A study by a British dental expert shows the degree of occupational risk of SARS-CoV-2 infection

A study of more than 1000 dental professionals led by the University of Birmingham showed an increased occupational risk of SARS-CoV-2 infection during the first wave of the pandemic in the United Kingdom. ..

The observation cohort study published today (June 3, 2021) is: Journal of Dental Research, 1,507 Midland Dental Care Workers Participated. Blood samples were taken from the cohort at the start of the study in June 2020 to measure antibody levels against SARS-CoV-2, the virus responsible for COVID-19.

The team found that 16.3% of study participants, including dentists, dental nurses, and dental hygienists, had SARS-CoV-2 antibodies. General population At the time. On the other hand, the proportion of SARS-CoV-2 antibody in the receptionist of the dental clinic who is not in direct contact with the patient is similar to that of the general population, supporting the hypothesis that occupational risk resulted from close contact with the patient. I am.

In this study, ethnicity was also an important risk factor for infection, with 35% of black participants and 18.8% of Asian participants carrying SARS-CoV-2 antibodies, compared with white participants. Was 14.3%.

Blood samples were taken from participants in September 2020, three months later. Infectious disease countermeasures Six months after the survey began, in January 2021, the second wave of the pandemic, healthcare workers were vaccinated.

The results showed that more than 70% of people previously infected with COVID-19 continued to retain SARS-CoV-2 antibody after both 3 and 6 months, reducing the risk of reinfection by 75%. I showed that. Virus.

The study also showed the immunological effects of the COVID-19 vaccine, with 97.7% of previously uninfected individuals showing antibody response at least 12 days after the first Pfizer vaccine. In patients with evidence of previous infection, the antibody response was faster and higher after a single dose of Pfizer vaccine.

In addition, there is no cohort of SARS-CoV-2 levels antibody During the 6 months from the first to the last blood test, more than 147.6 IU / ml in the blood was COVID-19 positive.

“Understanding what antibody test results mean to an individual with respect to the risk of infection is essential for controlling a pandemic,” said lead author Dr. Adrian Shields of the Institute of Immunology and Immunotherapy, University of Birmingham. is.

“Our study has taken the first step in defining the levels required to protect human blood antibody levels from infection for 6 months. In addition, we created antibody levels found by dentists. According to the World Health Organization, we hope that the levels of protection we find can be easily identified and compared in other laboratories by comparing them with the levels contained in the widely available references. “

The corresponding author, Professor Thomas Dietrich of the University of Birmingham School of Dentistry, adds: Natural infections alone are unlikely to produce meaningful and permanent herd immunity. “

Co-author Iain Chapple, professor of periodontology at the University of Birmingham and consultant for restorative dentistry at the Birmingham Community Healthcare Trust, adds: In the patient’s air gastrointestinal tract, perform periodic aerosol production procedures that result in the production of particles in the air.

“Through our research, we are clearly Dental specialist Prior to the new PHE guidance on PPE, there was an increased occupational risk of exposure to SARS-CoV-2. Occupational health measures introduced in general dental practice as a result of COVID-19 appear to eliminate the increased risk, but to see if they successfully blocked the transmission of SARS-CoV-. In addition, this should be thoroughly investigated-2 and other respiratory viruses. “

Co-author Alex Richter, also a professor at the University of Birmingham, said, “This is the first time a large dental cohort has studied the occupational risks of exposure to the lethal respiratory virus.

“It is important to proceed with research to ensure that people are protected from COVID-19 reinfection after spontaneous occurrence. infection And vaccination.

“The nature and duration of immunity in these cohorts becomes important to understand, especially with respect to the effectiveness of vaccination strategies as the COVID-19 pandemic progresses-single, multiple, and vaccinated. Combinations-and variants of concern in connection with new viruses. ”