Israeli Acute Paralysis Virus

Israeli acute paralysis virus (IAPV) is a widespread RNA virus of honey bees which has been linked with colony collapse disorder. IAPV was found to be the third most common virus infection in bee colonies after DWV and Black Queen Cell Virus (BQCV). IAPV attacks every stage and caste of honey bees and causes systemic infection in honey bees.

IAPV was first identified in 2004 and is closely related to viruses from the Family Dicistroviridae. A recent study showed that Varroa mites can also serve as vectors of IAPV; furthermore, the mite/virus association was shown to reduce host immunity and promote elevated levels of IAPV replication.

The infection rate of IAPV in adult bees in weak colonies increases from spring to summer and fall and peaks in the winter. Recent research indicates that for both strong and weak colonies, the prevalence of IAPV infection in the brood was found to be significantly higher than in adult bees. When honey bees live under stressful conditions such as Varroa mite infestation and overwintering stress, the virus replicates quickly and becomes more infectious, leading to the death of hosts and possible collapse of the colony.


IAPV is transmitted to bees through both horizontal and vertical pathways. Royal jelly, along with nectars shared among adult workers, thus provide an important route for viral movement within the colony.