Foodborne Viral Pathogens and Infective Protein

Abstract

Foodborne viruses such as rotavirus, norovirus, and hepatitis A virus cause enteric disease characterized by gastroenteritis and other complications and affect a large number of people every year. Foodborne enteric viruses are generally RNA virus, and they are shed in large numbers (about 10⁹ particles per gram) from infected patients through vomitus and feces. Person-to-person or fecal–oral transmission is a common mechanism for viral infection. Since viruses are highly infectious, only a small dose of 10–100 particles is sufficient to cause an infection. Zoonotic viral pathogens are transmitted from animals and avian species to humans, sometimes through direct contact with the animal or the meat. Avian influenza virus is transmitted primarily through contact or aerosol to the bird handlers and is not considered a foodborne pathogen, but it has the potential to cause human pandemics. Avian flu virus infection is fatal and affects lower respiratory tract resulting in pneumonia. The Nipah virus is transmitted by fruit bat while feeding on fruits or palm sap, and it is responsible for viral transmission to swine or directly to humans. It has a very high mortality rate. Likewise, Ebola virus is a zoonotic viral pathogen with 25–90% mortality rate. The infection may be the foodborne source, but the virus can spread from human-to-human through bodily fluids. Transmissible spongiform encephalopathy (TSE) diseases such as bovine spongiform encephalopathy (BSE) and varient Creutzfeldt-Jakob Disease (vCJD) are caused by misfolded neurodegenerative infectious prion proteins (PrP^Sc), which are highly resistant to heat and protease enzymes and can be transmitted by consuming contaminated meat. Preventing the use of meat–bone meal (MBM) or specific risk materials (SRM) can prevent the spread of prions among the meat-producing animals and to humans.