Prevalence of seven viruses in Africanized honey bees in Costa Rica

Apis mellifera bees can be infected by a multitude of parasites and pathogens that may cause colony losses. Among these pathogens, viruses are one of the main threats to the bees' health and well-being. This study aimed to determine the prevalence of 7 viruses in adult bees by real-time PCR in two descriptive cross-sectional studies; the first survey was carried out in 2011 during the rainy season and the second survey from March 2013 to February 2014 during the rainy (May to October) and dry seasons (November to April) in two regions of Costa Rica where most of the beekeeping activity is concentrated. Most viruses had a higher prevalence in 2013-2014 compared to 2011, however, CBPV went from 37% to 3% and KBV from 7% to 1%, both significantly (p-value < 0.05). DWV, BQCV, SBV, and ABPV had at least 10 times higher odds to be present in an apiary in 2013-2014 compared to 2011. IAPV showed identical prevalences in both time periods. Significant statistical differences in the virus prevalences were observed when seasons, regions, and years were compared.