key: cord-0962768-decrk6km authors: Gugnani, Neeraj; Gugnani, Shalini title: Do aspirating systems have a role in preventing COVID-19 transmission among dental healthcare workers? date: 2021-06-25 journal: Evid Based Dent DOI: 10.1038/s41432-021-0171-5 sha: 3bf62a20c11a26518dedef27a536a24325099ea0 doc_id: 962768 cord_uid: decrk6km Aim The aim of this retrospective cohort study was to determine and compare the seropositivity rates of SARS-CoV-2 among dental healthcare workers (HCWs) working in three different clinics using different types of aspirating systems. The study took place in Ekaterinburg (Russian Federation). Methods A total of 157 HCWs from three different clinics (56, 60 and 41 HCWs, respectively) who worked during the COVID-19 pandemic period (May to August 2020) constituted the cohort. All of the three chosen clinics had followed COVID-19 screening, triage and other recommendations for safe practice. In addition to using personal protective equipment and other common barrier methods to lower virus transmission, these clinics were equipped with different types of aspirating systems that included V6000 used in dry mode, V6000 used in semi-dry mode and VS900, respectively. All HCWs underwent serological testing once a week to detect immunoglobulin G and M antibodies against SARS-CoV-2 using SARS-CoV-2-IgG-EIA-BEST and SARS-CoV-2-IgM-EIA-BEST enzyme immunoassay kits (Vector-Best). Results An overall prevalence of seropositivity was observed to be 11.5% (19/157 HCWs) over a five-month follow-up. The prevalence of infection was not found to be associated with sex or the role of the member in the dental team (dentist/dental assistant). Significantly higher infection rates (p <0.001) were observed among HCWs working in the clinic equipped with the VS900 aspirating vacuum pump without HEPA filters, while the lowest infection rate was found among HCWs working in the clinic using the V6000 aspirating system in dry mode. Conclusions HCWs working in the clinic equipped with an aspirating system which has HEPA filters and released the air into an external environment (V6000) exhibited significantly lower seroprevalence rates compared to HCWs in the clinic using an aspirating system without HEPA filters which released air within the dental operatory away from the operation site (VS900). Methods A total of 157 HCWs from three different clinics (56, 60 and 41 HCWs, respectively) who worked during the COVID-19 pandemic period (May to August 2020) constituted the cohort. All of the three chosen clinics had followed COVID-19 screening, triage and other recommendations for safe practice. In addition to using personal protective equipment and other common barrier methods to lower virus transmission, these clinics were equipped with different types of aspirating systems that included V6000 used in dry mode, V6000 used in semi-dry mode and VS900, respectively. All HCWs underwent serological testing once a week to detect immunoglobulin G and M antibodies against SARS-CoV-2 using SARS-CoV-2-IgG-EIA-BEST and SARS-CoV-2-IgM-EIA-BEST enzyme immunoassay kits (Vector-Best). Results An overall prevalence of seropositivity was observed to be 11.5% (19/157 HCWs) over a five-month follow-up. The prevalence of infection was not found to be associated with sex or the role of the member in the dental team (dentist/dental assistant). Significantly higher infection rates (p <0.001) were observed among HCWs working in the clinic equipped with the VS900 aspirating vacuum pump without HEPA filters, while the lowest infection rate was found among HCWs working in the clinic using the V6000 aspirating system in dry mode. Conclusions HCWs working in the clinic equipped with an aspirating system which has HEPA filters and released the air into an external environment (V6000) exhibited significantly lower seroprevalence rates compared to HCWs in the clinic using an aspirating system without HEPA filters which released air within the dental operatory away from the operation site (VS900). Dental office personnel are considered to be at high risk for COVID-19 transmission owing to their occupational exposure via bio-aerosols and through indirect contact with surfaces that might have been contaminated by respiratory droplets from patients. 1 In fact, production of aerosols and splatter during dental procedures has always been considered a health concern as these may spread infections among dental healthcare workers (HCWs) and other patients. 2 There are many methods documented in the literature that can be used to contain the spread of these aerosols, 3 interventions that can prevent contamination of aerosols in the oral cavity (for example, use of mouthwash); interventions that can prevent aerosols escaping from the mouth (for example, use of rubber dam); interventions that may prevent the spread of aerosols away from the operating site and thereby reduce the overall concentration of aerosols in the dental operatory (for example, use of high-volume suction); and lastly interventions that can decontaminate the aerosols in the atmosphere (for example, use of UV light etc). 2 The authors of the Cochrane review indicated that due to the paucity of robust evidence, reliable conclusions could not be drawn in favour of any of the systems to limit aerosol transmission. However, in order to evaluate the efficacy of highvolume evacuation (HVE) systems, the authors of the Cochrane review conducted a meta-analysis and found these to be beneficial in reducing the level of aerosol contamination when compared to no HVE systems; however, there is still a need to determine and compare the efficacy of different commercially available aspirating systems in controlling COVID-19 transmission. 3 The current paper is an attempt to evaluate the effectiveness of three different aspirating systems used in dental clinics during the COVID-19 pandemic. During the pandemic, it is, of course, difficult and ethically unjustifiable to design randomised controlled trials (RCTs) to evaluate the risk of transmission of the disease. Hence, any data collected over time or in a retrospective manner adds to our understanding of the disease and its Do aspirating systems have a role in preventing COVID-19 transmission among dental healthcare workers? • Use of an aspirating system with HEPA filters and an in-built mechanism for air evacuations outside the clinical environment is useful in minimising the spread of COVID-19 in the dental clinic and hence clinicians should consider adopting such systems for a safe dental practice. behaviour. Contextually, this study was conducted in the peak of the pandemic period between May-August 2020, for which the authors have aptly chosen a retrospective cohort design. This research is indeed much needed at present and the results of studies that aim to determine the efficacy of various strategies to curb the spread of the virus are essential. The second/third wave of the pandemic is still rife in various countries, and many countries are reinstating lockdown and are only allowing limited mobility in order to curb the spread of the virus. In such circumstances, it is crucial that we safeguard our community of dental HCWs by providing them with evidence-based safety guidelines. The aim of this retrospective cohort study was to assess the SARS-CoV-2 seropositivity among dental HCWs working in three different clinics (two private clinics and one government centre) 4 The basic difference between the V6000 and VS900 is that the former is a central aspiration machine with a vacuum controller and a H14 HEPA bacterial filter, and which releases the collected air into an 'external' area outside the clinic, while the VS900 is an aspirating vacuum pump without a HEPA filter. Moreover, the VS900 collects the air and releases it in the same way, away from the operation site but within the clinical area. All HCWs underwent serological testing once a week to detect immunoglobulin G and M antibodies against SARS-CoV-2. Over the said five-month follow-up period, the overall prevalence of SARS-CoV-2 infection in the chosen cohort was observed to be 11.5% (19/157 HCWs were found to be seropositive). Pearson's correlation coefficient with Yate's correction was used for data analysis. The prevalence rate did not exhibit any association with sex or the role of the member in the dental team (dentist or dental assistant). are helpful in stopping aerosol-based contagion transmission. As this was a retrospective study, long-term prospective studies (prospective cohort and RCTs) including diverse cohorts should be done to substantiate these findings. Overall, the rate of seropositivity in the chosen cohort was observed to be higher than the general population residing in other parts of the Russian Federation, which clearly warrants the need to recognise the impending threat from these aerosols and to minimise these to the greatest possible extent. Keeping an optimistic view, the literature suggests that with ongoing vaccination, the pandemic will come to an end but the disease may still remain endemic in society. 5 The associated morbidity with the disease will therefore certainly require us to modify our dental practices and hence the use of very high-quality aspirating systems may become a necessary component of armamentarium in dental clinics worldwide. Safety protocols for dental practices in the COVID-19 era Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases Aerosols and splatter in dentistry: a brief review of the literature and infection control implications High volume evacuator (HVE) in reducing aerosol -an exploration worth by clinicians Endemic SARS CoV 2 will maintain post-pandemic immunity Yamunanagar, Haryana, India.