CARTAGENA, Colombia -- "Too much Coke and lime juice," Gillo Pontecorvo said, gingerly pressing his fingertips against his stomach. "We were out in the sun all day and we, drank too much. Ohhh. What's funny, it only makes you more thirsty. Come, we go home. My little boy is mal all day today; I must see him before he goes to sleep."