Acute gastroenteritis, one of the most common illnesses among the general population, is normally related to noroviruses, a group of virus that can affect the stomach and intestines. It is easily transmitted in closed spaces or by personal contact which explains why the outbreak epidemics frequently happen on cruise ships.
Its ability to resist hygiene practices or extreme environments is outstanding, converting it into one of the main causes of gastrointestinal illness.
In voluntary studies and in research about the virus outbreaks, a subgroup of individuals exposed to the virus did not become ill, a finding that suggests that there is a mechanism of natural protection. Although this natural protection may seem of immunologic origin, some volunteers having high levels of antibodies became ill while others who did not have antibodies did not. This apparent paradox is explained by the genetically determined susceptibility factors of the host; those factors that are related to union of the virus-like particles that attach to the intestinal secretions and red blood cells.
The nature of immunity to a norovirus is a determining key considering the perspective in the future of prevention by vaccine use. The prevention of norovirus outbreaks has been extremely difficult because the outbreaks that begin with a sole exposure to contaminated food or water may rapidly propagate through person-to-person contact.
Stopping the epidemic often requires great efforts to disinfect the environment in cruise ships, hospital rooms or disaster zones. Knowledge of the specific sequence of the epidemic may relate those cases to a common source such as exposure to raw oysters or contaminated foods, and occasionally identify the virus implicated in the food source.
The characteristics of resistance to adverse environmental conditions such as extreme temperatures and chlorine disinfectants make the norovirus difficult to eliminate from a specific setting, even when the persons in charge of workplace cleaning or of food preparation maintain high hygienic standards of cleanliness. To do so means that efforts to improve hygienic practices are necessary, both at community and domestic levels, to assure knowledge of the possible transmission mechanisms and the prevention of this type of illness.
Gene or region studied