American foulbrood disease

American foulbrood (AFB) is periodically found in hives in the ACT region. The last known incursion into the ACT was in early 2026 where AFB was detected in beekeepers’ hives.

About the pest

AFB is a serious and highly contagious bacterial disease of honeybee brood caused by Paenibacillus larvae. The disease affects the larval stage of honeybees. It spreads through hardy bacterial spores, which can remain viable for decades.

Why they are a problem

AFB is one of the most destructive diseases of honeybees. It poses a significant threat to Australian honey production and pollination‑dependent industries.

The disease begins in honeybee larvae after they swallow AFB spores with their food. Within 24 to 48 hours, the spores germinate in the gut of the larva and develop into vegetative 'rods'. The rods grow and invade the haemolymph and body tissues, killing the infected larva before pupation, usually immediately after the brood cell is capped.

It is a legal requirement under the Biosecurity Act 2023 to register your hives and report suspected or confirmed AFB.

What to look for

Beekeepers must regularly inspect brood frames for signs of AFB. Signs include:

• patchy brood patterns
• sunken, greasy or perforated cappings
• brown, ropy larval remains 3–5 cm long
• hard, dark scales stuck to the lower cell wall.

What to do to keep your hives safe

• Register as a beekeeper. Registration of hives is mandatory under the Biosecurity Act 2023. It also helps the ACT Government keep you informed about bee pests and diseases.  To apply for registration, complete the Application for Registration as a Beekeeper.
• Follow the Australian Honeybee Industry Biosecurity Code of Practice. As a registered beekeeper in the ACT you must meet your biosecurity obligations relating to AFB under the Australian Honey Bee Industry Biosecurity Code of Practice. In particular, beekeepers must comply with the requirements in sections 4 and 7 of the code.
• Report any suspected sightings. AFB is a notifiable disease under the Biosecurity Act 2023. If you suspect AFB in your hives, you must report it as soon as possible.

The following resources provide guidance on diagnosing and managing AFB and other notifiable bee diseases:

• Samples for bee disease diagnosis: Instructions on the correct collection and submission of samples for laboratory testing.
• EMAI Bee Disease Diagnostics Form: Required when submitting samples for official laboratory diagnosis of suspected diseases.

How it spreads

Although AFB does not spread easily on its own, its spores can be passed between hives and apiaries through beekeeping activities such as sharing equipment or moving infected combs.

Adult bees do not become sick, but they can still carry and spread the spores. This often happens through either:

• robbing, when bees enter weaker hives to steal honey and
• drifting, when bees accidentally enter the wrong hive.

If you require help, contact ACT Biosecurity for guidance before moving hives, bees, or equipment.

Report sightings