11.   Experts and health officials stress that the White Water E. coli outbreak is only the second known case of a pool spreading the disease.

12.   He is the only known human case of West Nile virus in the United States this year.

13.   He said he did not think a new review was planned because all recent known cases of abuse have been recently revisited.

14.   Health officials says there are no known cases of humans attracting the illness from antibodies to the virus.

15.   I explained that in about half the known cases, the cause is thought to be a viral infection.

16.   If confirmed, it would be the second known case of a doctor infecting a patient with the virus that causes AIDS during a medical intervention.

17.   If confirmed, it would mark the second known case of a doctor infecting a patient with HIV, the virus that causes AIDS, during a medical intervention.

18.   Improved reporting methods may account for a small portion of the increase in known cases, Majszyk said.

19.   In all known cases, the companies said, the counterfeits aroused suspicion before they were taken by patients, and no one is known to have been harmed.

20.   In Connecticut, a dead crow infected with the virus was found in the town of Columbia, the first known case in eastern Connecticut.