That person may be asymptomatic and considered to be a carrier.
They are called carrier's.
A 'pandemic'.
It is an epidemic.
Any agent that is capable of causing a disease is called as a pathogen. Vector is a DNA molecule carrying the gene of interest from one bacteria to the other to form a transformed cell.
It was called the plague.
When diseases spread worldwide it is called a pandemic of that disease.
Relapse is the medical term meaning the return of symptoms of disease. For instance, some people with multiple sclerosis have a relapsing/remitting pattern of disease, with periods of symptoms interspersed with periods of no symptoms.
There is no such thing as chromes disease. There is a disease called Crohn's and symptoms for it include diarrhea, abdominal pain, blood in your stool and weight loss.
it spreads a horrible disease called watertitis that when contracted makes you poo from your mouth
Occasionally, the symptoms of cat-scratch disease take the form of what is called Parinaud's oculoglandular syndrome.
Diagnosis
Flesh-eating disease is caused by a streptococcus bacterium called necrotizing fasciitis. It is an infection of the deeper layers of skin that spreads easily but does not affect the muscles.