Dolphin Morbillivirus and Toxoplasma gondii coinfection in a Mediterranean fin whale (Balaenoptera physalus)

On January 2011 an adult male of fin whale (Balaenoptera physalus) stranded along the Tyrrhenian coastline of Italy. During necropsy, tissue samples from heart, skeletal muscle, mesenteric lymph nodes, liver, spleen, lung, and kidney were collected and subsequently analyzed for Morbillivirus and Toxoplasma gondii by microscopic and molecular methods. Following the detailed necropsy carried out on this whale, molecular analysis revealed, for the first time, the simultaneous presence of a Dolphin Morbillivirus (DMV) and T. gondii infection coexisting with each other, along with high organochlorine pollutant concentrations, with special reference to DDT.This report, besides confirming the possibility for Mysticetes to be infected with DMV, highlights the risk of toxoplasmosis in sea water for mammals, already immunodepressed by concurrent factors as infections and environmental contaminants.Among the several threats to which free-ranging cetaceans are exposed, Morbillivirus and Toxoplasma gondii are believed to represent a serious hazard to their health and conservation [1]. Nevertheless, morbilliviral infections have been rarely described in mysticetes [2-4], while T. gondii has been also reported as a disease-causing protozoan agent in immunocompromised Odontocetes [5,6] affected by a severe meningo-encephalitis, as recently documented in the Mediterranean striped dolphin (Stenella coeruleoalba) population [7].An adult male fin whale (Balaenoptera physalus) was found stranded dead (length: 16.7 m; estimated weight: 25,000 kg) on January 25, 2011 (Figure 1A). Using a photo-identification method, the animal matched with one whale that was observed swimming slowly in shallow waters, in front of the coast of Tuscany (Tyrrhenian Sea), Italy, close to the cost of Follonica (GR) on January 16, 2011, as well as in front of the tourist port of Viareggio (PI) on January 23, 80 km north of the first sighting area. A detailed post-mortem examination was performed on site (43°44'