Dr John Haycock

Elephant endotheliotropic herpesvirus-1 (EEHV-1) is one of the major causes of fatality in juvenile Asian elephants (Elephas maximus). On occasions, other EEHV genotypes, i.e. EEHV-3, -4 and -5, have also been reported as the cause of Asian elephant deaths. In this case report we describe the investigation into a juvenile Asian elephant fatality in a European zoo. A fatal case of haemorrhagic disease in a juvenile Asian elephant from a European zoo was diagnosed with co-infection of EEHV-1 and -4. EEHV-4 had a wider organ distribution and a higher viral load; both viruses presented the highest load in the mesenteric lymph nodes. Detection of EEHV-4 in this fatal case in Europe underlines the importance of inclusion of all known Asian EEHVs in routine blood monitoring to facilitate early therapeutic intervention.

Lancing a finger elicits minimal pain in humans and is applied routinely to obtain small volumes of blood for clinical diagnostics. A modified lancet bleeding method and several blood sampling matrices were evaluated in this study for the purpose of routine elephant endotheliotropic herpesvirus (EEHV) surveillance in Asian elephants (Elephas maximus). The procedure enabled weekly sampling from elephants as young as 9 mo of age. The blood sampling matrices were evaluated for their sensitivity measuring β-actin, tumor necrosis factor α, and/or EEHV-1 by quantitative polymerase chain reaction assays. Foam and flocked swabs produced significantly (P < 0.05) lower quantitation cycles, ie, increased analytical sensitivity, than filter papers, Whatman® FTA cards, or conventional cotton-tipped swabs. The two swab types also demonstrated comparable analytical sensitivity to that of a similar volume of EDTA whole blood for the detection of EEHV-1 DNA. This lancet-and-swab technique proved satisfactory for the detection of EEHV-1 viremia in two Asian elephant calves, and in one instance viremia could be detected 5 days prior to the development of clinical signs. Low blood yield from the lancet application may reduce sensitivity and compromise early detection of viremia. Therefore, standard venipuncture remains the recommended blood sampling method, and training for consistent and regular vein access should continue to be the priority for collections holding elephants. However, if appropriate measures are taken to collect an optimum blood volume, this lancet-and-swab technique offers a suitable alternative for EEHV surveillance in situations where venipuncture may not be practical.