Pandemic coronavirus and its dental implications - Coronavirus is the only known genus of family coronaviridae which comprise of pleomorphic enveloped virus with unique club shaped peplomers projecting from surface, resembling the solar corona.
The viruses ; which earlier were known to be of low pathogenicity and were known only for causing mild seasonal flu in temperate climate zones; have emerged out to be a group of one of the most infectious organisms in last decade.
As demonstrated by recent out breaks like SARS (2002-2003) and MERS (2015); the zoonotic strains of this family are capable of causing widespread infections in humans.
The ongoing outbreak of CoVID- 19 has turned out to be the most severe; with 4,805,935 confirmed cases and 90,978 deaths worldwide as of 18th may 2020.
The SARS-CoV-2 (popularly known as covid-19) phylogenetically belongs to β-coronaviruses which includes SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome). These viruses are known to infect human, bats and wild animals.
The glycoprotein spikes on outer surface of viruses are responsible for attachment and entry of viruses to host cells. SARS Coronavirus (including COVID-19) require ACE-2 (angiotensinogen converting enzyme-2) as a key receptor.
The life cycle of SARS COV-2 in the host cell begins when spike protein binds to cellular receptor ACE-2. After Binding, there is fusion of virus with the host cell membrane through endosomal pathway, leading to release of viral RNA in host cell.
Relevant viral proteins are synthesized within host cytoplasm. These proteins are assembled in endoplasmic reticulum and Golgi bodies and are then extruded from the host cell. This leads to destruction of host cells.
Once in body, the virus is abundant in nasopharyngeal and salivary secretions of patients. The potential routes of transmission can be aerosols, fomites, fecal and oral routes and direct or close contact with infected person.
The clinical symptoms include fever, dry cough and fatigue. Other symptoms like nausea, diarrhea, hyposmia (decreased sense of smell) and dysguesia (abnormal taste sensations) are also evident.
Although, symptomatic patients are most infectious but there is still a chance of transmission in pre-symptomatic stage.
At present there is no specific antiviral drug or vaccine available against SARS CoV-2. Pre existing broad spectrum antiviral drugs are undergoing clinical testing for their effects against this novel coronavirus.
In one report, remdesivir (a broad spectrum antiviral drug) and Chloroquine (an anti-malarial drug) are found to be highly effective in vivo; in humans.
For pre and post exposure prophylaxis, there is need for development of a molecule that acts specifically against SARS CoV-2.The mechanism of drug action might involve the inhibition of enzymes which are responsible for viral replication or any other mechanism to attenuate it.
Attributed to the unique techniques of dental practice (like aerosol production, high speed rotary instrumentation usage) and proximity of dental operator to nasopharynx of patients, the operators are at high risk.
The dental professionals need to act diligently to prevent nasocomial spread of disease. Otherwise operators can act as potential carriers and the dental office can serve as place of cross infections to the community.
Non-emergency cases can be managed by telescreening (screening through telephone) and pharmacological management; for symptomatic relief. In suspected and confirmed cases of CoVID-19, elective dental care must be given.
In cases of emergencies judicial use of personal protective equipments must be taken care of. While providing dental treatment to suspected or confirmed CoVID 19 cases (emergencies) ; pre procedural mouth rinse; with 0.2% povidone-iodine or 0.5% hydrogen peroxide; might reduce the salivary load of virus.
Use of rubber dam will reduce the splatter. It is duty of health care professionals to protect public and maintain high level of infection control standards.
Thus; health care professionals can educate public to prevent panic while promoting the health and welfare of patients in these challenging times.
Written by:
Mansi Singh
B.D.S. II Year
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