New World camelids are sentinels for the presence of Borna disease virus.

Alexandra J Malbon,Aemero Muluneh,Norbert Nowotny,Christian Gerspach,Ralph Kobera,Eva Dervas,Jolanta Kolodziejek,Frank Steffen,Monika Hilbe,Giulia Paternoster,Dietrich Pöhle,Ralf Dürrwald,Christopher Cebra

doi:10.1111/tbed.14003

Abstract

Borna disease (BD), a frequently fatal neurologic disorder caused by Borna disease virus 1 (BoDV-1), has been observed for decades in horses, sheep, and other mammals in certain regions of Europe. The bicoloured white-toothed shrew (Crocidura leucodon) was identified as a persistently infected species involved in virus transmission. Recently, BoDV-1 attracted attention as a cause of fatal encephalitis in humans. Here, we report investigations on BoDV-1-infected llamas from a farm in a BD endemic area of Switzerland, and alpacas from holdings in a region of Germany where BD was last seen in the 1960s but not thereafter. All New World camelids showed apathy and abnormal behaviour, necessitating euthanasia. Histologically, severe non-suppurative meningoencephalitis with neuronal Joest-Degen inclusion bodies was observed. BoDV-1 was confirmed by immunohistology, RT-qPCR, and sequencing in selected animals. Analysis of the llama herd over 20years showed that losses due to clinically suspected BD increased within the last decade. BoDV-1 whole-genome sequences from one Swiss llama and one German alpaca and-for comparison-from one Swiss horse and one German shrew were established. They represent the first published whole-genome sequences of BoDV-1 clusters 1B and 3, respectively. Our analysis suggests that New World camelids may have a role as a sentinel species for BoDV-1 infection, even when symptomatic cases are lacking in other animal species.

Highlights

Borna disease (BD), caused by Borna disease virus 1 (BoDV-1), is a potentially fatal neurological disorder first described in Germany in the 19th century as ‘head disease’ of horses
The name is derived from the district around the city of Borna near Leipzig in Germany where from the 1880s until the 1960s, frequent sporadic cases of meningoencephalitis in horses were seen despite no epidemic occurring in the city itself (Dürrwald & Ludwig, 1997)
Mammalian 2 bornavirus, is represented by variegated squirrel bornavirus 1 (VSBV-1) which was first detected in asymptomatic squirrels and some of their breeders who developed fatal encephalitis (Hoffmann et al, 2015)

Summary

| INTRODUCTION

Borna disease (BD), caused by Borna disease virus 1 (BoDV-1), is a potentially fatal neurological disorder first described in Germany in the 19th century as ‘head disease’ of horses (reviewed by Dürrwald & Ludwig, 1997). BoDV-1 is endemically present in certain areas of Germany, Austria, Switzerland, and The Principality of Liechtenstein In these areas, infected mammals are indicators of its locally restricted distribution. Infected bicoloured white-toothed shrews (Crocidura leucodon) tolerate infection while sporadic cases of fatal neurological disease in higher mammals reveal the local presence of the virus (Dürrwald et al, 2006; Hilbe et al, 2006). We add data to the knowledge on BD in New World camelids by providing results of long-term analysis of clinically suspected BD in a llama herd in an endemic area of Switzerland and from alpacas of different holdings in Saxony in an area dormant for BD over decades

| MATERIAL AND METHODS

Findings

| DISCUSSION