From the Guidelines

Viral gastroenteritis from seafood can have a similar incubation period to human-to-human (H2H) transmission, typically ranging from 24-48 hours.

The incubation period for viral gastroenteritis, including norovirus, is generally between 24-48 hours 1.
This range is consistent across different modes of transmission, including foodborne and person-to-person transmission.

Norovirus can be transmitted through three general routes: person-to-person, foodborne, and waterborne 1.
Foodborne transmission can occur through contamination from infected food handlers or through contamination with human waste, as seen in outbreaks involving oysters and raspberries 1.

The clinical presentation of viral gastroenteritis includes symptoms such as nausea, abdominal cramps, vomiting, diarrhea, and fever 1.
The duration of illness is typically 12-60 hours 1.

The evidence supporting the incubation period and transmission modes of viral gastroenteritis is based on outbreak investigations and surveillance data from the CDC 1.
The studies cited are from MMWR Recommendations and Reports, a reputable source of public health information.

From the Research

The incubation period of viral gastroenteritis can vary depending on the type of virus and the mode of transmission 2.
For norovirus, which is a common cause of viral gastroenteritis, the incubation period is typically 1.2 days (95% CI 1.1-1.2 days) 2.
However, the incubation period for viral gastroenteritis from seafood is not explicitly stated in the provided studies.
It is known that norovirus can be transmitted through contaminated food, including seafood, and the incubation period may be similar to that of human-to-human transmission 3, 4.
A study on noroviruses in seafood found that the virus can be present in bivalve molluscs and ready-to-eat fishery products, which can lead to foodborne infections 4.
Another study discussed the importance of considering the incubation period in investigating and controlling infectious diseases, but did not provide specific information on the incubation period of viral gastroenteritis from seafood 2.

The incubation period of viral gastroenteritis from seafood may be different from that of human-to-human transmission, but there is limited information available to support this claim.
A study on the fate of bacteria in human digestive fluids found that the survival rate of Vibrio parahaemolyticus, a common cause of seafood-attributed gastroenteritis, was higher in gastric fluid with a higher pH level, which can be influenced by the consumption of seafood 5.
However, this study did not provide information on the incubation period of viral gastroenteritis from seafood.
More research is needed to determine the incubation period of viral gastroenteritis from seafood and to compare it to the incubation period of human-to-human transmission.