Dr. Jacob Chacko, D.V.M.,
Public Health Veterinarian
U.S. Department of
Diseases that are transmitted between animals and humans.
There are120 known Zoonoses agents according to CDC.
Risk of contracting
disease varies depending on the disease and
Focus on farming
Working on farms increase risks --- why?
Shared space and shared air with many animals.
Increased contact with animals.
Animals may appear
to be healthy but carry infectious diseases.
What kinds of animals transmit Zoonoses?
Swine, Goats, Cats, Dogs, Ticks, Squirrels, Raccoons
And Other wild animals.
How are diseases
Transporting carcasses and By-products
Scratches or bites
From milk and from milking
What are the common Zoonotic Diseases?
Common carriers: Cattle, Sheep, Pigs, Dogs, Rodents and
Direct contact with contaminated food Contaminated animals
Stomach ache, nausea,
Cattle, Cats, Dogs, Horses,
Direct contact with animal or feces,
Food contamination from
Chills, fever, headache, diarrhea and vomiting.
Horses and Rodents
Mosquito bite, tick bites.
Clinical presentation: Lethargy, fever, headache, and disorientation.
Cats, dogs, raccoons, bats, foxes and skunks.
Animal bites, contact with infected tissue, fluid and
Fever, headache, confusion,
Pigeons, parrots, turkeys,
Inhalation from infected birds, carcasses,
Fever, headache, and
Cattle and Cats
Cats, sheep and undercooked meat.
Ingestion of infected meat, fecal contaminated soil.
Fever, swollen lymph nodes. Abortion, still-birth.
Dogs, and Raccoons
Direct contact with infected animals
Itching skin lesions.
Prevention and Control.
1. Use an uncontaminated water supply. Many diseases are carried in
animal wastes that leak into water supplies
Make sure wells are properly
constructed to avoid contamination
from livestock, animal and
Add Chlorination to water.
Follow instruction for
appropriate disposal of wastes.
2. Prevent food contamination
milk. Wash hands and clean and disinfect
kitchen surfaces before,
during and after handling food.
Wash raw fruits and
Cook food immediately after
Cook all poultry to an
internal temperature of 180 degrees, and
ground beef to an internal
temperature of 160 degrees.
Refrigerate leftovers immediately.
Avoid contact with diseased animals and prevent pets from contact with
Rodents and wild animals. (e.g. Ticks carried by pets can cause Lyme
disease or Rocky Mountain Spotted Fever. Raccoons, foxes
and other mammals can transmit rabies.)
Protect pets from getting and transmitting disease.
Vaccinate cats and dogs
Do not keep wild animals as
4. Prevent Tick Bites
Wear appropriate clothing.
Use Tick repellent
5. Treat animal scratches and bites seriously
Wash the area with soap and
diseases in Kerala
zoonotic illness caused by Bacillus anthracis. Sporadic cases continue to be
reported from many parts of the India. anthrax meningo-encephalitis (AME)
are also becoming common in patients infected with Anthrax. Most cases seem
to occur in labourers who gave history of handling animal meat or skin of
infected animals. In a few instances `insect bite' has been attributed. The
meningo-encephalitic form of the disease has a very bad prognosis. Patients
with this form of disease died inspite of treatment with high dose
penicillin. The typical bacilli are easily seen in the CSF in AME cases and
is diagnostic of the condition. The cutaneous form of illness has a benign
course and responds favourably to penicillin treatment. The disease needs to
be prevented with proper legislation for meat handling as well as effective
immunisation of animals. (Indian Journal of Medical Microbiology. 1996
Apr; 14(2): 63-72 )
The clinical presentation is so
characteristic that the diagnosis is rarely missed by physicians familiar
with the disease. The exposed part of the skin begins to itch and
there is a papule at the inoculation site. The papule becomes a vesicle and
then a depressed, black, non-painful eschar 1-3 cm diameter that leaves a
permanent scar. There may be surrounding edema and draining lymph nodes may
become enlarged. If untreated, septicemia and death can occur in 5-20% of
cases. If treated, fatalities are extremely rare.
How disease transmitted
in human?Animals dying of anthrax
produce enormous quantities of bacteria in their tissues. If the carcass is
opened, the bacilli sporulate, contaminating the environment. Contaminated
soil, contaminated animal products (including hides, fur, food), or
environmental contamination by spores are also sources of the bacteria. The
bacterial spores prefer alkaline environments (pH > 6) with abundant organic
material, but can survive almost anywhere. Human to human transmission is
extremely rare, even with pulmonary disease.
[Weil's disease, Hemorrhagic jaundice (Leptospira icterohaemorrhagiae),
canicola fever (L. canicola)
Leptospira. Pathogenic leptospires belong to the species Leptospira
RESERVOIR AND INCIDENCE
Rats, mice, field moles, guinea pigs, gerbils, squirrels, rabbits, hamsters,
reptiles, nonhuman primates, livestock, and dogs. *Rodents are the only
major animal species that can shed leptospires throughout their life-span
without clinical manifestations. Active shedding by lab animals can go
unrecognized until personnel handling the animals become clinically ill.
Handling affected animals, contaminating hands, or abrasions with urine, or
aerosol exposure during cage cleaning are most common. The organism is often
transmitted to humans by the urine of the reservoir host. The organism may
also enter through minor skin lesions and probably via the conjunctiva. Many
infections have followed bathing or swimming in infected waters.
DISEASE IN MAN
Ranges from inapparent infection to severe infection and death. Biphasic
Illness a. Weakness, headache, myalgia, malaise, chills, & fever. b.
Leukocytosis, painful orchitis (testes not usually enlarged), conjunctival
effusion, and rash. Icteric leptospirosis (Weil's syndrome-usually caused by
L. icterohaemorrhagiae) is the most severe form of the disease,
characterized by impaired renal and hepatic function, abnormal mental
status, hypotension, and a 5-10% mortality rate. Signs and symptoms are
continuous and not biphasic.
Early in the disease, the organism may be identified by darkfield
examination of the patient's blood or by culture on a semisolid medium.
Culture is difficult and requires several weeks. A rapid diagnosis is made
with the DOT-ELISA test.
Penicillins or tetracyclines.
Vaccination in cattle, swine, and dogs Avoid swimming in or drinking from
potentially contaminated water. Protect workers by providing boots and
gloves. Rodent control. Drain wet ground. Doxycycline chemoprophylaxis for
persons at high exposure.