Journal Club- May 2020: COVID-19
Coronavirus Disease 19 (COVID-19): implications for clinical dental care. Ather, A., Patel, B., Ruparel, N.B., Diogenes, A., Hargreaves, K.M. J Endodontics 2020; ahead of print. DOI: 10.1016/j.joen.2020.03.008
Respiratory virus shedding in exhaled breath and efficacy of face masks. Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C., et al. Nat Med 2020; ahead of print. DOI: 10.1038/s41591-020-0843-2
Novel Coronavirus (COVID-19) Knowledge and Perceptions: A Survey of Healthcare Workers. BHAGAVATHULA A, Aldhaleei WA, Rahmani JR, Mahabadi MA, Bandari D. DOI: 10.2196/19160 URL: https://preprints.jmir.org/preprint/19160
Transmission routes of 2019-nCoV and controls in dental practice. Peng, X., Xu, X., Li, Y. et al. Int J Oral Sci 12, 9 (2020). https://doi.org/10.1038/s41368-020-0075-9
Coronavirus Disease 2019 (COVID-19): Emerging and Future Challenges for Dental and Oral Medicine. Meng L, Hua F, Bian Z. J Dent Res. 2020 Mar 12:22034520914246. DOI: 10.1177/0022034520914246.
Maxillofacial surgery and COVID-19, The Pandemic !! Bali RK, Chaudhry K. J Maxillofac Oral Surg. 2020 Apr 11:1-3. DOI: 10.1007/s12663-020-01361-8.
Epidemiological and Clinical Aspects of COVID-19; A Narrative Review. Kolifarhood G, Aghaali M, Mozafar Saadati H, Taherpour N, Rahimi S, Izadi N, Hashemi Nazari S S. Arch Acad Emerg Mede. 2020;8(1): e41.
COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy. Izzetti, R., et al. Journal of Dental Research, 2020, p. 002203452092058., doi:10.1177/0022034520920580.
The impact of COPD and smoking history on the severity of Covid-19: A systemic review and meta-analysis. Zhu et al. Journal of Medical Virology. 15 April 2020. Doi: 10.1002/jmv.25889
Renin–Angiotensin–Aldosterone System Inhibitors in Patients with Covid-19. Vaduganathan et al. The New England Journal of Medicine. March 30, 2020. DOI: 10.1056/NEJMsr2005760
Aerosol and surface distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards, Wuhan, China, 2020. Guo Z-D, Wang Z-Y, Zhang S-F, Li X, Li L, Li C, et al. Emerg Infect Dis. 2020 Jul [4/27/20]. https://doi.org/10.3201/eid2607.200885
The practice of wearing surgical masks during the COVID-19 pandemic. Chiang C-Ha, Chiang C-Hu, Chiang C-Hs, Chen Y-C. Emerg Infect Dis. 2020 Aug [4/27/2020]. https://doi.org/10.3201/eid2608.201498
Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Hellewell J, Abbott S, Gimma A, Lancet Glob Health 2020; 8: e488–96, February 28, 2020, DOI: https://doi.org/10.1016/ S2214-109X(20)30074-7
On the origin and continuing evolution of SARS-CoV-2. Tang X, Wu C, Li X, National Science Review, March 3rd 2020, DOI: https://doi.org/10.1093/nsr/nwaa036
The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak – an update on the status. Guo et al. Military Medical Research 2020; 7(11): 1-10 DOI: 10.1186/s40779-020-00240-0
Novel coronavirus disease (COVID-19): a pandemic (epidemiology, pathogenesis and potential therapeutics). Hamid, S., Mir, MY., and Rohela, GK. New Microbe and New Infect 2020; 35(C): 1-10 DOI: 10.1016/j.nmni.2020.100679
Author: Ather, A., Patel, B. et al.
Title: Coronavirus Disease 19 (COVID-19): Implications for Clinical Dental Care
Source: J Endodontics 2020 (March 27)
Reviewer: Mary Elizabeth Bush
Keywords: COVID-19, dental care, PPE
Purpose: To provide a summary of diagnosing and managing patients with COVID-19 as it relates to dentistry, as of March 2020.
Symptoms: Symptoms of COVID-19 include fever, dry cough, myalgia and less common symptoms including nausea, diarrhea, and hyposmia. Upon chest X-ray and CT abnormal findings in the chest include ground glass opacities. About 80% of patients have very mild symptoms either flu-like or mimicking seasonal allergies. These carriers can act as a reservoir for infection transmission, especially given the varying incubation time from 9 to 24 days.
Routes of Transmission: Typically, it is spread by contact, respiratory droplets or fomites. The SARS-CoV-2 virus is present in saliva, so aerosol transmission is a concern.
Patient Management and Prevention of Nosocomial Infection:
- Telescreening and Triage: Attempts should be made to prevent possibly infected individuals from arriving at the office. 3 main questions include: whether there has been contact with a COVID-19 positive patient, recent travel to a “hotspot” or any current respiratory illness. These patients should self-isolate and postpone care and/or contact their physician.
- Patient Evaluation and Cohorting: Patients arriving to an office should have a temperature screen. Any patient with fever should be separated from healthy patients. Additionally, masks should be worn by patients.
- Pharmacologic Management: In suspected COVID-19 patients pharmacologic management should be considered first in order to delay treatment if possible.
*What precautions are needed for presumed healthy patients?
*Additional graphs with reminders on proper PPE donning/removal.
Specific Dental Treatment Recommendations: Strict PPE must be observed including airborne precautions. At this time, COVID-19 positive patients should be treated in negative pressure rooms. All patients should use preprocedural mouth rinse, previous studies showed Povidone iodine rinses were effective against SARS-CoV-1 and MERS-CoV, additional hydrogen peroxide is virucidal against coronaviruses.
Discussion: Ultimately specialists will be needed to treat patients for emergencies during this time, and as things move forward dentistry needs to be able to provide care while mitigating the risk of spread of the infection. As we start seeing patients again, some of whom may be asymptomatic, standard precautions should be updated to protect patients and staff.
Author: Leung NHL, et al.
Title: Respiratory virus shedding in exhaled breath and efficacy of face masks.
Source: Nat Med 2020 (April 3)
Type: clinical study
Reviewer: Mary Elizabeth Bush
Keywords: virus shedding, transmission, aerosols, exhaled breath, face masks
Purpose: To explore the potential respiratory droplet and aerosol routes of transmission with a focus on coronaviruses, influenza viruses and rhinoviruses.
Methods: Patients were recruited from 2013-2016 who were experiencing respiratory infection symptoms including fever, cough, sore throat, runny nose, etc. Patients received rapid influenza testing as well as nasal and throat swabs. Patients were randomly allocated to either wearing a surgical face mask or no mask during collection of exhaled breath over a 30-minute period. Patients were instructed to breath normally, and the amount of coughing was noted. Samples were tested using a viral panel to detect 12 common respiratory viruses including coronaviruses (NL63, OC43, 229E, and HKU1), influenza A and B viruses, respiratory syncytial virus, parainfluenza virus, adenovirus, human metapneumovirus and enterovirus/rhinovirus. High frequency viruses including coronaviruses, influenza virus, and rhinovirus were further analyzed.
Results: 3,363 patients were screened and 246 were included for exhaled breath samples. 122 were assigned to the no mask group and 124 were randomized to the surgical face mask group. 50% (123) of the participants were confirmed to be infected by at least 1 respiratory virus, of which 90% (111) had seasonal coronavirus, influenza or rhinovirus. These 111 patients are included in the final analysis. Influenza patients were most likely to have a fever. While coronavirus-infected patients coughed the most (average of 17 per 30-min).
Viral Shedding: Viral shedding was higher in nasal swaps than in throat swabs for coronavirus, influenza and rhinovirus. Viral RNA was identified from respiratory droplets and aerosols for all three viruses.
|Virus Type||Respiratory Droplets (>5um)||Aerosol Particles (<5um)|
|Without face mask||With face mask||Without face mask||With face mask|
|Influenza Virus||26%||4% (0.04)||35%||22%|
Discussion: The results show that aerosol transmission is possible in exhaled breath for coronaviruses, influenza, and rhinoviruses. Surgical masks can significantly reduce the emission of influenza virus particles by respiratory droplets but not by aerosols with a surgical mask. For coronavirus, surgical masks were able to reduce both respiratory droplets and aerosol particles. Suggesting that mask wearing by ill patients can reduce transmission. Notably, the majority of patients did not shed virus particles during exhaled breath, and even after 30 minutes the overall viral load was low. Prolonged close contact may be necessary for transmission to occur via aerosols. Still virus RNA in a small number was detected even when no coughing occurred, which supports the potential for transmission when signs/symptoms are not apparent.
Author: BHAGAVATHULA A, Aldhaleei WA, Rahmani JR, Mahabadi MA, Bandari DK
Title: Novel Coronavirus (COVID-19) Knowledge and Perceptions: A Survey of Healthcare Workers
Reviewer: Hector Carmona
Purpose: This study aimed to investigate the knowledge and perceptions of HCWs about COVID-19.
Methods: A cross-sectional, web-based study was conducted among HCWs about COVID-19 during the first week of March 2020. The 23-item questionnaire was divided into three parts, including participant characteristics (3 items), awareness of COVID-19 (2 items), source of information (4 statements/4- point Likert scale: 1- least used to 4-most used), knowledge about symptoms of COVID-19-affected patients (2 items), different modes of transmission (2 items), precautions and risk prevention (3 items) and perceptions of COVID-19 (7 items/true or false questions) The survey covered the domains of HCWs characteristics, awareness, information sources, knowledge and perceptions related to COVID-19.A chi-square test was used to investigate the level of association among variables at the significance level of p<0.05.
Results: A total of 529 HCWs participated, 453 of whom completed the study questionnaire (85.6% response rate), including 234 (51.6%) men and 219 (48.3%) women; most of the participants were below 44 years of age (82.4%). The majority of participants were doctors (n=137, 30.2%) or medical students (n=134, 29.6%) and were from Asia (68%). Almost all participants agreed that they had heard about COVID-19 (97.8%), but only 44.1% of them had the opportunity to attend lectures/discussions about COVID-19.
Medical students 29.6%
Academic Doctors 13.5%
Approximately 30% of the participants reported that they used news media (TV/video, magazines, newspapers, and radio) and social media (Facebook, Twitter, Whatsapp, YouTube, Instagram, Snapchat) to obtain information about COVID-19. Moreover, nearly 40% of the participants sometimes discussed COVID-19-related topics with family and friends.
Approximately two-thirds of doctors and half of allied health workers thought that the origin of COVID-19 was bats (65.7% vs. 55.7%). A high majority of the HCWs (85.6%) agreed that maintaining hand hygiene, covering the nose and mouth while coughing, and avoiding sick patients could help to prevent COVID-19 transmission.
Nearly 90% of the youngest participants (<25 years) and 92% of the doctors believed that the symptoms of COVID-19 appeared as early as 2 to 14 days; the differences among the respondent groups were statistically significant. Only half (52%) of the HCWs aged 45-65 years believed that the symptoms of COVID-19 appeared as early as 2 to 14 days. Moreover, a significant proportion of the doctors perceived eating well-cooked/handled meat to be safe (83.2%). Medical students were found to have the perception that flu vaccination is not sufficient to prevent COVID-19 transmission (88%). More than a quarter of the medical students thought that eating meat during the outbreak was unsafe.
Conclusion: A significant gap in the source of information, poor knowledge levels, and discrepancies in perceptions of COVID-19 among study participants.
Author: Peng, X., Xu, X., Li, Y. et al.
Title: Transmission routes of 2019-nCoV and controls in dental practice.
Source: Int J Oral Sci 12, 9 (2020).
Reviewer: Hector Carmona
Purpose: To assess the possible routes of transmission in a Dental setting of COVID19.
Discussion: The common transmission routes of novel coronavirus include direct transmission (cough, sneeze, and droplet inhalation transmission) and contact transmission (contact with oral, nasal, and eye mucous membranes. The analysis if conjunctival samples from confirmed and suspected cases suggests that transmission in not limited to the respiratory tract. Studies have suggested that COVID19 may be airborne through aerosols formed during medical procedures. The virus was detected in the stool of patients on day 7 of illness. However, the aerosol transmission route and the fecal-oral transmission route still need to be further studied.
Dental patients and professionals can be exposed to pathogenic microorganisms, including viruses and bacteria that infect the oral cavity and respiratory tract. Dental care settings invariably carry the risk of 2019-nCoV infection due to the specificity of its procedures, which involves face-to-face communication with patients, and frequent exposure to saliva, blood, and other body fluids, and the handling of sharp instruments. The pathogenic microorganisms can be transmitted in dental settings through inhalation of airborne microorganisms that can remain suspended in the air for long periods, direct contact with blood, oral fluids, or other patient materials, contact of conjunctival, nasal, or oral mucosa with droplets and aerosols containing microorganisms generated from an infected individual and propelled a short distance by coughing and talking without a mask, and indirect contact with contaminated instruments and/or environmental surfaces.
A dental professional’s frequent direct or indirect contact with human fluids, patient materials, and contaminated dental instruments or environmental surfaces creates a route of transmission.
Here we recommend the infection control measures that should be followed by dental professionals, particularly considering the fact that aerosols and droplets were considered as the main spread routes of 2019-nCoV. First of all, dental professionals should be able to identify a suspected case of COVID-19. In general, a patient with COVID-19 who is in the acute febrile phase of the disease is not recommended to visit the dental clinic.
A contact-free forehead thermometer is strongly recommended for the screening. A questionnaire should be used to screen patients with potential infection of 2019-nCoV before they could be led to the dental chair-side.
These questions should include the following:
- Do you have fever or experience fever within the past 14 days?
- Have you experienced a recent onset of respiratory problems, such as a cough or difficulty in breathing within the past 14 days?
- Have you, within the past 14 days, traveled to Wuhan city and its surrounding areas, or visited the neighborhood with documented 2019-nCoV transmission?
- Have you come into contact with a patient with confirmed 2019- nCoV infection within the past 14 days?
- Have you come into contact with people who come from Wuhan city and its surrounding areas, or people from the neighborhood with recent documented fever or respiratory problems within the past 14 days?
- Are there at least two people with documented experience of fever or respiratory problems within the last 14 days having close contact with you?
- Have you recently participated in any gathering, meetings, or had close contact with many unacquainted people?
If a patient replies “yes” to any of the screening questions, and his/her body temperature is below 37.3 °C, the dentist can defer the treatment until 14 days after the exposure event. The patient should be instructed to self-quarantine at home and report any fever experience or flu-like syndrome to the local health department. If a patient replies “yes” to any of the screening questions, and his/her body temperature is no less than 37.3 °C, the patient should be immediately quarantined, and the dental professionals should report to the infection control department of the hospital or the local health department.
A preoperational antimicrobial mouth rinse is generally believed to reduce the number of oral microbes. However, as instructed by the Guideline for the Diagnosis and Treatment of Novel Coronavirus Pneumonia (the 5th edition) released by the National Health Commission of the People’s Republic of China, chlorhexidine, which is commonly used as mouth rinse in dental practice, may not be effective to kill 2019-nCoV. The use of rubber dams can significantly minimize the production of saliva- and blood-contaminated aerosol or spatter, particularly in cases when high-speed handpieces and dental ultrasonic devices are used.
Authors: Meng L, Hua F, Bian Z.
Title: Coronavirus Disease 2019 (COVID-19): Emerging and Future Challenges for Dental and Oral Medicine.
Source: J Dent Res. 2020 Mar 12:22034520914246
Reviewer: Hillary Wright
Keywords: COVID-19; dental offices; coronavirus
Purpose: to discuss relevant guidelines and research about COVID-19 in the dental setting.
Discussion: COVID-19 is a zoonotic origin respiratory virus with the Chinese horseshoe bats being the most probable origin. Mode of transmission based on genetic and epidemiologic research began with a single animal-human transmission and sustained human-human spread. Interpersonal transmission occurs mainly via respiratory droplets and contact transmission. There may also be a risk of fecal-oral transmission. Not only can symptomatic COVID-19 patients transmit the disease, but observations that asymptomatic COVID-19 patients can be carriers, which makes containment challenging. It also remains to be proven if recovering patients are a potential source of transmission. Incubation period has been estimated 5-6 days but can be up to 14 days, which is the adopted duration for medial observation and quarantine.
Healthcare workers and other patients in the hospital are at higher risk of contracting the virus. Clinical manifestations include fever, dry cough, some have shortness of breath, and fatigue. Chest CT majority shows bilateral pneumonia, with ground glass opacity and bilateral patchy shadows. Among hospitalized patients in Wuhan, 25-33% developed serious complications of acute respiratory distress, arrhythmia and shock. In general, older age and existence of co-morbidities were associated with poorer prognosis.
Diagnosis and treatment based on combination of epidemiologic studies. So far, no evidence from randomized controlled trials to recommend any specific anti-nCoV treatment. Treatment includes control of source of infection, use infection prevention measures, early diagnosis, isolation, and supportive care for affected patients.
Infection control in the dental setting: Hand hygiene is considered the most critical measure for reducing the risk of transmitting microorganisms. The use of PPE including masks, gloves, gowns, and googles or face shields is recommended to protect skin and mucosa from infected blood or secretion. Use of N-95 masks are recommended for routine dental practices.
Interim guidance on infection prevention and control: Clinicians should limit operations that can produce droplets or aerosols. Use of saliva ejectors with high or low volume can reduce production of droplets and aerosols. During the outbreak, dental clinics are recommended to establish precheck triages to measure and record the temperature of every staff and patient, ask questions about health status and history of contact or travel. If a patient has been to epidemic regions, a 14 day quarantine is suggested. Non-emergent dental practices should be postponed. Preoperative antimicrobial oral mouth rinse could reduce the number of microbes. Use of extraoral radiograph techniques should be used over intraoral to reduce coughing. Treatment of dental emergencies. Use of rubber dam and high-volume saliva ejectors can minimize aerosols. Absorbable sutures to reduce unnecessary is visits is also recommended.
Authors: Bali RK, Chaudhry K.
Title: Maxillofacial surgery and COVID-19, The Pandemic !!
Source: J Maxillofac Oral Surg. 2020 Apr 11:1-3
Reviewer: Hillary Wright
Keywords: coronavirus; dental surgery
Purpose: to discuss how to navigate fulfilling professional obligations.
Discussion: Current practices of infection control in the dental setting have always been rigorous. The COVID-19 can remain infectious on inanimate surfaces for 2 hours up to 9 days, depending on the temperature, humidity, type of surface and viral load.
Reinforcement of best practices in infection control including hand hygiene, barrier techniques, use of personal protective equipment, disinfection of surfaces, and sterilization of equipment. Disinfection with sodium hypochlorite 0.1% for 1 minute has been found to be effective.
Telescreening, telemedicine, and triaging will have to be utilized. The Medical Council of India has framed guidelines for the practice of telemedicine allowing consultations to be done online or via phone. Positive responses to relevant travel history to COVID-19 infected locations, presence of symptoms such as fever, shortness of breath, cough, and loss of smell/taste should raise concern and elective care postponed for 3 weeks. Recommendation to avoid elective procedures at all costs to protect our community patients, staff, and ourselves.
Droplets are the main source of transmission from COVID-19 patients. While treating positive or suspected patients, the N-95 masks in addition to a face shield should be used as a minimum requirement during aerosol and surgical smoke generating procedures. However, N-95 masks were not found to be adequate to prevent transmission in Chinese surgeons and powered air purifying respirators had to be used to prevent transmission from COVID patients. Triple layered protection gown and head caps are recommended to prevent fomite-based transmission.
SARS and MERS studies showed they were highly susceptible to Betadine rinse and can be assumed that a preprocedural rinse would reduce the load of the coronavirus in saliva. Povidone Iodine has also been shown to have significant viricidal activity for about three hours and has been recommended to coat the oral cavity and nasal passages of both the patient and the operating team before the procedure. When possible, patients with suspected or confirmed COVID-19 should not be treated in routine practice setting but managed in negative pressure theaters or airborne infection isolation rooms.
When doing open surgery, scalpel should be used over monopolar cautery and repeated suction/ irrigation should be minimized. Absorbable sutures should also be used to minimize unnecessary trips for removal.
Author: Kolifarhood G, Aghaali M, Mozafar Saadati H, Taherpour N, Rahimi S, Izadi N, Hashemi Nazari S
Title: Epidemiological and Clinical Aspects of COVID-19; a Narrative Review
Source: Archives of Academic Emergency Medicine
Type: Narrative review
Reviewer: Thao Nguyen
Keywords: COVID-19, Severe acute respiratory syndrome coronavirus; epidemiology, public health; diseases, emerging
Purpose: to review the different epidemiological and clinical aspects of the new emerging disease along with specific measures by countries in the community level.
Methods: A literature search was performed using articles published from 05 January to 28 February 2020 in PubMed, Web of Science, Scopus, ScienceDirect, JAMA, BMJ, Oxford and The Lancet. Key terms such as coronavirus, COVID-19 and 2019-nCoV were used. The studies were reviewed by each author who screened both the titles and abstracts and excluded studies that used old data, had inappropriate topics or were not pertinent to the focused purpose of the study. Results were then extracted from each study by all seven review authors collecting information regarding, genetic diversity of the coronavirus genus, mode of transmission, incubation period, infectivity, pathogenicity, virulence, immunogenicity, diagnosis, surveillance, clinical case management, and special measures in community level and health care facilities.
Results: The total number of articles included in the study was not disclosed by the researchers. Results were broken down into twelve unique categories.
Examining the genetic difference between COVID-19 and SARS and MERS, current literature suggests that the virus is most closely related to bat coronavirus at a 98% genome match and differs from both SARS and MERS which only has a 79% and 50% genome match respectively. COVID-19 pathogen is therefore classified as a member of the beta-coronavirus genus.
Current literature suggests that transmission of COVID-19 occurs either via respiratory droplets or close contact. COVID is unique in that it can spread via both oral and nasal droplets and can float in the air in the form of aerosols. There is some evidence to suggest transmission via fecal specimens in a limited percentage of cases. The conclusion from the current available literature regarding incubation period suggests onset of symptoms from 2 to 14 days in human to human transmission with median incubation period of 5-6 days.
Infectivity of the virus has varied amongst studies and has been reported with a R0 as low as 1.95 to as high as 6.47. The estimated average R0 based on current available research is 3.28 with a median of 2.79. The pathogenicity of the virus was discussed across several articles. According to WHO report 82% of patients have mild symptoms and recover immediately. Average time of onset of symptoms to death in more severe cases varied from 20.2-22.3 days. Those over 60 years of age and those with a background of chronic disease were found to be at higher risk of developing severe disease and death.
The current virulence of the disease is estimated to be approximately 2.3% in China, however other studies out of Beijing saw case fatality risk as high as 8.4%. Case fatality rate from early studies appears highest in those over 80 followed by 70 to 80year old persons.
Current immunogenicity of COVID-19 is not well understood with recent studies reporting cases of COVID19 with clinical symptoms and positive tests after meeting previous discharge criteria from the hospital. The diagnosis of COVID19 is based on positive RT-PCR tests and differ amongst countries based on lab testing capabilities available. CT scans have been proposed as an alternative test but early results demonstrate high risk of false positive results by CT.
The results of the literature search highlighted the importance of proper surveillance measures to identify and contain outbreaks as well as to employ proper tracing tactics to identify the spread of the virus. The response across the world has varied greatly in this respect with the conclusion of China having the most effective surveillance measures currently in place.
Clinical case management of COVID19 is complicated by the nonspecific initial symptoms and presentation of the disease. Several drug regimens have been proposed to include Remedesevir and Chloroquine but their effectiveness has not yet been proven.
Intervention at the community level has varied throughout the world and include issuing travel bans, limiting mass gatherings, closure of schools, sporting events, concerns etc. The special interventions for health care providers topic highlighted the importance of medical professionals having enough PPE supplies as well as the enormous mental and physical burden this disease could have on first line workers in close contact with positive patients.
Discussion: The current COVID-19 pandemic is a major international test for the medical community and world at large as current research and information regarding this disease continues to be sparse. The purpose of this study was to collect current available data regarding COVID-19 to help alleviate some of the significant misconceptions about this disease. Misinterpreting or ignoring evidence in both clinical practice and public health has significant consequences and can result in harmful decisions at both the individual and global level.
Author: Izzetti R, Nisi M, Gabriele M, Graziani F
Title: COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy
Source: Journal of Dental Research 1-9 2020
Type: Clinical Review
Reviewer: Thao Nguyen
Keywords: dental public health, dental education, infection control, practice management, prevention, virology
Purpose: To raise awareness of the potential risks of COVID=19 transmission in dental practice and discuss preventive measures for contagion limitation.
Methods: This study was conducted in a 2-step procedure. Current information in the literature regarding cliniclal management of dental patients in the SARS-CoV-2 pandemic era was analyzed in addition to the authors clinical experience and recommendations from Italian health agencies. A literature review was also performed to identify any current articles published regarding COVID19 and clinical dentistry. No inclusion criteria was used in the literature review.
Results: Four articles were identified that referenced the current COVID=19 pandemic and dental practice recommendations all of which were from mainland China. Only 1 by Meng et al., (2020) reported data on clinical activities. The study reported treatment of over 700 patients during the outbreak and virus quarantine at Wuhan university at the heart pandemic. The hospital provided only emergency dental treatments in addition to online consultations. The study reported the occurrence of 9 cases of COVID-19 among the 169 dental practitioners. The literature review highlighted the high biological risk of COVID-19 inhalation transmission due to use of handpieces under irrigation which favors diffusion of aerosol particles.
Based on best practice guidelines and clinical experience of the authors prophylactic measures to limit the contagion were suggested to include, patient triage for risk of exposure to COVID-19 and temperature monitoring prior to undergoing any dental treatment. Other prophylactic measures suggested included prescription of mouth rinses prior to dental treatment, hand hygiene, proper PPE to include gloves, masks, protective outerwear, surgical glasses and shields, limiting aerosol producing procedures and use of rubber damn isolation.
Current dental management practices adopted in Italy have included a four-phase plan consisting of patient triage, patients’ entrance into the practice, dental treatment and after-treatment management. Patient triage is conducted over the phone to determine if it is a true dental emergency and ask the patient relevant screening questions before permitting a face to face appointment. Patients entering the office are again asked the screening questions, body temperature measured, and hand hygiene performed. Patients are asked to perform a 1 min mouth rinse prior to the procedure and dental practitioners are required to have all recommended PPE. Current recommendations suggest use of only manual instruments if feasible and limiting treatment contact time with patients to under 15 minutes. Proper decontamination of all surfaces is required following treatment with a minimum 5-minute wait time between patients to account for any air particles still present. These measures adopted are highlighted in Table 2 below.
Discussion: Dental practitioners and the medical community as a whole are facing an unexpected and new situation. The limited data currently available highlights the increased risk health care workers face due to close contact with positive patients. Therefore, it is important to highlight the critical contributory role of dentistry during this pandemic to detect and screen out patients with symptoms and manage/reduce the spread of this disease by modifying current practice management. Both pre-triage and triage when the patient is present are critical components of minimizing risk to both dental practitioners and patients. Since emergency dental procedures are still warranted during this epidemic, the precautions and guidelines highlighted above are important measures to consider reducing the risk of exposure for dental professionals.
Author: Zhao Q, et al.
Title: The impact of COPD and smoking history on the severity of Covid-19: A systemic review and meta-analysis
Source: Journal of Medical Virology. 15 April 2020.
Type: systematic review
Reviewer: Maggie Weber
Keywords Covid-19, Coronavirus Disease 2019; COPD, chronic obstructive pulmonary disease; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; MINORS, Methodological Index Non-randomized Studies; OR, pooled odds ratio.
Purpose: This article sought to discover the risk of severe Covid-19 in patients with pre-existing chronic obstructive pulmonary disease (COPD) and ongoing smoking history.
Materials/Methods: A literature search was conducted for studies published from December 2019 to 22nd March 2020 from 5 databases. 11 case-series were included – with a total of 2002 cases. 10 studies were included to determine the effect of pre-existing COPD on the severity of Covid-19.
Results: The presence of COPD is associated with a nearly 4X higher risk of developing severe Covid-19. Two of the included studies reported the association between death and pre-existing COPD. The death rate was 60% of COPD patients and 34% of non-COPD patients. 7 studies reported the relationship between active smoking and the severity of Covid-19. Smoking increases risk of severe Covid-19 by 2X.
Pre-existing COPD is significantly associated with mechanical ventilation, ICU requirement or death. However, it should be noted, when the endpoint was defined as severe Covid-19 or disease progression, the subgroup analysis showed the effect of pre-existing COPD on Covid-19 was no longer significant
Conclusion: The results of our study show that active smoking increases the risk of developing severe Covid-19 by around 2 folds. One limitation is most included studies did not differentiate between current and ex-smokers. The included studies were mainly case studies.
Author: Vaduganathan, et al
Title: Renin–Angiotensin–Aldosterone System Inhibitors in Patients with Covid-19
Source: The New England Journal of Medicine. March 30, 2020
Reviewer: Maggie Weber
Keywords: renin-angiotensin; ACE; inhibitors; COVID-19
Background: The renin–angiotensin–aldosterone system (RAAS) is a cascade of vasoactive peptides that coordinate key processes in physiology. Severe acute respiratory syndrome coronavirus 1, SARS-CoV-2, and Covid-19, interface with the RAAS through angiotensin-converting enzyme 2 (ACE2), an enzyme that physiologically counters RAAS activation but also functions as a receptor for both SARS viruses. The interaction between the SARS viruses and ACE2 has been proposed as a potential factor in their infectivity, and there are concerns about the use of RAAS inhibitors that may alter ACE2 and whether variation in ACE2 expression may be in part responsible for disease virulence in the ongoing Covid-19 pandemic.
Discussion: Coexisting conditions, including hypertension, have been reported to be more common among patients with Covid-19. There are concerns that the use of RAAS inhibitors may have contributed to the adverse health outcomes observed.
Animal studies have inconsistent findings to the effects of ARBs on ACE2, with some showing that ARBs may increase messenger RNA expression or protein levels of ACE2 in tissue and others show no effect.
However, there are few studies in humans regarding the effects of RAAS inhibition on ACE2 expression. In one study, the intravenous administration of ACE inhibitors in patients with coronary artery disease did not influence angiotensin production; this was confirmed via a second additional study.
SARS-CoV-2 appears not only to gain initial entry through ACE2 but also to subsequently down-regulate ACE2 expression such that the enzyme is unable to have protective effects in organs. Down-regulation of ACE2 activity in the lungs enables the initial neutrophil infiltration in response to bacterial endotoxin and may show angiotensin II accumulation and local RAAS activation. Dysregulated ACE2 may theoretically also weaken cardio-protection in Covid-19. In autopsies of patients who died from SARS, 35% of heart samples showed the presence of viral RNA, which in turn was associated with reduced ACE2 protein expression.
There is clear potential for harm related to the withdrawal of RAAS inhibitors in patients in otherwise stable condition. Withdrawal of RAAS inhibitors that are being administered for the management of hypertension may be less dangerous than withdrawal of RAAS inhibitors that are being administered for heart failure.
Conclusion: ACE2, an enzyme that physiologically counters RAAS activation, is the functional receptor to SARS- CoV-2, the virus responsible for the Covid-19 pandemic. RAAS inhibitors may increase ACE2 expression, raising concerns regarding their safety in patients with Covid-19. Clinical trials are under way to test the safety and efficacy of RAAS modulators, including recombinant human ACE2 and the ARB losartan in Covid-19. Abrupt withdrawal of RAAS inhibitors in high-risk patients, including those who have heart failure or have had myocardial infarction, may result in clinical instability and adverse health outcomes. At this time, it is suggested that RAAS inhibitors should be continued in patients in otherwise stable condition who are at risk for Covid-19.
Author: Guo Z., et al.
Title: Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020.
Source: Emerg Infect Dis. 2020 Jul [April, 27, 2020]
Type: Hospital Trial
Reviewer: Ronald Young
Keywords: COVID-19, SARS, aerosol, surface, distribution
Purpose: To test surface and air samples from an intensive care unit (ICU) and a general COVID-19 ward (GW) at Huoshenshan Hospital in Wuhan, China.
Methods: From February 19 – March 2, swab samples from potentially contaminated objects in the ICU and GW were collected as previously described. ICU housed 15 patients with severe disease and GW housed 24 with milder disease. Indoor air and air outlets were also sampled to determine aerosol exposure. Sterile premoistened swabs were used on floors, computer mice, trash cans, sickbed handrails, patient masks, PPE, and air outlets for the open reading frame (ORF) 1ab and nucleoprotein (N) genes of SARS-CoV-2 by PCR.
Results: Almost all positive results were concentrated in contaminated areas, rate of positivity was higher for ICU (43.5%) than GW (7.9%).
Rate of positivity for floor surfaces: ICU 70% and GW 15.4%. This could be due to gravity and air flow causing virus droplets to float to the ground and medical staff walking between departments which was shown by a 100% positive rate for the floor of the pharmacy where no patients were present and 50% of ICU workers shoes testing positively. It is suggested that persons disinfect shoe soles before leaving wards containing ICU patients.
Rate of positivity for other surfaces: computer mice- 75% ICU, 20% GW; trash cans 60% ICU, 0% GW; sickbed handrails 42.9% ICU, 0% GW; doorknobs 8.3% GW. Sporadic positive tests were also found on sleeve cuffs and gloves of medical staff. It is suggested that medical staff perform hand hygiene immediately after patient contact.
The rate of positivity for patient masks was also very high due to exhaled droplets and oral secretions; it is suggested to adequately disinfect masks before discarding.
Testing aerosol transmission found positive results for 35% of ICU and 12.5% of GW samples. Air outlet swabs found positive samples for 66.7% of ICU and 8.3% of GW, which confirms that SARS-CoV-2 aerosol exposure poses risks. Rates of positivity differed depending on the sample site with 35.7% near air outlets, 44.4% in patient’s rooms, and 12.5% in doctor’s office. This indicates that aerosols were concentrated downstream of the patient, but that exposure risk is possible upstream and that the maximum transmission distance may be around 4m.
High risk ICU workplaces (patient care and treatment areas) had a 40.6% positivity rate, and low risk ICU workplaces (doctor’s office) had a positivity rate of 12.5%.
High risk GW workplaces (patient wards) had a 12.5% positivity rate; and low risk GW workplaces (outside of wards) had a positivity rate of 0%.
Discussion: SARS-CoV-2 is widely distributed in the air and on subject surfaces in both the ICU and GW implying a high infection risk for medical staff and close contacts. Environmental contamination was greater in the ICU than in the GW, so more strict measures should be enacted. Aerosol distribution characteristics in the GW indicate that the transmission distance may be 4m.
Author: Chiang C-Ha, Chiang C-Hu, Chiang C-Hs, Chen Y-C.
Title: The practice of wearing surgical masks during the COVID-19 pandemic.
Source: Emerg Infect Dis. 2020 Aug [April, 27, 2020]
Reviewer: Ronald Young
Keywords: surgical masks, COVID-19, pandemic
Purpose: To describe the function of surgical masks during the COVID-19 pandemic.
Discussion: A meta-analysis was conducted by Xiao et al. that found no significant reduction in influenza transmission with the use of surgical masks in the community based on 10 RCTs. However, mechanistic studies found that surgical masks could prevent transmission of human coronavirus and influenza viruses if worn by infected persons. Their recommendations for mask usage have varied results across different countries.
Looking at epidemiological studies show that as of April 3 there were 348 cases of COVID19, of which 13.8% were local. Singapore recorded 1,114 cases of which 51.3% were local. Taiwan and Singapore both employed stringent measures, but Taiwan recommended early use of masks in the pandemic. However, Singapore did not recommend mask usage until April 3 and a Stay Home policy until April 17.
Conclusion: There is limited evidence for the effectiveness of preventing transmission of SARS-2 either for source control or to reduce exposure. However, wearing masks of healthy persons may prevent potential asymptomatic or pre-symptomatic transmission. This marginal reduction may produce significant results especially if implemented early.
Topic: Contact Tracing
Author: Feasibility of controlling COVID-19 outbreaks by isolation of
cases and contacts
Title: Hellewell J, Abbott S, Gimma A
Source: Lancet Glob Health 2020; 8: e488–96, February 28, 2020
DOI: https://doi.org/10.1016/ S2214-109X(20)30074-7
Reviewer: Brian Goldfarb
Purpose: To examine how viable it is for countries at risk of imported cases to use contact tracing and isolation as a containment strategy.
Methods: In this study they implemented a branching process model in order to assess the number of potential cases spread from an individual. An example being someone has a potential to infect 3 people however only infected. 2 before being isolated. 3 variations of 5, 20 or 40 initial cases were used to simulate a newly detected outbreak in a population. Isolation was assumed to be 100% effective at preventing further transmission; therefore, in the model, failure to control the outbreak resulted from the incomplete contact tracing and the delays in isolating cases.
This Model demonstrates if person A infects person B and C, however person B was contacted traced. Since person B becomes isolated faster they will not infect any more people. Person C was not contact traced and will have delayed isolation and has potential to infect more people.
Results: in order to control 90% of outbreaks, 80% of contacts need to be traced and isolated. The number of initial cases was a big factor in the ability to control an outbreak. When 5 initial cases, 50% chance of controlling in 3 months with modest levels of contact tracing. The delay between symptom onset and isolation played the largest role in determine whether an outbreak was controllable.
Conclusion: case isolation and contact tracing alone is not sufficient for controlling outbreaks. Even near perfect contact tracing will still be insufficient, and further interventions would be required to achieve control. Rapid and effective contact tracing can reduce the initial number of cases, which would make the outbreak easier to control overall.
Author: Tang X, Wu C, Li X
Title: On the origin and continuing evolution of SARS-CoV-2
Source: National Science Review, March 3rd 2020
Reviewer: Brian Goldfarb
Keywords: SARS-CoV-2, virus, molecular evolution, population genetics
Purpose: investigated the extent of molecular divergence between SARS-CoV-2 and other related coronaviruses
Methods: This study used 103 complete genome sequences from the global initiative on sharing all influenza data (GISAID). Phylogenetic tree was constructed and analyzed.
Results: Sars-Cov-2 sequence was compared Sars-COV, 4 bat coronaviruses and 7 pangolin coronaviruses. The differences between the viruses were much larger than estimated and it is more likely that this is a mutation and natural selection rather than recombination of genetics. They believe that two types of the virus “L” and “S”. L being the major type (70%) and S being minor type (30%). Although the L type is more common, the L type is derived from the ancestral S type. It is believed that the L type is more aggressive and that it replicated and transmits faster. L type was found to be more prevalent in Wuhan. After the January the number of L type cases decreased compared to S type. This may be due to the screening and prevention control measures in placed to screen for the more aggressive type L while the type S has weaker selective pressures by humans leading to an increase in type S cases. Co-existence of L and S is very rare only being seen in 5 cases at the time of the paper’s publication.
Conclusion: There are two types of coronavirus, L type is more aggressive than the S type and that human interference may have shifted the relative abundance of L and S type soon after the SARS-CoV-2 outbreak
Authors: Guo, et al.
Title: The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak – an update on the statusSource: Military Medical Research 2020; 7(11): 1-10
Type: Status update
Reviewer: Eugene Rowell III
Keywords: Clinical characteristics, Coronavirus disease 2019 (COVID-19), Origin, SARS-CoV-2, Therapy, Transmission
Purpose: To provide an update on the status of the coronavirus disease 2019 outbreak.
Background: In December 2019, a cluster of pneumonia cases, caused by a newly identified β-coronavirus, occurred in Wuhan, China. This coronavirus was initially named as the 2019-novel coronavirus (2019-nCoV) on January 12, 2020 by World Health Organization (WHO). WHO officially named the disease as coronavirus disease 2019 (COVID- 19) and Coronavirus Study Group (CSG) of the International Committee proposed to name the new coronavirus as SARS-CoV-2, both issued on February 11, 2020.
Discussion: An acute respiratory disease, caused by a novel coronavirus (SARS-CoV-2, previously known as 2019-nCoV), the coronavirus disease 2019 (COVID-19) has spread throughout China and received worldwide attention. On 30 January 2020, World Health Organization (WHO) officially declared the COVID-19 epidemic as a public health emergency of international concern. The emergence of SARS-CoV-2, since the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, marked the third introduction of a highly pathogenic and large-scale epidemic coronavirus into the human population in the twenty-first century. As of 1 March 2020, a total of 87,137 confirmed cases globally, 79,968 confirmed in China and 7169 outside of China, with 2977 deaths (3.4%) had been reported by WHO. Meanwhile, several independent research groups have identified that SARS-CoV-2 belongs to β-coronavirus, with highly identical genome to bat coronavirus, pointing to bat as the natural host. The novel coronavirus uses the same receptor, angiotensin-converting enzyme 2 (ACE2) as that for SARS-CoV, and mainly spreads through the respiratory tract. Importantly, increasingly evidence showed sustained human-to-human transmission, along with many exported cases across the globe. The clinical symptoms of COVID-19 patients include fever, cough, fatigue and a small population of patients appeared with gastrointestinal infection symptoms. The elderly and people with underlying diseases are susceptible to infection and prone to serious outcomes, which may be associated with acute respiratory distress syndrome (ARDS) and cytokine storm. Currently, there are few specific antiviral strategies, but several potent candidates of antivirals and repurposed drugs are under urgent investigation. In this review, we summarized the latest research progress of the epidemiology, pathogenesis, and clinical characteristics of COVID-19, and discussed the current treatment and scientific advancements to combat the epidemic novel coronavirus.
Conclusion: The outbreak of COVID-19 swept across China rapidly and has spread to 85 countries/territories/areas outside of China as of March 5, 2020.
- The emerging pneumonia, COVID-19, caused by SARS-CoV-2, exhibits strong infectivity but less virulence, compared to SARS and MERS, in terms of morbidity and mortality. Originating from reservoir of bats and unknown intermediate hosts, SARS-CoV-2 binds to ACE2 with high affinity as a virus receptor to infect humans.
- The susceptible population involves the elderly and people with certain underlying medical conditions, which requires more attention and care.
- So far, the supporting treatments, combined with potent antiviral drugs, such as remdesivir, chloroquine, or lopinavir/ritonavir, have been conducted with definite effect on treat COVID-19 patients, while solid data from more clinical trials are needed.
Authors: Hamid, S., Mir, MY., and Rohela, GK.
Title: Novel coronavirus disease (COVID-19): a pandemic (epidemiology, pathogenesis and potential therapeutics)Source: New Microbe and New Infect 2020; 35(C): 1-10
Reviewer: Eugene Rowell III
Keywords: COVID-19, Pathogenesis, Phylogenetic analysis, Therapeutic strategies, Transmission
Purpose: Review of current knowledge regarding COVID-19.
Background: Coronavirus is one of the major pathogens which targets primarily the human respiratory system. Earlier coronaviral outbreaks (CoVs) include Middle East respiratory syndrome (MERS)-CoV and severe acute respiratory syndrome (SARS)-CoV which have significantly caused great threat to human beings. In December 2019, a number of patients were admitted to hospitals with an initial diagnosis of pneumonia. These patients were found to have epidemiological links with wet animal and seafood wholesale market in Wuhan, Hubei Province, China. At the time of preparation of this manuscript i.e. 5th April 2020 the WHO has reported 1,056,159 COVID-19 confirmed cases throughout the world including 57,206 confirmed death cases. So far COVID-19 has spread to 208 countries around the globe.
Symptoms: The COVID-19 infection symptoms starts to appear after an incubation period of 5-6 days. This time period depends on patient’s immune system and age of the patient. It is found shorter among patients of more than 70 years of age relative to those below 70 years patients.
Epidemiology: The first four cases of an acute respiratory syndrome of unknown etiology were identified among people linked to a local seafood market (“wet market”) in Wuhan City China on 29 December 2019. Eventually human-to-human transmission by close contact was found as secondary cause of COVID-19 infection. There has been rise in the frequency of infected individuals with no history of wildlife exposure or visiting Wuhan and several cases of infection have been identified among medical professionals as well.
Pathogenesis & Fatality Rate: Coronaviruses are single-stranded, zoonotic RNA viruses that cause symptoms ranging from common cold to more extreme respiratory, enteric, hepatic, and neurological symptoms. Besides, SARS-CoV-2 there are six other coronaviruses reported in humans. These are HCoV-OC43, HCoV-229E, SARS-CoV, HCoV-HKU1, MERS-CoV and HCoVNL63.
Transmission: It is anticipated that there is probable zoonotic origin of COVID19, based on the large number of infected people who were exposed to the wet animal market in Wuhan City where live animals are routinely sold. Efforts were made to look for a host reservoir or intermediate carriers from which the infection could spread to humans. The two snake species were identified which were thought the possible COVID-19 reservoirs. However, there is no clear-cut evidence for the reservoirs of coronavirus other than mammals and birds till date. The COVID-19 genomic sequence analysis showed its 88% identity with two bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses suggesting that bats are the most likely link between COVID-19 and humans.
Clinical Manifestation & Diagnosis: The most frequently reported symptoms include cough-producing phlegm, runny nose, myalgia, fever, pneumonia, and complicated dyspnea, while the less widely documented symptoms include headache, vomiting and hemoptysis. The case definition guidelines mentioned the following symptoms: decrease in lymphocytes and white blood cells, fever and new pulmonary infiltrates on chest radiography with no improvement in symptoms after 3 days of antibiotic treatment. In patients with suspected infection, the following techniques for diagnosis have been suggested: conducting real-time fluorescence (RTPCR) to detect SARS-CoV-2 positive nucleic acid in sputum, throat swabs, and lower respiratory tract sample secretions.
Vaccination: Currently no vaccine is available against COVID-19 infection, however vaccines or strategies used to develop a vaccine against SARS-CoV can be effective. The recombinant DNA from the Urbani strain of SARS-CoV (AY278741) was administered to hamsters and mice which leaded to production of neutralizing antibodies and protection against SARS-CoV. The DNA was found to inactivate whole virus or live-vectored strain of SARS-CoV (AY278741) and there by significantly reduced the viral infection in animal models. Although research teams around the world are working to explore key characteristics, pathogenesis, and combating the disease, appropriate attention should be drawn on therapeutic options and cross-resistance of other vaccines. For instance, vaccines for other diseases like for measles and rubella can create cross-resistance for SARS-CoV-2. This concept of cross resistance is based on the findings that children are found less vulnerable to infection as compared to elder population and children predominantly vaccinated for measles.
Future Perspectives: Combating the current outbreak requires rigorous steps to reduce the transmission of COVID-19 infection from person to person. Special attention and efforts should be applied for protecting or reducing transmission in vulnerable populations, including infants, health care providers and the elderly. For medical personnel, health care professionals, public health individuals and researchers involved in the 2019-nCoV guidelines to follow are published.
Conclusion: The coronavirus disease (COVID-19) is highly pathogenic viral infection caused by SARS-CoV-2. Currently, COVID-19 has caused global health concern. It is assumed that COVID-19 has zoonotic origin based on the large number of infected people who were exposed to the wet market in Wuhan City, China. The phylogenetic analysis has revealed that SARS-CoV-2 has significant sequence similarity with severe acute respiratory syndrome-like (SARS-like) bat viruses, thus bats could be primary possible reservoir. The intermediate host and their subsequent transfer is not known yet, although human to human transfer is widely confirmed. The transmission of COVID-19 infection from one person to another resulted in the isolation of patients who were subsequently given a variety of treatments. To monitor the current outbreak, robust steps have been taken around the globe to reduce the transmission of COVID-19 infection particularly banning international and domestic flights, inducting lockdowns in vulnerable areas, social distancing etc. No clinically approved antiviral drug or vaccine against COVID-19 is reported yet. However, in clinical trials, few broad-spectrum antiviral drugs were evaluated against COVID-19 infection which resulted in clinical recovery.