Leptospirosis Flashcards
What is the pathogenic species called ?
Leptospira interrogans
Structure
Gram-, aerobic, slender, motile, flexous, coiled organisms
possess an outer sheath and multi-layered membrane
Culture ?
really difficult as slow growers. specialist broths, 30 degrees and 8 weeks
Pathogenesis
enter the body through MMs
once inside, cause vascular damage
resulting in disseminated intravascular coagulation (DIC), damage to vascular endothelium (–> haemorrhage) and cytotoxic production
difficult to understand
Immunity ?
antibody production begins a few days after the onset
Abs persist in areas where activity is minimal
Diagnosis ?
serology
MAT (microagglutination test)
What samples are used for diagnosis ?
mid stream urine
liver tissue
kidney tissue
foetal tissue
blood
Reservoirs ?
virtually all species harbour the bacteria in their kidneys
rodents especially shed throughout their life with no clinical signs
Leptospirosis in dogs
[ L. canicola or L. icterohaemorrhagiae ]
subclinical (no symptoms)
acute (haemorrhagic, high fever, vomiting, prostration)
less acute (icterus, depression, fever, blood in urine and faeces)
uraemic (uraemia associated with kidney damage)
chronic (active, life-long hepatitis)
most cases result in tubulo-interstitial nephritis
Leptospirosis in pigs
[ L. pomona, L. icterohaemorrhagiae ]
subclinical with organisms present in urine
fever, mastitis, infertility, SMEDI, fever, anorexia, jaundice, high mortality
pig also acts as a reservoir host for some species
Leptospirosis in cattle
subclinical with or without organisms in urine
most common CS milk drop!
also abortion (foetuses are icteric), infertility, neonatal mortality, jaundice, fever
Leptospirosis in horses
not commonly seen
CS : recurrent iridocyclitis (moon blindness, cannot see well at night due to damaged peripheral vision), abortion, fever, anorexia, depression, icterus
Leptospirosis in sheep
[ L. hardjo and L. pomona ]
sub-clinical infections, occasionally see acute
high mortality in lambs
