coronaviruses33

Large, enveloped, positive sense stranded RNA viruses. They have the largest RNA genome.

Coronaviridae family was distinguished on basis of its distinctive morphology and received the name corona because of the crown like appearance of the surface projections.

The human coronaviruses(CoVs) are responsibe for about 30% of mild upper repiratory tract illnesses, ( common cold). Recentyly, CoVs have received the newly emerged SARS-CoV which causes the severe acute respiratory syndrome (SARS) that has been recently reported in Asia, North America and Europe.

Clinical aspects of SARS

- After an incubation period of 2-10 days, onset of the disease is characterized by fever, chills/rigors, headache, myalgia and malaise.

- Respiratory symptoms often begin 3-7 days ater symptom onset and peak in the second wee.

- Diarrhoea has been a prominent feature of early illness in some cases.

SARS transmission

Droplet s and contact of the skin or fomites that are contaminated with infectious dropekrs and then touchinh the eyes, nose or mouth.

N.B Causative agents of common cold include:
1.Rhinovirus causes about 50% of cases.
2. Human coronaviruses; are responsible for about 30% of cases.