County Resources

	Zoonotic diseases are those diseases that can be passed from animals to humans.
	There are a few zoonotic diseases in the U.S. (such as rabies).

I. Zoonotic Diseases Associated with Livestock
	A. Leptospirosis
	• Leptospira are found in many species of domestic and wild animals.
	• The organism is shed in urine.
	• Human infections are most common in farm and slaughter house workers.
	• Causes a flu-like illness in humans that can be serious.

	B. Non-typhoidal Salmonellosis
	• Different species of animals tend to be at risk for infection with different species of Salmonella organisms.
	• People can become infected if they come into contact with the manure of animals infected with Salmonella.
	• Salmonella can be spread by rodents, wild birds, and on objects such as clothes.

II. Rare Zoonotic Diseases
	A. Q Fever (Coxiella burnettii)
	• Reservoir:
			o Sheep, goats, and cattle are most common reservoirs.
			o Dogs, cats, rabbits, horses, pigs, camels, rodents, and birds may carry C. burnettii.
	• Transmission:
			o Aerosols or direct contact (animal-to-animal and person-to-person).
			o Ingestion of an infected placenta or other reproductive discharges or milk.
			o Ticks spread between ruminants and people.
	• Bacteria can be shed in milk, the placenta and reproductive discharges.
	• In the United States, Q fever outbreaks have resulted mainly from occupational exposure involving veterinarians, meat processing plant workers, sheep and dairy workers, livestock farmers, and researchers at facilities housing sheep. Prevention and control efforts should be directed primarily toward these groups and environments (i.e. appropriately dispose of placenta, birth products, fetal membranes, and aborted fetuses at facilities housing sheep and goats).

	B. Human-adapted-High Path Avian Influenza
	• Very few strains of High Path AI can affect humans.
	• No strains that affect humans are found in the U.S.

	C. Cryptosporidiosis
	• Clinically affected calves are the most likely animals to shed large numbers of oocysts.
	• In people there have been outbreaks associated with contaminated drinking water, food, and recreational exposure to water.
		These genotypes are designated H (or 1) and C (or 2). More recently these genotypes have been described as separate species: C. hominis (formerly genotype 1) and C. parvum (formerly genotype 2).
			o C. hominis (H or 1) is found predominately in isolates from humans.
			o C. parvum (C or 2) has a wide host range that includes cattle, humans and at least 10 other mammals.
	• None of the drinking water-associated outbreaks of Cryptosporidiosis in the United States (and 1 in Canada) that have had genotype analysis performed of parasite isolates have been associated with the zoonotic (C) genotype. In contrast, all the outbreaks in the U.S. and all but one in Canada were associated with the H (or1) genotype.

	D. Anthrax (Bacillus anthracis)
	• In the U.S., foci of infection: South Dakota, Nebraska, Mississippi, Arkansas, Texas, Louisiana, and California (small foci in other states)
	• Human forms (incubation 1 to 7 days):
			o Cutaneous – most common (95% of cases), skin contact with infected animal tissues such as hides, wool, bone meal, and blood.
			o Inhalation – inhalation of spores.
			o Intestinal – ingestion of contaminated meat containing viable spores.
	• From January 1955 to December 1999, there were 236 reported cases of anthrax, most of them cutaneous, in 30 states and the District of Columbia.
	• The last case of inhalational anthrax in the United States (other than the 2001 intentional exposure via the U.S. mail) was in 1976 in California. A home craftsman died of the disease. He was exposed through his work with yarn; Bacillus anthracis was isolated from some of the imported yarns used by the patient.
	• The last case of cutaneous anthrax, before 2001, occurred in North Dakota, in 2000. It was the only case since 1992.

	E. Brucellosis (Brucella abortus, B. ovis, B. suis, B. canis, B. melitensis)
	• Human – B. abortus, B. melintensis, B. suis, B. canis (rarely).
			o In the United States, < 0.5 cases per 100,000 population, primarily B. melitensis. Most cases are reported from California, Florida, Texas, and Virginia.
			o Infection from ingestion, through mucous membranes, and breaks in the skin.
			o Spread has occurred through raw milk and unpasteurized cheese.
			o Symptoms: influenza-like (fever, headache, malaise, back pain), gastrointestinal signs in adults (rarely children), irritability, insomnia, mental depression, and emotional instability sometimes develop.
	• Transmission – contact with the infectious placenta, fetus, fetal fluids, and vaginal discharges .
			o Ingestion, mucous membranes, broken skin, and possibly intact skin.
			o Venereal transmission of B. abortus is rare.
			o Udder can be infected and be colonized from contaminated milker’s hands.

III. Other Diseases in the News
	A. Foot and Mouth Disease - Does not affect humans.
	B. BSE - Only can affect humans by eating the brain or spinal cord of infected cattle.