Módulo 5

Gastroenteritis and Escherichia coli: Understanding Foodborne Illnesses

Introduction to Gastroenteritis

• The video is the fifth in a series on food handling, focusing on foodborne illnesses, specifically gastroenteritis caused by pathogenic Escherichia coli.

Characteristics of Escherichia coli

• Escherichia coli (E. coli) is a common bacterium found in the intestinal flora of mammals, including humans. Most strains are harmless and part of a healthy gut.

• Pathogenic strains can cause severe infections in the intestines and urinary tract, leading to conditions like meningitis and gastrointestinal diseases such as hemolytic uremic syndrome.

Transmission Routes

• E. coli can contaminate food through contact with animal intestinal material during processing, particularly in meat due to improper slaughtering practices.

• Contamination can also occur via contaminated water or poor hygiene practices, such as inadequate handwashing after using the restroom.

Symptoms and Affected Populations

• Common symptoms of E. coli infection include nausea, vomiting, abdominal cramps, diarrhea, fatigue, and fever; these typically affect children and immunocompromised adults.

• Most non-pathogenic E. coli infections resolve without treatment within 5 to 10 days; however, dehydration must be managed carefully.

Sources of Contamination

• E. coli is prevalent in both human and animal intestines; it can enter food through unsanitary processing methods or contaminated irrigation water for vegetables.

• Foods at risk include undercooked beef (especially ground), unpasteurized milk or juices, and raw vegetables that have not been properly washed.

Prevention Strategies

• Key prevention measures include thorough handwashing with potable water before preparing or consuming food and avoiding raw milk products.

• Cooking meats to an internal temperature of at least 71°C (160°F) effectively kills E. coli pathogens.

Hygiene Practices

• Prevent cross-contamination by storing raw foods separately from cooked items in refrigerators; wash fruits and vegetables thoroughly with safe water.

• Proper disposal of human waste is crucial to prevent contamination of water sources used for drinking or cooking.

Recreational Water Safety

• Avoid swimming in potentially contaminated waters such as lakes or untreated pools to reduce exposure risks associated with E. coli.

Focus on Hemolytic Uremic Syndrome

• The video highlights that certain strains of E. coli produce toxins leading to hemolytic uremic syndrome (HUS), which is endemic in some regions with approximately 400–500 new cases annually each year.

Understanding Hemolytic Uremic Syndrome

Overview of Hemolytic Uremic Syndrome (HUS)

• HUS primarily affects children under 5 years old and is the leading cause of acute renal failure in this age group. It accounts for at least 20% of kidney transplants in children and adolescents.

Clinical Manifestations

• Symptoms typically begin 3 to 4 days after bacterial infection, with initial signs including abdominal pain and watery diarrhea, which may progress to bloody diarrhea. Most cases resolve at this stage.

Progression of the Disease

• If left untreated, HUS can evolve into a more severe condition characterized by three main symptoms: acute renal failure, thrombocytopenia (low platelet count), and hemolytic anemia (destruction of red blood cells).

Transmission Pathways

• The bacteria responsible for HUS are transmitted through contaminated food or contact with livestock feces, particularly from cattle. Direct person-to-person transmission can also occur, especially in settings like daycare centers.

Characteristics of the Bacteria

• The primary strain causing HUS is E. coli O157:H7, which is resistant to pH changes and thrives between temperatures of 30°C to 42°C but cannot survive above 45°C or below 10°C. Proper cooking is essential as the bacteria do not withstand high temperatures well.

Symptoms and Diagnosis

Initial Symptoms

• Early symptoms include digestive issues such as acute diarrhea that often becomes bloody, vomiting, decreased urine output due to kidney impairment, and noticeable paleness in affected children.

Advanced Symptoms

• As HUS progresses, symptoms may include edema (swelling), weakness, neurological alterations like lethargy or somnolence, and potentially seizures due to neurological compromise associated with the disease's severity.

Classic Triad of Symptoms

• The classic presentation includes acute renal failure, thrombocytopenia (reduced platelet count), and hemolytic anemia (breakdown of red blood cells). Additional symptoms may involve vomiting and irritability along with varying degrees of neurological impact on the child’s health status. Hospitalization is often required for management.

Food Safety Concerns

Associated Foods

• Contaminated beef from improper handling during slaughtering processes poses significant risks; ground beef is particularly concerning if not cooked thoroughly. Other risk factors include vegetables irrigated with unsafe water and unpasteurized dairy products that have come into contact with animal feces or contaminated water sources. Special emphasis should be placed on ground beef as a common source during outbreaks.

Food Safety and Disease Prevention

Importance of Hygiene in Food Preparation

• Emphasizes the risk of contamination from individuals who may carry bacteria without showing symptoms, particularly through poor hygiene practices during food preparation.

• Highlights the necessity of cooking meat thoroughly, especially ground meat, to prevent bacterial presence; no pink or red parts should remain inside.

Safe Food Handling Practices

• Discusses rapid cooling of cooked foods to reduce microbial growth; emphasizes avoiding room temperature storage.

• Stresses the importance of handwashing with soap after using the restroom and before handling food, as well as washing fruits and vegetables properly.

• Recommends consuming pasteurized milk and boiling water if its safety is uncertain; suggests a method for home purification by adding bleach.

Cross-contamination Prevention

• Advises on preventing cross-contamination between raw and cooked foods; reiterates that control measures are generally similar across various diseases.

Triquinosis: Understanding the Disease

Causes and Transmission

• Defines triquinosis (or triquinelosis), caused by consuming undercooked or raw meat from infected animals, primarily pigs.

• Notes that infection can occur from various animal meats but highlights domestic pig sources as most significant in certain regions.

Risk Factors

• Points out that recent cases have been linked to wild boar consumption; stresses the need for controlling rodent populations around domestic pig farms to prevent disease spread.

Symptoms and Health Risks

• Describes variable symptoms ranging from asymptomatic infections to severe illness depending on larval ingestion quantity and host immunity.

• Lists common symptoms including muscle pain, eyelid swelling, fever, gastrointestinal distress occurring 1–2 weeks post-infection.

Long-term Effects and Complications

• Mentions potential complications such as photophobia, coordination issues, cardiac problems, and respiratory distress in severe cases.

Preventive Measures

• Urges public awareness about preventive measures against triquinosis for those raising pigs at home; emphasizes easy-to-adopt practices for disease prevention.

Guidelines for Safe Pork Consumption

Proper Pig Farming Practices

• Farmers should raise pigs in suitable facilities, free from rodents, and avoid feeding them waste to ensure meat safety.

• Preservation methods like salting, drying, and smoking can affect bacteria but not parasites; thus, proper analysis is crucial in slaughterhouses.

Meat Safety Analysis

• Samples for testing are typically taken from the diaphragm or jaw muscles of slaughtered pigs to check for contamination.

• Consumers must ensure that pork products are certified free from trichinosis by health authorities before consumption.

Cooking Recommendations

• Fresh pork should be cooked thoroughly until juices run clear at an internal temperature above 71°C (160°F), as the trichinella parasite cannot survive high cooking temperatures.

• Avoid consuming undercooked wild boar or puma meat unless it has been properly tested.

Understanding Listeriosis

Overview of Listeriosis

• Listeriosis is an infectious disease caused by consuming food contaminated with Listeria monocytogenes, which can grow at refrigeration temperatures but not during cooking.

Contamination Sources

• Animals can carry listeria in their intestines, contaminating meat and dairy products; fecal contamination is a common transmission route.

At-Risk Populations

• Individuals with weakened immune systems, including pregnant women and newborns, are at higher risk for severe listeriosis symptoms such as meningitis or septicemia.

Symptoms and Food Associations

• Common symptoms include chills, fatigue, nausea, vomiting, fever, headache, diarrhea; severe cases may lead to complications like miscarriage in pregnant women.

• Foods frequently linked to listeriosis outbreaks include deli meats, unpasteurized dairy products, raw vegetables, and smoked fish.

Preventive Measures Against Listeriosis

Hygiene Practices

• Key preventive measures include thorough handwashing and sanitizing kitchen utensils and surfaces that come into contact with raw foods.

Food Storage Guidelines

• Maintain cleanliness in refrigerators to prevent cross-contamination; refrigerate prepared foods promptly after cooking.

Cooking Instructions

• Cook all foods completely before consumption; reheating should also reach safe cooking temperatures. Avoid unpasteurized dairy products due to potential contamination risks.

Cholera and Hepatitis A: Understanding Transmission and Prevention

Cholera Overview

• Cholera is caused by the bacterium Vibrio cholerae, which can lead to severe symptoms in a small percentage of infected individuals, despite most cases being asymptomatic.

• The primary reservoir for Vibrio cholerae is humans, with transmission occurring mainly through contaminated water or food, particularly from feces or vomit of carriers.

• Symptoms typically appear 24 to 48 hours post-infection; however, 80-90% of those infected remain asymptomatic but still excrete the bacteria.

• Common symptoms include watery diarrhea without abdominal pain, sometimes accompanied by vomiting and muscle cramps due to dehydration. Severe dehydration occurs in less than 10% of symptomatic cases.

• Contaminated seafood (both shellfish and crustaceans), fruits, and vegetables are often linked to cholera outbreaks.

Control Measures for Cholera

• Essential control measures include ensuring access to potable water and practicing basic hygiene such as handwashing after using the toilet and before handling food.

• Proper sanitation systems for human waste disposal and treatment of wastewater are crucial in preventing contamination of water bodies with fecal matter.

• Food hygiene practices should involve washing raw fruits and vegetables with safe water; cooking seafood thoroughly eliminates risk since Vibrio cannot survive high temperatures.

• Avoiding the use of untreated human waste or sewage as fertilizers is critical in preventing foodborne diseases.

Hepatitis A Overview

• Hepatitis A is a contagious disease transmitted via the fecal-oral route through contaminated food or water, or person-to-person contact. It is caused by a virus rather than a bacterium.

• The illness can range from mild (lasting weeks) to severe (lasting months), especially prevalent in areas lacking proper hygiene facilities.

• The virus is shed in the feces of infected individuals; susceptible persons may contract it through contaminated food or water sources.

• Symptoms usually manifest between 2 to 4 weeks after exposure, including fever, malaise, nausea, vomiting, abdominal pain, and jaundice indicating liver involvement.

• Foods commonly associated with hepatitis A outbreaks include shellfish, salads made from ground-level vegetables, deli meats, fruit juices, dairy products, and any contaminated items handled by infected individuals.

Prevention Strategies for Hepatitis A

• Frequent handwashing before handling food and after using unsanitary facilities significantly reduces transmission risk.

Understanding Food Safety and Health Risks in Argentina

Hygiene Practices for Food Preparation

• Proper hygiene is crucial when handling food, including thorough cooking to eliminate viruses, as they cannot withstand high temperatures.

• It is essential to wash raw foods with safe water to ensure safety and maintain hygienic environmental conditions.

• Regular cleaning and disinfection of surfaces, along with proper disposal of waste, are necessary practices.

Vaccination Against Viruses

• In Argentina, vaccination against certain viruses has been mandatory since 2005, administered at one year of age to prevent diseases effectively.

Red Tide Phenomenon

Overview of Red Tide

• The "marea roja" or red tide is a natural phenomenon caused by the blooming of algae that contain harmful toxins.

• These algae can turn the water reddish or brownish during their proliferation.

Toxin Accumulation in Shellfish

• Shellfish feed on these toxic algae and accumulate the toxins in their edible parts; these toxins are heat-stable and resistant to cooking.

• Symptoms from consuming contaminated shellfish can appear quickly (30 minutes to 2 hours), starting with tingling sensations in the lips and face.

Symptoms and Severity of Poisoning

• As poisoning progresses, symptoms may include numbness, difficulty moving voluntarily, speech disorders, nausea, vomiting, and potentially respiratory paralysis leading to death without medical assistance.

Diagnosis and Reporting Protocol

• Diagnosis relies on symptom observation and food history; common shellfish involved include mussels and scallops.

• Cases must be reported immediately to local health authorities upon symptom onset.

Monitoring Programs for Shellfish Safety

Evaluation Procedures

• In Río Negro province, monitoring programs assess shellfish contamination through weekly studies evaluating physical and chemical variables in seawater.

Classification Zones for Harvesting

• Areas are classified based on contamination levels into zones A (safe for direct consumption), B (restricted), or C (not safe).

Recommendations for Safe Consumption

Purchasing Guidelines

• Always buy shellfish from licensed establishments that ensure traceability; avoid unknown sources or unregulated canned products.

Personal Harvesting Precautions

• If harvesting shellfish personally for family consumption, verify that the area is approved for collection according to public advisories.

Staying Informed

• Adhere strictly to public notices regarding harvesting restrictions due to health risks associated with contaminated areas.

Summary of Foodborne Illnesses in Argentina

Prevalence Data

• According to CONICET data from 2019 before COVID-19 pandemic impacts, 80% of infection outbreaks were linked to contaminated water or food items.

Health Risks of Foodborne Diseases

Overview of Foodborne Diseases

• Foodborne diseases pose a significant public health issue, with severe implications for community health. Data on these diseases have been consistently reported since the establishment of an information network from provinces to the national government.

Common Pathologies Associated with Foodborne Illnesses

• The most frequent foodborne illnesses include:

• Salmonellosis

• Listeriosis

• Trichinosis

• Gastroenteritis caused by Escherichia coli

• Hemolytic Uremic Syndrome (HUS)

• Botulism

Summary of Key Pathologies

• A simplified overview of the aforementioned pathologies includes:

• Identification of etiological agents responsible for each disease.

• Associated foods that can lead to infection.

• General symptoms experienced by affected individuals.

• Typical incubation periods before symptoms appear.

• Preventive measures that can be taken to avoid these illnesses.