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COVID19 Clinical Aspects

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/

[13] https://www.who.int/csr/sars/en/WHOconsensus.pdf

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

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

[16] https://pubs.rsna.org/doi/10.1148/radiol.2020200463

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

[18] EM-Crit COVID19 guidelines march 2, 2020

[19] https://jamanetwork.com/journals/jama/fullarticle/2762688

[20] EM-Crit COVID19 guidelines march 2, 2020

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