Quotes of the Day

What It Is

SARS (severe acute respiratory syndrome) is a respiratory illness that primarily affects the lungs but may also involve the digestive tract.

The Symptoms

In the first phase, patients get a fever of 100.4°F or more, with chills, headache and muscle aches. Within a week, most develop a dry cough and difficulty in breathing; about 10% to 20% require a ventilator. Some also get severe diarrhea.

The Cause

Scientists have identified a previously unknown virus in the coronavirus family as the primary cause of SARS. Coronaviruses often infect animals and until now caused only mild illness in people. It may turn out, however, that SARS results from simultaneous infection by several microbes.

How It Spreads

The most common route is direct person-to-person contact. Unlike influenza or tuberculosis, SARS is transmitted not through the air but most likely by droplets spread when an infected person coughs or sneezes. Doctors don't know how long an infected person remains contagious.

Treatments

There is still no cure. Patients are given supportive care for their symptoms, such as ventilators to aid breathing and fluids to prevent dehydration. Some researchers are searching for drugs that would block coronavirus infections; others are trying to develop a vaccine. Scientists have already sequenced the entire genome of the coronavirus, a major step in developing better treatments.

How to Protect Yourself

Doctors and nurses caring for SARS patients should take proper safety precautions and wear masks, gloves and gowns. Washing hands regularly is a good idea. It doesn't hurt to wear a mask in regions where there are large numbers of cases, such as Beijing, Hong Kong, Singapore and Toronto. Coronaviruses can survive for as long as 24 hours on surfaces, so remove and dispose of your mask carefully.

• Alice Park