Certain venues encourage or permit the public to be in contact with animals, resulting in millions of human-animal interactions each year. These settings include county or state fairs, petting zoos, animal swap meets, pet stores, feed stores, zoologic institutions, circuses, carnivals, educational farms, livestock-birthing exhibits, educational exhibits at schools and child-care facilities, and wildlife photo opportunities. Veterinarians are often involved or present at many of these events, or could provide assistance and advice to these venues on prevention of zoonotic diseases.
As reported in the May 6, 2011 Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report (MMWR), the National Association of State Public Health Veterinarians, Inc. (NASPHV) offers a Compendium of Measures to Prevent Disease Associated with Animals in Public Settings, 2011.
The report in MMWR says although human-animal contact has many benefits, human health problems are associated with these settings, including infectious diseases, exposure to rabies, and injuries. Infectious disease outbreaks have been caused by Escherichia coli O157:H7, species, Cryptosporidium species, Coxiella burnetii, Mycobacterium tuberculosis, Salmonella ringworm, and other pathogens. Such outbreaks have substantial medical, public health, legal, and economic effects.
Veterinarians (and their producers) are especially involved in livestock exhibitions such as at local, county and state fairs or shows, and many veterinary schools display birthing centers at these fairs and events to give the public some education on the birth/hatching of animals such as cows, sheep, pigs and poultry.
Minimizing zoonotic disease risks to the public as well as producers and veterinarians themselves include:
- Prohibiting food in animal areas
- Transition areas between animal areas and non-animal areas
- Information for visitors about disease risk and prevention
- Proper care and management of animals
While the report discusses many species of animals that can transmit zoonotic disease (reptiles, pets, exotics) of most interest to the livestock industry are diseases that can be transmitted by cattle, sheep, goats, pigs and poultry. Examples of zoonotic cases with livestock at these types of events include:
- In 2005, an E. coli O157:H7 outbreak among 63 patients was associated with multiple fairs in Florida where both direct animal contact and contact with sawdust or shavings were associated with illness, as well as persons who reported feeding animals.
- In 2004, an outbreak of E. coli O157:H7 infections was associated with attendance at the North Carolina State Fair goat and sheep petting zoo, where in addition to direct contact with animals, risk factors included manure contact and hand-to-mouth behaviors.
- Orf virus infection (i.e., contagious ecthyma or sore mouth in sheep and goats) has occurred after contact with sheep at a public setting and has also been described in goats and sheep at a children's petting zoo and in a lamb used for an Easter photo opportunity.
- Q fever (Coxiella burnetii), leptospirosis, listeriosis, brucellosis, and chlamydiosis are serious zoonoses that can be acquired through contact with reproductive materials such as at live-birthing exhibits. During birthing, infected animals shed large numbers of organisms, which can become aerosolized. A Q fever outbreak involving 95 confirmed cases was linked to goats and sheep giving birth at petting zoos in indoor shopping malls.