Kenneth
Rosenman
Michigan State University Extension
While
animals around the farm may appear healthy, they may be carrying
a disease that can infect you and family members. These diseases
can be transmitted through everyday contact with the animal,
or through contact with their carcasses or other by-products.
A person can also be infected by just entering a contaminated
animal housing facility. Diseases that can be transmitted
from animals to humans are referred to as zoonotic diseases
or zoonoses.
It is
important for farmers to know about zoonotic diseases because
the symptoms are frequently similar to other types of illnesses.
Symptoms of psittacosis (ornithosis) for example, range from
a flu-like illness to acute pneumonia. For proper diagnosis
and treatment, your healthcare professional must be also aware
of any potential sources of the infection. While there are
many zoonotic diseases, this factsheet will address those
where there is some potential for infection in Michigan. This
is only a partial list of zoonotic diseases in the state.
Some
of the more obvious zoonotic diseases can be the result of
being scratched or bitten by an animal or from milking. Symptoms
of one of the most common zoonotic diseases, Cat-Scratch Fever,
can include localized pain, swelling, redness and fever. Another
common zoonotic disease is Milkers' Nodules, which frequently
results in pustules on the hands and fingers after being infected.
Ringworm is a common zoonotic disease that causes pustular
nodules with hair loss in exposed areas of the body head or
arms.
Zoonotic
diseases are caused by bacteria, viruses, chlamydia, fungi
and parasites. Animal sources for zoonosis include cattle,
sheep, horses, pigs, chickens, turkeys, dogs, cats, rodents
and some wild animals. Depending on the disease, all of these
animals can be a source of infection (See Table 1).
Steps
to minimize the risk of contacting a zoonotic disease include
wearing gloves for certain activities, a well-managed vaccination
program, and good sanitation and personal hygiene.
Table
1. Animal Diseases that can infect humans |
Disease |
Common
Source |
Clinical
Effects |
Mode
of Acquisition |
Prevention |
Bacterial
Diseases
|
Campylobacter |
Cattle,
Sheep Pigs, Dogs Rodents Poultry |
Acute
gastroenteritis nausea headache, diarrhea |
Direct
contact food contaminated with animal feces |
Avoid
contact with infected animals and feces contaminated food |
Cat-scratch
diseases |
Cats,
Dogs Fomites |
Fever,
primary skin papule, regional lymphadenopathy |
Direct
contact with infected animals |
Avoidance
of animal scratches and puncture wounds |
Salmoneliosis |
Cattle,
Cats Dogs, Horses Poultry, Turtles |
Chills,
fever, headache, diarrhea, vomiting |
Direct
contact with animal or its feces, food contamination from
infected animals |
Improved
food processing and preparation |
Viral
Diseases
|
Encephalitis |
Horses
Rodents |
Lethargy,
fever headache, disorientation |
Mosquito
or tick bite |
Protective
clothing, insect repellents |
Rabies |
Cats,
Dogs Raccoons Skunks, Bats Foxes |
Fever,
headache, agitation, confusion, seizures, excessive salivation,
death |
Animal
bite, contact with infected tissue, body fluids or feces |
Avoid
contact with suspected animals, local wound care, pre-
and post- exposure immunization/ vaccination |
Chlamydial
Diseases
|
Psittacosis
(Ornithosis) |
Pigeons
Turkeys Parakeets Parrots |
Fever,
headache, pneumonia |
Inhaled
from infected birds, carcasses, secretions and contaminated
facilities |
Avoid
contact with infected birds, control of disease with antibiotics |
Fungal
Diseases
|
Ringworm |
Cats,
Cattle |
Skin
lesions |
Direct
contact |
Avoid
close contact with infected animals, Children and individuals
with immune suppressed system are more susceptible |
Parasitic
Diseases
|
Tosocariasis
(Visceral larval migrans) |
Dogs
Raccoons Cats |
Eye
disease, brain disease |
Ingestion
and contact with infected ovum of parasites |
Treat
pets, avoid fecal contaminated soil and sandboxes |
Toxoplasmosis |
Cats,
Sheep Undercooked meat |
Fever,
lymph- adenopathy, abortion, still- birth, mental retardation |
Ingestion
of infected meats, oocysts in fecal contaminated soil |
Proper
disposal of cat feces, cook meat well, avoid contaminated
soil (especially pregnant women and immune compromised
individuals) |
Scabies |
Dogs
Raccoons |
Itching
skin Lesions |
Direct
contact with infected animals |
Treat
pets, avoid contact with infected animals |
Disclaimer
and Reproduction Information: Information in NASD does not
represent NIOSH policy. Information included in NASD appears
by permission of the author and/or copyright holder. More
NASD Review: 04/2002
Michigan State University.
Kenneth D. Rosenman, M.D., Occupational Medicine, Michigan
State University, 5/92. Funded by the National Institute of
Occupational Safety and Health - #UO5/CC-4506052-01.
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