American Foulbrood

American Foulbrood Diaseases- (AFB)bee

 

What is AFB?

AFB is the most serious bacterial disease affect- ing honey bees in Fiji. It is caused by the spore forming bacterium Paenibacillus larvae.

AFB is a notifiable disease; which means the disease is required by law to be reported to government authorities including the Biosecurity Authority of Fiji (BAF). The collation of information allows BAF to monitor the disease and provide early warning of possible out- breaks.

 

If we look at the disease cycle of AFB, the bacterial spores that enter the hive are quickly spread and once they reach the larvae, the bacterium can multiply even more rapidly. The disease weakens the colony, which subsequently makes the colony a target for robbing bees that carry spores (the bacterial pathogen) back to their colony, hence further spreading the disease and starting the cycle in a new colony.

 

The disease starts with the transmission of spores from nurse bee mouthparts to larvae while feeding. The younger the larvae, the more susceptible and less spores required to cause infection. The spores then germinate in the larvae gut and begin to multiply rapidly after the larvae have been capped, eventually killing the infected larvae at the pre-pupal and pupal stage. A dead larva becomes a dried scale with billions of Paenibacillus larvae spores, which stick to the side of the cells. These spores can be spread around the hive by adult bees as they attempt to remove the dead pupae.