Revue sur l'épidémiologie du botulisme bovin en France et analyse de sa relation avec les élevages de volailles

Abstract

Le botulisme bovin est une affection mondialement connue. Elle est due à une contamination par Clostridium botulinum C ou D directement par léchage de cadavres botuliques dans le cas de bovins carencés et présentant du pica, ou ingestion d'aliment ou d'eau (maladie des forages) contaminés par de petits mammifères botuliques (rongeurs, chats) ou des oiseaux sauvages. La contamination tellurique de certains aliments (ensilage, céréales stockées dans des conditions d'humidité élevée) est aussi responsable de certains foyers de botulisme bovin. Les techniques actuelles d'alimentation, notamment la préparation de farines de viandes à partir de cadavres, peuvent être à l'origine d'une large dissémination de C. botulinum, si les normes sanitaires (surtout traitement thermique) ne sont pas respectées. Ainsi, en Europe et en particulier en France, de nombreux foyers de botulisme bovin se sont déclarés au contact d'élevages aviaires de type industriel. Les volailles sont naturellement résistantes au botulisme de type D, mais elles constituent un réservoir de C. botulinum et peuvent contaminer les bovins par l'intermédiaire des lisiers épandus sur les prairies.

Development and Validation of a New Reliable Method for the Diagnosis of Avian Botulism

“…Interestingly, almost half of the confirmed outbreaks in turkeys (46.7%) were type D or D/C. Although broilers have been described to be resistant to type D BoNT [36], turkeys appear to be sensitive to this BoNT type. Turkeys are known to be more sensitive to BoNT type C than broilers [37]; this seems to be also the case for the other BoNT types.…”

A large outbreak of bovine botulism possibly linked to a massive contamination of grass silage by type D/CClostridium botulinumspores on a farm with dairy and poultry operations

“…The first outbreaks reported were mainly attributed to bones licked by cattle grazing in phosphorous-deficient areas [10,11], ingestion of water or silage contaminated by small mammal or bird carcasses [12,13], use of poultry litter as a dietary supplement [14,15], ingestion of insufficiently acidified silage contaminated by telluric C. botulinum spores [16,17], or feeding silage made from contaminated brewers' grains [18]. In the past few decades, an increasing number of cattle botulism type D outbreaks linked to direct contact with or close proximity to poultry litter has been reported in Western Europe [19][20][21]. Most of these outbreaks have been attributed to the ingestion of BoNTs from poultry or small mammal carcasses that were present in poultry litter spread as fertilizer or stacked onto pastures, but the causal association has not always been proved [21][22][23].…”

Investigation of a type C/D botulism outbreak in free-range laying hens in France

“…Even if the existence of a healthy carriage of C. botulinum in poultry remains controversial (Hardy & Kaldhusdal, 2013) and no study has been able to demonstrate it (Hardy & Kaldhusdal, 2013;, poultry might be carriers of C. botulinum at a very low level, probably under the limit of detection of available methods (Popoff, 1989). The day before the first signs of the disease, more than 200 hens were found smothered.…”

“…The carcasses of the 200 hens could have also initiated the outbreak, even if they were removed rapidly. Carcasses are indeed an excellent medium for C. botulinum growth and BoNT production, because of the anaerobic conditions and presence of decomposing matter and could therefore have been a source of both BoNTs and spores (Popoff, 1989). The presence of the poultry carcass bin near the house and the fact that the truck carrying the carcasses passed in front of the house could also be considered as risk factors.…”