European Foulbrood

The European Foulbrood is a honey bee disease caused by a bacterium known under the name of Melissococcus pluton. The disease manifests itself mostly in spring when the queen bee lays the most eggs during a year. However, the first brood generation is no affected. The European Foulbrood can emerge out of the blue and causes lots of damages to apiaries. Other times the disease develops quite slowly with few victims. The infection subsides by the middle of the summer season but there are cases when the disease makes its presence felt in autumn as well. If the bee family is not strong enough, infestation with European Foulbrood might lead to its extinction.

The disease is spread by means of food. The nurse bees give the infested food to the young larvae and thus the bacterium enters the larva's organism. Here it multiplies extremely fats in the gut and midgut area. The infected larvae die very fast - in about four days after hatching. The larva usually dies before the worker bees cap the comb cell. If the larva has enough food than the young larva might manage to turn into an adult honey bee.

The bacterium is spread in the hive by the house bees that clean up the cells of the dead infested larvae. There are researchers who claim that the disease can also be spread by Varroa Destrutor. The disease is spread from hive to hive through infested beekeeping tools, infested honey and pollen, robber and drifting bees and by placing infested combs inside healthy hives.

It is important not to confuse the European Foulbrood with the American Foulbrood disease. In spite their similar names the two diseases are caused by different bacteria, they present different symptoms and require different prevention and treatment methods. Unlike the bacterium that cause the AFB, the bacteria responsible for EFB does not have spores. However, the combs that have already been infested have the power to infect bee families year after year.


The combs affected by the European Foulbrood are quite uniform in aspect since their cells are not capped. If the brood has a spotty pattern then EFB infestation should be taken into consideration. The bee larvae affected by this disease are restless and they die in a twisted position inside their cells. The tracheal tubes can be better observed in EFB infected individuals. The dead larvae look melted and have a color that ranges from yellow to brown. The larvae that have dried make brown scales that are loosely glued to the cell wall. The cells are also filled with remains that are quite ropey and have a length of about 1.5 cm or lees. The small of the dying and dead larva is not pleasant at all; it can either be sour or it can be absent.

The larvae that manage to outcome the infection turn into adult honey bees that are smaller and lighter than the uninfected individuals. It has been observed that if they have enough food the EFB infested individuals manage to survive and reach adulthood. This fact might provide an explanation for the fact that the disease does not manifest itself the same every year or from one season to another. The damages caused by EFB depend a lot on the number of larvae and nurse honey bees within a hive.


The only chemical medication recommended in the treatment of bee families that have been infested with European Foulbrood is the antibiotic known as oxytetracycline. There are various products that contain this antibiotic and which can be bought from registered suppliers.

In order to avoid the presence of antibiotics in honey, the oxytetracycline must be given to the infected families eight weeks before any honey harvesting. It is important to remove any extra honey before starting the medication administration. Lots of beekeepers provide antibiotics only to the bee families that display evident signs of European Foulbrood infestation. All bee families should be administered antibiotics if around ten percent of the hives in an apiary display symptoms of EFB. It is advisable to mark the hives that have been given antibiotics so as not harvest their honey. There are countries in which the law asks the beekeepers to burn down the infested hives and bee families.


In case of severe infestation the antibiotic treatment is the only solution available. However, most beekeepers do not like this practice since the antibiotics might ruin the honey purity and the EFB bacterium develops a certain resistance to antibiotics. Thus, it is better to prevent than to treat.

One very effective measure is the hive re-queening. A young queen is healthier and stronger than an old queen. The hygiene of hives is extremely important to prevent any bee disease not only European Foulbrood. The brood combs should be replaced on a regular basis so as to reduce the number of bacteria that cause the disease. Moving bees from one place to another, causes a lot of stress for both bees and beekeeper. If the bees are moved in closed hives an additional stress is added to them. Honey bees that have been moved recently can present symptoms of European Foulbrood.

Honey bee disease > Acarine mites > Acute bee paralysis virus > American Foulbrood > Black Queen Cell Virus > Bee louse> Chalkbrood > Chilled Brood > Chronic Bee Paralysis Virus > Cloudy wing virus > Colony Collapse Disorder > Deformed Wing Virus > Bee Dysentery > European Foulbrood > Israelii acute paralysis virus > Kashmir Bee Virus > Nosema > Sacbrood virus > Bee septicemia > Stonebrood > Varroa Mite >

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