The same technology employed by the Centers for Disease Control and Prevention (CDC) to reassess HIV incidence in the United States has allowed health officials to revise rates of new HIV infection at the local level, Newsday reports.

In New York, for example, scientists are able trace HIV infections by counties. Nassau County saw 113 new cases in 2006, 79 last year and 52 diagnoses so far this year.

“This new method for estimating the number of new HIV cases provides us with an important tool for better understanding and tracking the number of people infected with HIV,” says Richard F. Daines, MD, the New York State health commissioner, in a statement.

Federal scientists used new and more precise methods to determine that 56,300 people had been infected with HIV in 2006, not the 40,000 the CDC originally reported.