Foodborne illnesses are among the most prevalent public health problems. Yet only a small proportion of these illnesses come to the attention of health services, and even fewer are investigated. In developing countries, there are even fewer cases, mainly due to poverty and lack of resources for food safety management and food control services. Despite underreporting, an increase in foodborne illnesses in many parts of the world and the emergence of new or newly recognized foodborne problems have been identified (Tauxe, 2002). Microbiological food quality control criteria globally still rely on standard counts of coliform bacteria that were developed as indicators of fecal contamination. There is now ample evidence demonstrating that these criteria are not sufficient to protect against foodborne viral infections. For example, high loads of infectious human pathogenic viruses were detected in retail foods that met all microbiological control criteria, leading to discussions about the validity of evidence for a recall. It is therefore important to understand the fundamental properties of foodborne illnesses. According to data compiled by the Centers for Disease Control and Prevention, viruses have become causes of foodborne illnesses. Viruses cause a wide range of diseases in plants, animals and humans. These infections do not occur randomly: each group of viruses has its own typical host range and cellular preferences. Viruses have probably always been a cause of foodborne illness; however, with recent developments in detection, we are now able to confirm the presence of viruses. Previously, these outbreaks may have been recorded as having an unknown causative agent. CHARACTERISTICS OF VIRUSES AS AGENTS OF FOODBORNE ILLNESS Viruses that ...... middle of paper ...... nza like disease, rash and neurological symptoms Hepatitis Diarrhea, rash , neurological symptoms Viruses of food origin can be divided into three main categories (Kapikian, 2000):1. Viruses that cause gastroenteritis, including astrovirus, rotavirus, adenovirus, norovirus (formerly Norwalk-like virus) and SLV (Sapporo-like virus).2. Viruses transmitted by the fecal-oral route, including hepatitis A and hepatitis E.3. Viruses responsible for other diseases, notably enteroviruses. Although foodborne outbreaks are sometimes seen with rotavirus and astrovirus, these viruses usually affect children rather than adults. The viruses most at risk for foodborne transmission are norovirus and hepatitis A virus. The reasons may be due to their extreme stability in the environment and their highly infectious nature (Koopmans et al.., 2002).