Abstract
Melioidosis is an infectious disease caused by a gram-negative bacterium, Burkholderia pseudomallei, found in soil and water, mainly associated with tropical areas. Although considered endemic to northern Australia and Southeast Asia, it has increasingly been recognized in other regions, such as Central America, South America, and the Caribbean.1
It was first reported in marine mammals in Hong Kong in an outbreak in dolphins at Ocean Park in 1975, resulting in sudden death of 24 dolphins.2 Almost all reported cases of melioidosis in marine mammals are from that facility, with a preponderance of infections occurring during the rainy “typhoon season.”3-7
Dolphin Discovery facility in Saint Kitts and Nevis, located in the Leeward Islands chain of the Lesser Antilles, was affected by category five Hurricane Maria in September 2017. Dolphins were previously evacuated to a safe pool, showing normal attitude and appetite while evacuated. After the hurricane passed and damages were repaired, dolphins were transported back to the facility. Four days later, a 6-year-old male died after presenting an acute syndrome of anorexia, lethargy, and superficial breathing, not responding to antibiotics and supportive treatment.
Histology showed lesions consistent with acute septicemia, including severe multifocal necrohemorrhagic bronchopneumonia and necrotizing hepatitis, splenitis, and lymphadenitis - each with intralesional colonies of gram-negative bacilli. Burkholderia pseudomallei was isolated in pure culture from liver, bronchi, pericardium fluid and peritoneum fluid, and from mixed cultures collected from the lung.
Based on histopathological and bacteriological findings, it was concluded that the cause of death was melioidosis. Water and soil cultures were performed, but the specific source of the bacterium could not be determined, and no other dolphins showed any symptoms.
To our knowledge, this is the first case of melioidosis reported in a bottlenose dolphin (Tursiops truncatus) in the Lesser Antilles.
Acknowledgements
The authors wish to thank Dolphin Discovery Mammal Specialist staff for their assistance. Special thanks to the Microbiology Department of Lab Services from Ross University School of Veterinary Medicine, Saint Kitts.
* Presenting author
Literature Cited
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