Untitled Quiz

Community Medicine: Food Poisoning and Infection Control

• Food Poisoning
  • Definition: Acute illness from contaminated food
  • Causes: Bacteria, toxins, viruses, or natural poisons
  • Symptoms: Nausea, vomiting, abdominal cramps, diarrhea

Pathophysiology of Food Poisoning

• Non-Inflammatory Type

  • Cause: Enterotoxins affecting secretory mechanisms in the small intestines
  • Symptoms: Watery diarrhea without leukocytes
  • Examples: Vibrio cholera, Escherichia coli, Clostridium perfringens, Staphylococcus species, Giardia lamblia, various viruses (Adenovirus, Rotavirus, Norwalk virus)

• Inflammatory Type

  • Cause: Cytotoxins invading and damaging intestinal mucosa
  • Symptoms: Bloody diarrhea with leukocytes
  • Examples: E. coli (enterohemorrhagic and enteroinvasive), Campylobacter jejuni, Vibrio parahaemolyticus, Clostridium difficile, Entamoeba histolytica, Salmonella, Shigella species

Pathogenic Mechanisms in Food-Borne Diseases

• Toxins Produced in Food Before Consumption

  • Onset: Rapid (6-12 hours)
  • Symptoms primarily affect the upper intestine
  • Examples: Staphylococcus aureus, Bacillus cereus (emetic toxin), botulism

• Toxins Developed After Ingestion

  • Onset: Delayed (24 hours or more)
    • Can cause watery or bloody diarrhea
  • Examples: Vibrio cholerae, Enterotoxigenic Escherichia coli (watery diarrhea), Shiga toxin-producing E. coli (bloody diarrhea)

• Pathogens Damaging or Invading the Intestinal Epithelium

  • Symptoms: Range from watery diarrhea to inflammatory diarrhea or systemic disease
  • Examples: Cryptosporidium parvum, enteric viruses, Salmonella, Campylobacter, Shigella, Listeria monocytogenes

Etiologic Agents and Clinical Manifestations of Foodborne Illnesses

• Gastroenteritis (Vomiting)

  • Common agents: Norovirus, rotavirus, Staphylococcus aureus toxin, Bacillus cereus, heavy metals

• Non-inflammatory Diarrhea (Watery)

  • Agents: E. coli (ETEC), Giardia, Vibrio cholerae, enteric viruses

• Inflammatory Diarrhea (Bloody)

  • Agents: Shigella, Salmonella, Campylobacter, E. coli 0157, Yersinia enterocolitica, Entamoeba histolytica

• Persistent Diarrhea (>14 days)

  • Agents: Cyclospora cayetanensis, Cryptosporidium, Giardia

• Neurologic Symptoms

  • Agents: Clostridium botulinum (botulism), organophosphates, scombroid poisoning

• Systemic Illness (Fever, Weakness, Jaundice)

  • Agents: Listeria monocytogenes, Brucella, Trichinella spiralis, Hepatitis A & E

Foodborne Diseases – Impact and Surveillance in the US

• Annual Impact: 6-81 million illnesses, 9,000 deaths
• Common pathogens: Listeria, Salmonella, Toxoplasma (1,500 deaths)
• CDC Statistics (2013): 350 million diarrhea cases annually, 48 million foodborne, 125,000 hospitalizations, 3,000 deaths; economic cost: $150 billion

Foodborne Diseases – Impact and Surveillance in the US (International Comparison)

• Denmark study: 14.4% of 52,121 cases hospitalized; 1.2% with severe complications (intestinal perforation)
• High morbidity linked to Listeria, Shiga toxin-producing E. coli, non-typhoidal Salmonella

Food Poisoning Outbreaks in the Philippines

• Study Findings (Azanza, 2004): Analyzed 60 outbreaks (1995-2004) Common sources: Meat dishes in schools and workplaces Frequent pathogens/toxins: Salmonella, Vibrio, Staphylococcal enterotoxin, paralytic shellfish toxin, histamine

• Notable Outbreaks: 27 deaths in Philippine schools (2005), WHO report: Food contamination as a leading global health issue

• Case Example (Aspillera, 2014): Office worker sickened by contaminated caldereta from a carinderia, Incident highlights need for awareness in food safety and preparation

• Global and Local Concerns: Infected food handlers in all types of food outlets pose risks, Foodborne illness affects all socioeconomic levels, higher impact on impoverished populations

Notable Food Poisoning School Outbreaks in the Philippines (2005-2011)

• San Jose Elementary School, Bohol (March 2005)
• Tomas Earnshaw Elementary School, Manila (July 2011)
• Birthday Party in Calumpit, Bulacan (June 2011)

Morbidity and Mortality in Foodborne Illness

• Higher Mortality in Elderly: Increased susceptibility due to decreased immunity, low gastric acid, malnutrition
• Common pathogens: C. perfringens, E. coli, Salmonella, Campylobacter, Staphylococcus
• Complications: Dehydration as most common complication, Potential for electrolyte imbalance and renal failure in severe cases

Foodborne Disease Outbreaks

• Definition: Occurs when two or more people contract the same illness from the same contaminated food
• Common Settings: Catered events, restaurants, potluck dinners, Community outbreaks linked to specific foods (e.g., fish)
• Significance: Indicates issues in food safety practices, Public health investigations aim to control and prevent future outbreaks

Common Bacterial Causes of Food Poisoning

• Staphylococci

  • Source: Improperly cooked meat, dairy, bakery
  • Symptoms: Vomiting, diarrhea (2-6 hrs post-ingestion)
  • Treatment: Symptomatic and volume replacement

• Clostridium perfringens

  • Source: Under-cooked meat, poultry, legumes
  • Symptoms: Abdominal cramps (8-10 hrs post-ingestion)
  • Treatment: Symptomatic, stool culture for confirmation

• Bacillus cereus

  • Source: Contaminated fried rice
  • Symptoms: Emetic or diarrheal forms with varied incubation
  • Treatment: Symptomatic

• Clostridium botulinum

  • Source: Canned foods, mushrooms, vegetables
  • Symptoms: Paralysis, respiratory issues (1-4 days post-ingestion)
  • Treatment: Antitoxin, respiratory support

• Enterotoxigenic E. coli

  • Source: Contaminated water, salads, cheese, meat
  • Symptoms: Vomiting, abdominal cramps (1-2 days post-ingestion)
  • Treatment: Supportive

• Vibrio cholerae

  • Source: Contaminated water, food
  • Symptoms: Rice-water stools, severe dehydration
  • Treatment: Fluids, tetracycline

• Shigella

  • Source: Potatoes, eggs, lettuce
  • Symptoms: Bloody diarrhea, cramps, fever
  • Treatment: TMP-SMX, ampicillin (severe cases)

• Salmonella

  • Source: Beef, poultry, dairy
  • Symptoms: Abdominal pain, vomiting (1-2 hrs post-ingestion)
  • Treatment: Antibiotics for systemic infection

• Listeria monocytogenes

  • Source: Raw hot dogs, unpasteurized cheese
  • Symptoms: Meningitis, high mortality in elderly and pregnant women
  • Treatment: Supportive care, hydration

Common Parasitic and Toxic Causes of Food Poisoning

• Entamoeba histolytica

  • Source: Contaminated food and water
  • Symptoms: Diarrhea, abdominal cramps, vomiting (12-24 hrs post-ingestion)
  • Treatment: Stool examination, metronidazole or secnidazole

• Giardia lamblia

  • Source: Contaminated water, fecal-oral transmission
  • Symptoms: Bloody diarrhea, tenesmus (2-3 days post-ingestion)
  • Treatment: Stool examination, metronidazole

• Paralytic Shellfish Poisoning

  • Source: Bivalve mollusks from coastal areas
  • Symptoms: Numbness, headache, respiratory arrest (30-60 mins post-ingestion)
  • Treatment: Observation, oxygen support if needed

• Tetradotoxin Poisoning (Puffer fish)

  • Source: Puffer fish (Japan)
  • Symptoms: Paralysis, high mortality risk (10-40 mins post-ingestion)
  • Treatment: Close observation, symptomatic care

• Scombroid Poisoning

  • Source: Tuna, mahi-mahi, kingfish
  • Symptoms: Allergic reaction, rash, flushing (15-50 mins post-ingestion)
  • Treatment: Antihistamines, H2 blockers, epinephrine

• Fascioliasis (Liver Flukes)

  • Source: Infected watercress, consumption of contaminated livestock
  • Symptoms: Hepatomegaly, jaundice, right upper quadrant pain
  • Treatment: Anti-parasitic medications, stool examination for flukes

Heavy Metals as Causes of Food Poisoning

• Mercury: Source: Ingestion of inorganic salts, Symptoms: Metallic taste, salivation, thirst, oral discoloration, abdominal pain, vomiting, bloody diarrhea, acute renal failure, Treatment: Emesis, lavage, activated charcoal, cathartic; Dimecaprol

• Lead: Source: Chronic exposure, Symptoms: Bloody diarrhea, abdominal cramps, tenesmus, Treatment: Lead level monitoring; stool examination,

• Arsenic: Source: Ingestion of pesticides, industrial chemicals, Symptoms: Abdominal pain, watery diarrhea, vomiting, muscle cramps, dehydration, Treatment: Gastric lavage, activated charcoal, Dimecaprol injection, oral penicillamine

Viral Cause of Food Poisoning - Hepatitis A Virus

• Causative Agent: Hepatitis A virus
• Source of Contamination: Raw shellfish, green onions
• Clinical Features: Incubation period: 15-50 days, Symptoms: Fever, right upper quadrant pain, hepatomegaly, jaundice, vomiting, abdominal pain
• Diagnosis and Treatment: Serologic testing to confirm virus presence, Liver ultrasound for assessment, Supportive treatment

Steps in Epidemiological Investigation of Foodborne Outbreaks

• Initiation of Investigation: Team includes sanitation expert, food scientist, veterinarian, ichthyologist, food sanitation engineer
• Case Identification: Develop case definition based on symptoms, onset, and location, Create a map of affected individuals' locations and activities
• Data Collection and Analysis: Classify cases by demographics (age, sex, occupation, residence), Conduct interviews with ill and non-ill groups, Use statistical methods to identify potential food sources
• Laboratory Confirmation: Blood or stool tests to confirm pathogen, Further analysis of implicated food items for contamination details
• Outcome: Identify contamination source and mechanism, Implement prevention measures to reduce future risks

Diagnosing Foodborne Diseases

• Probable Diagnosis: Based on clinical manifestations, food history, and pathogenic mechanism relevance

• Clinical Manifestations: Common: Nausea, vomiting, fever, abdominal pain, diarrhea, Atypical symptoms: Paralysis (botulism, shellfish poisoning), tingling (ciguatera, scombroid), amnesia, meningitis (Listeria)

• Food History: Key factors: Symptoms, specific food exposure, time interval to onset

• Detailed History: Duration and type of symptoms, travel history, drug use

• Indicators: Diarrhea < 2 weeks (typical for foodborne illness), Fever (suggests invasive disease), Bloody/mucus stool (possible large bowel ulceration), Profuse rice-water stool.

• Physical Exam: Assess dehydration (mild, moderate, severe), Laboratory Tests: Fecalysis, CBC, electrolytes, stool culture

Management and Diagnosis of Foodborne Illness

• Initial Assessment: Determine dehydration level to guide treatment, Correct electrolyte imbalances, Administer antibiotics based on causative agent
• Antibiotic Selection: Tailored to specific pathogen identified, Diagnostic Flow Chart: Identifies causes of food poisoning and guides appropriate antibiotic therapy

Antibiotic Selection for Foodborne Illness

• Antibiotic Choice Factors: Based on likelihood of invasive organism and resistance patterns, Travel history critical for identifying resistance
• Indicators of Invasive Disease: Blood in stool suggests invasive infection, Fever not a reliable indicator of dysentery
• Common Treatments: Adults: Fluoroquinolones (traveler's diarrhea), Children <12: Co-trimoxazole (except G6PD deficiency), other alternatives include chloramphenicol or amoxicillin/ampicillin
• Philippine Context: Common cause of bloody diarrhea: Amebic dysentery.
• Treatment: Metronidazole a drug of choice

Food Contamination and Prevention of Food Poisoning

• Sources of Contamination: Naturally present in raw fish, meat, eggs, shellfish, Contamination during slaughter, food prep, Improper storage, Fruits/vegetables contaminated with animal manure or sewage water
• Food Handling Risks: Cross-contamination from unwashed utensils, infected food handlers (Salmonella, Shigella, Hepatitis A), Improper cooking and storage increases contamination risks
• Prevention Methods: Use of salt, sugar, vinegar for preservation inhibits bacterial growth, High temperatures can kill most microbes but Clostridium spores in canned foods require high-temp, pressurized cooking

General Measures to Prevent Food Contamination and Poisoning

• Hygiene Practices: Frequent hand washing, especially during food prep and after bathroom use

• Proper Cooking: Cook meat, poultry, and eggs thoroughly.

• Avoid Cross-Contamination: Wash hands, utensils, and surfaces after each use

• Storage and Cleaning: Refrigerate leftovers promptly, Wash fruits and vegetables under running water

• Food Handler Health: Screen for infections (Salmonella typhi, Shigella, hepatitis A),

• Avoid High-Risk Foods: Exotic or high-risk foods

• Special Precautions: Heat canned food, boil water for baby formula, Report cases to health authorities

• Infected Patients and High-Risk Groups: Encourage hand washing, Advise high-risk groups to avoid risky foods.

Family Education and Immunization for Food Poisoning Prevention

• Patient Education: Provide educational materials from reliable sources (CDC, USDA, FDA), Focus on high-risk populations.
• Immunizations: Hepatitis A vaccine, Typhoid vaccine (Salmonella enteritis), Rotavirus vaccine (infants 0-6 months), IPV (Inactivated Polio Vaccine)

Principles of Infection Control in Healthcare

• Definition: Discipline using epidemiology and scientific methods to prevent hospital-acquired infections
• Goal: Identify and reduce infection risks for patients, staff, visitors, and trainees
• Importance: Essential for safe healthcare delivery, Key application of occupational health in healthcare settings
• Measures: Range from basic hand washing to high-level disinfection of surgical tools, Effective in preventing disease transmission in both healthcare settings and the community

The Process of Infection and Prevention Strategies

• Vital Links in Infection Process: Environment, Reservoirs, Host Factors, Host Resistance (balanced nutrition, immunization, enhanced immunity, good hygiene practices)

Principles of Infection Control

• Administrative control: Train employees in safe work practices, No eating or drinking in areas with infection risk, No re-capping of used needles, Implementing administrative rules and guidelines.
• Engineering control: Use engineering methods to control droplet and airborne infections, Safety devices on sharp medical tools, Sharps disposal containers, Hand washing facilities, Air conditioning and exhaust ventilation, Proper waste disposal systems.
• Personal protective equipment (PPE): Last line of defense, Provides a physical barrier, Types of PPE: Gloves, goggles, mask, apron, lab gown, shoe covers, cap/hair cover
• Who should use PPE: Healthcare workers, Support staff, Family members.
• Best Practices: Use PPE correctly, Regularly maintain and replace PPE, Ensure continuous availability, Proper training.
• Medical control: Monitor and manage infection risks through screening, immunization, and treatment, Screening of patients and staff, Immunizations to prevent specific infections, Treatment of cases to prevent further spread, Pre-employment and annual physical exams, Laboratory tests

Standard Precautions in Infection Control

• Purpose: Treat all persons as potentially infected to prevent disease spread
• Scope: Protects against exposure to blood, body fluids, secretions, excretions, mucous membranes, and non-intact skin
• Key Practices: Hand hygiene, Use of PPE, Safe handling of patient equipment, Prevention of needlestick, Environmental cleaning and spill management, Proper waste handling

Standard Guidelines in Infection Control

• Hand Hygiene: Wash with soap and water (15-20 seconds) or alcohol-based sanitizer, Perform hand hygiene.
• Handling Needlestick and Sharps: Use puncture-resistant containers, Do not recap needles, Dispose of sharps properly
• Use of PPE: Choose PPE based on exposure risk (blood, body fluids), Avoid reusing or sharing PPE, Clean reusable equipment.
• Respiratory Hygiene/Cough Etiquette: Cover mouth and nose, Use tissues, Wash hands immediately afterward
• Handling of Linen and Equipment: Handle soiled linen, Place linen in closed containers, Proper handling is important.
• Management of Healthcare Waste: Properly isolate and label hazardous waste, Ensure all waste is properly collected.

PPE Requirements

• Gloves: Wear for blood, body fluids, and mucous membrane contact, Change between patients/tasks, Wash hands immediately after removal
• Masks: Protect nose and mouth, Use surgical masks. Dispose of single-use masks properly.
• Protective Eyewear (Goggles/Visors/Face Shields): Protect eyes during procedures with fluid splashes, Dispose or decontaminate Reusable eyewear properly.
• Gowns and Plastic Aprons: Wear impermeable gowns to prevent contamination, Use plastic aprons when needed, Dispose of single-use gowns safely.
• Caps and Boots/Shoe Covers: Use when there's a risk of blood splashing onto hair or shoes, Launder reusable items, Clean and disinfect reusable boots properly.

Hand Hygiene

• Importance: Essential practice to prevent infection transmission
• Method: Use soap and warm water.

Isolation Precautions for Highly Infectious Patients

• Purpose: Isolate highly infectious patients to prevent transmission to others,

• Single Room Benefits: Reduce infection spread, Limit contact.

• Recommended Room Features: Hand-washing facilities, Dedicated toilet and bathroom, Anteroom for PPE use

• Additional Infection Control Practices: Cohorting, Patient Transportation

Airborne Precautions

• Purpose: Prevent transmission of infections via airborne droplet nuclei
• Key Diseases: Pneumonia, pertussis, diphtheria, influenza type B, mumps, meningitis, measles, varicella, and tuberculosis
• Room Requirements: Negative pressure room with 6-12 air exchanges per hour
• PPE and Masking: N95 respirator, Surgical mask

Droplet Precautions

• Purpose: Prevent exposure to droplet nuclei
• Key Diseases: Pertussis, diphtheria, pharyngitis, pneumonia.
• Precautionary Measures: Use private rooms or cohorting, Maintain a spatial distance, and Ensure adequate spacing.

Contact Precautions

• Purpose: Prevent transmission of infections through direct or indirect contact
• Key Diseases: Multiple antibiotic-resistant organisms, Enteric infections, Skin infections.
• Sources of Infection: Patients, healthcare personnel, visitors, inanimate objects (equipment, fomites, medications).
• Precautionary Measures: Implement standard precautions, Place patients in single rooms, Wear clean, non-sterile gloves, Wear a gown when substantial contact is anticipated, Limit patient movement