Corona virus

·Corona virus are the second most important cause of common cold.

· The corona virus have also been reported to cause gastro-entritis in children and adult.

Morphology

· Size – 60 to 120 nm

· shape – spherical in shape

· enveloped – present

· genetic material- single stranded positive sense RNA virus

· motility- non-motile

Pathogenesis

· corona virus cause infection in upper respiratory tract

· Human corona virus is respiratory for 30% cases of common cold

# Source of infection: Infected droplet such as cough, sneeze, etc.

# Mode of infection: close contact with infected person

# Route of infection: fecal oral route

# Incubation period: incubation period varies from 2-5 days.

· Corona virus cause following condition.

1. Common cold:

• Corona virus cause more commonly upper respiratory tract or less commonly lower respiratory tract illness in human.

• Common cold caused by corona virus has an incubation period of 3 days.

2. Gastroenteritis:

• The corona virus have been reported to cause gastroenteritis in children and adult.

• The symptoms are mild and the condition is self limiting.

3. SARS:

• SARS is a potentially life threating infection associated with the onset of flu like syndrome.

• The incubation period varies from 2 to 7 days althrough it may be as long as 2 week.

• SARS characterized by:

  • Fever

  • Fatigue

  • Chills

  • Malaise

  • Anorexia

  • Myalgia

• SARS condition is associated with lymphadenopathy and thrombocytopenia.

• The mortality rate of SARS is higher than influenza and other respiratory illness.

# Symptoms

• Symptoms in corona virus include

  • Fever

  • Cough (usually dry)

  • Shortness of breath

  • Fatigue

  • Headache

  • Loss of taste

  • Sore throat

  • Nausea or vomiting

  • Diarrhea

  • Cheat pain

  • Skin rashes

Laboratory diagnosis

• Laboratory diagnosis of corona virus is done on the bases type of specimen, collection and transport, isolation of virus, antigen detection, antibody detection, etc.

# Specimen:

• Nasopharyngeal swab

• Throat swab

• Saliva

• Stool

• Tracheal aspirate

• Serum

• Sputum

# Collection:

• Specimen is collected with sterile swab or in leak proof sterile container.

# Transport:

• Most swab specimen are placed in viral transport medium (VTM) or sterile saline.

• Temperate 2 to 8 °C.

# Isolation:

• Human corona virus can be isolated in human foetal tracheal organ culture.

• Some strain grow on monolayer of diploid human embrayonic fibroblast with minimal cytopathic effect.

• Other specimen can be isolated on vero cell lines

# RT-PCR:

• High sensitivity and specificity can detect infection in early stages.

# Antigen detection:

• These test detect viral protein rather than DNA.

# Antibody detection:

• Enzyme linked immunosorbent assay (ELISA) are used to detect antibody.

Treatment

• No specific antiviral treatment is available against SARS.

Prevention and control

• Vaccination: most effective way to prevent corona virus infection

• Physical distance

• Hygiene

• Cover mouth and nose with mask

About author

Himanshu Paneru is the founder and author of DOC NOTE MASTER,

a platform dedicated to sharing insightful articles on medical topics

and education. Currently pursuing a master’s degree in Medical

microbiology at Netaji subhash chandra bose sybharti medical

college Dehradun, Uttarakhand. Himanshu combines his academic

knowledge with a passion for writing.