Foodborne Illnesses: Bacteria, Viruses, and Prevention

• Foodborne illnesses are infectious or toxic, caused by bacteria, viruses, parasites, or chemicals entering the body through contaminated food or water.
• They can result in severe diarrhea, debilitating infections like meningitis, acute poisoning, long-term diseases such as cancer, disability, and death.
• Unsafe foods include uncooked foods of animal origin, fruits/vegetables contaminated with feces, and raw shellfish containing marine biotoxins.

Bacteria

• Salmonella, Campylobacter, and Enterohaemorrhagic Escherichia coli are common foodborne pathogens.
• Symptoms include fever, headache, nausea, vomiting, abdominal pain, and diarrhea.
• Salmonella outbreaks are linked to eggs, poultry, and animal products.
• Campylobacter is mainly found in raw milk, raw or undercooked poultry, and drinking water.
• Enterohaemorrhagic Escherichia coli is associated with unpasteurized milk, undercooked meat, and fresh produce.
• Listeria infections can lead to miscarriages or death in newborns.
• Listeria is found in unpasteurized dairy and ready-to-eat foods and can grow at refrigeration temperatures.
• Vibrio cholerae infects through contaminated water/food, causing abdominal pain, vomiting, watery diarrhea, dehydration, and potential death.
• Rice, vegetables, millet gruel, and seafood have been implicated in cholera outbreaks.
• Overuse of antimicrobials leads to resistant bacteria, making treatment ineffective.
• Resistant bacteria like Salmonella can enter the food chain through animals (e.g., chickens).
• Antimicrobial resistance is a major threat to modern medicine.

Viruses

• Norovirus infections cause nausea, vomiting, watery diarrhea, and abdominal pain.
• Hepatitis A virus can cause long-lasting liver disease and spreads through raw/undercooked seafood or contaminated produce.
• Infected food handlers often contaminate food.

Parasites

• Some parasites (e.g., fish-borne trematodes) transmit only through food.
• Tapeworms (Echinococcus spp, or Taenia solium,) may infect via food or contact with animals.
• Parasites like Ascaris, Cryptosporidium, Entamoeba histolytica or Giardia enter the food chain through water/soil, contaminating produce.

Prions

• Prions are infectious protein agents linked to neurodegenerative diseases.
• Bovine spongiform encephalopathy (BSE, or "mad cow disease") is a prion disease in cattle, linked to variant Creutzfeldt-Jakob Disease (vCJD) in humans.
• Consuming bovine products with specified risk material (e.g., brain tissue) is the likely transmission route to humans.

Chemicals

• The greatest health concerns are naturally occurring toxins and environmental pollutants.
• Natural toxins include mycotoxins, marine biotoxins, cyanogenic glycosides, and toxins in poisonous mushrooms.
• Staple foods (corn, cereals) can contain mycotoxins like aflatoxin and ochratoxin from mold.
• Long-term exposure to mycotoxins can affect the immune system, development, or cause cancer.
• Persistent organic pollutants (POPs) accumulate in the environment and human body.
• Examples of POPs are dioxins and polychlorinated biphenyls (PCBs), by-products of industrial processes and waste incineration.
• POPs are found worldwide and accumulate in animal food chains.
• Dioxins are highly toxic and can cause reproductive/developmental problems, immune system damage, hormone interference, and cancer.
• Heavy metals (lead, cadmium, mercury) cause neurological and kidney damage.
• Heavy metal contamination in food occurs mainly through pollution of air, water, and soil.

Foodborne illnesses are caused by contaminated food or water, leading to infections and toxins in the body. Common pathogens include Salmonella, Campylobacter, and Escherichia coli. Unsafe foods include uncooked animal products, contaminated fruits/vegetables, and raw shellfish.