Acute bee paralysis virus, ABPV

Acute Bee Paralysis Virus Complex

Acute bee paralysis virus (ABPV), Kashmir bee virus (KBV), and Israel acute paralysis virus (IAPV) are a complex of associated viruses with similar transmission routes and affect similar life stages. These viruses are widespread at low titers and can quickly develop high titers due to extremely virulent pathology. Frequently associated with colony loss, this virus complex is especially deadly when colonies are heavily infested with Varroa mites. (Ball 1989; Genersch 2010, Genersh et al. 2010). These viruses have not been shown to cause symptoms in larval life stages, but show quick mortality in pupae and adult bees.

Acute Bee Paralysis Virus (ABPV)

Acute bee paralysis virus was accidentally discovered when CBPV was first isolated. ABPV displays similar symptoms as CBPV however the acute adjective describes a bees’ more rapid mortality compared to CBPV. Unlike CBPV, ABPV virulence is directly related to Varroa infestation. APBV is transmitted in larval jelly from asymptomatic infected adult bees to developing larva or when vectored by Varroa mites to larvae and pupae. ABPV is common and typically cause covert infections (no obvious symptoms) when transmitted orally from adult to developing bee. It takes about one billion viral particles to cause death via ingestion, but when vectored by Varroa and directly injected into the developing bee’s hemolymph, only 100 virus particles will cause death (Genersch & Aubert 2010). When the virus is picked up by Varroa, the transmission rate to pupae is between 50 and 90 percent. The longer the feeding period of Varroa, the greater the transmission rate will become. (Genersch & Aubert 2010). Pupae infected with ABPV die before emerging, making the appearance of paralysis symptoms less obvious. The decline in emerging bees causes a colony to dwindle towards collapse. A colony infected with an ABPV epidemic will die within one season (Sumpter and Martin 2004).