Contamination is the intrusion of a living being's body tissues by ailment causing specialists, their increase, and the response of host tissues to these life forms and the poisons they produce. Diseases are caused by irresistible specialists including infections, viroids, prions, microorganisms, nematodes. For example, parasitic roundworm sand pinworms, arthropods. For example, ticks, bugs, insects, and lice, organisms. For example, ringworm, and different macro parasites. For example, tapeworms and different helminths. A contamination caused by microorganisms. The development of numerous ailment causing microscopic organisms can be stopped by the utilization of anti-toxins.