Symptoms of Severe Acute Respiratory Syndrome(SARS)
Symptoms begin two to seven days after acquiring the virus. Initially, the illness resembles influenza and lasts for up to one week. Symptoms include fever, chills, headache, aches or pain in the muscles, general feeling of weakness (malaise), and poor appetite. Nausea, vomiting and diarrhea are less common. This period is followed by a syndrome suggesting atypical pneumonia, including dry cough and progressively worsening to severe shortness of breath (dyspnea) and inability to maintain oxygenation (hypoxia). Progression may be rapid or it may take several days. Severely affected people develop a potentially fatal form of respiratory failure, known as adult respiratory distress syndrome (ARD or ARDS). In addition to the attacking the alveoli (air sacs) in the lungs, the virus also infects other organs in the body, causing kidney failure, inflammation of the heart sac (pericarditis), or severe systemic bleeding from disruption of clotting system (disseminated intravascular coagulation), reduced lymphocyte cell counts (lymphopenia), inflammation of the arteries (vasculitis), and inflammation of the gut with diarrhea. People with compromised immune systems such as severe rheumatoid arthritis or organ transplantation may not experience respiratory symptoms but can have fever or diarrhea.