paranoia and parasitic infections question the validity of this statement other common paranoid delusions include the belief that the person has an imaginary disease or parasitic infection delusional parasitosis that the person is on a special quest or has been chosen by god that the person has had thoughts inserted or removed from conscious thought or that the person's actions are being controlled by an external force my research suggests that infections including parasitic ones can result in symptoms of paranoia the bodies reaction to a real threat of attack on the micro level look up organic infections of paranoia then there is the case of prescription drugs that cause this symptom levaquin side effects