In 1943, Britain planned to test a "very virulent" type of poison gas in what was Bechuanaland (now Botswana).

It was, of course, nothing more than sexism, the especially virulent type espoused by male techies who sincerely believe that they are too smart to be sexists.

"With a lot of infections you get waves, up and down, of resurgence, and we're now probably going into an up stage where we're getting more of this particular virulent type."

Sandford, however, urged us to defer going down there for at least two months: the rains had only recently ended and after the rains a virulent type of malaria was prevalent in the Awash valley.

To dream of this dread disease devastating the country, portends sickness of virulent type will rage and many disappointments will follow.

It was not of that virulent type which enters the room noisily and is promptly ejected to the accompaniment of appropriate comments.

Both are the Ames strain, which federal officials have identified as the particularly virulent type of anthrax used in the recent attacks.

The indigenous Americas also had a number of endemic diseases, such as tuberculosis and an unusually virulent type of syphilis, which soon became rampant when brought back to the Old World.

The dog was infested with a particularly virulent type of flea.

A particularly virulent type.