Invasive Diseases Invasive Diseases are human illnesses that occur in parts of the body where bacteria should not be present, like blood or cerebral spinal fluid. Invasive diseases are caused by bacteria and can cause severe illness. Acute Flaccid Myelitis (AFM) Fifth Disease Fungal Meningitis Hand Foot Mouth Disease Hansen's Disease (Leprosy) Impetigo Invasive Bacterial Diseases Leprosy (Hansen's Disease) Scarlet Fever Strep Throat Streptococcal Toxic Shock Syndrome Streptococcus (Group A) Invasive Disease Streptococcus (Group B) Invasive Disease Viral Meningitis