Molecular detection of a novel herpesvirus in the stone-curlew (Burhinus oedicnemus) from the Canary Islands

Abstract

Avian herpesviruses (AHVs) are widely distributed and associated with a variety of diseases affecting bird populations globally. Despite the increasing detection of AHVs in recent years, there remains a significant gap in knowledge regarding their classification and host range. This study aimed to detect herpesvirus (HV) in two vulnerable, endemic subspecies of stone-curlew (Burhinus oedicnemus) in the Canary Islands. Forty-six pooled tissue swabs (liver, kidney, and lung) and 135 individual swabs (brain, cloaca, and oropharyngeal cavity) were collected from 50 stone-curlews recorded as deceased wildlife specimens between 2020 and 2023. DNA from a novel alpha-HV was successfully amplified from seven out of the 181 tissue samples (4%) and from four out of 50 birds analysed (8%) using a semi-nested polymerase chain reaction (PCR) approach with degenerate primers. Positive samples were distributed across various tissue types: brain (n = 1), kidney (n = 1), lung (n = 2), coelomic cavity (n = 1), and oropharyngeal swab (n = 2). Some individuals tested positive in multiple tissue types, although no histopathological features indicative of HV infection were observed in any of the birds. Sequencing of all positive samples revealed identical HV nucleotide sequences across all specimens. The longest PCR amplicon, obtained with the TGV and KG1 primer combination, yielded identical sequences in two of the seven positive samples. Based on these findings, we propose the designation of this novel HV as Burhinus oedicnemus alphaherpesvirus.