during the time cholera was a big issue, technology such as internet or computers didn't exist. Today, technology is what can help us access information from any place really fast.
What do you mean by ‘casual contact’? Like, if you mean hugging someone, then no. Any type of contact where a person may transfer any type of bodily fluids may it be sweat, blood, semen, tears. Any fluid.
Carbohydrates and sources of carbohydrates include breads, pasta, cereals, fruits and vegetables.