probable and suspect cases

[Dave Wilton]

> Everyone knows the meaning of the two words in isolation, but
> in this specific context, how does the CDC or the doctors
> distinguish between the two? Does one become a probable case
> first and then a suspect if more symptoms are manifested or
> is it the other way around? Or are suspect and probable cases
> free-standing entities? (I forgot to ask my doctor when I saw
> him last. Anyone got any idea?)

A probable case is more likely to actually be the disease in question than a
suspect case.

In terms of SARS, the WHO definitions of "suspect case" and "probable case"
are as follows:

"Suspect case
1.   A person presenting after 1 November 2002 with history of:
-  high fever (>38 °C)
AND
-   cough or breathing difficulty
AND one or more of the following exposures during the 10 days prior to onset
of symptoms:
-  close contact with a person who is a suspect or probable case of SARS;
-  history of travel, to an affected area
-  residing in an affected area

"2.  A person with an unexplained acute respiratory illness resulting in
death after 1 November 2002, 1 but on whom no autopsy has been performed
AND one or more of the following exposures during to 10 days prior to onset
of symptoms:
-  close contact,2 with a person who is a suspect or probable case of SARS;
-   history of travel to an affected area
-  residing in an affected area

"Probable case
1.  A suspect case with radiographic evidence of infiltrates consistent with
pneumonia or respiratory distress syndrome (RDS) on chest X-ray (CXR).
2.  A suspect case with autopsy findings consistent with the pathology of
RDS without an identifiable cause."

From: http://www.who.int/csr/sars/casedefinition/en/