Chapter 2.3 Virus, Parasite & Fungi PDF

Chapter 2.3 The Microworld Learning Objectives  Differentiate between foodborne intoxication, infections, and toxin- mediated infections  Identify major food borne illnesses and their symptoms  Identify characteristics of major food borne pathogens including sources, food in...

Chapter 2.3 The Microworld Learning Objectives  Differentiate between foodborne intoxication, infections, and toxin- mediated infections  Identify major food borne illnesses and their symptoms  Identify characteristics of major food borne pathogens including sources, food involved in outbreaks, and methods of prevention. Virus Basic Characteristic s of Viruses Some may survive freezing Can be transmitted from: Person to person People to food People to food-contact surfaces Usually contaminate food through a foodhandler’s improper hygiene Can contaminate both food and water supplies Viral Foodborne Illnesses Hepatitis A Norovirus Gastroenteritis Major Foodborne Illnesses Caused by Viruses Infection: Hepatitis A Illness: Hepatitis A Virus: Hepatitis A Commonly Associated Food MostCommon Most Common Symptoms Symptoms Ready-to-eat food Initially: including: Fever (mild) General weakness Deli meats Nausea Produce Abdominal pain Salads Later: Jaundice Raw and partially cooked shellfish Preventing Hepatitis A To prevent the transfer of the virus to food: Wash hands properly Exclude employees who have jaundice or hepatitis A Minimize bare-hand contact with ready-to-eat food Other prevention measures: Purchase shellfish from approved, reputable suppliers Inform high-risk populations to consult a physician before regularly consuming raw or partially cooked shellfish Infection: Norovirus Gastroenteritis Illness: Norovirus Gastroenteritis Virus: Norovirus Commonly Associated Food Most MostCommon CommonSymptoms Symptoms Ready-to-eat food Vomiting Shellfish Diarrhea contaminated by Nausea sewage Abdominal cramps Preventing Norovirus Gastroenteritis To prevent the transfer of the virus to food: Exclude foodhandlers with diarrhea and vomiting Exclude employees who have been diagnosed with Norovirus Gastroenteritis Wash hands properly Other prevention measures: Purchase shellfish from approved, reputable suppliers Parasite Basic Characteristics of Parasites Are living organisms that need a host to survive Are small, often microscopic Infect many animals and can be transmitted to humans Are a hazard to food and water Parasitic Foodborne Illnesses Anisakiasis Cyclosporiasis Cryptosporidiosis Giardiasis Major Foodborne Illnesses Caused by Parasites Infection: Anisakiasis Illness: Anisakiasis Parasite: Anisakis simplex Most Common Symptoms Commonly Associated Food Most Common Symptoms Raw and undercooked: Non-invasive Herring Tingling in throat Cod Coughing up worms Halibut Invasive Stomach pain Mackerel Nausea Pacific salmon Vomiting Diarrhea Preventing Anisakiasis Most Important Prevention Measures Cook fish to required minimum internal temperatures Purchase fish from approved, reputable suppliers If fish will be served raw or undercooked: Purchase sushi-grade fish Ensure sushi-grade fish has been frozen properly by the supplier Infection: Cyclosporiasis Illness: Cyclosporiasis Parasite: Cyclospora cayetanensis Commonly Associated Food Most Common Symptoms Produce irrigated Nausea (mild to or washed with severe) water containing the parasite Abdominal cramping Mild fever Diarrhea alternating with constipation Preventing Cyclosporiasis It is critical to: Purchase produce from approved, reputable suppliers To prevent the transfer of the parasite to food: Exclude foodhandlers with diarrhea Wash hands properly to minimize the risk of cross- contamination Infection: Cryptosporidiosis Illness: Cryptosporidiosis Parasite: Cryptosporidium parvum Commonly Associated Food Most Common Symptoms Untreated or Watery diarrhea improperly treated water Stomach cramps Contaminated Nausea produce Weight loss Preventing Cryptosporidiosis It is critical to: Purchase produce from approved, reputable suppliers Use properly treated water To prevent the transfer of the parasite to food: Exclude foodhandlers with diarrhea Wash hands properly to minimize the risk of cross-contamination Infection: Giardiasis Illness: Giardiasis Parasite: Giardia duodenalis Commonly Associated Food Most Common Symptoms Initially: Improperly treated Fever water Later: Loose stools Abdominal cramps Nausea Preventing Giardiasis Most Important Prevention Measure Use properly treated water To prevent the transfer of the parasite to food: Exclude foodhandlers with diarrhea Wash hands properly to minimize the risk of cross-contamination Fungi  Fungi Commonly cause food spoilage and sometimes illness Fungi Molds Yeasts Basic Characteristics of Mold Mold Spoils food and sometimes causes illness Grows well in acidic food with low water activity Is not destroyed by freezing Can produce toxins such as aflatoxins Basic Characteristics of Yeast Yeast Can spoil food rapidly May produce a smell or taste of alcohol as it spoils food May appear as a pink discoloration or slime and may bubble  