The Ayatollah also used extremely virulent language against the United States and Britain, calling them Iran's top enemies.

VOA: standard.2009.12.07

It says Iranian President Mahmoud Ahmadinejad continues a "virulent anti-Semitic campaign,"

VOA: standard.2009.10.26

The virus did not mutate to a more virulent form.

VOA: standard.2010.01.18

Angus Nicoll of the European Center for Disease Prevention says that at this point no one knows whether the virus will become more or less virulent in the months ahead.

VOA: standard.2009.04.30

It's a virulent strain that occurs when a person with TB fails to complete the six to nine-month course of medication or catches TB from another person who is ill with a drug resistant-strain.

VOA: standard.2010.07.12

that you are not as good. So the message of the Buffalo Soldiers is that in that time when racism was at its most virulent, that there were people, there were men who said, 'No,you're wrong, I am just as good as you are.

VOA: standard.2009.11.25

"Since we know that these kinds of threats can emerge at any moment, even if it turns out that the H1N1 is relatively mild on the front end, it could come back in a more virulent form during the actual flu season,"

VOA: standard.2009.05.01