Outbreak of rabbit hemorrhagic disease virus 2 in the southwestern United States: first detections in southern California

Abstract

An outbreak of rabbit hemorrhagic disease virus 2 (RHDV-2)-associated disease occurred in the southwestern United States following its first detection in New Mexico in March 2020. The disease spread throughout several states and was diagnosed for the first time in California on May 11, 2020, in a black-tailed jackrabbit ( Lepus californicus). The following day, the California Department of Food and Agriculture (CDFA) issued an order banning the entrance into California of several lagomorph species and their products from any state in which the disease had been detected in the last 12 mo. RHDV-2 is a threat to wild lagomorph species in California, including the endangered riparian brush rabbit ( Sylvilagus bachmani riparius). Therefore, the California Department of Fish and Wildlife (CDFW) started tracking any mortality event in wild lagomorph populations. As of August 9, 2020, RHDV-2 had been detected in wild and domestic lagomorphs of several counties in southern California that were submitted to the California Animal Health and Food Safety laboratory system by the CDFA or the CDFW. These positive cases included 2 additional black-tailed jackrabbits and 3 desert cottontail rabbits ( Sylvilagus audubonii). In addition, the infection spilled over to domestic populations, whereby it was confirmed on July 10, 2020, in a domestic rabbit ( Oryctolagus cuniculus).

Viral Disease in Lagomorphs: A Molecular Perspective

“…Reports of substantial outbreaks in the absence of local rabbit populations in Sweden demonstrate potential hare-to-hare transmission of RHDV GI.2 [215]. Wide spread deaths in different lagomorph species have also been reported from across the USA ( [216] and news article therein) including black-tailed jackrabbit (Lepus californicus) and desert cottontail rabbits (Sylvilagus audubonii) [217]. Therefore, RHDV GI.2 exhibits a broader host range than classical RHDV (GI.1) by infecting not only different rabbit species but also different hare species (Lepus capensis mediterraneus, Lepus corsicanus, Lepus europaeus, and Lepus timidus).…”

Development and Evaluation of a Duplex Lateral Flow Assay for the Detection and Differentiation between Rabbit Haemorrhagic Disease Virus Lagovirus europaeus/GI.1 and /GI.2

“…), several cottontail rabbit species (Sylvilagus spp.) and other native American lagomorphs, in which it produces similar lesions [11][12][13][14][15][16][17][18]. It has also been identified in some non-lagomorphs [19,20].…”

Rabbit Haemorrhagic Disease Virus 2 (RHDV2; GI.2) in Ireland Focusing on Wild Irish Hares (Lepus timidus hibernicus): An Overview of the First Outbreaks and Contextual Review

“…mediterraneus ), Iberian ( L. granatensis ) and Italian ( L. corsicanus ) hares, black-tailed jackrabbit ( L. californicus ), and antelope jackrabbit ( L. alleni ) [ 9 , 10 , 11 , 12 , 13 , 14 ]. RHDV2 has been reported to infect several Sylvilagus (cottontail) species also, including eastern ( S. floridanus ) , desert ( S. audubonii ), and mountain ( S. nuttallii ) cottontails [ 13 , 15 , 16 ]. The GI.1/RHDV1 affects adult lagomorphs only, however, GI.2/RHDV2 viral infection has been shown to kill kits (as young as 11 days) as well as adults [ 1 , 3 , 10 ].…”