Prevalence of Brucellosis in Costa Rica Strandings 2004-2009 and Public Health Concern
Abstract
Twenty three cetaceans belonging to six different species stranded in the Pacific coast of Costa Rica during 2004-2009. Sixteen of the animals were striped dolphins (Stenella coeruleoalba), two spotted dolphins (S. attenuata), one spinner dolphin (S. longirostris), one bottlenose dolphin (Tursiops truncatus), one dwarf sperm whale (Kogia sima), one humpback whale (Megaptera novaengliae) and one Cuvier's beaked whale (Ziphius cavirostris). Four animals were in an advanced state of decomposition and samples were unattainable. From nineteen animals sera and tissue were obtained for pathological, microbiological and serological analysis. Seventeen animals belonging to four different species S. coeruleoalba (14), S. attenuata (1), T. truncatus (1), Z. cavirostris (1) had positive serological reactions against Brucella antigens.1 Brucella ceti was isolated from nine striped dolphins from brain tissue, cerebrospinal fluid and from the placenta and fetus of one pregnant female.1 The fourteen positive striped dolphins regardless of sex or age had mononuclear meningoencephalomyelitis.2 This finding was consistent with the clinical symptoms demonstrated such as tremors, opisthotonus and seizures.3 The positive animals from the other species did not have pathological evidence of neurological pathologies compatible with neurobrucellosis. This finding calls attention to possible increased susceptibility of striped dolphins to this neurological pathology as well as being a reservoir of Brucella ceti in the Eastern Tropical Pacific. Modes of transmission of these bacteria must be taken into consideration in terms of zoonotic transmission, especially in coastal areas where the stranded animals are in close contact with inhabitants that attempt to return them to the ocean, and when working with cetaceans with neurological symptoms. Also the stranded cetaceans could come in contact with domestic animals like dogs and cows from coastal farms that can be a source of infection to humans. Future research is necessary to estimate the prevalence and the real impact of this disease in the wild populations and misdiagnoses of human cases.
Acknowledgments
The authors would like to thank all the people who helped during the strandings from the coastal areas of Costa Rica, Programa de Investigación en Enfermedades Tropicales (PIET), UNA, Costa Rica; Dr. Charles A. Manire from Atlantis, Paradise Island, Bahamas; William Rossiter from Cetacean Society International (CSI), USA and José María Blazco, Sanidad Animal Zaragoza, Spain.
References
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