15/03/2020
Coronavirus Disease 2019 (COVID-19): Emerging and Future Challenges for Dental and Oral Medicine
L. Meng, F. Hua, Z. Bian
First Published March 12, 2020 Research Article
https://doi.org/10.1177/0022034520914246
Article information Open epub for Coronavirus Disease 2019 (COVID-19): Emerging and Future Challenges for Dental and Oral Medicine
Article has an altmetric score of 149 Free Access
Abstract
The epidemic of coronavirus disease 2019 (COVID-19), originating in Wuhan, China, has become a major public health challenge for not only China but also countries around the world. The World Health Organization announced that the outbreaks of the novel coronavirus have constituted a public health emergency of international concern. As of February 26, 2020, COVID-19 has been recognized in 34 countries, with a total of 80,239 laboratory-confirmed cases and 2,700 deaths. Infection control measures are necessary to prevent the virus from further spreading and to help control the epidemic situation. Due to the characteristics of dental settings, the risk of cross infection can be high between patients and dental practitioners. For dental practices and hospitals in areas that are (potentially) affected with COVID-19, strict and effective infection control protocols are urgently needed. This article, based on our experience and relevant guidelines and research, introduces essential knowledge about COVID-19 and nosocomial infection in dental settings and provides recommended management protocols for dental practitioners and students in (potentially) affected areas.
Keywords virology, infection control, dental public health, dental education, transmission, dental practice management
Introduction
On January 8, 2020, a novel coronavirus was officially announced as the causative pathogen of COVID-19 by the Chinese Center for Disease Control and Prevention (Li et al. 2020). The epidemics of coronavirus disease 2019 (COVID-19) started from Wuhan, China, last December and have become a major challenging public health problem for not only China but also countries around the world (Phelan et al. 2020). On January 30, 2020, the World Health Organization (WHO) announced that this outbreak had constituted a public health emergency of international concern (Mahase 2020). The novel coronavirus was initially named 2019-nCoV and officially as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of February 26, COVID-19 has been recognized in 34 countries, with a total of 80,239 laboratory-confirmed cases and 2,700 deaths (WHO 2020b).
Due to the characteristics of dental settings, the risk of cross infection may be high between dental practitioners and patients. For dental practices and hospitals in countries/regions that are (potentially) affected with COVID-19, strict and effective infection control protocols are urgently needed. This article, based on our experience and relevant guidelines and research, introduces the essential knowledge about COVID-19 and nosocomial infection in dental settings and provides recommended management protocols for dental practitioners and students in (potentially) affected areas.
What Is COVID-19?
Viral Etiology
According to recent research, similar to SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV-2 is zoonotic, with Chinese horseshoe bats (Rhinolophus sinicus) being the most probable origin (Chan et al. 2020; Lu et al. 2020) and pangolins as the most likely intermediate host (The Chinese Preventive Medicine Association 2020).
Epidemiologic Characteristics
Mode of Transmission
Based on findings of genetic and epidemiologic research, it appears that the COVID-19 outbreak started with a single animal-to-human transmission, followed by sustained human-to-human spread (Chan et al. 2020; Del Rio and Malani 2020). It is now believed that its interpersonal transmission occurs mainly via respiratory droplets and contact transmission (The Chinese Preventive Medicine Association 2020). In addition, there may be risk of fecal-oral transmission, as researchers have identified SARS-CoV-2 in the stool of patients from China and the United States (Holshue et al. 2020). However, whether SARS-CoV-2 can be spread through aerosols or vertical transmission (from mothers to their newborns) is yet to be confirmed (Chen, Guo, et al. 2020; WHO 2020c; Zhu et al. 2020).
Source of Transmission
Although patients with symptomatic COVID-19 have been the main source of transmission, recent observations suggest that asymptomatic patients and patients in their incubation period are also carriers of SARS-CoV-2 (Chan et al. 2020; Rothe et al. 2020). This epidemiologic feature of COVID-19 has made its control extremely challenging, as it is difficult to identify and quarantine these patients in time, which can result in an accumulation of SARS-CoV-2 in communities (The Chinese Preventive Medicine Association 2020). In addition, it remains to be proved whether patients in the recovering phase are a potential source of transmission (Rothe et al. 2020).
Incubation Period
The incubation period of COVID-19 has been estimated at 5 to 6 d on average, but there is evidence that it could be as long as 14 d, which is now the commonly adopted duration for medical observation and quarantine of (potentially) exposed persons (Backer et al. 2020; Li et al. 2020).
Fatality Rate
According to current data, the fatality rate (cumulative deaths divided by cumulative cases) of COVID-19 is 0.39% to 4.05%, depending on different regions of China, which is lower than that of SARS (severe acute respiratory syndrome; ≈10%) and MERS (Middle East respiratory syndrome; ≈34% (Malik et al. 2020) and higher than that of seasonal influenza (0.01% to 0.17%) according to data for 2010 to 2017 from the US Centers for Disease Control and Prevention (2020).
People at High Risk of Infection
Current observations suggest that people of all ages are generally susceptible to this new infectious disease. However, those who are in close contact with patients with symptomatic and asymptomatic COVID-19, including health care workers and other patients in the hospital, are at higher risk of SARS-CoV-2 infection. In the early stage of the epidemic, in an analysis of 138 hospitalized patients with COVID-19 in Wuhan, 57 (41%) were presumed to have been infected in hospital, including 40 (29%) health care workers and 17 (12%) patients hospitalized for other reasons (Wang et al. 2020). As of February 14, 2020, a total of 1,716 health care workers in China were infected with SARS-CoV-2, consisting of 3.8% affected patients nationally, 6 of that group who have died.
Clinical Manifestations
The majority of patients with COVID-19 represent relatively mild cases. According to recent studies (Guan et al. 2020; Yang et al. 2020) and data from the National Health Commission of China (2020b), the proportion of severe cases among all patients with COVID-19 in China was around 15% to 25%.
The majority of patients experienced fever and dry cough, while some also had shortness of breath, fatigue, and other atypical symptoms, such as muscle pain, confusion, headache, sore throat, diarrhea, and vomiting (Chen, Zhou, et al. 2020; Guan et al. 2020). Among patients who underwent chest computed tomography (CT), most showed bilateral pneumonia, with ground-glass opacity and bilateral patchy shadows being the most common patterns (Guan et al. 2020; Wang et al. 2020).
Among hospitalized patients in Wuhan, around one-fourth to one-third developed serious complications, such as acute respiratory distress syndrome, arrhythmia, and shock, and were therefore transferred to the intensive care unit (Chen, Zhou, et al. 2020; Huang et al. 2020; Wang et al. 2020). In general, older age and the existence of underlying comorbidities (e.g., diabetes, hypertension, and cardiovascular disease) were associated with poorer prognosis (Kui et al. 2020; Wang et al. 2020; Yang et al. 2020).
Diagnosis and Treatment
The diagnosis of COVID-19 can be based on a combination of epidemiologic information (e.g., a history of travel to or residence in affected region 14 d prior to symptom onset), clinical symptoms, CT imaging findings, and laboratory tests (e.g., reverse transcriptase polymerase chain reaction [RT-PCR] tests on respiratory tract specimens) according to standards of either the WHO (2020a) or the National Health Commission of China (2020a). It should be mentioned that a single negative RT-PCR test result from suspected patients does not exclude infection. Clinically, we should be alert of patients with an epidemiologic history, COVID-19–related symptoms, and/or positive CT imaging results.
So far, there has been no evidence from randomized controlled trials to recommend any specific anti-nCoV treatment, so the management of COVID-19 has been largely supportive (WHO 2020a). Currently, the approach to COVID-19 is to control the source of infection; use infection prevention and control measures to lower the risk of transmission; and provide early diagnosis, isolation, and supportive care for affected patients (Wang et al. 2020). A series of clinical trials are being carried out to investigate interventions that are potentially more effective (e.g., lopinavir, remdesivir; Del Rio and Malani 2020).
Infection Control in Dental Settings
Risk of Nosocomial Infection in Dental Settings
Dental patients who cough, sneeze, or receive dental treatment including the use of a high-speed handpiece or ultrasonic instruments make their secretions, saliva, or blood aerosolize to the surroundings. Dental apparatus could be contaminated with various pathogenic microorganisms after use or become exposed to a contaminated clinic environment. Thereafter, infections can occur through the puncture of sharp instruments or direct contact between mucous membranes and contaminated hands (Kohn et al. 2003).
Due to the unique characteristics of dental procedures where a large number of droplets and aerosols could be generated, the standard protective measures in daily clinical work are not effective enough to prevent the spread of COVID-19, especially when patients are in the incubation period, are unaware they are infected, or choose to conceal their infection.
Effective Infection Control Protocols
Hand hygiene has been considered the most critical measure for reducing the risk of transmitting microorganism to patients (Larson et al. 2000). SARS-CoV-2 can persist on surfaces for a few hours or up to several days, depending on the type of surface, the temperature, or the humidity of the environment (WHO 2020c). This reinforces the need for good hand hygiene and the importance of thorough disinfection of all surfaces within the dental clinic. The use of personal protective equipment, including masks, gloves, gowns, and goggles or face shields, is recommended to protect skin and mucosa from (potentially) infected blood or secretion. As respiratory droplets are the main route of SARS-CoV-2 transmission, particulate respirators (e.g., N-95 masks authenticated by the National Institute for Occupational Safety and Health or FFP2-standard masks set by the European Union) are recommended for routine dental practice.
Recommended Measures during the COVID-19 Outbreak
Recommendations for Management
In January 2020, the National Health Commission of China added COVID-19 to the category of group B infectious diseases, which includes SARS and highly pathogenic avian influenza. However, it also suggested that all health care workers use protection measures similar to those indicated for group A infections—a category reserved for extremely infectious pathogens, such as cholera and plague.
Since then, in most cities of the mainland of China, only dental emergency cases have been treated when strict implementation of infection prevention and control measures are recommended. Routine dental practices have been suspended until further notification according to the situation of epidemics.
Additionally, dentistry-related quality control centers and professional societies in many provinces and cities have put forward their recommendations for dental services during the COVID-19 outbreak, which, as supplementary measures, should be helpful in ensuring the quality of infection control (Li and Meng 2020).
Current Status of Our School and Hospital
The School and Hospital of Stomatology, Wuhan University provided dental care (including oral and maxillofacial surgery) to around 890,000 patients last year and is home to 1,098 staff and 828 students. Our hospital does not have a fever clinic or belong to a designated one for patients with COVID-19. Any staff member who has fever, cough, sneezing, or COVID-19–related symptoms or has a close family member who is confirmed with the infection is advised to undergo a medical examination in a designated hospital and cease working. Since this epidemic, 9 of our colleagues have been confirmed to have COVID-19, including 3 doctors, 3 nurses, 2 administrative staff, and 1 postgraduate student (Fig. 1, Table). So far, there have been no further cases among colleagues or patients who had close contact with them. According to analyses of epidemiologic investigation and medical history, all these cases are without obvious aggregation, except 2 nurses from the same department (patients 2 and 3), and are unlikely to result from cross infection. The infection was possibly limited because medical masks and gloves worn during routine clinic work of dental practitioners prevented further transmission.
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Figure 1. Location of staff and student confirmed with coronavirus disease 2019 (COVID-19) in the main buildings in the School and Hospital of Stomatology, Wuhan University. There are 3 main buildings in our hospital. Building 1 mainly contains outpatients, classrooms, and a library. Its air renewal system depends on air conditioners. Building 2 contains outpatients, wards, and administrative regions. This building was equipped with central air conditioners and a fresh air system. Building 3 is a research laboratory, and it also depends on air conditioners. See Table for details.
Table
Table. A Brief Introduction to the Staff and Student Confirmed with COVID-19 in School and Hospital of Stomatology, Wuhan University.
Table. A Brief Introduction to the Staff and Student Confirmed with COVID-19 in School and Hospital of Stomatology, Wuhan University.
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Despite the increasing number of confirmed cases during this period in Wuhan, we (169 staff involved in duty of dental emergency) have treated >700 patients with emergent dental treatment need since January 24 (Fig. 2), under the premise of adequate protection measures. All the dental procedures were recorded daily, and patients and their accompanying persons were requested to provide their phone number and home address in the case that either our staff or patients are suspected or confirmed with COVID-19 in the future. We have also provided consultations to >1,600 patients on our online platform since February 3. No further COVID-19 infection has been reported among our staff, which confirmed the effectiveness of our infection control measures in COVID-19 prevention within dental settings (Fig. 3).
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Figure 2. Number of outpatients treated at the School and Hospital of Stomatology, Wuhan University (WHUSS), and cumulative number of confirmed cases with coronavirus disease 2019 (COVID-19) in Wuhan city from December 30, 2019, to February 25, 2020. *Weekends and national holidays (including the extended spring festival holiday). Seafood Market was closed in Wuhan city after the majority of the earliest COVID-19 cases were linked to the Huanan Seafood Wholesale Market. &Lockdown of Wuhan city started. According to the epidemic situation, the notification of city lockdown was made to stop any transportation, including airplane, train, and bus, from Wuhan city to prevent COVID-19 transmission, especially because of population movement during Chinese Spring Festival. Before January 21, WHUSS staff had only medical masks and gloves. On January 22, we started to use disposable surgical masks, N95 masks, and gowns. Goggles and protective suits were not available until January 28.
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Figure 3. The personal protective equipment (PPE) diagram for divisions in the emergency care area at the School and Hospital of Stomatology, Wuhan University, during the coronavirus disease 2019 (COVID-19) outbreak. Yellow: triage and waiting area. Orange: dental clinic. Red: isolation clinic. Green: resting area for staff only. As shown in the diagram, our triage staff in the yellow area wear disposable surgical mask, cap, and work clothes. In the orange area, dental staff is provided with PPE, including disposable N95 masks, gloves, gowns, cap, shoe cover, and goggles or face shield. The area is disinfected once every half day. Before February 21, all the patients were treated in this area. The isolation clinic in the red area was set up on February 21. It is designed for patients who are suspected with COVID-19, who are recovering from COVID-19 (but
WHO is continuously monitoring and responding to this outbreak. This Q&A will be updated as more is known about COVID-19, how it spreads and how it is affecting people worldwide. For more information, check back regularly on WHO’s coronavirus pages. https://www.who.int/emergencies/diseases/novel-c...
