This has led to a small number of human infections, including fatalities during 2011.

With treatment, the number and severity of infections is reduced.

Since the first case was identified in 1990, the number of infections has continued to grow.

Officials said if the trend continued the number of new infections could rise 60 percent in 2003.

But the number of infections per 1,000 patient days rose to 9.77 from 7.18.

But then the number of infections began to grow in 1985.

The estimated number of new infections nearly doubled to 900 last year.

The total number of infections has increased by about 2,500 per year.

The number of new infections in America is still rising.

From 1982 to 1984, the number of new infections in homosexual men declined by more than 80 percent.