Malignant catarrhal fever: An emerging yet neglected disease in captive sika deer ( Cervus nippon ) herds in China

Abstract

Malignant catarrhal fever (MCF) is a fatal lymphoproliferative disease that represents a serious problem in the deer‐rearing industry. To better understand an MCF‐like disease that has emerged in northern China since 2015, we investigated ten cases by documenting clinical and epidemiological data and analysing causative agents and histopathological changes. In addition, a retrospective screen for Macavirus DNA and a questionnaire‐based survey were conducted. Epizootic MCF in Chinese sika deer herds has emerged with a low morbidity of 3.8% (95% CI: 2.5%–5.1%) and a high mortality of 93.2% (95% CI: 86.6%–99.9%). The disease course varied from 3 to 12 days. Aetiologically, OvHV‐2 was predominant in the MCFV, accounting for most MCF cases (21/23). In contrast, only two CpHV‐2 isolates were phylogenetically closely related to CpHV‐2. Diarrhoea and nasal discharges were the most frequent manifestations, although clinical signs varied in some cases. Pathologically typical lesions of haemorrhage, necrosis and lymphoid cell infiltration were readily observed in a variety of organs. Vasculitis caused by vascular and perivascular lymphoid cell infiltration was common. The retrospective survey suggested a low positive rate (3/275) of MCFV DNA in peripheral blood lymphocytes (PBL). The questionnaire‐based survey suggested the disease was neglected by local veterinarians, who did not acknowledge the risk of co‐rearing deer with reservoir species. Collectively, the emerging epizootic MCF in Chinese sika deer herds remains neglected, emphasizing the urgency of initiating full‐field diagnoses and control strategies.

Molecular survey of selected viruses in Pudus ( Pudu puda ) in Chile revealing first identification of caprine herpesvirus—2 (CpHV-2) in South American ungulates

“… 2013 ; Zhu et al. 2020 ). In contrast, CpHV-2 infections have been reported in six deer species, but some authors described that the virus is well adapted to this family (Zhu et al.…”

“…In contrast, CpHV-2 infections have been reported in six deer species, but some authors described that the virus is well adapted to this family (Zhu et al. 2020 ), because of the lack of acute infectious presentations. Although three of the four Pudus that tested positive for CpHV-2 died acutely between 1 and 3 days after sampling within this study, we lack scientific evidence to confirm that MCF generated by CpHV-2 was the cause of death.…”

Molecular and phylogenetic analysis of herpesviruses in endangered free-ranging cervids of Chile: ovine gammaherpesvirus-2—A novel threat to wild and domestic animal health in Chilean Patagonia

“…Previous molecular surveys of herpesvirus in cervid species showed variable levels of occurrence, ranging from 0.01% of ovine gammaherpesvirus-2 in sika deer ( Cervus nippon ) ( 19 ) in China to 4.7% of Elk gammaherpesvirus in Javan rusa ( Rusa timorensis ) in the USA ( 20 ). Both studies were conducted on animals under human care.…”

“…The occurrence of pudu gammaherpesvirus-1 in free-ranging huemuls in Torres del Paine National Park and in pudus of Chiloe, an island located ∼1,100 km to the north, suggests that the detected virus circulates in Chilean wild deer despite the distance and geographic barriers between populations. Previous molecular surveys of herpesvirus in cervid species showed variable levels of occurrence, ranging from 0.01% ovine gammaherpesvirus-2 in sika deer (Cervus nippon) (19) in China to 4.7% of Elk gammaherpesvirus in Javan rusa (Rusa timorensis) in the USA (20). Both studies were conducted on animals under human care.…”

“…Although herpesviruses have been widely investigated, little is known about herpesvirus prevalence and host specificity in cervid species in wild environments. Indeed, to date, most of the reports come from populations under human care (18)(19)(20)(21). In Chile, caprine gammaherpesvirus-2 was recently reported in southern pudus (Pudu puda) from a zoological collection (or zoo), possibly associated with an MCF outbreak (22).…”