American Foulbrood
Krankheiten
American Foulbrood is a bacterial brood disease caused by Paenibacillus larvae.
American Foulbrood is a bacterial brood disease caused by Paenibacillus larvae. The pathogen forms extraordinarily resistant spores that survive for decades in wax, combs, and honey. Only young larvae are infected, taking up the spores with their food. Adult bees do not fall ill but spread the spores within the colony and between apiaries through robbing, moved combs, shared equipment, or purchased colonies.
In the colony, a patchy, irregular brood pattern is the first thing to stand out. The cell cappings over affected cells are dark, sunken, and often perforated. The dead larva decomposes into a sticky, brown mass. In the matchstick test it can be drawn out of the cell as a stringy thread, which is the most important field sign. Later, the remains dry into a firm, dark scale that sticks tightly to the cell wall and can no longer be removed by the bees. The brood nest often has a strong, glue-like smell.
American Foulbrood is a notifiable animal disease in Germany. Any suspected case must be reported immediately to the responsible veterinary office (Veterinäramt). Once officially confirmed, the area within a radius of at least one kilometer around the affected apiary is declared a restricted zone. There, all apiaries are inspected by the official veterinarian, movable apiaries may not be moved, and colonies, combs, and equipment may not be removed from the sites. Follow-up inspections take place no earlier than two months and no later than nine months later, until the restricted zone is lifted.
Officially recognized sanitation procedures are available: destroying the colonies, the classic artificial swarm method, and the open artificial swarm method. In every case the old combs are melted down or safely disposed of, and hives, frames, and tools are thoroughly cleaned and disinfected, for example with hot soda lye or by flaming. Compensation for colony losses can be applied for through the Animal Disease Fund (Tierseuchenkasse).
Treatment with antibiotics is not a solution: it merely suppresses the symptoms, does not eliminate the spores, and leads to residues in the honey, which is why it is not permitted in beekeeping. Likewise to be avoided are feeding foreign or purchased honey, moving combs between colonies without knowing their health status, and buying colonies without a health certificate (Gesundheitszeugnis). Feed ring tests (Futterkranzproben) serve for early detection, allowing spores to be identified in a colony before clinical symptoms become visible.