Israeli Acute Paralysis Virus (IAPV) and Deformed Wing Virus (DWV) infection progression in honey bees

Honey bees are often exposed to and infected by multiple viruses, including Israeli Acute Paralysis Virus (IAPV) and Deformed Wing Virus (DWV). However, our ability to understand and model infection and transmission dynamics is hampered by gaps our knowledge about the timeline of virus infection, specifically how virus titers change post-exposure. We hypothesized that, while both viruses are infectious and can result in mortality, each will result in different virus titer dynamics and infection timelines. To test this, we exposed day-old honey bees to IAPV and DWV via carefully-controlled experimental injections and tracked mortality and virus titers. After exposure, bees were maintained in the lab for 10 days and sampled daily for viral titer quantification. Based on previous studies that partially observed these dynamics, we predicted that exposure to IAPV results in a rapid spike in virus titers, followed by either mortality or a decline in titers as bees recover from infection. Similarly, we expected DWV exposure to also result in a sudden spike followed, however, by ongoing elevated DWV titers as survivors tolerate an elevate virus levels. These data help us understand virus infection beyond simply observing the most dramatic pathologies, like deformations or paralysis, and will help us better understand how these pathogens spread and persist within and between honey bee colonies.