Is a person more likely to catch a zoonotic infection from a pig or a goat?

Zoonotic Infection Risk: Pigs vs Goats

Pigs pose a higher risk for zoonotic disease transmission to humans compared to goats due to their ability to harbor a wider range of pathogens and their biological similarities to humans. 1

Comparative Risk Assessment

Pig-Associated Zoonotic Risks

• Pigs share more biological traits with humans than goats do, making cross-species transmission more likely 1
• Swine influenza virus (H1N1) has demonstrated transmission between pigs and humans, as evidenced by an outbreak at an Ohio county fair where the virus was isolated from both swine and human exhibitors 2
• Pigs can serve as "mixing vessels" for influenza viruses, potentially creating novel strains transmissible to humans
• Pigs can harbor parasites like Sarcoptes scabiei (scabies mites) that readily infest humans, causing skin irritation and itching 2

Goat-Associated Zoonotic Risks

• Q fever (Coxiella burnetii) is a significant concern with goats, particularly during birthing when large numbers of organisms are shed and can become aerosolized 2
  • A documented Q fever outbreak linked to goats and sheep in indoor petting zoos resulted in 95 confirmed cases and 41 hospitalizations 2
• Chlamydophila infections from goats can occasionally cause reproductive problems in women 2
• Goats can transmit orf virus (a parapoxvirus) through direct contact, causing skin lesions 2

Transmission Routes and Settings

High-Risk Settings

• Live-birthing exhibits involving livestock (including both pigs and goats) present significant transmission risks 2
• Indoor animal exhibits pose heightened risk due to inadequate ventilation, particularly for airborne pathogens like Q fever 2
• Agricultural fairs and petting zoos are common settings for zoonotic disease transmission 2

Transmission Mechanisms

1. Direct contact with infected animals or their bodily fluids
2. Indirect contact through contaminated environments
3. Aerosol transmission (particularly concerning with goats during birthing)
4. Vector-borne transmission through fleas, ticks, or other arthropods
5. Foodborne transmission through contaminated animal products

Prevention Strategies

• Practice thorough hand washing after any contact with animals or their environments 2
• Avoid contact with animals showing signs of illness 2
• Take extra precautions around birthing animals, particularly goats and sheep 2
• Ensure proper ventilation in indoor animal exhibits 2
• Implement proper veterinary care and husbandry practices for animals in public settings 2
• Higher-risk individuals (immunocompromised, pregnant women, young children, older adults) should take additional precautions when interacting with farm animals 3

Key Considerations

While both animals present zoonotic risks, pigs harbor a wider variety of pathogens transmissible to humans and share more biological similarities with humans, making cross-species transmission more likely. The documented cases of swine influenza transmission directly between pigs and humans represents a significant public health concern not observed with goats.

However, it's important to note that goats can cause severe outbreaks in specific circumstances, particularly through Q fever transmission during birthing events in enclosed spaces with poor ventilation.