Common Foodborne Illnesses and Their Causes

Foodborne illnesses occur when people consume food or drinks contaminated with harmful bacteria, viruses, parasites, or toxins. Understanding the most common foodborne illnesses and their causes helps prevent food poisoning and promotes safer food handling practices.

1. Salmonellosis (Salmonella)

Cause: Salmonella bacteria
Common Sources: Raw or undercooked poultry, eggs, unpasteurized milk, contaminated fruits and vegetables
Main Risk Factors: Poor hygiene, cross-contamination, inadequate cooking

2. Escherichia coli (E. coli)

Cause: E. coli bacteria (especially O157:H7)
Common Sources: Undercooked minced meat, raw milk, contaminated water, unwashed produce
Main Risk Factors: Improper cooking and unsafe water

3. Listeriosis

Cause: Listeria monocytogenes
Common Sources: Soft cheeses, deli meats, unpasteurized dairy products, refrigerated ready-to-eat foods
Main Risk Factors: Long refrigeration storage, poor temperature control
High-Risk Groups: Pregnant women, elderly people, and immunocompromised individuals

4. Campylobacteriosis

Cause: Campylobacter bacteria
Common Sources: Raw or undercooked poultry, unpasteurized milk, contaminated water
Main Risk Factors: Cross-contamination and inadequate cooking

5. Staphylococcal Food Poisoning

Cause: Staphylococcus aureus toxins
Common Sources: Cooked foods handled with bare hands, meat dishes, dairy products
Main Risk Factors: Poor personal hygiene and improper food storage

6. Clostridium perfringens Food Poisoning

Cause: Clostridium perfringens bacteria
Common Sources: Stews, soups, gravies, cooked meat kept warm for long periods
Main Risk Factors: Improper hot holding and slow cooling

7. Botulism

Cause: Clostridium botulinum toxin
Common Sources: Improperly canned foods, fermented foods, preserved meats
Main Risk Factors: Poor canning practices and anaerobic storage conditions
⚠️ Botulism is rare but life-threatening.

8. Norovirus Infection

Cause: Norovirus
Common Sources: Contaminated ready-to-eat foods, water, shellfish
Main Risk Factors: Poor hand hygiene and infected food handlers

9. Shigellosis

Cause: Shigella bacteria
Common Sources: Contaminated food and water, salads, raw vegetables
Main Risk Factors: Poor sanitation and hand hygiene

10. Parasitic Infections (e.g. Giardia, Toxoplasma)

Cause: Parasites
Common Sources: Contaminated water, undercooked meat, unwashed produce
Main Risk Factors: Unsafe water and poor food hygiene

Key Prevention Measures

• Wash hands thoroughly before handling food
• Cook foods to safe internal temperatures
• Avoid cross-contamination
• Use safe water and clean ingredients
• Refrigerate perishable foods promptly

References

• Centers for Disease Control and Prevention (CDC) – Foodborne Illness Source Estimates
https://www.cdc.gov/food-safety/php/data-research/foodborne-illness-sources/index.html

• European Food Safety Authority (EFSA) – Foodborne Zoonotic Diseases (overview of major pathogens)
https://www.efsa.europa.eu/en/topics/topic/foodborne-zoonotic-diseases

• World Organisation for Animal Health (WOAH) – Food Safety (global food safety context, hazards & One Health approach)
https://www.woah.org/en/food-safety/introduction/

• Pan American Health Organization (PAHO)
https://www.paho.org/en/topics/food-safety