Approximately 600 million (almost 1 in 10 people in the world) become sick after consuming contaminated food. As a result, 420 000 die every year. Food contaminated with bacteria, parasites, viruses, or chemical substances such as heavy metals or mycotoxins causes over 200 diseases ranging from diarrhea to cancers.
Viruses
Many different viruses can cause foodborne illness.
Noroviruses are a group of non-enveloped viruses in the Caliciviridae family. The infection is characterized by myalgias, nausea, explosive vomiting, watery diarrhea, and abdominal pain. The disease is self-limiting. The primary route of infection is person-to-person transmission through the fecal-oral and vomit-oral routes. Another source of this virus is ready-to-eat foods, leafy vegetables, herbs, berries; crustaceans, shellfish, mollusks, and their products; and meals handled after cooking, as well as water and the environment.
Another group of non-enveloped viruses rotaviruses in the Reoviridae family, consisting of 8 species named A−H. Rotavirus A is endemic worldwide and is responsible for approximately 80% of rotavirus gastroenteritis in humans, with water as a primary source of infection. Symptoms include vomiting followed by 3−7 days of diarrhea. If the diarrhea is not treated with fluids and electrolyte replacement it may result in exacerbation and death. Particularly susceptible are children of 6 months to 2 years of age, the elderly, and the immunocompromised individuals.
Hepatitis A virus belongs to a group of enteroviruses of the Picornaviridae family. It spreads typically through feces contaminated water or sewage-contaminated raw or undercooked seafood and can cause long-lasting liver disease. Infected food handlers are often the source of food contamination. The infection causes usually a mild illness with symptoms similar to influenzas such as the sudden onset of fever, nausea and abdominal discomfort, joint pain, malaise, dark-colored urine, pale stools. In few days it is followed by jaundice, with complete recovery within 2 months.
Hepatitis E is another representative of the Picornaviridae family. Although this virus is found worldwide, it is rare in the EU but most common in East and South Asia. It is transmitted primarily through fecally contaminated drinking water. Thus hepatitis E is related to poor sanitation. Other routes of infection include consumption of undercooked meat or meat products of infected animals (e.g. pork liver), blood transfusion from an infected person, or vertical transmission from mother to the baby during pregnancy.
How do the viruses and bacteria find their way to vegetables, which do not have gastrointestinal track themselves?