Coxiella burnetii
Phylum Proteobacteria
Class Zymobacteria
Sub-class Alphaproteobacteria
Order Legionellales
Family Coxiellaceae
Genus Coxiella
Species C. burnetii
Goat placenta from Q fever abortion. Note the thickened intracotyledonary areas and tan exudate. The cotyledons have tan necrotic margins and congested, red centres. Copyright CFSPH Iowa State.


Q fever

  • Caused by Coxiella burnetti
  • Influenza-like disease of humans in contact with farm animals
  • Transmitted to humans by inhalation from parturient sheep, goats and cattle
  • Organisms replicate in female genital tract and mammary glands of ruminants
  • Shedding occurs in uterine discharges, foetal fluid and milk
  • Infections in animals usually subclinical
  • Sporadic abortions occur in sheep, goats, cattle, cats
  • Infertility may result in ruminants, as well as placentitis or endometritis
  • Hepatitis, myocarditis and interstitial pneumonia may occur in affected foetuses
  • Diagnosis: MZN-stained smears of placental tissue and uterine discharges; immunofluorescence; PCR; culture; serology
  • Control: disposal of infected placenta and separation of pregnant ruminants; inactivated vaccines


Coxiella burnetti (rickettsia) Infection by inhalation, ingestion or tick bites. Leads to late abortion or birth of weak lambs/kids. See a thickened leathery placenta covered in exudate. ZN stains can be use to demonstrate organisms.