Norovirus, often called the “stomach bug” or “stomach flu,” is a highly contagious virus that causes acute gastroenteritis. This common illness is characterized by the sudden onset of symptoms like vomiting, diarrhea, and stomach pain. While the illness is usually short-lived, lasting only one to three days, it can cause discomfort and dehydration. This article examines the specific risks associated with cats and norovirus transmission.
Is Transmission from Cats Possible
The human norovirus (HNoV) that causes gastroenteritis is considered species-specific, meaning it primarily infects humans. Scientific understanding indicates that cats are not a significant reservoir for the human norovirus strain. Although noroviruses have been detected in various animal species, these viruses are genetically distinct from the ones that infect people.
The risk of a cat becoming infected with HNoV and then passing it to a human is virtually non-existent. While a cat’s fur or paws could theoretically act as a contaminated surface if exposed to human vomit or feces, the cat itself does not contract or spread the human illness. Documented cases of a cat infecting a human with norovirus are absent from public health records.
How Norovirus Spreads Among Humans
Understanding the transmission routes of norovirus is important for prevention. The primary method of spread is the fecal-oral route, which involves accidentally ingesting microscopic particles of feces or vomit from an infected person. An infected person can shed billions of viral particles, but it takes fewer than 100 particles to cause illness.
Transmission frequently occurs through contaminated food or water. Food can become contaminated if handled by a sick worker or if produce is grown or washed with contaminated water. Person-to-person contact is another common pathway, particularly in environments where people are in close quarters, such as schools, hospitals, or cruise ships.
The virus is highly resistant and can linger on surfaces for days or weeks, making spread through contaminated objects (fomites) a significant factor. Tiny drops of vomit can become aerosolized, landing on surfaces or entering another person’s mouth. Infected individuals can continue to shed the virus for up to two weeks after their symptoms resolve.
Feline Viruses and Human Illness
The confusion about cats and norovirus often stems from Feline Calicivirus (FCV), a similar-sounding virus that affects felines. FCV belongs to the Caliciviridae family, the same viral family as norovirus, but it is a separate pathogen. FCV is a common cause of upper respiratory infections in cats, leading to symptoms like sneezing, nasal discharge, and mouth ulcers.
FCV is species-specific to cats and does not infect humans. The illness FCV causes in cats is not the same as the acute gastroenteritis caused by human norovirus. Although FCV is highly contagious among cats, it poses no risk of causing the “stomach bug” in human family members. If a cat owner experiences norovirus symptoms, they contracted the human strain from another person, a contaminated surface, or food.
Preventing Illness Spread in Pet Households
Maintaining rigorous hygiene in a pet household helps minimize the spread of germs. Handwashing is the most effective preventive measure against enteric viruses like norovirus. Always wash hands thoroughly with soap and running water for at least 20 seconds, especially after using the bathroom, before preparing food, and after interacting with your pet or cleaning up their waste.
When cleaning a cat’s litter box, wash hands immediately afterward, as cat feces can carry other pathogens like Toxoplasma gondii. Frequent cleaning of pet food and water bowls, ideally using a dishwasher or hot soapy water daily, prevents the growth of bacteria. If a human family member is sick with norovirus, they should take extra care to disinfect shared surfaces, such as door handles and faucets, using an EPA-approved disinfectant to stop the virus from spreading to others in the home.