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.
Fluorouracil topical may cause skin irritation, dryness, scaling or peeling (exfoliation), rash, and other local reactions. Eye irritation has also been reported. If these side effects are excessive or worsen with continued treatment, contact your doctor. Side effects other than those listed here may also occur.