Norovirus Infection in Harbor Porpoises

Abstract

A norovirus was detected in harbor porpoises, a previously unknown host for norovirus. This norovirus had low similarity to any known norovirus. Viral RNA was detected primarily in intestinal tissue, and specific serum antibodies were detected in 8 (24%) of 34 harbor porpoises from the North Sea.

Keywords: Norovirus; Phocoena phocoena; genotype GI; intestine; marine mammals; porpoise; viruses; zoonoses.

Figure 1

Genetic characterization of harbor porpoise norovirus. A) Genome organization of harbor porpoise norovirus. The putative cleavage sites are shown with arrowheads. B, C) Maximum-likelihood trees of the RNA-dependent RNA-polymerase (B) and ORF 2 (C) were inferred by PhyML 3.0 software (http://www.atgc-montpellier.fr/phyml/) by using the general time reversible nucleotide substitution model. Selected bootstrap values >70 are depicted. Scale bars indicate nucleotide substitutions per site. NS, nonstructural; NTPase, nucleoside triphosphatase; ORF, open reading frame; P, protein; Pol, polymerase; Pro, protease; VP, viral protein.

Figure 2

Detection of harbor porpoise norovirus transcripts in intestinal tissue of a harbor porpoise (Phocoena phocoena) using in situ hybridization with probes designed by Advanced Cell Diagnostics (Hayward, CA, USA), based on the 6,293 nt of harbor porpoise norovirus (A, C, E; original magnification ×40, ×100, ×100, respectively). Consecutive slides were stained with hematoxylin and eosin (B, D; original magnification ×40, ×100, respectively) and pankeratin (F, original magnification ×100), as described previously (11).