

The local drug scene casts a dark shadow on the sunny lifestyle of Puerto Rico, a place where addicts roam the streets in search of their next fix. For Dr. Panelli, treating abusers for jungle rot,Â"a ghastly condition that comes with using injected drugs, can be an overwhelming task.

The gambling mecca Sin City plays host to 40 million tourists a year. In storm drains beneath the Las Vegas strip, homeless addicts get high on crack in underground shanties, while in half-built suburbs, police battle marijuana gangs for control of the city's slump-hit homes.