COVID-19 Clinical Topics

Overview and Clinical Management Reviews

Biology of the Virus

  • SARS-CoV-2 is a type of coronavirus, called this because of the ringed appearance of a crown, resulting from the surface spike proteins. These are important for initial ‘docking’ on the host cell. It is enveloped, thus more vulnerable to soap/alcohol. The virus encode its genetic information in what is referred to as a positive-sense, single-stranded RNA genome.

  • Many coronaviruses are responsible for causing the “common cold” - however, SARS-CoV-2 is closely related to the virus that causes severe acute respiratory syndrome (SARS). And like SARS, MERS (Middle Eastern Respiratory Virus), COVID-19 is a zoonotic disease with the associated virus, SARS-CoV-2 having originated most likely in bats, and subsequently crossed over from animals to humans. A small ant-eater like mammal called a “pangolin” is implicated.

  • More information available from the American Society of Microbiology.

Transmission

  • Current evidence suggests that SARS-CoV-2 is a truly novel virus, and we are learning more every day about this virus. The primary transmission route between people is through respiratory droplets that are aerosolized. Droplet transmission mainly occurs when a person is in close proximity to someone with respiratory symptoms such as cough or sneezing. While viral particles can travel, this infection is not considered “airborne” like measles or tuberculosis. Keeping a safe distance of 6 feet or more from potential aerosols will likely be sufficient to prevent exposure/infection.

  • Viral particles enter via mucous membranes within the nose, mouth, and even the eyes. (As far as we know at present, it is not transmitted via oral-fecal routes, nor sexually transmitted.)

  • Transmission also occurs through fomites (e.g., stethoscope or thermometer) in the immediate environment around the infected person meaning that transmission can occur via indirect contact contaminated with viral particles. While viruses are not “living” in the same way that bacteria, fungi, or parasites are, they can persist as viable particles.

  • When viable viral particles enter the human body, they must enter the host cell. One can think of the virus turning the cell into a ‘xerox machine’ or a 3-D printer without an “off” switch, leading to thousands of copies of itself, resulting in progression of illness. Ultimately recovery from COVID-19 is associated with viral containment and decreases in viral burden as a result of a functioning immune system. Unfortunately in some patients who progress to severe illness, unrelenting viral replication and a “cytokine storm” results in respiratory failure and widespread organ dysfunction.

    More information available from the WHO.

Pathogenesis

  • Data show that levels of replicating virus appear to be high after symptom onset but may be present in sufficient quantities that asymptomatic/presymptomatic transmission can occur. Most transmission still occurs from symptomatic people. Later there is very high replication of virus in the lower respiratory tract
    (~ 2nd week).

  • The incubation period of this virus is ~ 5 days (2-14 day range). The duration of viral shedding has a wide range and may also depend mainly on the severity of the illness, with a potentially longer duration of viral shedding.

  • At this point, we think that protective antibodies do form after infection, supporting the rationale behind the currently investigational approach (US) of using convalescent plasma from infected patients (who have recovered from the illness) for ill patients, infected with COVID-19 associated virus.

  • More information available from UpToDate and Journal of Autoimmunity.

Diagnosis

  • COVID-19 is typically a viral upper respiratory illness (with ~80% people with mild illness and recovering quickly). However 20% of individuals may become sick enough to need medical care, including hospitalization and ICU support. COVID-19 is fatal when refractory respiratory failure ensues often with other irreversible organ system dysfunction.

  • Nasopharyngeal swab - specimen collection procedure - NETEC INSTRUCTIONAL VIDEO ***

    • This procedure, which can be performed in the hospital (or appropriately set-up office setting) requires training and careful execution, to ensure the specimen is carefully collected and the person collecting the specimen is not exposed to viral particles. The specimen is then processed via “RT-PCR” testing technology, a form of molecular diagnosis, identifying the presence of SARS-CoV-2. Testing “positive” supports a diagnosis of COVID-19. Testing is becoming much more widespread; even being done in ‘drive-through’ and outpatient settings.

    • More information to help people identify testing sites will be available on this page soon.

  • Serological (antibody) testing is needed with vigorous efforts underway to release such a test to help identify people who have truly recovered (and may be immune) from COVID-19, people “at-risk” and perhaps even people who have been recently infected (and possibly contagious despite lack of symptoms).

Clinical Management

  • Management of the disease depends mainly on the severity of symptoms from patients with known COVID-19 infection. Patients most frequently present with the following:

    • Fever

    • Cough

    • Fatigue

    • Anorexia

    • Shortness of breath

    • Production of sputum

    • Myalgias

  • The spectrum of disease presentation range from mild disease (no or mild pneumonia), severe disease (dyspnea, hypoxia, symptomatic lung pathology), and critical disease (respiratory failure, shock, or multiorgan dysfunction/failure). Patients with other cardiovascular or pulmonary comorbidities are at increased risk for severe illness.

  • There are a growing number of reports suggesting atypical or unusual symptoms that COVID-19 patients could have:

    • From UpToDate:

      • “Other, less common symptoms have included headache, sore throat, and
        rhinorrhea. In addition to respiratory symptoms, gastrointestinal
        symptoms (e.g., nausea and diarrhea) have also been reported; and in some
        patients, they may be the presenting complaint [40,42,72].

        Although not highlighted in the initial cohort studies from China,
        smell and taste disorders (e.g., anosmia and dysgeusia) have also been
        reported as common symptoms in patients with COVID-19 [70,71].
        In a survey of 59 patients with COVID-19 in Italy, 34 percent
        self-reported either a smell or taste aberration, and 19 percent reported both [71].
        Whether this is a distinguishing feature of COVID-19 is uncertain.”

  • Clinical management of patients with COVID-19 depends on the severity of illness. Home management is appropriate for patients with non-severe infections that can be adequately isolated in the outpatient
    setting, with the focus being on the prevention of transmission. However, severe disease and symptoms require hospital admission and care to ensure infection control and adequate supportive care.

  • Currently, there are no data concerning the possibility of reinfection after recovery.

  • More information available from the CDC.

Critical Care and Management of COVID-19 Patients


** Treatment Options for Moderate to Severe COVID-19 (Updated 4.9.2020) - PDF

Infection Prevention

  • Health care workers can stay protected with PPE and the appropriate level of respirator (i.e., fit-tested N95 masks or if unavailable, surgical facemask (level III) is a safe alternative) when evaluating individuals who are suspected or confirmed to have COVID-19. Know the differences (CDC infographic)!

  • More information from CDC - FAQs about PPE and NIOSH.

  • Cardinal measures to prevent infection include frequent hand washing (soap and water preferred), avoiding touching one’s face/eyes, and being mindful about not being in close proximity (within 6 feet) to people who are coughing or sneezing. That said, more information about the potential role of asymptomatic infection has resulted in CDC guidance, suggesting more widespread mask usage by the public (non-medical, cloth coverings).

Pandemic Interventions

  • Minimize social interaction by staying at home, working from home, practicing social distancing, avoiding gatherings, and staying at least 6 feet away from others.

  • More information available from the CDC.

How to Stay Updated with COVID-19 Science

  • Keep visiting this site for periodic updates.

  • Visit Cerahgeneve for a compiled list of scientific resources.

Additional Resources

COVID-19 Apps.jpg

COVID-19 Apps

Click on COVID-19 Apps …for an article on useful apps! We’ll try to keep this link updated as well!