Can u only catch aids from someone who has aids? There isn't a third person who could carry it to you?

AIDS & HIV Different. Aids is a syndrome, where a person who has HIV has developed opportunistic illnesses. Therefore, you do not catch aids, but you can contract hiv. The only way to contract HIV is from exposure to body fluids from someone who has the HIV virus. The only way for a 3rd person to be involved is exposure to contaminated equipment or blood transfusions.