Initial characterization of novel beaked whale morbillivirus in Hawaiian cetaceans

Abstract

Cetacean morbillivirus (CeMV) is a causative factor in epizootics that have resulted in thousands of deaths throughout the Atlantic and Mediterranean since 1987, but less is known of its presence and significance in the Pacific. The first case of CeMV reported in Hawai'i was in a Longman's beaked whale that stranded in 2010. The initial CeMV sequence from this individual indicated the possibility of a novel strain. To address this, archived samples from cetaceans that stranded in Hawai'i between 1997 and 2014 were screened for CeMV. The beaked whale morbillivirus (BWMV) was detected in 15 individuals representing 12 different species (24% of Code 1 and 2 stranded cetaceans). The earliest detected case was a humpback whale that stranded in 1998. Sequence comparisons of a 2.2 kb sequence spanning the phosphoprotein (P) and nucleocapsid (N) genes strongly suggest that the BWMV represents a novel strain of CeMV present in Hawai'i and the Central Pacific. In contrast to recently reported isolates from Brazil and Australia that may represent a distinct clade, BWMV appears to be more closely related to known strains of CeMV (dolphin morbillivirus; porpoise morbillivirus; and pilot whale morbillivirus). Detection rates with repeat sampling of positive lymph nodes were between 2 and 61%, illustrating the extreme heterogeneity that can occur in affected tissues. Taken together, these results suggest that BWMV may be common and established in Hawaiian cetacean populations. BWMV will be important for understanding CeMV and health threats in the relatively understudied cetaceans of the Pacific.

Pathology and causes of death in stranded humpback whales (Megaptera novaeangliae) from Brazil

“…gondii and dolphin morbillivirus infection [ 73 ]. In humpback whales, serological evidence of exposure and RT-PCR CeMV genetic material have been detected in one animal from the Gulf of Maine, US [ 74 ] and one animal from Hawaii [ 75 ], respectively. The recent report of CeMV infection in a Guiana dolphin from the coastal waters of Abrolhos Bank [ 24 ] and recent confirmed cases of toxoplasmosis in Brazil [ 34 ], prompted IHC investigation for these agents.…”

Dolphin Morbillivirus in a Cuvier’s Beaked Whale (Ziphius cavirostris), Italy

“…Until now, DMV infection has not been described as a pathological condition affecting Ziphidae , with the only exception in such context being represented by Beaked Whale Morbillivirus (BWMV), a CeMV strain infecting these species, which has been reported only in the Pacific Ocean ( West et al, 2013 ; Jacob et al, 2016 ). In the Mediterranean Sea, beaked whales were never involved during previous DMV outbreaks ( Van Bressem et al, 2014 ).…”

Neuropathologic Findings in Cetaceans Stranded in Italy (2002–14)

“…Since 1988, at least four species have been classified as being pathogenic for aquatic mammals: cetacean morbillivirus (CeMV), phocine distemper virus, canine distemper virus (CDV), and monk seal morbillivirus. Cetacean morbillivirus includes three main strains-porpoise morbillivirus, dolphin morbillivirus (DMV), and pilot whale morbillivirus-along with the newly characterized CeMV clade members from Hawaii and the southern hemisphere (Di Guardo et al 2005;Van Bressem et al 2014;Jacob et al 2016).…”