The data used for this measure, Number of reported HIV diagnoses among persons age 13 and older during a calendar year is not a precise measure of new HIV infections.
Excerpt from August 2008 CDC Fact Sheet entitled, Estimates of New HIV Infections in the United States: Monitoring trends in new HIV infections has historically posed a major challenge, in part because many HIV infections are not diagnosed until years after they occur. New technology developed by the Centers for Disease Control and Prevention (CDC) can now be used to distinguish recent from longstanding HIV infections. CDC has applied this advanced technology to develop the first national surveillance system of its kind that is based on direct measurement of new HIV infections. This new system represents a major advance in HIV surveillance and allows for more precise estimates of HIV incidence (the annual number of new infections) than ever before possible.
In 2016, data from 2009 to 2014 were re-run using an updated data set. Updated rates differ from past values posted on this website.
In the future, DHMH may be able to obtain data on new infections, but until then, the measure will remain new diagnoses.