Infectious Diseases - Severe Acute Respiratory Syndrome

Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus that first was reported in Asia in late 2002. The illness spread to more than two-dozen countries in North America, South America, Europe, and Asia before the global outbreak was contained in July 2003. SARS seems to be transmitted primarily by person-to-person contact, through respiratory droplets, which travel via coughs or sneezes to the mucous membranes of other people or to surfaces that others touch. Symptoms of the disease may include high fever (more than 104 degrees Fahrenheit), body aches, malaise (overall discomfort), diarrhea, and mild respiratory symptoms; after two to seven days the infected person may develop a dry cough. The disease then progresses to pneumonia in most people.

According to the WHO, 8,098 people worldwide became sick with SARS during the outbreak, and 774 died. In the United States eight people—all of whom had traveled to parts of the world where the virus was present—contracted the disease.

In 2005 the NIAID applied its resources to developing diagnostics, vaccines, and identifying antiviral compounds to combat SARS-associated coronavirus (SARS-CoV). Among the many projects that have received NIAID support are the development of a "SARS chip," a DNA microarray to rapidly identify SARS sequence variants, and a SARS diagnostic test based on polymerase chain reaction (PCR) technology. (PCR is a technique for amplifying DNA sequences by as many as one billion times, and it is important in biotechnology, medicine, and genetic research.)

The CDC reports in Emerging Infectious Diseases that researchers have developed two candidate vaccines that protect mice against SARS. Another promising vaccine protects against infection in monkeys when delivered as a nasal spray. Passive immunization (immunity acquired by the transfer of antibodies from another individual) is also being assessed as a treatment for SARS. In 2004 screening of more than twenty thousand chemicals identified about fifteen hundred compounds with activity against SARS-CoV, and at least one has been deemed a candidate for further clinical development.