> We have taken samples of honey from individual beekeepers (N = 64), and of domestic (N = 35) and imported honey (N = 15) retailed in supermarkets in several sub-Saharan countries and cultivated these samples for Paenibacillus larvae 

> Swedish honey frequently contains P. larvae subsp. larvae spores although the general level of visibly infected bee colonies is low (roughly 0.5%). The results suggest that large parts of Africa may be free from American foulbrood. Behavioral studies (hygienic behavior) on Apis mellifera subsp. scutellata Lepeletier in Zimbabwe suggest that hygienic behavior of African bees could influence the apparent low level, or even absence of American foulbrood in large parts of Africa.

> at least five aspects may contribute to the absence of American foulbrood in sub-Saharan Africa. First, the reaction of African honey bee colonies to disturbance or rapid environmental changes in food availability may inßuence the level of detectable disease. 

> Second, the comparatively primitive beekeeping practiced in much of Africa may help prevent the establishment of American foulbrood in such regions. Third, hygienic behavior and physiological suscep- tibility of the bees may inßuence the incidence of the disease. Fourth: Mortality of treated Africanized larvae was lower than that of European larvae (Danka and Villa 1994).

> Finally, imported honey contaminated with American foulbrood spores may not substantially increase the risk of establishing the disease into uninfected honey bee populations. Large spore doses, often several billion spores, are required to produce disease symptoms when honey is fed to disease free colonies

Source: Journal of Economic Entomology, 96(6):1641-1646. 2003.

* * *

> Although this disease was identified >100 years ago, it still plagues beekeeping in the EU. On a global scale, antibiotic treatment for AFB is standard, although less common in Europe. Employing selection for resistant honeybee strains has had pri- ority in breeding work for many years, as has the disruption of infection pathways as tools to develop contamination-free remedy schemes. Clearly, the prime goal is to make antibiotic treatments obsolete.

> Although there is wide variation in virulence between P. larvae strains, the most virulent strains at the individual larval level are the least virulent strains at the colony level (Genersch et al., 2005), since the larvae die and are removed by hygienic behaviour before spore production can be maximised. 

Apidologie 41 (2010) 227–242

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