A recent analysis of surveillance data found that the rates and transmission routes of HIV among Latinos vary by region of the United States, suggesting that testing, prevention and treatment efforts could be better tailored to reflect these differences. Analyzing data from 46 states and Puerto Rico, researchers at the Centers for Disease Control and Prevention (CDC) found that, while the Northeast has twice the overall prevalence of HIV as any other region, the South has the highest number of HIV-positive Latinos (35.4 percent). Sex between men was the primary cause of transmission for Latinos nationally (66.5 percent), but those in the Northeast and Puerto Rico were more likely to contract the virus through injection drug use or heterosexual sex. Also, Northeastern Latinos with HIV tended to descend from Puerto Rico, while those in other U.S. regions predominantly had a Mexican or Central American background.