American Foulbrood

American Foulbrood (AFB) is a bacterial disease spread by spores. The spores can remain active for several years, causing new outbreaks when conditions are favourable. AFB will usually enter a hive on a forager bee that has come in contact with an infected bee in the field. The spores infect the colony when nurse bees transmit the disease to larva during feedings. This cycle is perpetuated until the entire hive is contaminated. Over time the hive weakens, at which time bees will flee looking for a new home in another colony, carrying the AFB spores with them.

Symptoms

• Coffee-coloured larvae that eventually decay, leaving puddles in the bottom of the cells.
• Dead larvae have a ropey consistency if drawn out with a toothpick.
• The dead larvae are scale-like when they dry; the scale contains dormant spores.
• The cell-capping will look shrunken and dark brown.
• The hive may smell like rotting fish

Prevention and Treatment

• Buy and use disease-free equipment.
• Burn your hive tool in your smoker after visiting each hive.
• Manage hives to minimize robbing and drifting.
• Ensure bees have enough honey stores, and feed if needed. Watch for discoloured brood.
• If infection is severe, burn the hives.