Major foodborne illness causing viruses and current status of vaccines against the diseases.

Even though viruses, unlike bacteria, cannot grow in or on foods, foodborne illnesses are associated with viruses due to contamination of the fresh produce or processed food by virus-containing fecal material. The commonly reported major foodborne illnesses are due to Noroviruses, hepatitis A and E viruses, rotaviruses, and astroviruses. Among all illnesses caused by foodborne pathogens, recent estimates of as high as 67% have been attributed to viruses alone, and an upward trend in the of transmission of viruses by food and water has been recently acknowledged. Due to the highly infectious nature of these viruses and their survival under drastic conditions such as high acidic pH and low temperatures, it has long been recognized that immunization against such pathogens is the ideal solution to provide protection against the illness and disease outbreaks associated with these viruses. With an increased recognition of the clinical significance and impact of acute viral illness associated with food and water in humans of all ages, there has been a recent surge in developing prophylactic vaccines against such viruses. So far, except for hepatitis A virus, there are no vaccines available to prevent illness associated with foodborne viruses. Outbreaks of hepatitis A have been significantly reduced due to widespread immunization of some risk groups. It is clear from the literature that novel strategies currently in development may lead to vaccines against noroviruses and rotaviruses in the near future, offering hope that such vaccines will significantly reduce the burden associated with foodborne illnesses associated with these viruses.