Prevalence of bee viruses in Austria in the year 2018

Abstract

Bee viruses pose a considerable risk for the health of honeybee colonies all over the world. In this project we aim to collect representative data for eight bee viruses in Austrian honeybee colonies to identify the most problematic virus species. Additionally, we want to raise the awareness of beekeepers for virus infections and to encourage them to integrate preventive measures into their beekeeping routine. In September 2018, 198 beekeepers sampled bees from five of their colonies and sent the living bees to AGES (Austrian Agency of Health and Food Safety Ltd.) for analysis. Bees were killed by freezing upon arrival and analysed for the presence and virus titer of eight honeybee viruses by quantitative real-time RT-PCR. Six of the eight viruses were detected in the samples. The prevalence varied strongly between the viruses, some of them nearly ubiquitous and others rare. However, the presence of the viruses did not correlate with health status of the colonies. This demonstrates that viruses are widely present in Austrian apiaries as covert infections, as has been described for other European countries. The presence of an infection in a seemingly healthy colony was a new information for many of the participating beekeepers. They were informed about preventive beekeeping measures to avoid an outbreak of an overt virus infection. The project will be continued until 2021, including two additional samplings.