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  Bonamiosis and Marteiliosisslide

Description - Control measures - Diagnostic manual - Community Reference Laboratory - Links


Bonamiosis is a lethal infection by the protistan parasite Bonamia ostrea of the haemocytes of flat oysters. Lesions occur in the connective tissue of the gills, mantle and digestive gland. These intrahaemocytic protistants quickly become systemic with overwhelming numbers of parasites coinciding with the death of the oysters. The parasite occurs throughout the year but prevalence and intensity of infection tend to increase during the warm season.

Marteiliosis is caused by the protistan parasite Marteilia refringens that is a lethal parasite of the European flat oyster, Ostrea edulis. The parasite develops mainly in the epithelia of the digestive gland and is associated with poor condition index, emaciation of the oyster and exhaustion of its reserves of energy (glycogen), discoloration of the digestive gland, cessation of growth, and mortality. Mortality appears to be related to the sporulation of the parasite. Earlier stages occur in the epithelia of the palps, stomach, digestive ducts and possibly the gills. The period of infection for M. refringens in O. edulis is confined to spring and summer, when water temperatures are greater than 17°C.

Control measures

  • Directive 2006/88/EC of 24 October 2006 on animal health requirements for aquaculture animals and products thereof, and on the prevention and control of certain diseases in aquatic animals
  • Commission Decision 2001/293/EC
  • Council Regulation 2003/806
  • Council Regulation 2006/775/EC pdf

Notification and Health Status

None of the mollusc diseases are notifiable according to Council Directive 82/894/EEC.

Diagnostic Methods and Sampling Plans

  • Commission Decision 2002/878/EC of 6 November 2002 establishing the sampling plans and diagnostic methods for the detection and confirmation of the presence of the mollusc diseases Bonamiosis (Bonamia ostreae) and Marteiliosis (Marteilia refringens).

Disease free zones or disease free farms in non-approved zones. Approved zones, farms and zones/farms under program for achieving free status.

  • Commission Decision 94/722/EC of 25 October 1994 approving the programme concerning bonamiosis and marteiliosis submitted by France (Only the French text is authentic)
  • Commission Decision 2006/559 on the list of approved zones with regard to Bonamia ostreae and/or Marteilia refringens.

Community Reference Laboratory

Boîte postale 133
F-17390 La Tremblade

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