Clinical Aspects of COVID19

Summary

The name of the virus is “SARS-CoV-2 and the disease caused by it is COVID-19
From the Coronavirus family and related to MERS-CoV and SARS CoV
Frequently reported signs and symptoms include fever (83–98%), cough (46%–82%), myalgia or fatigue (11–44%), and shortness of breath (31%) at illness onset[1]
Spread via respiratory droplets in the air and from touching contaminated surfaces
Incubation period of 2-14 days is current most accurate data
Developing and distributing a reliable test has been a struggle
At present, treatment is largely supportive care (fever control, hydration and rest)
Patients with a mild clinical presentation may not initially require hospitalization. Clinical signs and symptoms may worsen with progression to lower respiratory tract disease in the second week of illness1
Deaths associated with COVID-19 are most commonly from Adult Respiratory Distress Syndrome (ARDS) and sepsis
Data from Italy looks at 10% of all positive patients requiring Intensive Care (ICU) Support[2]
Elderly patients and medically fragile people appear to have the greatest risk of complications and mortality
The current best protection is to avoid sick people, wash your hands, avoid touching your face, eyes, nose and mouth and to cover your cough and sneeze
Clean frequently touched surfaces with commercial household cleaning solutions
Surgical masks are for those already with symptoms and not required for uninfected people in the general population.
Healthcare workers should adhere to strict contact, airborne and eye protection precautions
Vaccine development is currently underway
Treatment medications, antivirals and patient care protocols are being developed and studied

Virus Family and Genealogy

Newly recognized nomenclature is the name of the virus is “SARS-CoV-2 and the disease caused by it is COVID-19”.[3]
Non-segmented RNA virus
Binds via ACE-2 (angiotensin converting enzyme 2) found on Type II alveolar cells and intestinal tissue[4]
- Same receptor used by SARS
Viral respiratory illness from the Coronavirus family
- COV19 is previously unrecognized in humans[5]
Spread from human to human via respiratory droplets
Symptoms can appear 2-14 days after exposure[6]
- Limited reports show an incubation period of up to 27 days[7]
Reports are emerging of two related but separate strains of SARS-CoV-2[8]
This concept is in dispute and being researched
- “L-type”
  - Dominant strain in early days of the Wuhan outbreak
    - Now not as common, globally
    - Believed to have evolved from S-type
  - “S-type”
    - More commonly seen globally as pandemic spreads
    - More closely resembles coronavirus from bats and pangolins
    - May have been circulating for a longer period than known
      - Clinically undetected in human population
    - Researchers are in disagreement on accuracy of this report[9]
  - SARS-CoV-2 is related to Middle East Respiratory Syndrome (MERS-CoV)[10]
    - Emerged in 2012 in Saudi Arabia
    - Regional cases include Bahrain, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, United Arab Emirates (UAE), and Yemen[11]
    - 2494 confirmed cases
    - 858 attributable deaths and case fatality rate of 34.4%
  - SARS-CoV-2 is related to Severe Acute Respiratory Syndrome (SARS CoV)
    - Emerged in 2003 in Guangdong province, southern China[12]
    - Thought to be an animal virus that spread to humans
    - Spread to more than 24 countries (Asia, Europe, North America, South America)
    - Mean incubation period of 5.7 days[13]
    - 8094 confirmed cases
    - 774 attributable deaths and case fatality rate of 9.6%
    - No cases reported since 2004

Signs and Symptoms

Common symptoms include fever, cough and shortness of breath[14]
Frequently reported signs and symptoms include fever (83–98%), cough (46%–82%), myalgia or fatigue (11–44%), and shortness of breath (31%) at illness onset[15]
Fevers are considered a temperature greater than 38 C or 100.4 F
Radiology exam with Chest CT scans shows 78% of known cases with either ground-glass appearance and/or consolidation on imaging [16]
Cause of death due to CoVID-19 is typically from Acute respiratory Distress Syndrome (ARDS) and sepsis11
In one report, among patients with confirmed COVID-19 and pneumonia, just over half of patients developed dyspnea a median of 8 days after illness onset11
Clinical signs and symptoms may worsen with progression to lower respiratory tract disease in the second week of illness11
Data from Italy indicates 10% of all positive patients require intensive care unit (ICU) support [17]

Stages of Illness

Replicative stage[18]
- Viral replication occurs over several days. Host immune response fails to contain the virus and relatively mild symptoms may occur
Adaptive immunity stage
- As a stronger immune response begins to work, titers of the virus begin to fall. However, this also may lead to increased levels of inflammatory cytokines and subsequent tissue damage.
- This is the proposed explanation for patients are relatively stable for several days only to suddenly deteriorate when they enter this stage. [19]
Understand these stages are important for the following reasons[20]
- Initial symptoms do not predict possibility for future deterioration
- Risk stratification will become increasingly important
- Early antiviral therapy will likely play a more important role during the early replicative stage
- Low dose steroids (immunosuppressive therapy) could be initiated during the adaptive immune stage to try and blunt the overwhelming immune response. (speculative)

[1] https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html

[2] https://mailchi.mp/esicm/the-future-of-haemodynamic-monitoring-first-webinar-of-the-year-1009715

[3] https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it

[4] https://www.ncbi.nlm.nih.gov/pubmed/15141377

[5] https://www.who.int/health-topics/coronavirus

[6] https://www.cdc.gov/coronavirus/2019-ncov/about/symptoms.html

[7] https://www.pharmaceutical-technology.com/news/coronavirus-incubation-period-27-days/

[8] https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaa036/5775463?searchresult=1

[9] http://virological.org/t/response-to-on-the-origin-and-continuing-evolution-of-sars-cov-2/418

[10] https://www.who.int/emergencies/mers-cov/en/

[11] https://www.cdc.gov/coronavirus/mers/index.html

[12] https://www.who.int/ith/diseases/sars/en/