TIMELY TOPICS:

Newly Emerging Infectious Diseases (Part 1)

Howard G. McQuarrie, M.D.
Medical Director, PEHP

Newly Emerging Infectious Diseases (Part 2)
Newly Emerging Infectious Diseases (Part 3)

Introduction:
Newly emerging infectious diseases are now affecting humans around the world; diseases that previously have only been seen in animals. This article will be the first of several articles on SARS (Severe Acute Respiratory Syndrome). WEST NILE VIRUS AND MONKEYPOX will be reported in subsequent articles. The articles will be posted on the PEHP website.

A new disease called SARS
Severe Acute Respiratory Syndrome (SARS) is a respiratory illness that has recently been reported in Asia, North America, and Europe. The respiratory illness has been declared, “contained” as of July 25, 2003. There is concern, however, that the disease may become “seasonal”, much like the flu or influenza epidemics.

The cause of SARS
Scientists around the world have detected a previously unrecognized coronavirus (SARS-CoV) in patients with SARS. Coronavirus presumably originated in animals and mutated or recombined in a fashion that permitted it to infect, cause disease, and pass from person to person. Although some known human coronaviruses are associated with a mild disease (common cold), the ability of coronavirus to cause severe disease in animals raises the questions that coronavirus could also cause severe diseases in humans.

Symptoms of SARS
In general, SARS begins with a fever greater than 100.4 degrees Fahrenheit. Other symptoms may include headache, an overall feeling of discomfort and body aches. After 2-7 days, SARS patients may develop a dry cough and have trouble breathing.

How SARS spreads
The primary way that SARS appears to spread is by close person-to-person contact. Most cases of SARS have involved people who cared for, or lived with, someone already infected with SARS, or who had direct contact with infectious material (respiratory secretions). It is further believed that SARS can be spread more broadly through the air or by other ways, not currently known.

Who is at risk for SARS
Most of the U.S. cases of SARS have occurred among travelers returning to the United States from other parts of the world with SARS. There is no evidence that SARS is spreading more widely in the United States.

• Restrict Travel to areas with SARS. (See Travel Advisory on CDC Website: “Persons
  Traveling to Areas with SARS)
• For Individuals who must travel to an area with SARS:
  - Wash their hands frequently to protect against SARS infection.
  - Avoid close contact with large numbers of people as much as possible to minimize the possibility of infection

The CDC (Center for Disease Control) Fact Sheet SARS

Clinical Criteria:

• No symptoms or mild respiratory illness
• Moderate respiratory illness
  - Temperature of > 100.4 degrees F, and
  - One or more clinical findings of respiratory illness (e.g. cough, shortness of breath, difficulty breathing, or hypoxia (insufficient oxygen)
• Severe respiratory breathing, or hypoxia, and
  - Temperature over 100.4 F, and
  × Radiographic evidence of pneumonia
  × Respiratory distress syndrome
  × Autopsy finding consistent with pneumonia

Epidemiologic Criteria

• Travel within 10 days of onset of symptoms to an area with current or previously
  documented or suspected community transmission of SARS.

Laboratory Criteria

• Confirmed
  - Detection of antibody to SARS-associated coronavirus (SARS-CoV) in serum.
  - Isolation of SARS-CoV
• Negative
  - Absence of antibody to SARS-CoV in a convalescent-phase serum sample obtained >28 days after symptom onset.
• Undetermined
  - Laboratory testing either not performed or incomplete.

Case Classification

• Probable case: meets the clinical criteria for severe respiratory illness of unknown etiology and epidemiologic criteria for exposure; laboratory criteria confirmed or undetermined
• Suspect case: meets the clinical criteria for moderate respiratory illness of unknown etiology, and epidemiologic criteria for exposure; laboratory criteria confirmed or undetermined.

Exclusion Criteria

A case may be excluded as a suspect or probable SARS case if:

• An alternative diagnosis can fully explain the illness
• The case has a convalescent-phase serum sample which
  is negative for the antibody to SARS-CoV

References:

www.cdc.gov/ncidod/sars/ (Center for Disease Control)
www.cdc.gov/ncidod/sars/factsheet.htm
www.who.int/csr/sars/en/ (World Health Organization)
CBARTON@utah.gov (Utah Department of Health)
www.pehp.org (Public Employees Health Program Website)

Other Valuable Health Resources

• The book: Health Tracks, A Practical Guide to Managing Your Health (PEHP) – available from your employer/Human Resource Department or through this website.
• There is now new and updated information regarding cholesterol, and how it relates to coronary artery disease and its associated risk factors. This important information is covered in the article below (in Adobe Acrobat format). This copyright-free document has been produced by the National Cholesterol Education Program, and released by the National Institutes of Health (NIH). It is in an easy-to-read and understand format, and is recommended for everyone.