Dengue is like that, a lottery. In 2008 it was Brazil's bad lot, 2009 was Bolivia, 2010 saw Paraguay and northern Argentina hard hit. This year there's a major outbreak in the jungle regions of Peru centred around the city of Iquitos, with 7943 cases reported as at January 25th (dengue season tends to run until April) with 68 people seriously ill and 10 fatalities so far. To give an idea of the speed dengue spreads, the case number was at 4,450 on Janaury 20th. Not funny.
If you're travelling there, be careful and use those creams and pills. Meanwhile, Peru's fairly decent emergency health reaction teams are now getting into gear and the fumigation campaigns have started.