[Chronic bee paralysis virus - quo vadis? Incidence in Bavaria and consideration of therapeutic measures]. / Chronische-Bienenparalyse-Virus ­ quo vadis? Auftreten in Bayern und Betrachtung von Therapiemaßnahmen.

OBJECTIVE: Chronic bee paralysis virus (CBPV), a so far unclassified RNA virus that may cause neurological signs and hairless black syndrome in honey bees, has become increasingly prevalent in various European countries in recent years. The disease occasionally leads to immense losses of worker bees and a significant drop in performance, especially in strong colonies. The aim of this retrospective study was to analyse the spread of CBPV in Bavaria from 2018 to 2020 as well as to evaluate therapeutic measures. MATERIAL AND METHODS: In part 1 of the study, analysis results of the Tiergesundheitsdienst Bayern e. V. (Bavarian Animal Health Service) from 302 bee colonies were examined with regard to virus diagnostics and clinical signs with a focus on CBPV. In part 2, data collected with the help of a questionnaire regarding 105 CBPV-positive and symptomatic colonies were evaluated. RESULTS: In part 1, a significant (p = 0.004) increase in CBPV-positive samples from 2018 to 2020 was detected within Bavaria. In addition, the number of cases with clinical signs also increased during the last 2 years. Part 2 of the study showed a clustering of reports of initial onset of CBPV symptoms during springtime. The colonies mostly with a combination of symptoms recovered from the disease in 57 % of the cases. Therapeutic intervention was one decisive factor. A large number of different combinations of measures led to survival, and a lack of intervention mostly resulted in the death of the colony. In 62 % of the diseased and isolated colonies, isolation prevented further spread in the apiary. CONCLUSION UND CLINICAL RELEVANCE: Based on the results, CBPV occurred more frequently in connection with clinical signs in Bavaria in recent years. Due to the large number of applied combinations of measures, no evidence-based therapy recommendation may be derived based on the current evaluations. However, it has been shown that any therapeutic intervention is superior to withholding treatment. For precise therapy recommendations, trials with treatment under standard conditions are necessary.

Veterinary Diagnostic Approach of Common Virus Diseases in Adult Honeybees.

Veterinarians are educated in prevention, diagnosis and treatment of diseases in various vertebrate species. As they are familiar with multifactorial health problems in single animals as well as in herd health management, their knowledge and skills can be beneficial for the beekeepers and honeybee health. However, in education and in practice, honeybees are not a common species for most veterinarians and the typical veterinary diagnostic methods such as blood sampling or auscultation are not applicable to the superorganism honeybee. Honeybee colonies may be affected by various biotic and abiotic factors. Among the infectious agents, RNA-viruses build the largest group, causing covert and overt infections in honeybee colonies which may lead to colony losses. Veterinarians could and should play a more substantial role in managing honeybee health-not limited to cases of notifiable diseases and official hygiene controls. This review discusses the veterinary diagnostic approach to adult bee examination with a special focus on diagnosis and differential diagnosis of the common virus diseases Acute Bee Paralysis Virus (ABPV)-Kashmir Bee Virus (KBV)-Israeli Acute Paralysis Virus (IAPV)-Complex, Chronic Bee Paralysis Virus (CBPV) and Deformed Wing Virus (DWV), as well as coinfections like Varroa spp. and Nosema spp.

Overt Infection with Chronic Bee Paralysis Virus (CBPV) in Two Honey Bee Colonies.

Chronic Bee Paralysis Virus (CBPV), a widespread honey bee RNA virus, causes massive worker bee losses, mostly in strong colonies. Two different syndromes, with paralysis, ataxia and flight incapacity on one hand and black hairless individuals with shortened abdomens on the other, can affect a colony simultaneously. This case report presents two Apis mellifera carnica colonies with symptoms of paralysis and hairless black syndrome in 2019. Via RT-PCR, a highly positive result for CBPV was detected in both samples. Further problems, such as a Nosema infection and Varroa infestation, were present in these colonies. Therapy methods were applied to colony 1 comprising queen replacement, shook swarm method and Varroa control, whereas colony 2 was asphyxiated after queen loss and colony weakening. After therapy, colony 1 was wintered without symptoms. Beekeeping and sanitary measures can save a CBPV-infected colony, while further complications result in total colony loss.