State laws that make it a crime for people to potentially expose someone to HIV without first disclosing their HIV status don’t appear to prevent transmission. Thus concluded Centers for Disease Control and Prevention (CDC) researchers after analyzing 2001 to 2010 HIV diagnosis data on 33 states from the National HIV Surveillance System. They also examined AIDS diagnosis rates in the same database, looking at data from all 50 states and covering 1994 to 2010. After adjusting the data to account for various factors, the investigators found that the criminal exposure laws that are on the books in 30 states were not associated with differences in HIV or AIDS diagnosis rates. Instead, they found that states with higher rates of HIV and AIDS diagnoses had a more urban overall population and a greater proportion of adult residents lacking a high school diploma.