Coronavirus

Background

• Coronaviruses were first discovered in the 1960s and named after the crown-like spikes on their surface seen on electron microscopy.
• They are enveloped, positive-stranded RNA viruses.
• They have a nucleocapsid around them and are the largest RNA virus.
• Four main subtypes of Coronavirus: alpha, beta, gamma, delta.
• Coronavirus is very common and most people will get infected atleast once in their lifetime, esp children but route of infection is controversial. Most common time of infection is fall or winter.
• The cause of Coronavirus is hard to assess since it cannot be grown in laboratories, the way Rhinovirus can be grown (another common cold virus).
• Commonly cause up to one-third of upper respiratory tract infections in adults and children.
  • Also thought to cause diarrhea in infants, children, and farm animals.
• MERS-CoV and SARS-CoV types of Coronavirus cause the most severe infections.
  • SARS stands for severe acute respiratory syndrome.
  • SARS began in 2002 in Asia.
    • SARS started off in the Guangdong Province in southern China in November 2002. Finally it reached Hong Kong, then it rapidly spread around the world, infecting the people in 37 countries.
  • Up till now there have been more than 700 cases of death due to SARS, but during the epidemic (many called it a pandemic), there were 8,098 confirmed cases of SARS.
• The following human coronaviruses are currently known to virologists:
  • MERS-CoV
  • SARS-CoV
  • HCoV-229E
  • HCoV-OC43
  • HKU1-CoV
  • NL63/NL/New Haven coronavirus
  • MERS-CoV

Method of Replication

• Coronavirus enters the cell cytoplasm and viral particle is uncoated causing RNA genome to deposit into cytoplasm.
• RNA viral genome is transcribed into new RNA copies via replicase protein.

Clinical Features

• Coronavirus usually presents like the common cold with an upper respiratory tract infection:
  • runny nose
  • cough
  • fever
  • sore throat
  • asthma exacerbation
  • fatigue
  • sneezing
• Symptoms show two to four days after coronavirus infection.
• Pulmonary - coughing, dyspnea/wheezing, respiratory failure (seen in elderly/immunocompromised), pneumonia, secondary bacterial pneumonia.
• GI - vomiting, diarrhea, Necrotizing enterocolitis (in neonates)
• HEENT - otalgia, coryza, rhinorrhea, sneezing

Differential Diagnosis

• Rhinovirus: most common cold virus. Causes around 40% colds.
  • as opposed to Coronavirus, this causes cold in other seasons besides winter.
  • Rhinovirus is NOT encapsulated as opposed to Coronavirus.
• respiratory syncytial virus (RSV)
• influenza
• parainfluenza

Evaluation

• Generally no evaluation indicated
• If needed, nasal swabs can be sent for PCR and immunofluorescent antigen assay

Prevention

• No vaccines have been made thus far to prevent Coronavirus.
• Measures to reduce risk of transmission: fully wash hands, do not touch face without washing hands, avoid close contact with sick contacts.

Management

• There is no specific treatment for Coronavirus, since most infections spontaneously resolve.
• Supportive care
  • Rest
  • Hydrate patient (Drink adequate water)
  • Clean humidifier or Cool mist vaporizer
• Pain and fever medications can be taken (do not give aspirin to kids).
  • Take acetaminophen, ibuprofen or naproxen.

External Links

http://www.cdc.gov/coronavirus/about/ https://en.wikipedia.org/wiki/Coronavirus