Utah Department of Agriculture and Food

Foulbrood Information

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Foulbrood disease comes in two varieties European Foulbrood (EFB) and American Foulbrood (AFB). While both are rare in the State of Utah, American Foulbrood is of particular concern to beekeepers. Please consult the information provided below and contact UDAF with any questions or concerns you may have.

American Foulbrood

Every beekeeper should be familiar with the signs and symptoms of American foulbrood (AFB). AFB is the most serious of the brood diseases and often results in the death of infected colonies. AFB is highly contagious and can quickly infect many beehives in an area. Please contact UDAF to schedule an inspection if you suspect one of your hives is showing signs of AFB or submit a sample.

American foulbrood (AFB) is not characterized by any single symptom. Pictured above are three of the primary visible symptoms:

  • Spotty (inconsistent) brood pattern — As larvae die it creates a spotty brood pattern.
  • Black Scale — The young larvae are reduced to a blackened scale that is difficult to remove.
  • Ropey Dead Larvae — The dead larvae (that have not yet dried out) rope for an inch or more because the AFB bacteria link together like a chain.

See our fact sheet for a more detailed overview of the symptoms: American Foulbrood Fact Sheet

AFB Treatment

Burning is the safest and most effective way to control AFB. For Beekeepers who do not wish to burn their hives, there are two treatment options:

  1. The beekeeper can contact a veterinarian who will be able to discuss options for appropriate antibiotic treatment
  2. The beekeeper can contact the Phage Hunters program at BYU if they are interested in treating their hives with phages instead of antibiotics. This does not require the approval of a veterinarian.

It is important that robbing is not allowed to occur when a hive is infected with AFB because robber bees may transmit the disease to their colony. If treatment is unsuccessful burning the equipment is the most prudent course of action. Burning is necessary due to the long lived (40 years) AFB spores that are left behind on exposed equipment.

European Foulbrood

European foulbrood (EFB) infections are significantly less serious than American foulbrood infections. Healthy colonies are even sometimes able to overcome infections without intervention from the beekeeper. However it is still important that beekeepers be aware of the signs and symptoms so they can handle EFB infections according to their management philosophy. Please contact UDAF to schedule an inspection if you suspect one of you hives is showing signs of EFB or submit a sample.

European foulbrood (EFB) is not characterized by any single symptom. Pictured above are three of the primary visible symptoms:

  • Spotty (inconsistent) brood pattern — As larvae die it creates a spotty brood pattern.
  • Developing larvae that turn light brown – much like coffee with cream.
  • Larvae that die before they have been capped – EFB kills developing bees before they are capped over.

European foulbrood will also cause the dead brood to be ropey and will leave scales. It can be difficult to visually differentiate between American and European foulbrood, which is why lab testing so essential.

EFB Treatment

The only course of treatment for European foulbrood requires beekeepers to contact a veterinarian who will be able to discuss options for appropriate antibiotic treatment. Thankfully equipment from hives that had European foulbrood does not need to be destroyed. Further information on European foulbrood and how to handle exposed equipment can be found here.