Suspicion + PCR. Sars is very rare, and you are unlikely to ever see or know anyone who has it... However, if someone is traveling to the us from an endemic area or there is an outbreak, most state labs and some reference labs can either do an eia or rt-pcr test on sputum, urine, or feces for the virus. As it is so rare other forms of pneumonia should be tested for as well - even in an outbreak.
Http://www.cdc.gov/n. According to the world health organization (who), a total of 8, 098 people worldwide became sick with sars during the 2003 outbreak. Of these, 774 died. In the United States, only eight people had laboratory evidence of sars-cov infection. All of these people had traveled to other parts of the world with sars. Sars did not spread more widely in the community in the United States. http://www.cdc.gov.