A female, neonate sperm whale (335 cm long) stranded alive near Laie, Hawaii in May of 2011 and died shortly after stranding on the beach. The calf was estimated to be less than 48 hours old based on the fresh condition of the umbilicus. Congestion of the cerebrum and prominent lymph nodes (tracheobronchial, scapular and mesenteric) were noted on gross necropsy. Pathologic findings indicated chronic inflammation in utero, with evidence of meningitis and pneumonia. Cerebrum, lung, umbilicus and select lymph nodes (tracheobronchial and mediastinal) were tested for Brucella by PCR. Sequences of approximately 3000 bp each were amplified from the tracheobronchial lymph node, mediastinal lymph node and the lung, which were most similar to marine Brucella sp. Brucella sp. isolates were also obtained from culture of the cerebrum and the mediastinal and tracheobronchial lymph nodes. Due to the recent discovery of morbillivirus in the central Pacific in a stranded Longman's beaked whale in 2010, 12 different frozen tissues from this neonate sperm whale were screened for cetacean morbillivirus by PCR. Cetacean morbillivirus was detected only in the tracheobronchial lymph node by the presence of an approximately 429 bp sequence. A 313 bp consensus sequence of the sperm whale P gene isolate was 100% similar to the Longman's beaked whale sequence previously isolated (JX195718), 83.9% similar to dolphin morbillivirus (AJ608288), and 80.4% similar to pilot whale morbillivirus (AF200817). This is the first report of either Brucella or morbillivirus in a sperm whale from any region of the world. Vertical transmission of both pathogens likely occurred given the age and pathologic findings. Although morbillivirus was only detected in one tissue, the occurrence of Brucella and morbillivirus presents a unique case of coinfection, representing two pathogens that are both known to negatively impact marine mammals.
We would like to thank David Schofield, Dera Look and stranding response volunteers that aided in the beach response and necropsy of this neonate sperm whale. We are also grateful to Christine Quance at the National Veterinary Services Laboratory and Karen Terio at the Zoological Pathology Program Molecular Diagnostic Laboratory. Erin Hanahoe assisted with the references. This work was funded by the Prescott Grant Program and the Hawaii Pacific University Trustees Scholarly Endeavors Program.
* Presenting author