of morbidity and mortality associated with SARS-CoV call for careful monitoring for the recurrence of transmission and preparations for the rapid implementation of control measures. The 2003 global outbreaks demonstrated the ease with which SARS-CoV can seed and spread in human populations when cases remain undetected or when infected persons are not cared for in controlled environments that reduce the risk of transmission to others. The two laboratory-acquired infections and the recent cases in Southern China show that SARS-CoV continues to be a threat. Early detection of SARS cases and contacts, plus swift and decisive implementation of containment measures, are therefore essential to prevent transmission. Although the United States had only a limited SARS-CoV outbreak during the 2003 epidemic—with only eight laboratory-confirmed cases and no significant local spread—the U.S. population is clearly vulnerable to the more widespread, disruptive outbreaks experienced in other countries. During this period of no known person-to-person transmission of SARS-CoV in the world, healthcare and public health officials must therefore do what they can to prepare for the possibility that SARS-CoV transmission may recur.
This document provides guidance for surveillance, clinical and laboratory evaluation, and reporting in the setting of no known person-to-person transmission of SARS-CoV worldwide. Recommendations are derived from Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS) www.cdc.gov/ncidod/sars/guidance/index.htm. If such transmission recurs anywhere in the world, CDC will promptly review all available information and provide additional guidance via the Health Alert Network (HAN), Epi-X, and partner organizations. Current information will also be posted on CDC’s SARS website: www.cdc.gov/sars.
The median incubation period for SARS-CoV appears to be approximately 4 to 6 days; most patients become ill within 2 to 10 days after exposure. Early clinical features of SARS-CoV disease can be similar to other viral illnesses and are not sufficiently distinct to enable diagnosis by signs and symptoms alone. The illness usually begins with systemic symptoms such as fever, headache, and myalgias. Respiratory complaints often develop 2 to 7 days after illness onset and usually include a non-productive cough and dyspnea. Upper respiratory symptoms such as rhinorrhea and sore throat may occur but are uncommon. Almost all patients with laboratory evidence of SARS-CoV disease evaluated to date developed radiographic evidence of pneumonia by day 7-10 of illness, and most (70 percent-90 percent) developed lymphopenia. The overall case-fatality rate of approximately 10 percent can increase to >50 percent in persons older than age 60.