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.
â¢ Norovirus is the most common cause of acute gastroenteritis in the U.S. â¢ Each year, norovirus causes 19 to 21 million cases of acute gastroenteritis in the U.S. â¢ There are many types of norovirus and you can get it more than once.orovirus illness is often called by other names, such as food poisoning and stomach flu. Noroviruses can cause food. poisoning, as can other germs and chemicals. Norovirus illness is not related to the flu (influenza).