Top 30 Zoonotic Diseases Part 3

What disease is linked to variant Creutzfeldt-Jakob disease (vCJD)?

Bovine spongiform encephalopathy (BSE) or mad cow disease.

What are the key clinical signs of BSE in cattle?

Ataxia, low head carriage, increased responsiveness to stimuli, and recumbency.

What is the etiology of BSE?

BSE is caused by prions (infectious proteins) that convert normal cellular proteins into prion copies.

List some zoonotic transmission routes for Campylobacteriosis.

Fecal-oral transmission, ingestion of contaminated meat, blood transfusions, organ transplants.

What is a classic clinical sign of Campylobacteriosis in puppies and kittens?

Watery, possibly bloody or mucoid diarrhea.

What is the infectious agent that causes Enterohemorrhagic Escherichia coli infections?

Escherichia coli, specifically the O157:H7 strain.

Which animals are considered reservoir hosts for pathogenic E. coli?

Ruminants, especially cattle.

How is Giardiasis typically transmitted to humans?

Through fecal-oral transmission, primarily by ingestion of cysts.

What symptoms are associated with Giardiasis in humans?

Diarrhea, flatulence, greasy floating stool, nausea, abdominal cramps, and dehydration.

What is tularemia also known as?

Rabbit fever.

What are the common forms of tularemia in humans?

Ulceroglandular, glandular, oculoglandular, oropharyngeal, pneumonic, and typhoidal.

What bacterium is responsible for tularemia?

Francisella tularensis.

What are some zoonotic transmission routes for tularemia?

Tick or deer fly bites, ingestion of contaminated food or water, inhalation of aerosols, ocular exposure.

Which precautions are recommended when dealing with tularemia victims?

Use personal protective equipment (PPE) with respiratory protection.

What is a notable feature of the liver and spleen in animals with tularemia?

'Starry sky' appearance due to necrotic foci.

Why is BSE a concern for both veterinary and human health?

It has led to the emergence of vCJD in humans, linked to consumption of infected beef.

What is a significant preventive measure against BSE transmission in cattle?

Avoid feeding meat and bone meal to cattle.

BSE CS in cows?

Ataxia, low head carriage, increased responsiveness to stimuli and recumbency in a cow thats min 2yo because of the long incubation period (2-8y)

BSE CS in humans?

Linked to Creutzdeldt-Jakob diz. See psychiatric abnormalities, painful sensory signs, ataxia, memory loss and tremor

BSE etiology?

The BSE prion protein. The infectious protein converts normal cellular protein into prion copies. Its a member of the transmissible spongioform encephalopathy group that includes scrapie and chronic wasting diz of cervids.

How are humans infected with BSE?

1. Ingestion of BSE prior in animal tissues

2. Blood transfusions

3. Organ transplants

4. Contaminated Sx equipment

Precautions: avoid eating PrPBSE infected tissues, use biosafety level 3 precautions in necropsies of susp. cases, both human and bovine and avoid feeding meat and bone meal to cattle

Campylobacteriosis CS in small animals?

Puppies <6 mos = watery, possibly bloody or mucoid diarrhea

Kittens <6 mos = Diarrhea, occasionally with blood

Vibriosis CS in poultry?

Most have no CS, very young can develop enteritis

CS of campylobacteriosis in farm animals?

1. Cattle, sheep and goats - important cause of abortion

2. Pigs - colitis in weaners

CS of campylobacteriosis in humans?

1. Diarrhea, may be bloody

2. Abdominal pain and cramping

3. ± Nausea and vomiting

Etiology of vibriosis?

Campylobacter jejuni, a G- spiral bacterial rod that has a wide host distribution.

Animals, esp. chickens are reservoirs, and its present worldwide.

How is campylobacteriosis transmitted to humans?

1. Feco oral from inf. animals or people

2. Ingestion of cont. meat

Use PPE and good food safety practices

Enterohemorrhagic E. coli CS?

Most animals are asymptomatic.

Humans - diarrhea or hemorrhagic colitis and hemolytic uremic syndrome

What is E. coli?

A G- bacterial rod that is a normal commensal intestinal organism.

How is E. coli classifies based on virulence factors?

Into 6 pathotypes. Enterohemorrhagic (eg EHEC O157:H7) produces toxins (vero or shiga toxins)

Who are maintenance hosts for E. coli?

Ruminants, young are more likely to shed the bacteria

How is E. coli transmitted to humans?

Feco oral route wither by cont. food and water or due to contact with animals, feces or soil.

Use PPE and practice good food safeyy.

Giardiasis CS in small animals?

WL, chronic diarrhea - soft, pale, malodorous and greasy, usually with no blood. May be asymptomatic

CS of giardiasis in humans?

1. Diarrhea

2. Flatulence

3. Greasy stool that can float

4. Nausea

5. Abdominal cramps

6. Dehydration

CS of giardiasis in calves?

Pasty, fatty, mucoid diarrhea

Cause of giardiasis?

Giardia duodenalis, also called G. interstinalis or G. lamblia, a protozoan intestinal parasite. Its divided into 7 genetic assemblages: A and B are zoonotic, others are more host specific.

Reservoirs of giardiasis?

Humans are the most important reservoirs. Found in many animals worldwide.

How are humans infected?

Feco-oral transmission (ingestion of cyst): fomite, drinking untreated water from wells, swallowing water while swimming in lakes, rivers, etc and eating cont. food.

Human to human is more important that zoonotic transmission. In humans (unlike animals) its a nationally notifiable disease

Tularemia CS in cats?

1. Lymphadenopathy (sometimes suppurative) that may drain

2. Generalized, severe illness

3. ± hepatosplenomegaly and incterus

Tularemia cs in dogs?

1. Relatively resistant

2. ± mild illness and spont. recovery.

Tularemia CS in sheep?

Abortions and weak lambs

Tularemia CS in wild animals?

Rabbits, muskrates, beavers and voles:

1. Generalized illness due to septicemia

2. Starry sky appearance of the liver and spleen due to disseminated necrotic foci

3. Acute death

4. May be asymptomatic

What are the forms of tularemia in humans?

Ulceroglandular, glandular, oculoglandular, oropharyngeal, pneumonic and typhoidal. All forms are accompanies by a fever and regional lymphadenopathy

Ulceroglandular tularemia CS?

Most common form, see skin ulcers at the site of entry and headache

Glandular tularemia CS?

See ulceroglandular but without ulceration

Oculoglandular tularemia CS?

1. Eye pain, reddness, swelling and discharge

2. ± Ulcer inside eyelid

3. Photophobia

Oropharyngeal tularemia CS?

1. Sore throat

2. Oral ulcers

3. Tonsillitis

Pneumonic tularemia CS?

Most serious form:

1. Cough

2. Chest pain

3. Dysphenea

Typhoidal tularemima CS?

Unlocalized combination of above signs

Tularemia etiology?

Francisella tularensis, a G- cocobacillary bacterium.

Tularemia hosts and vectors?

Probable reservoir hosts - lagomorphs and rodents. Vectors - ticks (and other arthropods). Mostly found in northern hemosphere

Tularemia transmission to humans?

Routes and associated syndrome(s):

1. Tick or deer fly bites, dermal contact with infected animals: ulceroglandular, glandular, or typhoidal

2. Ingestion of cont. food or water: pneumonic or typhoidal tularemia

3. Inhalation of cont. aerosols: pneumonic or typhoidal

4. Ocular exposure: ocular or typhoidal tularemia

Precautions PPE with resp. protection

What is tularemia clinically indistinguishable from?

The plague (Y. pestis) in dogs and cats