APV is a 9491 base pair-long RNA virus with a size of 30 nm. The virus has reached all corners of the world.

According to literature, the virus is found mainly in bees, specifically in the salivary glands and in various tissues, such as fat tissue, for example. As long as it stays there and multiplies, the bees remain healthy for the most part and the virus doesn’t cause many problems for the time being.

When the virus gets into the hemolymphs is when it causes problems for the bees. Hemolymphs refer to the body fluid of anthropods. This liquid is a mixture of blood and lymph fluid and serves as a transport for nutrients, as well as regulating body temperature and closing up wounds.

The virus can get into the hemolymphs in one of two ways. One way is by varroa mites carrying the virus. The other way a virus can get into the hemolymphs is if the viruses found in the tissue are able to be carried into the blood due to damage in the tissue caused by the varroa mite.

Proteins in the saliva of mites stimulate the virus to multiply. Through the hemolymphs, the virus can be carried to all of the vital organs, e.g., the heart and lungs.Signs of an APV infection are:
The bees are barely able to move, the body hair falls out and the wings are noticeably shaky. In addition, the sick bees are avoided by the others and are driven away.

The final stage is an early death for the bee. Severe cases of the virus may result in the brood dying out in an early stage. When combined with other diseases, it can mean a collapse of the whole colony.

The disease is spread within the hive through fecal matter, saliva, pollen, spores in the food and, most importantly, the varroa mite. From hive to hive, APV is spread mainly by bees leaving their own hives, by looting, and by the beekeeper himself, for example, through the exchange of honeycombs or cleaning.

Fighting the disease is only possible by keeping the varroa mite population at bay and by cleaning and disinfecting the equipment.