What type of illness is caused by Bacillus cereus?

Bacillus cereus is primarily associated with food intoxication, which occurs when toxins produced by the bacteria cause illness rather than the bacteria itself infecting the body. This distinction is crucial in understanding foodborne illnesses. In the case of Bacillus cereus, two different types of foodborne illnesses can be caused: one associated with emetic (vomiting) symptoms, typically linked to rice dishes, and the other involving diarrhea, associated with a variety of foods including meats and vegetables.

When discussing food intoxication, it highlights that the bacteria produces toxins that can cause disease when ingested, as opposed to infections where the living bacteria invade the host's body and multiply there. This classification is significant for food safety practices, as it points to the importance of controlling temperature and properly handling food to prevent the growth of Bacillus cereus and the associated toxin production.

The other options involve different mechanisms of illness. Allergic reactions occur due to the immune system's response to allergens, parasitosis is caused by parasites, and infection suggests a pathogenic invasion, which are not the primary concern with Bacillus cereus.