Top 30 Zoonotic Diseases Part 4

What disease is known as the Black Death and caused by Yersinia pestis?

Plague

What is the most common form of plague in cats and humans in the US?

Bubonic plague

What are the three forms of plague that can affect humans?

Bubonic, septicemic, and pneumonic plague

What are the classic symptoms of bubonic plague in humans?

Fever, chills, weakness, headache, and painful swollen lymph nodes (buboes).

What bacterium causes salmonellosis?

Salmonella spp.

What is a common reservoir of Salmonella spp. that can cause gastrointestinal illness in humans?

Reptiles and poultry.

How is cystic echinococcosis primarily transmitted to humans?

By ingestion of eggs from contaminated food, water, or fomites.

What are the clinical manifestations of leptospirosis in humans?

Biphasic disease starting with flu-like symptoms, followed by headache, muscle aches, fever, and potentially multiorgan failure.

What organism causes lymphocytic choriomeningitis?

Lymphocytic choriomeningitis virus (LCMV).

Which animals are the primary natural hosts of the Lymphocytic choriomeningitis virus?

House mice and other rodents.

What precaution should be taken to prevent leptospirosis?

Using personal protective equipment (PPE) and avoiding contaminated environments.

What is a potential biological weapon listed in zoonotic diseases?

Plague (Yersinia pestis).

What condition can result from the rupture of an echinococcal cyst?

Anaphylactic reaction and possible death.

Plague CS in rodents (rock squirrels, wood rats, ground squirrels, prairie dogs, chipmunks, mice, voles) and rabbits?

1. May be subclinical or peracute and fatal

2. Petachiae and ecchymoses in skin and other organs

3. Hemoptysis

Plague CS in cats?

1. Lymphadenopathy (esp. cervical LNN)

2. Fever

3. Dyspnea

4. Hemoptysis

5. DIC

6. Death

Forms of human plague?

Bubonic, septicemic and pneumonic. All 3 present with fever, chills, weakness

Bubonic plague CS?

1. Fever

2. Chill

3. Weakness

4. Headache

5. Painful, swollen LNN (buboes)

Septicemic plague CS?

1. Fever

2. Chill

3. Weakness

4. Abdominal pain

5. Shock

6. Petechiae and ecchymoses in skin and other organs

7. Necrosis of fingers, toes or nose

Pneumonic plague CS?

1. Fever

2. Chill

3. Weakness

4. Headache

5. Shortness of breath

6. Chest pain

7. Productive cough: may be bloody or contain watery mucus

8. Most serious form

Plague etiology?

Yersenia pestis, a G- bacillus. Rodents and lagomorphs are host species, its transmitted by fleas among animals. Western 1/3 of NA with a patchy worldwide distribution

Plague transmission to humans?

1. Flea bite (bubonic or septicemic)

2. Direct contact with infected animals (septicemic)

3. Respiratory inhalation of infectious droplets (pneumonic)

Precautions: flea control, rat control, prevent pets from roaming and hunting, insect repellants, PPE.

Salmonellosis CS in reptiles and poultry?

Typically asymptomatic

Salmonellosis CS in newborn ruminants, pigs, horses, fowl, ± pups and kittens?

Enteritis and septicemia

Salmonellosis CS in older animals?

Gastroenteritis without septicemia

Salmonellosis CS in humans?

Gastroenteritis and septicemia

Salmonellosis etiology?

Salmonella spp. G-, facultatively anaerobic rods. The most pathogenic isolate is S. enterica subsp. enterica

Salmonellosis transmission to humans?

1. Feco-oral

2. Food cont. esp. eggs, poultry ± dairy products

3. Handling infected animals

Precautions: PPE, careful food handling, wash hands after handling potentially inf. animals (eg. poultry and reptiles), cull or isolate carriers in a herd

Echinococcosis CS in sheep?

Cystic:

1. Usually asymptomatic

2. Ascites

3. Icterus

Echinococcosis forms in humans?

Cystic and alveolar

Cystic echinococcosis CS?

1. Signs are dependent on location of cysts

2. Abdominal discomfort

3. Nausea, vomiting

4. ± Seizures, dementia

Alveolar echinococcosis CS?

1. Asymptomatic for years

2. Abdominal discomfort

3. Weakness

4. WL

5. Liver failure: icterus, ascites

Etiology echinococcosis?

1. Echinococcus granulosis - cystic

2. E. multilocularis - alveolar

Definitive echinococcosis hosts?

Definitive hosts are infected by ingesting cysts in tissues of infected intermediate animals

1. E. granulosis - dogs, other canids, hyenas, cats

2. E. multilocularis - foxes, coyotes

Intermediate echinococcosis hosts?

1. E. granulosus - herbivores and humans, ingest eggs from cont. pastures or soil, cysts develop in liver, lungs, and rarely brain

2. E. multilocularis - microtine rodents (voles) and field mice, cysts in livers

Echinococcosis transmission to humans?

Ingesting eggs from food, water or fomites cont. with feces of definitive hosts.

Precautions: reduce human exposure by preventing infections in dogs and cats (dog allow ingestion of livestock entrails) and use PPE

Leptospirosis CS in dogs?

1. Non spec. - fever, lethargy, anorexia

2. Liver disease - icterus

3. Coagulopathy - petechiae, ecchymoses, hematuria, epistaxis

4. Resp. signs - tachypnea, dyspnea, increased lung sounds

5. Renal disease - PU/PD

Leptospirosis CS in young horses and ruminants?

1. Fever

2. Icterus

3. Renal disease (horses)

Leptospirosis CS in adult horses and ruminants?

1. Abortion

2. Uveitis - horses

Leptospirosis CS in humans?

1. Biphasic disease starting with flu like illness (fever, chills, vomiting, diarrhea) with brief recovery, then

2. Headache, muscle aches

3. Fever, chills

4. Vomiting, diarrhea

5. Abdominal pain

6. Icterus

7. Meningitis

8. Multiorgan failure

Leptospirosis etiology

• Leptospira spp, spirochete bacteria.

• Serovars are adapted to one or more mammalian maintenance hosts; host adapted species do not tend to cause CS in their maintenance hosts as they do in other species.

• Shed in urine of inf. animals

Human transmission of leptospirosis?

Direct transmission to humans via ingestion or exposure across mucous membranes or abraded skin:

1. infected urine

2. Infected placenta or fetus after abortion

3. Cont. water

PPE with face protection and avoid cont. environments

Lymphocytic choriomeningitis CS in rodents

1. Stunted growth

2. Inappetence

3. WL

4. Photophobia

5. Seizures

6. Glomerulonephritis

7. Lethargy

Lymphocytic choriomeningitis CS in humans?

1. Mild flu like illness

2. Meningitis

3. Severe developmental defects

4. Abortions

Lymphocytic choriomeningitis etiology?

• Lymphocytic choriomeningitis virus and arenavirus.

• Natural host in house mouse, other rodents are reservoirs

Lymph. choriomeningitis human transmission?

1. Direct contact with inf. rodents or their excretions/secretions (aerosol, MM, or abraded skin)

2. Infected solid organ transplants

PPE - face protection