When a person becomes infected with a norovirus, the virus begins to multiply within the small intestine. After approximately 1 to 2 days, norovirus symptoms can begin. This period between the norovirus transmission and the start of symptoms is the  norovirus incubation period ..In some cases, the norovirus incubation period can be as short as 12 hours.his period between the norovirus transmission and the start of symptoms is the  norovirus incubation period .. In some cases, the norovirus incubation period can be as short as 12 hours.
Drug type: Fluorouracil is an anti-cancer (antineoplastic or cytotoxic) chemotherapy drug. Fluorouracil is classified as an antimetabolite.. (For more detail, see How Fluorouracil Works section below). What Fluorouracil Is Used For: 1  Colon and rectal cancer. 2  Breast cancer.
What is fluorouracil topical (Carac, Efudex, Efudex Occlusion Pack, Fluoroplex)? Fluorouracil interferes with the growth of skin cells. Fluorouracil works by causing the death of cells which are growing fastest, such as abnormal skin cells.