'Probable' U.S. SARS Cases Now at 35
CDC Adopts Stricter WHO Definition of Likely SARS Cases
Sewers Implicated in Hong Kong Outbreak continued...
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.
SARS Transmission and Testing in the U.S.
The CDC also released information today about two instances of SARS transmission among people who are thought to have contracted the disease from an infected family member who traveled abroad.
In the first case, a 40-year-old American male traveled to mainland China and Hanoi and developed symptoms of SARS one day after returning to the U.S. on March 10. He later developed pneumonia and was hospitalized. His 7-year-old child subsequently developed a fever and cough on March 16 and was hospitalized for observation.
In the second case, a 39-year-old man traveled to Hong Kong with his wife March 1-6 and stayed in a hotel where many of the first SARS cases are known to have stayed. On March 13, he developed a fever and respiratory symptoms, was later hospitalized with pneumonia, and tested positive for the coronavirus. On March 19, 13 days after returning home from Hong Kong, his wife also became ill and was hospitalized with pneumonia.
Although the genetic sequencing of the coronavirus now confirmed as the cause of SARS means researchers can further refine tests to screen for the disease, Gerberding says not enough is known yet about their accuracy and reliability for them to be the sole indicator of SARS.