CDC tracking may mask increased HIV infections in several areas. (Data Reported by only 25 States).

BARCELONA, SPAIN -- Newly diagnosed cases of HIV infection held fairly steady during the late 1990s in the states that track these cases, at about 16,600 per year in 1998 through 2000.

But this plateau is deceptive because it misses major parts of the national epidemic and because it may mask increases in HIV infections among certain segments of the U.S. population, Dr. Ronald O. Valdiserri said during a satellite press briefing during the 14th International AIDS conference.

The reliable numbers that the Centers for Disease Control and Prevention has been able to collect "may be masking increases in HIV among heterosexuals and among gay and bisexual men in some areas of the United States," said Dr. Valdiserri, who is deputy director of the National Center for HIV, STD, and TB Prevention at the Centers for Disease Control in Atlanta.

A large gap exists in the way that the CDC tracks HIV infection. Reliable information on newly diagnosed people with HIV is available only from states that use some method to identify cases and thereby ensure that tallied cases are not duplicated.

Through 2000, these data were reported by only 25 states; the totals lack reports from California, Florida, New York, and 22 other states as well as Washington, D.C.

One indication of the scope of the hole in the CDC's data is that the 25 states that comprise the data set for newly diagnosed patients account for roughly one-quarter of known U.S. cases of AIDS.

For the entire country, the CDC estimates that there were about 40,000 new HIV infections in 2000 and a total of about 900,000 people infected with HIV nationwide.