Zoonoses Flashcards
What are zoonoses?
Diseases that pass between people and animals.
>70% of emerging human infectious diseases come from animals.
What are examples of new emerging infectious diseases?
VHF
Respiratory diseases: MERS
Novel influenza viruses: pH1N1
How are zoonotic diseases transmitted?
Every day contact with animals:
- Scratches or bites
By-products (feces/urine):
- Contaminated soil
- Litter
Foodstuffs:
- Carcass processing
- Milk and milking
- Raw/undercooked meats
Which zoonoses are UK farm/wild animal associated?
Campylobacter
Salmonella
Which zoonoses are tropical farm/wild animal associated?
Brucella
Coxiella
Rabies
VHF
Which zoonoses are UK companion animal based?
Bartonella
Toxoplasmosis
Ringworm
Psitticosis
Which zoonoses are tropical companion animal associated?
Rabies
Tick-borne diseases
Spirilum minus
What is the reservoir and transmission for Campylobacter?
Reservoir:
- Poultry
- Cattle
Transmission:
- Contaminated food
80% of campylobacter food poisoning in the UK come from contaminated poultry, especially chicken. One of the main ways to get and spread campylobacter poisoning is through cross-contamination from raw chicken. Campylobacter is also found in red meat, unpasteurised milk and untreated water.
What is the clinical presentation of Campylobacter? What are investigations and management for Campylobacter?
- Diarrhoea
- Bloating
- Cramps
Investigations: Stool culture
Management: Supportive
What is the reservoir and transmission for Salmonella?
Reservoir:
- Poultry
- Reptiles/amphibians
Transmission:
- Contaminated food
- Poor hand hygiene
What is the clinical presentation of Salmonella? What are investigations and management for Salmonella?
Clinical presentation:
- Diarrhoea
- Vomiting
- Fever
Investigations: Stool culture
Management:
- Supportive
- Ciprofloxacin
- Azithromycin
What is the reservoir and transmission of Bartonella henselae?
Reservoir: Kittens > cats
Transmission:
- Scratches
- Bites
- Licks of open wounds
- Fleas
Which two diseases can Bartonella henselae cause?
Cat Scratch Disease
Bacillary angiomatosis
Why do kittens cause Bartonella henselae more than adult cats?
Bartonella is a slightly curved Gram negative rod.
Kittens are more likely to infect people because they scratch more often and have a higher prevalence of Bartonella.
Prevalence in cats of all ages can be 30 to 50%.
What is the clinical presentation of cat scratch disease? What are investigations and management for cat scratch disease?
Clinical presentation:
14% of cases can progress to more severe symptoms which can include eye problems, encephalopathy, arthritis, osteolysis, vascular system lesions, hepatitis, or pneumonia.
- Macule at site of innoculation
- Becomes pustular
- Regional adenopathy
- Systemic symptoms
Investigations: Serology
Management: Erythromycin, Doxycycline
What is the clinical presentation of bacilliary angiomatosis?
Mostly in HIV - infected and other immuno-suppressed individuals. Much more severe disease than is CSD. Vascular lesions may involve many organs, with skin being the most common.
Clinical presentation:
- Occurs in immunocompromised
- Skin papules
- Disseminated multi-organ and vasculature involvement
What are investigations and management for bacilliary angiomatosis?
Prevention: Wash hands after handling cats, use flea control, do not let cats lick areas of abraded skin or open wounds.
Investigations:
- Histopathology
- Serology
Management:
- Erythromycin
- Doxycycline
PLUS rifampicin
What is the reservoir and transmission of Toxoplasmosis?
Reservoir:
- Cats
- Sheep
Transmission:
- Infected meat
- Faecal contamination
What is the clinical presentation of toxoplasmosis?
Fever
Adenopathy
Still-birth
Progressive visual, hearing, motor, & cognitive issues
Seizures
Neuropathies
What are investigations and management of toxoplasmosis?
Investigations: Serology
Management:
- Spiramycin
- Pyrimethamine plus sulfadiazine
What is the reservoir and transmission of Brucellosis?
Reservoir:
- Cattle
- Goats
Transmission:
- Unpasteurised milk
- Undercooked meat
- Mucosal splash
- Aerosolisation/inhalation
What is the clinical presentation of Brucellosis?
Incubation period - usually 30 days but can be up to 5 months
Symptoms: Non-specific. Fever, chills, headache, myalgia, arthralgia, anorexia, fatigue, lymphadenopathy and splenomagaly.
The ratio to subclinical to clinical cases is 1:1 to 12:1.
- Fever
- Back pain
- Orchitis
- Focal abscesses (Psoas, liver etc)
What are investigations and management for Brucellosis?
Investigations:
- Blood/pus culture
- Serology
Management:
Doxycycline PLUS Gentamicin OR Rifampicin
What is the reservoir and transmission of Coxiella burnetii - Q fever?
Reservoir:
- Goats
- Sheep
- Cattle
Transmission:
- Aerosolisation/inhalation of secretions, waste, or milk of infected animals.
- Unpasteurised milk
What is the clinical presentation of Coxiella burnetti - Q fever?
Incubation period: Usually 30 days but can be up to 5 months.
Symptoms: Non-specific. Fever, chills, headache, myalgia, arthralgia, anorexia, fatigue, lymphadenopathy and splenomagaly.
The ratio to subclinical to clinical cases is 1:1 to 12:1.
- Fever
- ‘Flu-like illness
- Pneumonia
- Hepatitis
- Endocarditis
- Focal abscesses (Para-vertebral/discitis etc)
What are investigations and management of Coxiella burnetti - Q fever?
Investigations: Serology
Management: Doxycycline (hydroxychloroquine)
What is the reservoir and transmission of Rabies (Lyssa virus)?
Reservoir:
- Dogs
- Cats
- Bats
- Racoons
Approximately 120,000 animals or more are tested for rabies each year in the United States, and approximately 6% are found to be rabid.
Transmission:
- Bites
- Scratches
- Contact with infected fluid
What are similar viruses to Rabies (Lyssa virus)?
All of the newly identified australian bat viruses are Rhabdoviruses which are related to the viruses that cause rabies and Lyssa fever. Viruses in this family have a high fatality rate often near 100%.
Henda Virus (Equine Morbillivirus): Infects humans, horses, cats and Guinea pigs. Fruit bats are the natural reservoir.
Australian bat lyssa viruses (Ballina virus): This is a close relative of rabies.
Menangle virus: Carried by fruit bats and causes disease in pigs.
What is the clinical presentation of Rabies?
Seizures
Excessive salivation
Agitation
Confusion
Fever
Headache
What are investigations and management of Rabies (Lyssa virus)?
Investigations:
- Serology
- Brain biopsy
- (USA saliva PCR)
Management:
- Immunoglobulin
- Vaccine
HRIG only given if direct exposure to saliva of likely infected animal and no pre-exposure vaccinations received by the patient.
What is the reservoir and transmission of rat bite fever?
Reservoir:
- Rats: Nasopharyngeal carriage rates in healthy laboratory rats range from 10% to 100%; carriage rates in wild rats range from 50% to 100%.
Transmission:
- Bites
- Contact with infected urine or droppings
Transmission is usually through a rat bite. However, some cases have rat exposure but no reported bite.
What are the responsible agents for rat bite fever?
Streptobacillus moniliformis
Spirillum minus
What is the clinical presentation of rat bite fever?
2-10 days after rat bite:
- Fevers
- Polyarthralgia
- Maculopapular progressing to purpuric rash
- Can progress to endocarditis
What are investigations and management for rat bite fever?
Investigations:
- Joint fluid microscopy & culture
- Blood culture
Management:
- Penicillins
What is the reservoir and transmission for Hantavirus Pulmonary Syndrome?
Reservoir:
- Deer mouse: Sin Nombre virus
- White footed mouse: Sin Nombre virus
- Cotton rat: Black canal virus
- Rice rat: Bayou virus
Transmission:
- Contact with infected urine or droppings
- Aerosolisation
Where is Hantavirus pulmonary syndrome endemic and what is it associated with?
Western & southern USA and most of central & South America.
HPS has also been linked with hypertensive renal disease in the inner city.
What is the clinical presentation for Hantavirus pulmonary syndrome?
Fever
Myalgia
Flulike illness
Respiratory failure
Bleeding
Renal failure
What are investigations and management for Hantavirus pulmonary syndrome?
Investigations:
- Serology
- PCR
Management:
- Supportive
What is the reservoir and transmission of viral haemorrhagic fever?
Reservoir:
- Ebola:?Bats
- Marburg:?Bats
- Lassa: Rats
- CCHF: Ticks
Transmission:
Most are transmitted by direct contact of bodily fluids in the later stages of the disease. Vomiting, diarrhea, shock and hemorrhage.
Not transmissible via air.
Caregivers often infected.
What are causative organisms of viral haemorrhagic fever?
- Lassa
- Marburg
- Ebola
- Congo-Crimean Hemorrhagic Fever
Ebola and Marburg are RNA viruses in the filovirus family.
What is the clinical presentation of viral haemorrhagic fever?
Fever
Myalgia
Flulike illness
Bleeding
What are investigations and management for viral haemorrhagic fever?
Investigations:
- Serology
- PCR
Management: Supportive
A 35 year old patient presents with abdominal cramps and diarrhoea after a BBQ. What is the most likely source?
A. Beef
B. Pork
C. Chicken
D. Unpasteurised cheese
E. Playing with the tortoise
C. Chicken
A 35 year old patient presents with fever after a bat bite.
What potential infection is most concerning?
A. Spirillum minus
B. Hanta virus
C. Lassa virus
D. Rabies virus
E. Streptobacillus moniliformis
D. Rabies virus
A 35 year old patient is suspected of having a Brucella infection in their right psoas after drinking unpasteurised goats milk.
What is the first investigation to obtain?
A. Blood culture
B. Psoas pus culture
C. Serology
D. Whole blood PCR
E. Psoas muscle histopathology
A. Blood culture
A 35 year old patient presents with fever of 38.8C after return from 3 months in Rwanda, when they co-habited in a hut with a family and their livestock.
How should this patient be managed?
A. Admit into a bay
B. Transfer to HCID unit at Royal Free
C. Admit into side room
D. Discharge
E. Discharge to return to infectious diseases clinic in 3 days
C. Admit into side room
