GARGLING with a mouth wash and brushing the teeth could reduce the hospital stay of COVID-19 patients.
That’s because overall good oral health care could reduce the time noninfectious viral nucleic acid remains in the oral cavity.
The noninfectious remains may still be detected by the RT-PCR or Real Time-Polymerase Chain Reaction swab test used to detect the coronavirus from nasopharyngeal secretions or secretions from the nose.
When swab tests detect the noninfectious remains, it prolongs unnecessary stay in the hospital. The reason is that the patient is deemed positive of the virus when, in fact, all that remains is the noninfectious viral nucleic acid.
This, according to a new study published July 24, in Special Care in Dentistry.
The study was conducted by Yoko Warabi, Shinsuke Tobisawa, Tomoya Kawazoe, Aki Murayama, Ryohei Norioka, Ryo Morishima, Tomoyuki Inoue, Toshio Shimizu and Kazushi Takahashi of the Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.
The study assessed the effects of oral care on prolonged viral shedding in Coronavirus Disease 2019 (COVID‐19) patients. In very simplistic terms, viral shedding refers to the expulsion and release of the virus after it has reproduced in the host cells and caused infection.
By PCR testing of nasopharyngeal swabs, the study evaluated the clinical course of eight COVID‐19 patients, including the duration of viral shedding. There are no data on the duration of viral shedding after clinical recovery from COVID‐19.
The average duration of viral shedding was reported to be 20 days, but prolonged SARS‐CoV‐2 RNA shedding was reported to be common regardless of symptomatic relief among cases in Wuhan, China.
Inappropriate oral care may influence the prolonged duration of viral shedding after clinical recovery in patients with COVID‐19. This results in positive PCR tests, which prolong the hospitalizations of patients.
The researchers evaluated eight COVID‐19 patients who were admitted to the Department of Neurology, Tokyo Metropolitan Neurological Hospital, between April 30 and May 14, and followed these patients until their discharge from the hospital.
All the patients had passed the acute phase of COVID‐19. But they were transferred to the Tokyo Metropolitan Tama Medical Center, a designated medical facility for infectious diseases.
They could not be discharged due to persistent positive PCR tests for the coronavirus, and they had underlying diseases, which included mental retardation and psychiatric disorders, hypertension, dyslipidemia, cerebral hemorrhage, bronchial asthma and cancer.
According to the criteria for hospital discharge of COVID‐19 patients, patients could be discharged only when two PCR tests are negative on consecutive days.
The researchers considered why the PCR tests of Patients 1 and 2 continued to be positive for an extended period. ‘’We found that these two patients had mental retardation and/or psychiatric disorders and did not voluntarily brush their teeth during hospitalized life isolated in private rooms,’’ they observed.
In comparison, Patients 3 through 8 were able to voluntarily brush their teeth on a regular basis.
Patients 1 and 2 were instructed on the importance of oral care, including tooth brushing and gargling. Subsequently, their PCR tests became negative in four to nine days, and they were able to leave the hospital.
“Oral care, including tooth brushing and gargling, may be a factor in the duration of viral shedding, especially in patients with mental retardation and psychiatric disorders who cannot brush their teeth voluntarily during isolated hospitalized lives,” the researchers observed.
“When patients who cannot brush their teeth voluntarily must be isolated due to an infectious disease, including COVID‐19, clinicians should be conscious that the patients have appropriate oral care. Proper oral hygiene may decrease the observed viral shedding period and prevent unnecessarily long hospital stays.”
In such prolonged viral shedding cases, noninfectious viral nucleic acid may accumulate in an uncleaned oral cavity and may continue to be detected by PCR. “We propose tooth brushing and gargling to remove accumulated noninfectious viral nucleic acid, leading to consistently negative PCR test results and thus avoiding unnecessarily long hospital stays,” the researchers concluded.
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Dr. Joseph D. Lim is the former Associate Dean of the UE College of Dentistry, former Dean of the College of Dentistry, National University, past president and honorary fellow of the Asian Oral Implant Academy, and honorary fellow of the Japan College of Oral Implantologists. Honorary Life Member of Thai Association of Dental Implantology. For questions on dental health, e-mail jdlim2008@gmail.com or text 0917-8591515./PN
