Leptospirosis Flashcards
1
Q
Why is Leptospira so important?
A
- 0.5 million cases in humans a year
- zoonotic
- economic impacts in production
- 25% human mortality
- dogs - kidney failure
- rats carry it
2
Q
What is the highest risk factor for humans?
A
- water sports
- rat bite
3
Q
What is Leptospira?
A
- G-ve
- aerobic
- helically coiled
- flexous
- slender
- motile
- 0.1-8um
- can fit through filters and stays in glass cracks
4
Q
Whats its order?
A
- Spirochaetales
5
Q
Whats its family?
A
- leptispiracaea
6
Q
What are the characteristics of leptospira?
A
- outer sheath
- multi layered membrane (surrounds periplasmic flagella)
7
Q
Describe the classification?
A
- L.biflexa - non pathogenic
- L. interrogans - pathogenic
- e.g. L. interogans canicola
- 250 pathogenic serovars
- 25 serogroups
8
Q
How do you culture Leptospira?
A
- Korthof broth
- Stuarts broth
- Fletchers semi-solid medium
- EMJH
- 30 degrees, 8 weeks, anaerobically
9
Q
Describe the pathogenesis of Leptospira
A
- gains access to body through mucous membranes/ gut
- causes vascular damage
- DIC - disseminated intravascular coagulation
- damage vascular endothelium - haemorrhages
- liposacchide
- flagella
- haemolysin
- cytotoxic protein
10
Q
Describe the immunity and persistence
A
- antibody production - a few days after onset
- maternal antibodies - short lived
- activity greatest where few antibodies:
- eyes
- urethra
- tubules
11
Q
How do you diagnose Leptospira?
A
- phenotypic test developed by Martin and Pettit - 1918
- agglutination-lysis test (RAL)
- developed - MAT ( microagglutination test)
12
Q
What samples are needed for diagnosis?
A
- mid stream urine
- liver tissue
- kidney tissue
- foetal tissue - abomasal contents, cotyledons, uterine discharge
- blood
13
Q
What are the different methods for diagnosis?
A
- clinical signs
- MAT - test for antibodies in blood
- FAT - fluorescent antibody test
- dark field microscopy
- culture
- PCR
- ELISA
- PM (gross and histo)
14
Q
Which animals are reservoirs?
A
- all mammals - in kidneys
- rodents, cattle, buffalo, sheep, goats, pigs and horses common
15
Q
Rodents and leptospira?
A
- shed throughout lives with no clinical signs
- primary source of infection to humans
- associated serovars = icterohaemorrhagica, copenhageni, grippotyphosa, ballum
16
Q
How does transmission occur in humans?
A
- through tissues, urine, secretions and contaminated water of infected animals
- through damaged skin/ intact mucosa/ eyes
17
Q
What is Leptopira also known as?
A
- Canicola fever
- haemorrhagic jaundice
- infectious jaundice
- sewermans flu
- cavers flu
- mud fever
- swamp fever
18
Q
What increases the risk in humans?
A
- water sports
- underground workers
- pot holers
- vets
- swimming in lakes
- abattoir workers
- immuno-suppressed
- fishing
19
Q
What about cans and bottles in cellars?
A
- rat urine
- tiny abrasions when open bottle
20
Q
Where is leptispira normally found?
A
- tropical/ subtropical climates
- lots of rainfall
- wherever humans come into contact with urine/ urine contaminted water
21
Q
What about control and treatment?
A
- no vaccine for humans
- vaccine for animals
- penicillin and doxycyline - in early stages - before jaundice, fever
22
Q
What types of leptospira do animals get?
A
- cattle - L.pomona, L.icterohaemorrhagiae, L.hardjo
- pigs - L.canicola, L.icterohaemorrhagiae, L.ponoma
- dogs - L.canicola, L.icterohaemorrhagiae
- sheep/ goats - L.hardjo, L.ponoma
23
Q
Significance of sea lions?
A
- aerosols - zoos
24
Q
Descrive Leptospirosis in dogs
A
- L.canicola/ icterohaemorrhagiae
- acute
- high fever, vomiting, prostration, early death
- less acute
- intense icterus, fever, haemorrhage, blood in urine/ faeces, depression
- uraemic
- uraemia associated with extensive kidney damage
- chronic
- acute hepatitis
25
Q
What is this showing?
A
- leptospira in kidney
26
Q
Leptospira in pigs?
A
- L.ponoma, L. icterohaemorrhagiae, L. canicola
- subclinical
- fever
- anorexia
- jaundice
- still births/ abortion
- mastitis
- haemoglobinuria
- infertility
- high mortality in young pigs
27
Q
What is the pig a reservoir host for?
A
- L.pomona
- L.tarassovi
- L.bratislavia
- L.muenchen
28
Q
What is this?
A
- intersitial nephritis
- pelvis coming out into medulla and cortex
29
Q
What is SMEDI?
A
- stillbirth
- mummification
- embryonic death
- infertiltiy
30
Q
Leptospirosis in cattle?
A
- subclinical with or without leptospiruria
- fever
- infertility
- abortion
- neonatal death
- milk drop syndrome - 10-15%
- jaundice
- haemoglobinuria
31
Q
What is the prevalence in cattle herds?
A
- 70-80% - beef
- 20 - 55% - dairy
32
Q
Immunity?
A
- natural immunity develops
- but any new animals - acute infection
33
Q
A
- serious haemorrhage
- necrosis in liver, spleen, lungs
34
Q
A
- jaundiced, aborted foetus
35
Q
Photosensitisation?
A
- young light calves
- vascularisation close to skin
36
Q
Signs of Leptospirosis in horses?
A
- recurrent iridocyclitis
- abortion
- fever, icterus, anorexia, depression
37
Q
A
- interstitial nephritis
- can be chronic
- necrosis in medulla and cortex
38
Q
Sheep?
A
- mainly L.pomona, L.hardjo
- mainly subclinical
- acute - depression, haemoglobinuria, dyspnoea, anaemia
- high mortality in lambs
39
Q
A
- acute septicaemic nephritis (sheep)
40
Q
A
- necrotic nephritis (sheep)
41
Q
Animal vaccinations?
A
- inactivated - cant manipulate
- 5 months - cattle - annual booster
- sows before farrowing
- dogs - 8 wks - annual booster
- +ve MAT test
42
Q
A
