% CI: [9.5, 27.7]). The median and interquartile range of cycle quantification (Cq) for NASO/ORO and BIO samples were 15.9 [6.9] and 35.9 [4.0] (p = .001), respectively. BIO-positive participants showed a higher virus load in NASO/ORO samples (p = .012) than those testing negative (Cq = 20.4 [6.1]).
Conclusions:
Dental biofilms from symptomatic COVID-19 patients harbour SARS-CoV-2 RNA and might be a potential reservoir with an essential role in COVID-19 transmission.
