19 February 2015

Diagnosing the Foulbroods

Both European Foulbrood and American Foulbrood are notifiable diseases here in UK. This means that cases MUST be reported to the Beekeeping Inspectorate, who will then inspect your bees and, if there is a positive diagnosis, will tell you what you should do next.

The Inspectors will then inspect all known colonies within the nearby area, and support those other beekeepers whose colonies are also infected. The aim is to restrict the spread of the disease.

There is no shame in admitting that your bees are infected, the greater shame would be trying to hide or ignore either of these diseases and hope they will go away on their own. They won't! All you would achieve is to let foulbrood spread throughout the local honey bee population, with potentially catastrophic results for both other beekeepers's bees and feral colonies.

Please, learn how to recognise these diseases, and ask for help if you think you spot either in any of your colonies.

If you are lucky enough to have a the services of volunteer Bee Health Advisor (BHA) then ask them to come and take a look, if not then you'll need to contact either your Regional or Seasonal Bee Inspector.

Do not seal up your hives
Current advice from the Inspectorate is NOT to close the hive before there has been a second opinion and diagnosis - you may be wrong, and closing the hive(s) could be detrimental to the bees.

Identifying Foulbrood.
It's often easier to understand by seeing than by reading, but I can't find any UK-based videos showing how to tell the difference between the two foulbroods, so will leave it to Jamie Ellis from the University of Florida to discuss both.
Please remember that the inspection and support programme here in Britain is NOT the same is in USA.

Useful? I hope so.

Now let's look at the two diseases individually.

1) American Foulbrood.
American Foulbrood (Paenibacillus larvae larvae) kills larvae after capping.
Symptoms of AFB (taken from Beebase):
The characteristic disease signs of AFB include some or all of the following:
  • Uneven or 'Pepper-pot' brood pattern
  • Sunken, greasy or perforated, darkened cell cappings
  • Roping, sticky larval remains when drawn out with a matchstick
  • Dark "scales", which are difficult to remove from cells
Here are two US-based videos showing how to identify the disease.

A sad, but very helpful video, "Identifying foul brood in a bee hive"


"Learn to identify American Foulbrood in 90 seconds."

2) European Foulbrood
European Foulbrood (Melissococcus plutonius) is an early disease, affecting early, uncapped, larvae.
Symptoms of EFB (taken from Beebase):
An infected colony may show some or all of the signs below:
  • Erratic or uneven brood pattern
  • Twisted larvae with creamy-white guts visible through the body wall
  • Melted down, yellowy white larvae
  • An unpleasant sour odour
  • Loosely-attached brown scales
Unlike AFB, the remains of larvae that die from EFB do not rope when drawn out with a matchstick.

If you're still unsure about EFB please refer back to the first video, and watch it as many times as you need to, until you're sure you can recognise what it shows.

Inspectors and Advisors use the same testing kit called a Lateral Flow Device (LFD), which is a fancy name for a chromatograph. The test material flows sideways through a medium and, if a line forms at a given point - marked on the container - there is a positive diagnosis. There should always be a blue line as a 'control' - indicating that the kit has worked properly. It is rare for there to be a false positive, although a negative result can be erroneous.

In this video, Max Watkins from Vita Europe demonstrates the LFD.

 I think that's enough for now. The 'what happens next' will follow in another post.


No comments:

Post a Comment