Microbiology - Zoonoses Flashcards
What are zoonoses?
Diseases + infections which are transmitted naturally between vertebrate animals + man
What are some diseases associated with mice?
- Hantan viruses (fleas)
- Lyme borreliosis
- Ehrlichia
- Bartonella
- Lymphocytic choriomeningitis
What are some diseases associated with rats?
- Rabies
- Leptospirosis
- Lassa fever
- Hantan viruses
- Plague
- Pasteruellosis
- Haverhill fever (rat-bite)
What are some diseases associated with cats?
- Bartonellosis (cat scratch)
- Leptospirosis
- Q-fever
- Toxoplasmosis
- Rabies
- Ringworm
- Toxocariasis
What are some diseases associated with small ruminants?
- Anthrax
- Brucellosis
- Q-fever
- Cryptosporidiosis
- Enzootic abortion
- Louping ill
- Orff virus
- Rift valley fever
- Toxoplasmosis
What are some diseases associated with cattle?
- Anthrax
- Leptospirosis
- Brucella
- Bovine TB
- Anaplasmosis
- Toxoplasmosis
- E. coli 0157
- Rift valley fever
- ringworm
What are some diseases associated with swine?
- Brucellosis
- Leptospirosis
- Erysipeloid
- Cysticercosis
- Trichinella
- HEV
- Influenza A
- Streptococcal sepsis
What are some diseases associated with birds?
- Psitticosis
- Influenza
- Cryptococcus
- Influenza A
- Poultry-salmonella
- West-Nile Fever
What are some diseases associated with water-sports?
- Leptospirosis
- HAV
- Giardia
- Toxoplasmosis
- Mycobacterium marinum/ulcerans
- Burkholderia pseudomallei
- E. coli
What are some water-borne diseases?
- Campylobacter
- Salmonella
- VTEC O157
- Cryptosporidium
What are some food-associated diseases?
- Listeria (cow cheese-human)
- Taenia
- Cysticercosis
- Toxoplasmosis
- Trichinellosis
- Yersiniosis
- Giardia
What sign is associated with Bartonellosis (cat scratch) + what is the treatment?
- Regional lymphadenopathy
- Tx: Doxycycline
What organism causes Brucellosis and what are its features?
Gram -ve aerobic bacilli
- Facultative intracellular
What is the transmission of Brucellosis?
- Contaminated food (untreated milk/dairy products)
- Direct animal contact (cows, goat, sheep, pigs)
What is the presentation of Brucellosis?
- Undulant fever (2-wk incubation - peaks in evening)
- Myalgia
- Arthritis
- Spinal tenderness
- Hepatosplenomegaly
- Epididymo-orchitis
How is Brucellosis diagnosed?
- Serology: anti-O-polysaccharide antibody (Dx with cultures)
- WCC normal/neutropenia
What is the treatment for Brucellosis?
- 4-6wks Doxycycline + Streptomycin
What are some complications associated with Brucellosis?
- Endocarditis
- Osteomyelitis
- Meningoencephalitis
What is the causative organism for Rabies and some features associated with it?
- Rhabdovirus (Lyssaviruses)
- Dogs + Bats = most common vectors
- Incubation = 1-3mths
How does Rabies present?
Prodrome:
- Fever
- Headache
- Sore throat
Hyperactive State:
- Encephalitis
Months/years later:
- Migration to CNS (fatal encephalitis, hypersalivation, hydrophrobia)
How is Rabies diagnosed?
- Serology for IgM
- Fluorescent Ab Test: Negri bodies (pathognomonic)
- CSF PCR
How is Rabies treated?
- Rabies IgG post-exposure (pre-Sx - doesn’t work otherwise + will die)
- Full Rabies vaccination course
What is the causative organism of the Plague, its features and transmission?
Yersinia pestis
- Gram -ve lactose fermenter
Transmission:
- Reservoir in rats
- Transmitted by fleas
- Still seen in some American National Parks (e.g. Yosemite)
How does the Plague present?
Bubonic plague:
- Flea bites human
- Swollen LN (bubo = dense, black fluid)
- Dry gangrene
Pneumonic plague:
- Usually seen during epidemics
- Person-person spread
Septicaemic plague
How is the Plague diagnosed?
PCR, microscopy, culture
What is the treatment for the Plague?
- Streptomycin
- Doxycycline
- Gentamicin
- Chloramphenicol (in meningitis)
What is the causative organism of Leptospirosis, its features + transmission?
L interrogans
- Gram -ve
- Obligate aerobic, motile spirochaetes
Transmission:
- Excreted in dog/rat urine
- Penetrates broken skin
- Swimming in contaminated water (lakes)
- 1wk incubation
How does Leptospirosis present?
- High fever
- Conjunctival haemorrhages
- Jaundice
- Meningism
- Renal failure
- Haemolytic anaemia
How is Leptospirosis diagnosed?
- Microscopy/cultures
What is the treatment for Leptospirosis?
- Amoxicillin
- Erythromycin
- Doxycycline
- Ampicillin
What is the causative organism of Anthrax and its features?
Bacillus anthracis
- Farm/wild animals (spread by spores in hair)
What are the two types of Anthrax and how do they present?
Cutaneous
- Painless round black lesions (eschar)
- Rim of oedema
Pulmonary:
- Massive lymphadenopathy
- Mediastinal haemorrhage
How is Anthrax diagnosed?
Microscopy
What is the treatment for Anthrax?
Doxycycline/Ciprofloxacin
What is the causative organism of Lyme disease and its transmission?
Borrelia burgdoferi (spirochaete)
- Arthropod-borne (Ixodes = tick)
Transmission:
- Ixodes tick on deer (hiking)
- Incubation = days/wks
How does Lyme disease present?
Early:
- Erythema chronicum migrans (bulls-eye rash)
- Flu-like
Late persistent:
- Focal neurology
- Neuropsychiatric
- Arthritis
How is Lyme disease diagnosed?
- Biopsy edge of rash
- ELISA for Lyme Abs
Clinical Sx IF erythema migrans
What is the treatment for Lyme disease?
- Doxycycline 2-3wks
(or amoxicillin, cephalosporins)
IF CNS Issues:
- IV ceftriaxone 2-4wks
What is the causative organisms for Q fever + its transmission?
- Coxiella burnetii
Transmission:
- Cattle
- Sheep
How does Q fever present?
Atypical pneumonia:
- Dry cough
- Fever
- No rash
What is the treatment for Q fever?
Doxycycline
What is the causative organisms of the different types of Leishmania?
Protozoa
- Cutaneous = L. major, L. tropica
- Muco-cutaneous = L. braziliensis
- Visceral (Kala Azar) = L. donovani, L. infantum, (L. chagasi in S. America)
What are the different types of Leishmania and how do they present?
Cutaneous:
- Skin ulcer at site of bite
- Multiplies in dermal macrophages
- Heals after 1yr = Depigmented scar
- Single/mulitple painless nodules that grow + ulcerate
Diffuse Cutaneous:
- Pts with immunodeficiency
- Nodular skin lesions
- Don’t ulcerate
Muco-cutaneous
- Dermal ulcer (same as cutaneous)
- Months-years later = Ulcers in mucous membranes of nose + mouth
Visceral (Kala Azar):
- Young + malnourished child
- Sx: Abdo discomfort + distension, anorexia, weight loss, fever, hepatosplenomegaly, pancytopenia
How is Leishmania diagnosed?
Microscopy
What is the treatment of Leishmania?
- Liposomal amphotericin B
How does Leishomania donovani cause visceral leishmania (Kala Azar)?
- Invasion of reticuloendothelial system
- Causes Hepatosplenomegaly
- BM invasion
- Later = disfiguring dermal disease (PKDL)
