In the absence of mites the virus is thought to persist in the bee populations as a covert infection, transmitted orally between adults (nurse bees) since the virus can be detected in hypopharyngeal secretions (royal jelly) and broodfood and also vertically through the queen's ovaries and through drone sperm. The virus may replicate in the mite but this is not certain.
In the absence of parasites, the virus is thought to persist within bee populations as a concealed infection, transmitted orally among adults (nurse bees) since the virus can be found in saliva (royal jelly), food for young, and also vertically through the queen's reproductive organs and drone sperm. The virus may multiply inside ticks but this has not been proven.