Coronavirus or SARS CoV2 is one of the major pathogens that primarily targets the human respiratory system. There have been previous outbreaks of coronaviruses (CoVs) which include; the severe acute respiratory syndrome (SARS)-CoV and the Middle East respiratory syndrome (MERS)-CoV which have also been characterized as great public health threat.
In late December 2019, a cluster of patients were admitted to hospitals in Wuhan with a primary diagnosis of pneumonia of an unknown etiology. These patients were linked to a seafood and wet animal wholesale market in Wuhan, Hubei Province, China. Coronavirus disease caused by SARS COV2 represents the causative agent of a potentially fatal disease which is of global public health concern. Based on the large number of infected people that were exposed to the wet animal market in Wuhan City, it is suggested that COVID − 19 is most likely of zoonotic origin i.e. transfer of infection from animals to human.
The novel coronavirus is a single stranded RNA virus which belongs to Coronaviridae family Betacoronavirus genus and Severe acute respiratory syndrome- related coronavirus species. The World Health Organization on 11th February 2020 named the novel coronavirus as SARS CoV − 2 i.e. Severe acute respiratory syndrome coronavirus. The presence of SARS CoV–2 has been reported in various species of the Rhinolophus genus of bat species. Studies done using PCR and Serological tests have shown close relation between the genetic material of SARS CoV-2 and R. sinicus. R. pearsoni, R. marcotis, R. pussilus and R. ferrumequinum are the other species of bat that have shown some correlation with SARS CoV–2. Malayan Pangolins have been considered as intermediate host as they have shown 91% genetic correlation with SARS CoV–2.[5, 6] The outer part of the virus is made of 4 proteins namely Spike, Envelope, Membrane and Nucleocapsid. SARS CoV 2 uses spike glycoprotein for neutralizing antibodies, receptor binding, mediate membrane fusion and to gain entry into the system. A two-step sequential protease cleavage model has been proposed for activation of S proteins of coronaviruses, priming cleavage occurs between S1 and S2 and activating cleavage on S2’ site.[7, 8] The receptor utilized for entry is Angiotensin-Converting Enzyme 2 (ACE-2). The virus is primarily transmitted through respiratory droplets and direct or indirect contact. Droplet transmission occurs when a person is within 1 m of someone who has symptoms like coughing or sneezing and is therefore at risk of having himself exposed to potentially infective droplets.[10, 11] Indirect contact with surfaces in the immediate environment or with objects used on the infected person like stethoscope can transmit virus. Airborne transmission can occur in specific circumstances and procedures or support treatments that generate aerosols like endotracheal intubation, bronchoscopy, etc. Sign and symptoms appear within two to 14 days after exposure. Common features include fever, cough, shortness of breath or difficulty in breathing. Other symptoms include fatigue, body aches, chills, sore throat, loss of smell and taste, diarrhea and severe vomiting. The severity of symptoms can range from mild to severe i.e some people can have show absolutely no symptoms and some might have combination of symptoms.People who are old or who have underlying heart, lung, liver, kidney disease, diabetes, severe obesity, or who have compromised immune systems may be at higher risk of serious illness.[13, 14]
Person-to-person transmission of this disease makes isolation of patients an indispensable part of treatment. Once in the body, this virus is abundantly present in salivary and nasopharyngeal secretions of patients. Given the widespread transmission of SARS-CoV-2 and reports of its transmission to health care providers dental professionals are at maximum risk for nosocomial infection and can become potential carriers of the disease.
Dental care settings have the risk of 2019-nCoV infection due to the aerosols generated during procedures, handling of sharps, proximity of the dentist to the patient’s oropharyngeal region. If adequate precautions are not taken, the dental office can potentially lead to cross contamination. As the understanding of this novel disease is evolving, dental students and professionals should have an in-depth knowledge, a better understanding and should be updated with the practices that have to be adapted to identify a possible COVID-19 infection, and refer patients with suspected, confirmed, or a history of COVID-19 infection to appropriate treatment centers.