B156 - ENZOOTIC ABORTION (CHLAMYDIOSIS)

IDevice Icon

B156 - ENZOOTIC ABORTION (CHLAMYDIOSIS)

Nature of the disease
Enzootic abortion of ewe and goats due to Chlamydophila abortus formerly known as Chlamyda psittaci. The disease causes abortion and is a potential zoonosis. 
Classification
OIE, List B disease
Susceptible species
Goats and sheep and less commonly cattle and deer. Humans are also susceptible.  
Distribution
Enzootic Abortion of ewe is present in Europe, North America and in some African Countries. In the Pacific Region is only suspected in French Polynesia.
Clinical signs 
  • Abortion,
  • Placentitis,
  • Low fertility result (as a consequence of abortions)
Post-mortem findings 
No fatality
Differential diagnosis 
Other causes of abortion in small Ruminants:
Specimens required for diagnosis 
Smear from placenta material is the best specimen. Identification of the agent is best done by antigen detection (ELISA, fluorescent antibody test) or PCR. Culture and isolation is also possible.

For serological test Fixation Complement and ELISA are available. 

Transmission   
Enzootic abortion is transmited orally by food, water and straw. It can also be transmitted by aerosol. The organism is shed in blood and milk for up to 4 months and in the urerus for 6 months. 
Risk of introduction   
Enzootic abortion of ewe can be introduced by importation of infected small ruminants. It seems that there is no link between Chlamydophila abortus and the possibility Chlamydophila abortus  of birds.
Control / vaccines  
Inactivated and live vaccines are available that reduce the incidence of abortion, but do not prevent infection. They assist in control of the disease but will not eradicate it. Serological screening during the period after parturition helps to identify infected flocks, to which control measures can then be applied.
References
  • Caprine arthritis/encephalitis, In Merck Veterinary Manual, National Publishing Inc. Eight ed, 1998, Philadelphia, p 523-526
  • Caprine arthritis/encephalitis, In Veterinary Medicine, Saunders, Eight ed, 1997, London p. 1110-1112
  • Office International des Epizooties, 2002