The American Foulbrood (aka "Vicious Foulbrood")
This highly contagious disease is harmless to adult bees and humans, and honey is in no way endangered. However, the brood cells in the bee colony are fatally affected. The cause is a bacterium that forms spores that spread rapidly and lead to the death of the brood. Because of the high risk of infection for other bee colonies, foul brood is notifiable.
The European foulbrood (also called "benign foulbrood")
This is also a bacterial disease, but the pathogen is less resistant and only larvae less than 48 hours old are affected. The hive bees usually recognize sick bees themselves and dispose of them. Although this type of foulbrood is less dangerous and also less contagious, a reporting obligation applies here as well. However, the bee colonies are often able to rid themselves of this disease.