Public Health Perspective on SARS Diagnostics Stephen M. Ostroff Deputy Director National Center for Infectious Diseases, CDC

Outline International & Domestic Experience with SARS International & Domestic Experience with SARS Public health imperatives for SARS diagnostics Public health imperatives for SARS diagnostics

SARS Case Definitions (USA) Clinical Criteria Clinical Criteria –Fever (>38 C) & respiratory illness –Radiologic findings (pneumonia, RDS) –Autopsy findings (pneumonia, RDS) Epidemiologic Criteria Epidemiologic Criteria –Travel history (10 days) to SARS-affected area –Close contact with known or suspected SARS patient Laboratory Criteria Laboratory Criteria –Antibody to SARS-coV (acute or >28 days) –SARS-coV RNA by RT-PCR & 2 nd PCR assay –Virus isolation

SARS Case Definitions (USA) Suspect Suspect –Clinical & epidemiology criteria Probable Probable –Clinical & epidemiology criteria plus radiologic or autopsy evidence of pneumonia/RDS Confirmed Confirmed –Positive serology, PCR (x2), culture

US SARS Situation >17,000 individual reports received >17,000 individual reports received 423 persons met case definition 423 persons met case definition 348 (80%) suspected cases 348 (80%) suspected cases 75 (20%) probable cases 75 (20%) probable cases

SARS Case Demographics FactorSuspect CasesProbable Cases Age group <1822%22% %56% 65+ 6%21% Male/female 53%/47% 53%/47% Race/ethnicity White61%48% Asian36%49% Hospitalized >1 day24%61%

Number of Probable and Suspect SARS Cases by Date of Illness Onset, United States, 2003 N = 423* *Includes 5 suspect/probable cases with illness onset before 2/1/03; data reported through July 10, 2003.

U.S. Probable SARS Cases Data as of 6/18/03 HI N = 75 CT 3 MA 2 MD 0 NJ

73 (97%) reported travel to areas with documented or suspected community transmission of SARS within the 10 days before illness onset 1 (1%) HCW caring for SARS patient 1 (1%) household contact of SARS patient U.S. Probable SARS Cases N = 75 Data as of 6/18/03

SARS Lab Specimens* Received at CDC (as of 7/9/03) Specimen Type No. Specimen Type No. Autopsy tissue 105Stool 344 BAL/tracheal asp. 31Urine 224 NP SwabSerum acute 546 acute 1,535 convalescent 73 convalescent 530 unknown 225 unknown 1,420 Sputum 325 Other 80 Throat wash/swab 141 TOTAL 5,579 *Includes both domestic & international

Diagnostic Findings Test No. Tested No. (%) Pos. Coronavirus Serology 2, (7%) RT-PCR 1, (4%) HMPV RT-PCR (10%)

SARS-CoV Antibody Testing Interpretable Results United States, 2003 Data through 6/20/03 Type of Case CoV+ Probable8/45 (18%) Suspect0/138 (0%)

SARS-CoV+ Cases United States, 2003 N = 8 Data through 6/18/03 MMWR 2003;52: reported travel* –4 reported travel to Hong Kong –2 reported travel to Toronto –1 reported travel to both Singapore and Taiwan 1 spouse of lab-confirmed SARS patient who had traveled to Hong Kong *defined as travel to areas with documented or suspected community transmission of SARS within the 10 days before illness onset

Why do we need availability of good SARS diagnostic tests for public health purposes?

Public Health Rationale Appropriate clinical management Appropriate clinical management –Current –Future (therapeutics and prophylaxis) Disease surveillance Disease surveillance

Respiratory Tract Infections in Travelers >600 million persons travel annually >600 million persons travel annually >25% develop respiratory symptoms during travel; 10% following travel >25% develop respiratory symptoms during travel; 10% following travel 10-20% develop acute respiratory infection 10-20% develop acute respiratory infection Returning travelers seeking health care Returning travelers seeking health care –7.8% present with ARI (#2 complaint) –Travel to east Asia associated with ARI (OR 1.26 [95% CI ]) Leder, et al CID 2003:

Public Health Rationale Public health control measures: Public health control measures: –Hospital in- and out-patient management

Institutional Quarantine

Public Health Rationale Public health control measures: Public health control measures: –Community-based isolation & quarantine

Community Controls Cordon Sanitaire

4:30pm July 11, 2003 Initial test results negative DYESS AIR FORCE BASE, ABILENE, Texas – The initial test results from the laboratory samples taken from eight Dyess Air Force Base members that may have been exposed to Sudden Acute Respiratory Syndrome are negative for the virus, according to health professionals with the 7th Medical Group at Dyess Air Force Base. Of the first samples that were sent to an Air Force lab and the Center for Disease Control and Prevention (CDC) for testing, two were positive for a common infectious bacteria known as Streptococcus pneumoniae, often seen in patients with pneumonia. Although the early samples are negative for SARS coronavirus, more testing is being conducted to rule out infection. Definitive results may not be in for another two to three weeks. So far, 10 people associated with Dyess Air Force Base have now been identified and isolated in their homes for possible SARS infection. All are currently stable or improving as of this morning. They remain isolated in their homes and have been instructed to stay there until released. CDC guidelines recommend release 10 days past the date of fever and respiratory symptoms.

Public Health Rationale Public health control measures: Public health control measures: –Contact tracing and testing –Epidemiologic investigations –Environmental/product sampling –Evaluation of viral shedding –Blood supply –Screening

Additional issues SARS co-factors (HMPV, chlamydia) SARS co-factors (HMPV, chlamydia) Need to know it is SARS Need to know it is SARS Need to know it is something else Need to know it is something else Ideal would be a multiplexed assay Ideal would be a multiplexed assay