What is severe acute respiratory syndrome (SARS)?
Severe acute respiratory syndrome (SARS) - a contagious and sometimes fatal respiratory illness - first appeared in China in November 2002. SARS is a severe form of pneumonia, where infected individuals develop a fever, followed by respiratory symptoms such as cough, shortness of breath or difficulty breathing. In some cases, the respiratory symptoms become
increasingly severe, and people require oxygen support and mechanical ventilation. It is not to be confused with the common cold.
The illness usually begins with a high fever (temperature greater than 100.4 degrees F). The fever is sometimes associated with chills or other symptoms, including a headache, a general feeling of discomfort, and body aches. Some people also experience mild respiratory symptoms at the outset. Approximately 10-20 percent of patients have diarrhea. After two to seven days, SARS patients may develop a dry cough with most developing pneumonia. SARS appears to be caused by a new type of coronavirus. Other coronaviruses cause common colds or infect various animals. Transmission of SARS occurs through face-to-face personal contacts, such as health care workers; family members; and people in nearby seats on airplanes or beds in hospitals. Because other infections transmitted in a similar fashion are spread by contact with secretions from the respiratory tract (such as the lungs or possibly the nose or throat), SARS probably spreads in the same way. A person becomes infected when his hands touch secretions from a person who is infected and he then touches his nose, mouth, or eyes, or when he inhales such secretions. However, some people who have developed SARS may not have had face-to-face contact, and many people who have face-to-face contact with people infected with SARS do not catch the illness. The virus is also in stool, and some people appear to have been infected after coming into contact with water supplies contaminated with sewage.
SARS is mainly spread by close person-to-person contact. The virus that causes SARS is thought to be transmitted most readily by being within 3 feet of respiratory droplets produced when an infected person sneezes and/or by touching a surface or object contaminated with infectious droplets. Close contact is defined as having cared for or lived with a person known to have SARS or having direct contact with secretions and/or body fluids of a patient known to have SARS. Examples include kissing or embracing, sharing eating or drinking utensils, close conversation (within three feet) or physical contact. Close contact does not include walking near a person or sitting across a waiting room or office for a brief time.
The Atlanta-based Centers for Disease Control (CDC) announced their belief that a strain of coronavirus, possibly a strain never seen before in humans, is the infectious agent responsible for the spread of SARS. Disease transmission is currently not well understood. It is suspected to spread via inhalation of droplets expelled by an infected person when coughing or sneezing, or possibly via contact with secretions on objects. Health authorities are also investigating the possibility that it may be airborne, which would increase the potential contagiousness of the disease.
The chances that SARS-infected people could be "asymptomatic," meaning that carriers could be infectious without developing any of the tell-tale signs and hence move around within a population undetected, are small, WHO officials said. "If asymptomatic carriers were playing an important role we would see it by now," WHO spokesman Dick Thompson told Reuters.