Safety of STA travel tour - Peru, Honduras, Guatemala & Ecuador?

My brother is looking at going on a 6mth STA Travel tour to the above Latin American countries. I am a bit concerned given that most travel sites recommend exercising a high degree of caution in these countries. Crime and terrorism rates are high. I'm not sure if the organised tour is enough to ensure safety for young travellers. Has anyone been on an STA tour or have experience with these countries? Thanks.