1 The incubation period of the virus is 3-16 days (average 7-10 days) with gradual fever (at onset and fever remains high for 2-3 weeks), chills, headache and body aches.
2 The first week, features nausea and vomiting, abdominal pain and diarrhoea.
From the second week severe sore throat, cough and chest pain, and swallowing becomes painful; the eyelids, face and neck are swollen, jaundice appears.
3 A rash may appear all over the body. Abnormal bleeding takes place into the skin, gastrointestinal track and airways with low blood pressure.
4 The condition worsens with breathing difficulty. Drowsiness and unconsciousness precede death from shock and kidney failure.
Convalescence lasts for 2-4 weeks for recovered person (though extreme weak).