# Presentation: 711623

## Public Health Perspective on SARS Diagnostics

- Stephen M. Ostroff
- Deputy Director
- National Center for Infectious Diseases, CDC

## Outline

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

## SARS Case Definitions (USA)

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

## SARS Case Definitions (USA)

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

## Slide 5

## US SARS Situation

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

## SARS Case Demographics

- _Factor__	__	__	__Suspect Cases__	__Probable Cases_
- Age group
- 	<18				22%			22%
- 	18-64			72%			56%
- 	65+				 6%			21%
- Male/female	      	      53%/47%	     53%/47%
- Race/ethnicity
- 	White			61%			48%
- 	Asian			36%			49%
- Hospitalized >1 day		24%			61%

## Number of Probable and Suspect SARS Cases by Date of Illness Onset, United States, 2003

- 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 2**

**24**

**4**

**4**

**1**

**2**

**1**

**2**

**3**

**1**

**1**

**10**

**1**

**1**

**1**

**3**

**2**

**2**

- N = 75

- CT 3MA 2MD 0NJ 1

**1**

**1**

**1**

**1**

## U.S. Probable SARS CasesN = 75

- 1 (1%) HCW caring for SARS patient
- 1 (1%) household contact of SARS patient

- U.S. Probable SARS CasesN = 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	  105		Stool		        344
- BAL/tracheal asp.	   31		Urine                    224
- NP Swab				Serum
- 	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	   2,742		188 (7%)
- 	RT-PCR		   1,235		  44 (4%)
- HMPV
- 	RT-PCR		     218		  21 (10%)

## SARS-CoV Antibody TestingInterpretable Results United States, 2003

- Data through 6/20/03

- _Type of Case_		      _CoV+_
- Probable			8/45 (18%)
- Suspect			0/138 (0%)

**Notes:**
Many cases US associated with other respiratory infections.
Epi link usually travel and GI and respiratory illnesses associated with wide range of agents, common in returning travelors
GI and resp most common illness of man
Problem – concern about SARS in context of other respiratory illness outbreaks
Possible role of co-infection in disease and/or transmission

## SARS-CoV+ Cases United States, 2003N = 8

- Data through 6/18/03

- MMWR 2003;52:570.

- 7 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

**Notes:**
Many cases US associated with other respiratory infections.
Epi link usually travel and GI and respiratory illnesses associated with wide range of agents, common in returning travelors
GI and resp most common illness of man
Problem – concern about SARS in context of other respiratory illness outbreaks
Possible role of co-infection in disease and/or transmission

## Why do we need availability of good

-  SARS diagnostic tests
- for public health purposes?

## Public Health Rationale

- Appropriate clinical management
- Current
- Future (therapeutics and prophylaxis)
- Disease surveillance

## Respiratory Tract Infections in Travelers

- >600 million persons travel annually
- >25% develop respiratory symptoms during travel; 10% following travel
- 10-20% develop acute respiratory infection
- Returning travelers seeking health care
- 7.8% present with ARI (#2 complaint)
- Travel to east Asia associated with ARI (OR 1.26 [95% CI 1.01-1.57])

**Leder, et al CID 2003:399-406**

## Public Health Rationale

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

## Slide 19

## Institutional Quarantine

## Public Health Rationale

- 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:
- Contact tracing and testing
- Epidemiologic investigations
- Environmental/product sampling
- Evaluation of viral shedding
- Blood supply
- Screening

## Additional issues

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