'Probable' U.S. SARS Cases Now at 35
CDC Adopts Stricter WHO Definition of Likely SARS Cases
April 17, 2003 -- The number of SARS (severe acute respiratory
syndrome) cases in the U.S. reported to the World Health Organization (WHO)
dropped to only 35 from more than 200 suspected cases today, as CDC officials
adopted a stricter definition of "probable" rather than
"suspected" SARS cases.
The WHO has advocated the use of the probable SARS case
definition since the outbreak began, and CDC officials say they will now use
their broader definition only for their own epidemiological purposes.
According to the WHO definition, a probable SARS case requires
the presence of pneumonia or acute respiratory distress syndrome in addition to
high fever and travel within 10 days to a SARS affected area and/or recent
contact with a known SARS case. Until now, the CDC has also included in its
SARS reporting people who met the latter two requirements but had milder
respiratory symptoms, such as cough or difficulty breathing.
"Our approach in SARS containment in U.S. was that we did
cast a very wide net, and we have many more people in that net than actually
have SARS," says CDC director Julie Gerberding, MD, in a briefing
Of the 208 suspected SARS cases the CDC is investigating, 35
meet the probable SARS case definition. Of those 35 probable SARS cases, 33 had
traveled to areas in Asia hardest hit by the SARS epidemic, including mainland
China, Hong Kong, Singapore, and Hanoi, Vietnam. One of those probable SARS
cases was a healthcare worker who provided care for a SARS patient and the
other was a household contact of a SARS patient.
As of April 17, 3,225 probable SARS cases have been reported to
the WHO, including 165 deaths. The most recent increases in SARS cases and
deaths have occurred primarily in mainland China, Hong Kong, Canada and
Singapore. Officials say the SARS epidemic has been largely contained in other
Sewers Implicated in Hong Kong Outbreak
Health officials in Hong Kong today released the findings of
its investigation into a SARS outbreak in the Amoy Gardens apartment complex.
More than 300 people became ill with SARS in March, which prompted officials to
quarantine one block of the residential complex.
Yeoh Eng-kiong, MD, Hong Kong's Secretary for Health, Welfare
and Food, said not one single factor explained completely the unusual outbreak
among Amoy residents and it was most likely due to a combination of
person-to-person spread, environmental contamination, and transmission of the
virus through the sewage system.
Yeoh says about two-thirds of the SARS patients in this outbreak had
diarrhea, and a swab sample taken from the toilet of an infected resident
tested positive for the coronavirus' genetic material.
Investigators suggest SARS virus droplets may have entered the
apartments when virus particles from contaminated stools became lodged in dried
out, U-shaped water seals in the pipes at the complex. Water vapor and the use
of fans then allowed tiny droplets containing the virus to circulate throughout
the apartment and may have led to infection.
But Gerberding says these results are not conclusive, and the
fact that genetic evidence of a virus was found in a stool sample or swab is
not the same thing as determining it as the cause of infection.