Any disease caused by the entrance, growth, and multiplication of microorganisms in the body; a germ disease. It may not be contagious.
Sometimes, as distinguished from contagious disease, such a disease communicated by germs carried in the air or water, and thus spread without contact with the patient, as measles.
or contagious disease, generally a bacterial, viral or fungal organism that is transferred from one organism to another by four main methods of transmission (contact, vehicular, airborne or vector). Contagiousness refers to the ease of transmission of the infective agent. (More? Abnormal Development)