There are two kinds of foul brood
Foul Brood is a term used to describe two diseases of honey bee larvae, American Foul Brood (AFB), and European Foul Brood (EFB). They are unrelated and of no geographical significance other than these were the areas where they were first scientifically investigated. Until 1906 the two diseases were both referred to simply as "Foul Brood", when Everett Franklin Phillips separated them, by referring to them as "American" and "European".
I have read a number of accounts of "Foul Brood" in colonies in the U.K. in the latter part of the 19th and early part of the 20th centuries. Some of the incidents are so high that I can't help thinking that many may have simply been chalk brood, especially as it can often look a bit like EFB. At that time the recommended treatment for Foul Brood varied, including the use of household disinfectant, suggesting to me that Foul Brood wasn't always correctly identified.
In England and Wales they are both notifiable and there is an inspection service that is considered to be one of the best in the world.
All beekeepers need to be able to recognise both diseases which are both killers of colonies. They are both relatively uncommon, which means many beekeepers will never see them. This is the danger, as they aren't always recognised by the beekeeper, and may be a source of infection for some time until the Bee Inspector discovers it.
It is my view that local BKAs should make every effort to educate their members and have Foul Brood recognition events, which can be done in conjunction with the Bee Inspection Service.
It is also my view that every time a colony is inspected, the first frame that is removed from each colony that has brood in all stages should have the bees shaken off it and checked for foul brood. It has become a habit with me and I teach others to do the same.
In teaching and demonstrating beekeeping I try to point out that beekeepers should know what healthy brood looks like. If there appears to be anything wrong with it, there usually is. It may be only a minor problem, but it could be serious. It is important that beekeepers know and can recognise all the options, as some diseases can look a bit like others.
Foul Brood can hit any beekeeper at any time, there is nobody who is free of the threat. Some beekeepers blame bad beekeeping practices of others, but even those who perform the strictest apiary hygiene are just as likely to get it. In 2010 I was involved with three teaching situations where foul brood was discovered. In each case, those who were teaching beekeeping had missed it. I won't identify the locations, but to show how easy it is to miss I will just give the circumstances:-
In addition to the above at least two adjoining BKAs to me have had foul brood, one insisted on disposable gloves being worn and when I visited them they had a footbath - but they still got it.
I have heard it said on more than one occasion that if you practice apiary hygiene and sterilise everything between colonies you won't get foul brood. What twaddle! All this does is to get beekeepers to think they are safe, so they don't have to look.
Both foul broods can be confirmed in the field by the Bee Inspector with what is called a "Lateral Flow Device" (LFD). These are sold by equipment suppliers, but I would advise caution when using them. There is a fairly short shelf life and they have to be used correctly, otherwise they can give a negative result on a positive sample. Read the instructions carefully.
In some regions EFB and AFB are notifiable diseases and should be dealt with by the Bee Inspector. You may see reference to treatments in other countries, but the sensible thing to do is to contact the Bee Inspector and let them deal with it.
This foul brood page is not intended to give much information, but to signpost you to the real experts, the National Bee Unit. Their information will be as good as you will get and up to date. There is no point in me repeating it.