What Is Food Science?

Module 18

Food SafetyIntroduction to Food Science& TechnologyMoving straight ahead into Chapter 2 - Food composition and Food categories1ObjectivesWhat hazards are associated with food safety?The microorganisms associated with foodborne illnessThe common causes of foodborne illnessThe number of illnesses from food in the United States and how much it costs societyThe difference between biological infections, intoxications, and intoxificationsThe onset time, and what that is, the symptoms and duration of illness associated with bacteria and parasites found in food, and their sources

There are three common types of hazards associated with food:Biological Bacteria, viruses, fungus, parasites, etc.Chemicalpesticides, cleaning solutions, etc.Physical glass, metal, wood, etc.Foodborne HazardsIn order to give you the background that you need to feel comfortable with this lecture, let us first describe the types of hazards that are involved with food and foodborne illness. The underlying principles of food safety deal with the source of contamination. These categories of hazards are biological, chemical, and physical. So, if you were in charge of a referendum to implement a food safety program for a processing environment, you would have to determine all of these sources so that you may make your food safety plans. Biological hazards come from bacteria, viruses, fungi, and parasites that either live on the raw product or food products are contaminated from another source during food handling by humans, ineffective washing procedures of fruits and vegetables, or sources of contamination on the food contact surfaces of processing equipment.Chemical hazards that are associated with immediate illness or illness associated with long-term exposure are included in the chemical hazard category. Pesticides that might cause liver damage or cancer, in addition to leftover cleaning solutions from sanitary process scheduling, are sources of chemical contamination in foods.Physical hazards are not nearly as prevalent in a food product as there are biological and chemical, but they do have a significant part of food safety. Most consumers are really not affected or worried about by glass, metal, wood, or truly strange substances that might be contained within a processed food. But trust me, theres nothing worse than having a glass shard or metal shaving incident in any food product. 3Common Foodborne PathogensThe most commonly recognized foodborne infections are those caused by:Salmonella spp.Campylobacter jejuniE. coli O157:H7 / STECand by a group of viruses called calicivirus, also known as Norwalk, Norwalk-like, or noroviruses We will talk more about this later, but Salmonella is the number one microorganism associated with foodborne illness in the US. For many years prior to 2010, Campylobacter was the number one source of foodborne illness, so although Salmonella is now the number one source of foodborne illness in the US, the number of Campylobacter infections is very close to Salmonella. I assume this is likely to be the case for future decades, so the understanding of how these microorganisms find their way to foods for human consumption, how truly virulent they are, and ways to control them will be increasingly important as time goes on.4SalmonellaSalmonella is a bacterium that is widespread in the intestines of birds, reptiles and mammalsIt can spread to humans via a variety of different foods of animal originThe illness it causes, salmonellosis, typically includes fever, diarrhea and abdominal crampsIn persons with poor underlying health or weakened immune systems, it can invade the bloodstream and cause life-threatening infections, called septicemia.

Source USDA-FSIS (2009)

Salmonella bacteria are found primarily in the gut of poultry and on the skin of some reptiles, as it is associated with becoming contaminated with Salmonella. There are a number of ways Salmonella can find to infect the human body, but predominantly comes from animal origins. Salmonellosis, the illness caused by Salmonella, includes fever, diarrhea, and abdominal cramps. This can be life threatening to the very young, the very old, and those who are immunocompromised.5CampylobacterCampylobacter is a bacterial pathogen that causes fever, diarrhea, vomiting, and abdominal cramps It is the most commonly identified bacterial cause of diarrheal illness in the worldThese bacteria live in the intestines of healthy birds, and most raw poultry meat has Campylobacter on itEating undercooked chicken, or other raw or moderately processed food that has been contaminated with juices or drippings from raw chicken is the most frequent source of this infection Source USDA-FSIS (2009)

As I mentioned earlier, it was only recently that Campylobacter was not the number one source of foodborne illness in the United States. In fact, it is the most commonly identified bacterial cause of diarrheal illness in the world. Campylobacter are found in the intestines of healthy birds and most raw poultry has some amount of Campylobacter on it. Drippings and juices from raw chicken that contaminate other foods prepared at the same time is the most frequent source of infection. This process is called cross-contamination.6E. coli O157:H7 or STECE. coli O157:H7 is a bacterial pathogen that has a reservoir in cattle and other similar animalsHuman illness typically follows consumption of food or water that has been contaminated with microscopic amounts of cow fecesThe illness it causes is often a severe and bloody diarrhea and painful abdominal cramps, without much feverIn 3% to 5% of cases, a complication called hemolytic uremic syndrome (HUS) can occur several weeks after the initial symptomsSource USDA-FSIS (2009)

E. coli O157:H7 or Shiga-toxin producing E. coli, is a pathogenic strain of E. coli that comes primarily from beef cattle. This type of E. coli is not to be confused with generic E. coli that resides in the human intestine that is essentially harmless. Human illness typically follows consumption of food or water that has been contaminated with microscopic amounts of cow feces. The organism causes severe and bloody diarrhea and painful abdominal cramps, without much fever. In 3% to 5% of cases, a complication called hemolytic uremic syndrome (HUS) can occur several weeks after the initial symptoms. This severe complication includes temporary anemia, profuse bleeding, and kidney failure.

7NorovirusCalicivirus, or Norwalk-like virus is an extremely common cause of foodborne illness, though it is rarely diagnosed, because the laboratory test is not widely availableIt causes an acute gastrointestinal illness, usually with more vomiting than diarrhea, that resolves within two daysUnlike many foodborne pathogens that have animal reservoirs, it is believed that Norwalk-like viruses spread primarily from one infected person to anotherInfected kitchen workers can contaminate a salad or sandwich as they prepare it, if they have the virus on their handsInfected fishermen have contaminated oysters as they harvested them

Source USDA-FSIS (2009)

Norovirus is a calicivirus, and up until recently was called Norwalk-like virus. Norovirus is thought to be a common cause of foodborne illness, though it is rarely diagnosed, because laboratory tests for norovirus in food is not widely available. It causes an acute gastrointestinal illness, usually with more vomiting than diarrhea, that resolves within two days. Norovirus isnt JUST associated with food, since it causes approximately 90% of epidemic non-bacterial outbreaks of gastroenteritis around the world. Some estimates have norovirus as high as 50% of all foodborne outbreaks of gastroenteritis in the US. Unlike many foodborne pathogens that have animal reservoirs, it is believed that Norwalk-like viruses spread primarily from one infected person to another Infected kitchen workers can contaminate a salad or sandwich as they prepare it, if they have the virus on their hands. Infected fishermen have contaminated oysters as they harvested them.8Cases of Foodborne IllnessAccording to CDCs FoodNet:2009 - 17,458 confirmed casesReductions in Campylobacter, Listeria, Salmonella, STEC, Shigella, YersiniaMost infections in children less than 4 years of ageCase fatality rate (CFR) highest among 50+ age groupSalmonella15.19 incidents per 100,000 people~47,250*Campylobacter13.02 incidents per 100,000 people~40,500*Shigella3.99 incidents per 100,000 people~12,500*STEC0.99 incidents per 100,000 people~3,000*According to the Centers for Disease Control, there were 17,458 confirmed cases of foodborne illness. Confirmed cases are ones that match DNA tests from sick patients in clinics to their food source. Epidemiologists and food microbiologists believe foodborne illnesses to be greatly underreported because typically the symptoms are not severe enough to cause hospitalization. One way to estimate the actual cases of foodborne illness is by determining the number of incidents per 100,000 people or a multiplication factor of some sort, or both. For example, Salmonella, 15.19 incidents per 100,000 were reported. With 311 million people in the US, this equates to roughly 47,250 cases of Salmonella, 40,500 cases of Campylobacter, 12,500 cases of Shigella, and 3,000 cases of E. coli O157:H7. Keep in mind that these are rough estimates and true numbers are very likely different.

Reductions in illness associated from Campylobacter, Listeria, Salmonella, STEC, Shigella, and Yersinia were also reported. As I mentioned previously, the very young, the very old, and those who are immunocompromised have the greatest risk of fatality if infected by foodborne illness. For example, most infections in children less than 4 years of age and more people over the age of 50 die than any other demographic.9Foodborne Illness Reporting ConsiderationsYoung children and the elderly are more likely to go to the doctor if they come down with diarrhea and/or vomitingIts estimated that there are realistically 5 to 10 times more illnesses associated with food than what is reported

Other considerations to make in regard to foodborne illness reporting is that the very old and very young are far more likely to go to the doctor or hospital if they come down with diarrhea and vomiting. Most scientific agencies use a 5 to 10 times more estimation when associating the estimated with the real reported illnesses.10Estimated Frequency of Bacterial Foodborne Illness in Humans in the U.S.Escherichia coli O157:H7Salmonella spp.Campylobacter spp.Listeria monocytogenes

Escherichia coli O157:H7Salmonella spp.Campylobacter spp.Listeria monocytogenes73,480 cases in 19991,412,498 cases in 19992,453,926 cases in 19992,518 cases in 1999

61 deaths582 deaths124 deaths504 deaths*Emerging Infectious Disease, Vol. 5, 1999.(http://www.cdc.gov/ncidod/eid/vol5no5/mead.htm)So, a paper in 1999 from Emerging Infectious Diseases, which was published by the Centers for Disease Control, provides us the data you see here. As you can see, Campylobacter held the title as the number one cause of foodborne illness for a long time and was only recently usurped by Salmonella. One thing to note, however, is how much more virulent Listeria monocytogenes is compared to other organisms. For example, in 1999, 20% of Listeria monocytogenes cases resulted in death. On the contrary, Campylobacter infections resulting in death were only 0.005%.11The Cost of Foodborne IllnessGetting sick from food can be expensiveCalculated based on:Medical costsProductivity lossLitigationOthersEstimated at $10 billion per year in the US (USDA, 2009)12The cost of foodborne illness, based on medical costs, productivity loss, litigation, and other factors, is estimated at 10 billion dollars per year in the United States, according to the US Department of Agriculture. Not only is this a huge cost to society, but the amount of money spent to reduce or eliminate foodborne illness by governmental regulatory agencies, food processors, and consumers, likely adds another few billion to the totalCost of Foodborne Illness (2009)Pathogen CDC estimate of annual number of cases cost estimate (2009 dollars) Est. CasesCost Campylobacter (foodborne sources) 2,000,000 Salmonella (all sources) 1,397,187 $2,649,413,401 Shiga toxin E. coli O157 (all sources) 73,480 $478,381,766 Non-O157 STEC 31,229 Listeria (all sources) 2,797

Cost Calculator: http://www.ers.usda.gov/Data/FoodborneIllness/Heres a breakdown of the cost of foodborne illness by responsible organism. As you can see, Salmonella and E. coli O157:H7 account for about a third of the cost estimate of 10 billion dollars in the previous slide. This information comes from a cost calculator that the USDA developed a few years back, and is found in the link at the bottom of the slide. It could come in handy if you are doing a paper on foodborne illness or just to pad your general knowledge of food safety. Ive only provided a few estimates from the calculator, but please feel free to visit this link, play around with the variables, and see what you get.13MicroorganismsCommon places for food poisoningFood serviceHomesVery little from commercially processed foods

Cross-contamination

Interesting Articlehttp://www.foodsafetynews.com/2010/06/according-to-a-north-carolina/14Believe it or not, very little tainted food comes from commercially processed foods. In fact, the majority of food poisoning comes from restaurants and from your homes. Many food service workers do not have the luxury of missing long periods of work due to illness. Sometimes, if the worker is on the verge of getting sick or has been sick and is still an asymptomatic carrier, theres really no good way to know this, until he or she spreads the infection to others through contact with their food. Its also difficult to tie this together when you become ill due to food poisoning. Additionally, according to a North Carolina State University study based on video cameras placed in commercial kitchens, foodservice workers, on average, commit one act of cross-contamination with the potential of leading to illness per hour, which agrees with their hypothesis that 70% of food poisoning outbreaks comes from meals prepared outside the home.

Let us discuss the term cross-contamination. Cross-contamination occurs when pathogens, such as Salmonella, are transferred from a raw or contaminated source to food that is ready to eat. The use of cutting boards with raw animal products and salad preparation, knives used to cut raw products that then slice a ready-to-eat sandwich, or raw meat dripping on to vegetables during thawing are examples of cross-contamination and are quite common in the food service kitchen. Most of these food safety errors occur when the kitchen is busier than normal and not only do cross-contamination events happen at a higher frequency, the amount of compliant hand washing is decreased during peak hours.

Most Common Causes of Foodborne Illness (CDC)Poor Personal HygieneImproper Holding or Storage TemperaturesInadequate CookingContaminated Equipment/Cross ContaminationFood From an Unsafe Source15According to the Centers for Disease Control & Prevention, the most common causes of foodborne illness are poor personal hygiene, like washing your hands frequently, improper food holding or food storage temperatures, inadequate cooking of food, contaminated equipment and cross-contamination, or food from an unsafe source that may have very high levels of bacteria and reduction of those organisms reduced during cooking are not reduced enough to keep illness from being a factor.

Microbial Food SafetyThere are three common types of biological hazards associated with food:

BacteriaShiga-toxin producing E. coli, Salmonella, Shigella, etc.VirusesHepatitis A, Norwalk, RotavirusParasitesGiardia, Toxoplasma, Crytosporidium, etc.16We covered food hazard on one of the first slides of this lecture, where there are three major types of hazards associated with food, biological, chemical, and physical hazards. Lets discuss the biological category. There are three types of biological hazards associated with food, BACTERIA, which include STEC, Salmonella, Shigella, etc., VIRUSES, which are often associated with norovirus, but may also include Hepatitis A and C, and rotaviruses, and PARASITES, like trichinella, toxoplasma, giardia, and several others.Foodborne disease (food poisoning)Food intoxicationThe result of toxic substances produced by the bacteria prior to consumption that cause illness upon ingestionClostridium botulinum = botulismStaphylococcus aureus = staphAspergillus flavus = aflatoxins17There are several different mechanisms that you may become sick from microorganisms. The first way that well discuss is food intoxication. What food intoxication means is that toxic substances are produced by bacteria prior to consumption that act as toxins in the human body. Toxins are formed in this manner by Clostridium botulinum, which causes botulism using a powerful neurotoxin, Staphylococcus aureus, which creates staph toxin that causes vomiting and diarrhea, and Aspergillus species that cause the formation of liver damaging aflatoxins.Foodborne disease (food poisoning)Food intoxificationThe result of toxic substances produced by the bacteria that once inside the small intestine, begin to produce toxin that cause illness upon ingestionE. coli O157:H7Campylobacter jejuni18Food intoxification, is pretty close in spelling to intoxication, so be sure to carefully read the term so that there wont be any confusion. Intoxification is the result of toxic substances that bacteria produce once inside the body. In other words, the bacteria produce the toxin in the body and not outside of the body. STEC and Campylobacter jejuni produce toxin when inside the body, so that process is food intoxification.

Foodborne disease (food poisoning)Food infectionBacteria are present at time of consumption and grow in the host to cause illness and diseaseClostridium perfringensSalmonella enteritidisListeria monocytogenesVibrio parahaemolyticusViruses 19Food infections are defined as bacteria growing in the host to cause illness and disease. This is commonly found in the case of Clostridium perfringens,Salmonella enteritidis, the Salmonella commonly associated with illness from shell eggs, Listeria monocytogenes, Vibrio parahaemolyticus, which is commonly associated with raw or undercooked shellfish, like oysters, which causes diarrhea, abdominal cramping, nausea, vomiting, fever and chills, and Viruses.

Symptoms, Duration, Onset, SourceOrganisms Associated with Foodborne IllnessThe remaining slides for this lecture will go over bacteria, viruses, and parasites associated with foodborne illness and the symptoms, duration, onset time from ingestion, and source of contamination will be covered.20BacteriaStaphylococcus aureusOnset Time / Latency Period0.5 to 8 hoursDuration6 to 48 hoursSymptomsNausea, vomiting, diarrhea, crampsTypically Found InMeats, cream filled pastries, whipped butterSource of ContaminationFood handlers, infected cuts, food slicersStaphylococcus aureus. The amount of time it takes for a person to start having symptoms is known as the onset time or latency period. In the case of Staphylococcus aureus, its anywhere between a half-hour to 8 hours. Because of the short onset time, the symptoms most people associate with food poisoning are from staphylococcus aureus. For example, if you eat something and get sick in the next few hours, you would associate what you last ate to your illness. As you will see, most other organisms have a longer onset time which complicates the source of illness. The duration of illness is 6 to 48 hours of nausea, vomiting, diarrhea, and cramps. You might find staphylococcus aureus in meats, cream filled pastries, and whipped butter from food handling, infected cuts by food handlers, food slicers, like you might find in a deli.

22Escherichia coli (enterotoxigenic)Onset Time / Latency Period10 to 72 hoursDuration3 to 5 daysSymptomsProfuse watery diarrhea, cramps, vomitingTypically Found InRaw foodsSource of ContaminationFecal oral route, direct or water-borneEscherichia coli (enterotoxigenic). This is just another name for the pathogenic E. coli we have been talking about in this lecture. Not the generic E. coli. Onset Time is 10 to 72 hours. Illness lasts for 3 to 5 days with symptoms of profuse watery diarrhea, cramps, vomiting. Enterotoxigenic E. coli is found in raw foods, most often from a beef cattle source. The source of contamination is the something called the fecal oral route, which is a term that describes ingesting minute amounts of fecal material, either directly or from a contaminated water source. For example, feces from beef cattle during slaughter is a possible source of contamination.23Clostridium perfringensOnset Time / Latency Period8 to 24 hoursDuration12 to 24 hoursSymptomsDiarrhea, cramps, rarely nausea and vomitingTypically Found InCooked meat and poultrySource of ContaminationSoil, raw foodsClostridium perfringens. Onset Time 8 to 24 hours, lasts for 12 to 24 hours, with symptoms of diarrhea, cramps, rarely nausea and vomiting. C. perfringens is typically found in cooked products, especially meat and poultry. The source of contamination, as is the case with spore formers, is soil and raw foods.24Clostridium botulinumOnset Time / Latency Period12 to 36 hoursDurationmonthsSymptomsFatigue, weakness, double vision, slurred speech, respiratory failure, deathTypically Found InVeggies, fruit, meat, fish, poultry, condimentsSource of ContaminationSoil, dust, water

DONT FEED INFANTS HONEYInfant botulism C.bot spores colonize intestineClostridium botulinum. Onset time 12 to 36 hours for what could be months. Symptoms of botulism toxin are fatigue, weakness, double vision, slurred speech, respiratory failure, death. Canning operations make sure that Clostridium botulinum is inactivated by proper heat treatment of the canned food. You might find C. botulinum in vegetables, fruit, meat, fish, poultry, and even condiments. Soil, dust, and water are common sources of contamination.

One other thing to note about Clostridium botulinum is that you DONT WANT TO FEED AN INFANT HONEY. You may have heard this before. The reason why is that C. botulinum spores that are commonly found in honey can actually colonize the intestines of infants causing infant botulism.

25Bacillus cereusOnset Time / Latency Period0.5 to 15 hoursDuration5 to 24 hoursSymptomsNausea, vomiting, diarrhea, crampsTypically Found InMeat products, soups, sauces, riceSource of ContaminationSoil or dustBacillus cereus. Fast onset time of a half-hour to 15 hours for 5 to 24 hours with symptoms of nausea, vomiting, diarrhea, and abdominal cramps. Typically found in meat products, soups, sauces, and rice. Soil and dust are sources of contamination.26Campylobacter jejuniOnset Time / Latency Period2 to 5 daysDuration2 to 10 daysSymptomsNausea, vomiting, diarrhea, chills, crampsTypically Found InInfected food-source animalsSource of ContaminationPrimarily poultry, raw milkCampylobacter jejuni. It takes about 2 to 5 days for Campylobacter jejuni to colonize the human digestive system. Symptoms such as nausea, vomiting, diarrhea, chills, and abdominal cramps last for about 2 to 10 days. Camylobacter jejuni is typically found in infected food-source animals, especially poultry, and sometimes raw milk.27E. Coli O157:H7 / STECOnset Time / Latency Period12 to 60 hoursDuration2 to 9 daysSymptomsWatery, bloody diarrheaTypically Found InRaw or undercooked beef, raw milkSource of ContaminationInfected beef cattleSTEC. There are many types of E. coli, like the enterotoxigenic E. coli we reviewed earlier, but this one is the most infamous E. coli that most people associate with deadly E. coli. Onset Time is 12 to 60 hours, with watery, bloody diarrhea for 2 to 9 days. You might find STEC in raw or undercooked beef from infected beef cattle and raw milk.28Vibrio choleraeOnset Time / Latency Period2 to 3 daysDurationHours to daysSymptomsProfuse rice-watery stools, often fatal if untreatedTypically Found InRaw or undercooked seafood, contaminated waterSource of ContaminationFecal-oral route transmissionVibrio cholerae is the source of cholera, the water-borne disease caused by insanitary water supplies. Cholera takes about 2 to 3 days to come on and lasts from as little as a few hours to several days. Symptoms include profuse, rice-watery stools, and is often fatal if untreated, due to dehydration. The foodborne sources of Vibrio cholerae is raw or undercooked seafood through fecal-oral route transmission.

29VirusesHere, well describe foodborne viruses.30Hepatitis A VirusOnset Time / Latency Period10 to 50 daysDuration2 weeks to 6 monthsSymptomsNausea, vomiting, diarrhea, cramps, jaundiceTypically Found InRaw or undercooked shellfish, contaminated waterSource of ContaminationFecal-oral route transmissionHepatitis A is a virus with an onset time of 10 to 50 days and lasts for 2 weeks to 6 months with symptoms of nausea, vomiting, diarrhea, cramps, and jaundice from raw or undercooked shellfish or contaminated water through fecal-oral route transmission.

31NorovirusesOnset Time / Latency Period1 to 2 hoursDuration1 to 2 daysSymptomsNausea, vomiting, diarrhea, headache, feverTypically Found InRaw or undercooked shellfish, sandwiches, saladsSource of ContaminationFecal-oral route transmissionNoroviruses take about 1 to 2 hours and lasts for 1 to 2 days. If youve ever heard of a 24-hour bug, it may very well be norovirus. Symptoms include nausea, vomiting, diarrhea, headache, and fever. You might find norovirus in raw or undercooked shellfish, sandwiches, salads from contamination by food handlers through fecal-oral route transmission.

32RotavirusesOnset Time / Latency Period1 to 3 daysDuration4 to 6 daysSymptomsDiarrhea, especially in infants and young childrenTypically Found InRaw or mishandled foodsSource of ContaminationFecal-oral route contaminationRotaviruses take about 1 to 3 days from inoculation to onset of symptoms, which is primarily diarrhea, and lasts for 4 to 6 days. You might find rotaviruses in raw or mishandled foods through fecal-oral route transmission.

33ParasitesAnd finally, parasites.34Giardia lambliaOnset Time / Latency Period5 to 25 daysDurationvariesSymptomsGreasy diarrhea, cramps, bloatingTypically Found InMishandled foodSource of ContaminationCysts in human and animal feces, waterGiardia lamblia is a parasite that takes about 5 to 25 days until the onset of symptoms. Symptoms are described as greasy diarrhea, abdominal cramps, and bloating. It comes from cysts in human and animal feces or contaminated water.

35Cryptosporidum parvumOnset Time / Latency Period2 to 14 daysDuration2 to 3 weeksSymptomsNausea, vomiting, diarrhea, sometimes feverTypically Found InMishandled foodsSource of ContaminationOocysts in human fecesCryptosporidium parvum takes about 2 to 14 days from inoculation until nausea, vomiting, diarrhea, and sometimes fever, to onset and lasts for 2 to 3 weeks. When foods are mishandled by food handlers with poor hygiene, oocysts of Cryptosporidium parvum may still be found on the hands of the food handler and transferred to food.36CyclosporaOnset Time / Latency Period2 to 14 daysDuration2 to 3 weeksSymptomsDiarrhea, loss of appetite, fatigue, weight lossTypically Found InRaw fruits and veggies irrigated w/ contaminated waterSource of ContaminationCysts in fecesCyclospora. The onset of Cyclospora is about 2 to 14 days and lasts for about 2 to 3 weeks. Symptoms of Cyclospora are diarrhea, loss of appetite, fatigue, and weight loss. Cyst contamination through fecal-oral route transmission is found in raw fruits and vegetables irrigated with contaminated water.37Toxiplasma gondiiOnset Time / Latency Period10 to 23 daysDurationvariesSymptomsResembles mononucleosis, fetal abnormality or deathTypically Found InRaw or undercooked meat, raw milk, mishandled foodsSource of ContaminationOocysts in cat feces, cysts in pork or muttonToxiplasma gondii causes symptoms resembling mononucleosis, fetal abnormality, or even death and has a widely variable duration. It typically takes 10 to 23 days for onset. You might find Toxiplasma gondii in raw or undercooked meat, raw milk, and mishandled foods. This is the also the reason pregnant women should not handle cat feces. Oocysts in cat feces and cysts in pork or mutton are sources of contamination.

38Trichinella spiralisOnset Time / Latency Period8 to 15 daysDurationWeeks to monthsSymptomsMuscle pains, swollen eyelids, fever, sometimes deathTypically Found InMeatsSource of ContaminationRaw or undercooked pork or meat of carnivorous animals (bear, etc.)Trichinella spiralis is the parasite that is commonly associated with raw or undercooked pork. It might even be found in the meat of carnivorous animals, like bear. The onset of illness takes about 8 to 15 days and lasts for weeks to months. Symptoms include muscle pains, swollen eyelids, fever, and sometimes death.39Taenia solium (pork tapeworm)Onset Time / Latency Period8 weeks to 10 yearsDuration20 to 30 yearsSymptomsWorm segments in stool, cysticerosis of muscles, organs, heart, or brainTypically Found InRaw or undercooked pork, food mishandled by a T. solium carrierSource of Contaminationcysticerol in pork muscle, food with T. solium eggsTaenia solium (pork tapeworm) takes anywhere from 8 weeks to 10 years for symptoms to show up and lasts for 20 to 30 years. If you find worm segments in stool, cysticerosis of muscles, organs, heart, or brain, you probably have a pork tapeworm. Cysticerol in pork muscle and food infested with Taenia solium eggs are the common sources of contamination. You might find Taenia solium in raw or undercooked pork or food mishandled by a carrier of Taenia solium.40