American foulbrood and European foulbrood are bacterial diseases that affect honey bee brood. The causative organism for American foulbrood is Paenibacillus larvae. European foulbrood is caused by Melissococcus plutonius. A preliminary diagnosis of these two separate diseases can be made based on their symptoms. After these symptoms have been observed, a diagnostic field kit can be used to more clearly establish the presence of the causative agent of these diseases.
Using a diagnostic kit to identify American foulbrood (AFB) or European foulbrood (EFB) is easy and reasonably reliable. These test kits are readily available from some of the major beekeeping supply companies for around $14 each. Step by step directions are included with the test kits, which are easily used in the field.
These diagnostic kits are Lateral Flow Devices that detect specific antigens that bind to antibodies in in the device. Separate kits are manufactured for EFB and AFB, since two different antigens are involved. Be sure to use the correct kit for the disease suspected in your apiary.
Using the diagnostic kit
To use the kit, remove a diseased larva from a cell with the provided, plastic tool. Then place the larvae into the buffer solution. Metal beads are in the buffer to aid in mixing.
Next, close the lid and shake the buffer virtuously for 20 seconds. Then, immediately remove some of the liquid with the provided dropper.
Finally, place two drops on the well plate of the testing device. Keep the test device horizontal and wait about 3 minutes for the control line to appear.
If two lines appear for both test (T) and control (C), the sample has tested positive for the infective organism. If only a single line for control (C) appears then the test is negative for the organism. If the control line does not appear, then the device is defective.
False negative results can occur. If a test is negative, it may only mean that the sample did not contain the bacterial organism. Very rarely, a false positive may occur. For definitive diagnosis, a sample of comb should be mailed to the Beltsville Bee Lab for lab culture and diagnosis. Read more infomation on lab diagnosis of European Foulbrood on the following page
In most US states, American foulbrood is a regulated disease. Laws generally require notification of the applicable state apiarist/inspector whenever the disease is suspected.
For information about the epidemiology of European foulbrood, see the following page
Tomkies, V, Flint, J., Johnson, G., Ruth, W., Wilkins, S., Danks, C., Watkins, M., Cuthbertson, G., Carpana, E., Marris, G., Budge, G., and Brown, M. (2009). Development and validation of a novel field test kit for European foulbrood. Apidologie 40: 63-72.
Michael Wilson, John Skinner, Paul Rhoads, Debbie McCalaster, and Ariana McCalaster, University of Tennessee