WHAT IS SARS-Co-V-2/COVID-19?

In December 2019, a group of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate the virus, which now goes by SARS-CoV-2 and COVID-19. The virus has since been identified almost 200 countries, reaching pandemic status.  

Current tolls

Sentinel cases from Wuhan, China and the US

COVID-19 at a glance

VIROLOGY & TESTING

Molecular (real-time) PCR fluid tests have been targeted to the Nucleocapsid (N) and the Open reading frame 1ab (Orf) genes of the COVID-19 virus. Upper respiratory swabs have been validated for early phases of disease including nasopharyngeal (preferred) as well as oropharyngeal swabs. Lower respiratory tract sputum, BAL and tracheal fluid always can be detected with the PCR assay. It is believed virus shedding peaks 24h before symptom onset and is likely the reason for high rates of community spread (before symptoms). It is thought that early on in disease, around 3-5 days, the swab is more likely to be positive. The clinical sensitivity of the PCR fluid is yet to be determined and is based on timing of collection, sample type, and quality of the test. 

Serologic testing is typically reserved for using as a marker of previous infection via IgG subclass detection. Currently serology testing is not approved by the FDA, but emergency status has been applied for by Euroimmun Inc. (Lubeck, Germany). Their assay detects antibodies to the Spike protein. Sensitivity is time dependent, but thought to be near 100% in later disease stages (>14d).  Specificity is currently 97%. The cross-reactivity data is unknown. If the test is positive, it is evidence of recent or prior infection but does NOT infer protective immunity at this time. Currently, serology testing is approved for epidemiology, contact tracing, plasma donation trials, and immune response for vaccine candidates. Serology is not valid for diagnosing acute infection or inferring protective immunity. There is often the question of testing asymptomatic health care providers, and at this time, there are still limited numbers of tests still available. Therefore, there is no recommendation for serial testing of health care workers at this time. 

The Abbott rapid test has been approved for emergency use by the FDA but has been diverted to high impact zones. 

Personal Protective Equipment (PPE)

COVID-19 is transmitted largely by respiratory droplets but indirect and direct spread has also been shown. Respiratory droplets, when expelled,  typically travel 3 to 6ft—hence the current social distancing recommendations of 6ft. Airborne transmission is mainly seen in aerosol generating procedures and is not thought to be the main mode of transmission.  Covid-19 is 114nm particle therefore it is thought that an N95 or higher mask is needed along with isolation gowns, gloves and eye protection during aerosolizing procedures.  The CDC is recommending at least a N95 respirators or higher instead of a face mask when performing (or in the presence of) an aerosol-generating procedure.

Patient Triage

AAO recommendations are to continue delay all elective ambulatory visits and reschedule any elective or non-urgent admissions. However, this practice may vary depending on system-based triage and testing availability in your area (see screening and testing limitations above). 

Tracheostomy

The COVID-19  global pandemic is characterized by respiratory symptoms and possible airway decompensation with the need for supportive interventions such as endotracheal intubation with mechanical ventilation. Early intubation is often tried after failed proning to avoid aerosolizing therapies such as bag-mask ventilation, high-flow nasal cannula, CPAP and BiPAP.  Standard early conversion to tracheostomy is typically between 5-7 days with the benefits of ventilator weaning, reduced sedation, improved pulmonary toilet, and shortened ICU stays. However, the decision to perform tracheotomy in COVID-19 patients is complex and evolving. Tracheostomy is currently considered a high-risk procedure due to being potentially highly aerosol generating. Additionally, there is the increased risk it then carries thereafter to the healthcare team when performing routine tracheostomy cares. Consideration should be given to the high mortality rate of mechanically ventilated patient, risk of viral shedding and the initial and ongoing exposures to the healthcare team including but not limited to airway secretions, bleeding, and cannula cares.  The resources below have been linked to help support decision making.

Subspecialty information

Facial Plastic Surgery & Trauma

Head & Neck

Otology

Pediatrics

In contrast with infected adults, most infected children appear to have a milder clinical course. Asymptomatic infections are not uncommon. Surgical drape tents have been suggested in recent literature but no data has been collected to show if this reduces transmissions during microdirect laryngoscopy and bronchoscopy. 

Rhinology

Aerosolization presents a risk to the endonasal skull base surgeon both in the clinical and surgical setting. In the outpatient setting, use of a barrier significantly reduces aerosol spread. In the surgical setting, cold surgical instrumentation and microdebrider use pose significantly less aerosolization risk than a high‐speed drill although the entire surgery is denoted as aersol-generating.

                  

Vaccination & Treatment

Vaccination against COVID-19 is not yet available. A phase 1 clinical trial is available at: Safety and Immunogenicity Study of 2019-nCoV Vaccine (mRNA-1273) for Prophylaxis of SARS-CoV-2 Infection (COVID-19)

Convalescent plasma transfusion for the treatment of COVID- 19: Systematic review. J Med Virol. 2020 May 1

Moderna’s COVID-19 Vaccine Candidate Gets Fast Track Designation. Monthly Prescribing Reference

 

Other Resources