Systematic Determination of Herpesvirus in Free-Ranging Cetaceans Stranded in the Western Mediterranean: Tissue Tropism and Associated Lesions

Abstract

The monitoring of herpesvirus infection provides useful information when assessing marine mammals’ health. This paper shows the prevalence of herpesvirus infection (80.85%) in 47 cetaceans stranded on the coast of the Valencian Community, Spain. Of the 966 tissues evaluated, 121 tested positive when employing nested-PCR (12.53%). The largest proportion of herpesvirus-positive tissue samples was in the reproductive system, nervous system, and tegument. Herpesvirus was more prevalent in females, juveniles, and calves. More than half the DNA PCR positive tissues contained herpesvirus RNA, indicating the presence of actively replicating virus. This RNA was most frequently found in neonates. Fourteen unique sequences were identified. Most amplified sequences belonged to the Gammaherpesvirinae subfamily, but a greater variation was found in Alphaherpesvirinae sequences. This is the first report of systematic herpesvirus DNA and RNA determination in free-ranging cetaceans. Nine (19.14%) were infected with cetacean morbillivirus and all of them (100%) were coinfected with herpesvirus. Lesions similar to those caused by herpesvirus in other species were observed, mainly in the skin, upper digestive tract, genitalia, and central nervous system. Other lesions were also attributable to concomitant etiologies or were nonspecific. It is necessary to investigate the possible role of herpesvirus infection in those cases.

Neuropathological Characterization of Dolphin Morbillivirus Infection in Cetaceans Stranded in Italy

“…CNS damage has been confirmed in association with αHV [ 52 , 53 , 54 ], and lesions typically referable to the infection are consistent with non-suppurative meningoencephalitis. Identifying the pathogenic role of ˠHV is more difficult, since the association between encephalitis and meningoencephalitis and ˠHV infection was first established in 2021 [ 55 ] in 8 animals and in one more with co-infection with αHV. Since the pathological changes observed in 2 animals with ˠHV co-infection (ID 11 and 20) closely matched the lesions characteristic for DMV, a specific role for ˠHV in the neuropathogenesis of these lesions cannot be confirmed or ruled out.…”

Brucella ceti Infection in Striped Dolphins from Italian Seas: Associated Lesions and Epidemiological Data

“…and CeMV [ 21 , 71 , 74 ] or T. gondii [ 18 , 23 ]. Moreover, co-infection with Herpesvirus (HV) was also detected in three cases [ 71 , 75 ].…”

“…A potential pathogenic role could have also been played by Herpesvirus in one of the cases of co-infection detected, specifically in Case 21, where classical CNS lesions associated with the presence of alphaherpesviruses [ 19 , 71 , 75 , 76 , 77 , 78 ], represented by neuronal necrosis, were detected. On the other hand, the absence of HV antigens in the CNS of the other two cases (Cases 17 and 22), and the absence of specific lesions in HV-positive tissues or the evidence of systemic infections [ 79 , 80 , 81 ], make the role of HV infection uncertain.…”

Discovery of the first PD-1 ligand encoded by a pathogen

“…Members of the γ-herpesvirinae subfamily, such as Epstein-Barr (EBV) or Kaposi sarcoma-associated herpesvirus (KHSV), are implicated in multiple human malignancies, including a variety of lymphoproliferative and neoplastic disorders. However, nothing is known about the potential role of cetacean γ-herpesvirus encoded proteins in the development of tumors ( 37 , 38 ). Interestingly, TTGHV1 was isolated from a proliferative cutaneous lesion of a lactating female bottlenose dolphin ( 39 ).…”