Feline infectious peritonitis is a viral disease of cats seen worldwide. Not all cats infected with the virus causing FIP will become ill, but cats who do develop signs of FIP will likely succumb to the disease eventually.t is thought that the mutation in the virus that leads to FIP is more common in cats with immature or weakened immune systems. The coronavirus is spread through direct contact via the nose and mouth with infected feces, so sharing litter boxes is a major route of transmission of coronavirus.
After infection, immunity to norovirus is usually incomplete and temporary, with one publication drawing the conclusion that protective immunity to the same strain of norovirus lasts for six months, but that all such immunity is gone after two years.
Welcome to Stop The Stomach Fluâ > â How long is a person contagious after having the stomach flu (stomach virus)? (What is the contagious period for norovirus and others?) Answer: A person is still contagious for at least 3 days after symptoms have stopped. A person is contagious starting from the moment they start to feel sick and possibly even a little bit before that. In one study, Noroviruses were detected in the stool 15 hours after the people ingested the norovirus1. Usually symptoms don't start until 24-72 hours after ingestion (but can take longer).