WHAT IS AFB?

American foulbrood (AFB) is a bacterial disease affecting beehives, with serious consequences. In New Zealand, it is a notifiable disease and governed by a national pest management plan. AFB is a disease caused by the spore-forming bacterium Paenibacillus larvae. The disease primarily affects and kills the developing pre-pupae and pupae, or brood, subsequently weakening the bee colony. Spore-forming bacteria are extremely robust and resilient.

The spores themselves are the key to the bacterium’s long survival under extreme conditions, having the ability to remain viable for decades. Billions of spores are produced by the dying larvae, and their remains are difficult to remove by worker bees and are a continuous source of infection for the new brood.

The disease can be easily spread between hives and apiaries. One major problem for the control of AFB is that clinical symptoms appear late in the epidemic when the colony’s hygienic behaviour to remove infected larvae can no longer keep up. It is therefore important to keep on top of any infection and use an array of tools for early detection and prevention.