European foulbrood
Introduction
European Foulbrood (EFB) is a serious bacterial disease of honeybee brood caused by several agents, the main being the bacterium Melissococcus plutonis. Incidences of EFB are increasing although it is not yet thought as serious as American Foulbrood. However, the two diseases are easily confused and misdiagnosed.
European Foulbrood occurs most frequently in the spring or early summer during brood rearing and is thought to be caused by stress in the colony and lack of pollen.
Symptoms can be variable which makes EFB difficult to identify with certainty; frequently disappearing when there is a nectar flow. But EFB can seriously affect brood development and needs to be identified as soon as possible.
In the UK, around 50% of EFB-infected colonies per year are destroyed, with costs to beekeepers also imposed by standstill notices on infected apiaries (in place for years in some areas) and losses of honey yields, pollination contracts and sale of bees.
Figure 1
Detection
Early detection is essential because just one infected cell can lead to the destruction of an entire apiary. In colonies infected with either European or American Foulbrood the brood pattern can appear very patchy and irregular (sometimes termed 'pepper-pot') in distribution. [Fig 1]
Unlike with AFB, cadavers of EFB infested larvae cannot be stretched (or 'roped out') with a matchstick or similar instrument.
European Foulbrood can be identified by costly and time consuming laboratory tests but perhaps the best, and easiest, method is to use Vita's EFB Diagnostic Kit - a simple to use field kit that gives a clear result in just three minutes.
Prevention
Since stresses on the colony can be a contributing factor to infestation, these should be removed wherever possible. It is vital to ensure that all equipment is properly sterilised between colonies and, particularly, between apiaries, to reduce risk of disease transfer.
Treatment
European Foulbrood can be controlled by the use of antibiotics but this can leave residues in wax and honey and is banned in many European countries.