Early Days of Food and Environmental Virology

In July 1962, the author joined the Food Research Institute (FRI), then at the University of Chicago, to become its food virologist. There was a limited record of waterborne viral disease outbreaks at the time; recorded data on foodborne outbreaks were fewer still. Laboratory environmental (water and wastewater) virology was in its infancy, and food virology was in gestation. Detection of viruses was most often attempted by inoculation of primary primate cell cultures, with observation for plaque formation or cytopathic effects. Focus was initially on enteroviruses and reoviruses. Environmental and food samples had to be liquefied if not already in liquid form; clarified to remove solids, bacteria, and fungi; and concentrated to a volume that could be tested in cell culture. Cytotoxicity was also a concern. Studies at the FRI and some other laboratories addressed all of these challenges. The FRI group was the World Health Organization’s Collaborating Center for Food Virology for many years. Other topics studied were virus inactivation as functions of temperature, time, matrix, disinfectants, and microbial action; peroral and ex-vivo infectivity; and the suitability of various virus surrogates for environmental monitoring and inactivation experiments. Detection of noroviruses and hepatitis A virus required molecular methods, most often RT-PCR. When it was found that inactivated virus often gave the same RT-PCR signal as that of infectious virus, sample treatments were sought, which would prevent false-positive test results. Many laboratories around the world have taken up food and environmental virology since 1962, with the result that a dedicated journal has been launched

Capsid and Infectivity in Virus Detection

The spectacular achievements and elegance of viral RNA analyses have somewhat obscured the importance of the capsid in transmission of viruses via food and water. The capsid’s essential roles are protection of the RNA when the virion is outside the host cell and initiation of infection when the virion contacts a receptor on an appropriate host cell. Capsids of environmentally transmitted viruses are phenomenally durable. Fortuitous properties of the capsid include antigenicity, isoelectric point(s), sometimes hemagglutination, and perhaps others. These can potentially be used to characterize capsid changes that cause or accompany loss of viral infectivity and may be valuable in distinguishing native from inactivated virus when molecular detection methods are used

Control of Viral Contamination of Food and Environment

Viruses are often transmitted via food and the environment. Contamination may be controlled either by preventing its occurrence or by inactivating the contaminating virus. The majority of agents transmitted in this way are human enteric viruses, produced either in the intestines or the liver. They are shed in human feces (noroviruses also in vomitus) in a broad range of circumstances, and they are relatively stable outside the host. Non-enteric viruses are less often transmitted via foods and are generally less environmentally stable. Insofar as vaccines are available, they are able to prevent fecal shedding. Viruses shed in feces via the water-carriage toilet may be eliminated by proper treatment and disinfection of the wastewater. In the foods context, the most effective antiviral measures are cooking and hand washing. Detection methods are most useful after the fact, in investigating outbreaks and devising preventive measures

Control of Viral Contamination of Food and Environment

Viruses are often transmitted via food and the environment. Contamination may be controlled either by preventing its occurrence or by inactivating the contaminating virus. The majority of agents transmitted in this way are human enteric viruses, produced either in the intestines or the liver. They are shed in human feces (noroviruses also in vomitus) in a broad range of circumstances, and they are relatively stable outside the host. Non-enteric viruses are less often transmitted via foods and are generally less environmentally stable. Insofar as vaccines are available, they are able to prevent fecal shedding. Viruses shed in feces via the water-carriage toilet may be eliminated by proper treatment and disinfection of the wastewater. In the foods context, the most effective antiviral measures are cooking and hand washing. Detection methods are most useful after the fact, in investigating outbreaks and devising preventive measures