1.   A virulent strain of the disease malignant catarrhal fever is on the increase.

2.   They were scared by the virulent strains of virus Salk insisted on using in his vaccine.

3.   Animal manure is the primary reservoir for a virulent strain of E. coli.

4.   Ashley accepted that if Ron stopped using condoms it was theoretically possible that she might get infected with a more virulent strain of HIV.

5.   A virulent strain of A-Rod Fever is causing an epidemic of salary envy around the major leagues.

6.   But a terrorist who sought to use germs from one of these outbreaks to kill people would have to find a virulent strain.

7.   But in September, after a number of failed attempts, Drysdale and a postdoctoral fellow, Agathe Bourgogne, created a virulent strain.

8.   But in rare cases a virulent strain of N. meningitidis manages to penetrate mucosal cells in our respiratory tract.

9.   But it could anger metro Atlanta residents, seeing it as a particularly virulent strain of Atlantis bash-itis.

10.   But Tucker said the former Soviet Union is believed to have developed more virulent strains of the virus, and unauthorized supplies may have reached North Korea and Iraq.