L43 Zoonosis Flashcards
List 2 causative organisms that are related to ingestion of diary products.
- Listeria monocytogenes
2. Brucella species (causing brucellosis)
Pet owners, e.g. parrot owners are in risk of?
- Agricultural workers and veterinary surgeons are also in risk of zoonoses.
Psittacosis by Chalmydia psittaci
This is a gram -ve coccobacilli, non-motile and fastidious. It causes zoonosis that is related to cattles, sheep and pigs. Name the respective species.
Brucella abortus - cattle
Brucella melitensis
Brucella suis - pigs
What are the modes of transmission of Brucellosis? (3)
- Direct contact
- Ingestion (meat/diary product, sheep placenta)
- Inhalation
The patient has 2 weeks of incubation after getting infected by Brucella species. What are the clinical features? (3)
- Persistent Undulant fever (rising and falling)
- Profuse sweating
- Flu-like illness
Name 2 complications of brucellosis.
- Osteomyelitis
- Hepatitis
- Meningoencephalitis
- Endocarditis
- Orchitis
How is Brucellosis diagnosed and treated?
Diagnosis
- blood culture, bone marrow culture (osteomyelitis)
Treatment
- Rifampicin + Doxycycline x6 weeks***
How can Brucellosis be prevented? (2)
- Vaccination of herds
- Pasteurisation of milk
Plague/ Black Death is caused by which organism?
It is Gram _ _______? Belonging to which family?
Yersinia pestis
- Gram -ve bacilli, Enterobacteriaceae
Mode of transmission of plague? (3)
- Direct contact - rodent
- Vectors: Flea bite
- Inhalation: in pneumonic plague (human to human transmission)
Plague: incubation is within 1 week
What are the 3 different types of clinical presentation of Plague?
Which has the highest mortality?
- Bubonic plague: fever, painful lymphadenopathy (esp. inguinal and axilla LN), may lead to septicaemic plague
- Septicaemic plague: fever, hypotension
- Pneumonic plague: fever, cough, hemoptysis
Mortality 50% in bubonic, 100% in septicaemia and pneumonic
What are the investigations for suspected plague patients? (4)
- Sputum for culture for pneumonic plague
- Bubo aspirate for culture for bubonic plaque (LN)
- Blood culture for septicaemic plaque
- Serology for detection of F1 antigen
What is the treatment for Yersinia pestis infection?
Gentamicin and Doxycycline x7-10 days
Prevention of plague? (2)
- Rodent control
2. Post-exposure prophylaxis
List other examples of organisms that causes zoonoses other than Yersinia pestis and Brucella species.
______ causing ______.
all of them are notifiable disease in HK?
- Coxiella burnetii causing Q fever
- Borrelia burgdorferi causing Lyme disease
- Leptospira interrogans causing Leptospirosis
Only 2 is not notifiable disease in HK.
Both Borrelia burgdorferi and Leptospira interrogans are Gram -ve spiral rods that have to be visualised by ? Why?
They are too thin to be visualised by light microscopy, requires dark-field microscopy.
Borrelia burgdorferi causes _________ disease and it is diagnosed by? (2)
Lyme disease
- Wright and Giemsa stains
- Serology: IgM (undetectable in the 1st week)
What is the mode of transmission for Lyme disease?
Rodent and deer as reservoir,
transmitted by tick bite (Zoonosis)
What is Lyme disease? (3)
Infection by Borrelia burgforferi
3 stages
1. Localised disease: Bull-eye rash, flu-like symptoms, erythema migrans (if multiple > spirochetemia)
- Early disseminated disease: Bell’s palsy, Heart block causing myocarditis
- Late stage: CNS meningitis, neuropathy; Migratory polyarthritis
Treatment for Lyme disease?
Doxycycline, amoxicillin x2-3 weeks
For leptospirosis, it is transmitted via?
Direct contact of rat/ livestock urine through skin lesion during swimming and waterspouts
How to diagnosis leptospirosis?
Serology: LMAT - Leptospira microscopic agglutination test
Others
- Culture: Fletcher’s medium
- Dark field microscopy for blood/urine (Question mark shape)
Describe the disease caused by Leptospira interrogans.
Biphasic courses of clinical features
- Flu-like illness > brief resolution > Weil’s disease
- Leptospirosis: Flu-like illness,
- Severe phase: Weil’s disease
- Conjunctival suffusion
- Liver and renal failure via hematogenous spread
- Myocarditis
Treatment for Leptospirosis?
Penicillin G
Doxycycline
Q fever is caused by which organism? What mode of transmission?
Coxiella burnetii
- inhalation
How is Q fever diagnosed?
By serology: Complement fixation test
Clinical features of Q fever?
- Flu-like illness
- Atypical pnemonia
- Hepatitis
- Endocarditis (rare)
How to treat Q fever?
Doxycycline x2 weeks
Q fever endocarditis: Doxycycline + hydroxychloroquine x18 months
