Affected hosts
- Apis mellifera
Infection by Paenibacillus larvae
American foulbrood
Severe bacterial brood disease caused by highly resistant spores of Paenibacillus larvae. It can persist for long periods in contaminated equipment.
Agent
Paenibacillus larvae
Legal status
Yes
Signs and symptoms
Brood
- Irregular brood pattern
- Dark, sunken, or perforated cappings
- Brown larvae in decomposition
- Scales adhering to the cells
Colony
- Progressive weakening
- Abnormal odor in some cases
Diagnosis and confirmation
Field methods
- Brood inspection
- Ropiness test as a field indicator, not conclusive
Laboratory methods
- Culture, PCR, or other validated laboratory methods
Control and prevention
Good practices
- Isolate the suspected colony
- Do not move hives or material
- Contact veterinary services or the competent sanitary organization
- Disinfect or destroy material according to official instructions
Prevention
- Buy colonies from known sources
- Do not feed honey from unknown origin
- Disinfect tools
- Avoid indiscriminate exchange of frames
Monitoring
Indicators
- Brood pattern
- Abnormal cappings
- Altered larvae
- Scales
Frequency
- During brood inspections