Of all the diseases that attack the honeybee, the most destructive is American foulbrood. This disease attacks the developing bee— the “brood.”
American foulbrood has been known for centuries. But even so, it continues to kill bees. Many beekeepers don’t recognize the disease or know how to fight it.
Complete eradication of American foulbrood is impossible, but proper control measures can keep it at a minimum. Every beekeeper, therefore, should know its signs and its control so that he can attack the disease in its early stages.
Foulbrood starts in a small way in a colony. If not checked, it continues until it destroys the entire colony.
The colony dies because few young bees are produced to maintain the adult population. Even with the death of a colony a beekeeper may not learn the cause is foulbrood. These colony deaths are often blamed on winterkilling and wax moth.
Paddock, F. B.
"Control of American foulbrood,"
Bulletin P: Vol. 4
, Article 1.
Available at: http://lib.dr.iastate.edu/bulletinp/vol4/iss105/1