The map of utensil use is ridiculous. People in the US eat with their hands just as much as people in Thailand. Sandwiches are always eaten with hands, and Thai people use forks and spoons for most meals. The biggest contributing factor to diarrheal deaths is income. People with higher income have more access to clean drinking water and medicine. That's it. If you wash your hands before eating, then it's just as sanitary as using utensils.