Issue 1: What causes COVID-19 and CDC recommendations on infection prevention and control (MARCH 4, 2020)

WHAT CAUSES COVID-19?

COVID-19 is caused by SARS-CoV-2 (aka the COVID-19-virus), which Is a novel beta –Coronavirus. It was first recognized as a human pathogen in December 2019 following identification of a cluster of pneumonia cases in Wuhan, China1.

BASIC SCIENCE

  • Coronaviruses are positive-strand, enveloped RNA viruses that are known to cause respiratory illness in humans and in animals e.g., the highly pathogenic SARS-CoV and MERS-coronaviruses2.
  • A full genomic sequence for SARS-CoV-2, has been determined1.
  • The virus targets the angiotensin-converting enzyme 2 (ACE2) protein in humans but with less affinity than the SARS virus1,3.

TRANSMISSION

  • Animal coronaviruses may evolve and subsequently infect humans, leading to human-to-human transmission.
  • Person-to-person transmission of SARS-CoV-2, like SARS-CoV and MERS viruses, is believed to occur through respiratory droplets with close contact4.*
  • People are thought to be most contagious when they are most symptomatic 4.

DIAGNOSIS

  • Symptoms include fever (not present in all), cough and shortness of breath, and can manifest 2-14 days following exposure with varying degrees of illness, including mild cold-like symptoms to ARDS, pneumonia, and even death in 3.4%  to date5.
  • Bilateral ground-glass opacities on chest CT scans confirmed early COVID-19 cases6.
  • The CDC has developed a new laboratory test kit specifically for detecting SARS-CoV-2 in patient specimens4.
  • A recent study identified virus shedding in saliva of patients up to 11 days after symptoms started7.

TREATMENT

  • Currently, there are no vaccines or other specific treatments for patients affected by COVID-19, and supportive care should be used. For severe cases, vital organ function should be supported7.
  • Routine administration of systemic corticosteroids should not be done, according to WHO interim guidelines8.
  • Treatment options are actively being investigated, including broad-spectrum antiviral agents and vaccines1.

INFECTION PREVENTION AND CONTROL4

The CDC recommendations include:

  • Wash hands often with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer (at least 60% content).
  • Avoid touching eyes, nose, and mouth with unwashed hands.
  • Avoid close contact with people who are sick.
  • Stay home when  sick.
  • Cover cough or sneeze with a tissue, then throw the tissue in the trash.
  • Clean and disinfect frequently touched objects and surfaces.
  • Persons with suspected SARS-CoV-2 infection should be asked to wear a surgical mask when identified.
  • Healthcare providers should adhere to standard, contact, and airborne precautions including eye protection.

 

*Close contact: Being within approximately 6 feet (2 meters), or within the room or care area, of a COVID-19 case for a prolonged period of time while not wearing recommended PPE. Includes caring for, living with, visiting, or sharing a health care waiting area or room with a COVID-19 case, OR having direct contact with infectious secretions from a COVID-19 case (e.g., being coughed on) while not wearing recommended PPE.

REFERENCES:

  1. Paules CI, Marston HD, Fauci AS. JAMA. January 2020. doi:10.1001/jama.2020.0757;
  2. de Wilde AH, Snijder EJ, Kikkert M, van Hemert MJ. In: Current Topics in Microbiology and Immunology. Vol 419. Springer Verlag; 2018:1-42. doi:10.1007/82_2017_25;
  3. https://www.scmp.com/news/china/science/article/3047114/coronavirus-weak…. Accessed January 24, 2020;
  4. https://www.cdc.gov/coronavirus/2019-ncov/index.html Accessed  Mar 4, 2020;
  5. https://www.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd4029942…. Accessed Mar 4, 2020
  6. Huang C, Wang Y, Li X, et al. Lancet. 2020. doi:10.1016/S0140-6736(20)30183-5;
  7. K-w KT, T-y OT, C-y CY, et al. Clinical Infectious Diseases BRIEF REPORT • cid 2020:XX (XX XXXX) • 1 Clinical Infectious Diseases ® 2020;XX(XX):1-3 Consistent Detection of 2019 Novel Coronavirus in Saliva. 2020. doi:10.1093/cid/ciaa149
  8. https://www.who.int/health-topics/coronavirus. Accessed January 24, 2020