We reviewed prominent emerging infectious diseases of cetaceans, examined their potential to impact populations, re-assessed zoonotic risk and evaluated the role of environmental stressors. Cetacean morbilliviruses and papillomaviruses as well as Brucella spp. and Toxoplasma gondii are thought to interfere with population abundance by inducing high mortalities, lowering reproductive success or by synergistically increasing the virulence of other diseases. Severe cases of lobomycosis and lobomycosis-like disease (LLD) may contribute to the death of some dolphins. The zoonotic hazard of marine mammal brucellosis and toxoplasmosis may have been underestimated, attributable to frequent misdiagnoses and underreporting, particularly in developing countries and remote areas where carcass handling without protective gear and human consumption of fresh cetacean products are commonplace. Environmental factors seem to play a role in the emergence and pathogenicity of morbillivirus epidemics, lobomycosis/LLD, toxoplasmosis, poxvirus-associated tattoo skin disease and, in harbour porpoises, infectious diseases of multifactorial aetiology. Inshore and estuarine cetaceans incur higher risks than pelagic cetaceans due to habitats often severely altered by anthropogenic factors such as chemical and biological contamination, direct and indirect fisheries interactions, traumatic injuries from vessel collisions and climate change.

In July 2007, >100 striped dolphins, Stenella coeruleoalba , were found dead along the coast of the Spanish Mediterranean. Of 10 dolphins tested, 7 were positive for a virus strain closely related to the dolphin morbillivirus that was isolated during a previous epizootic in 1990.

No abstract

No abstract

A previously unidentified morbiUivirus was isolated from two harbour porpoises , (Phocoena phocoena)

Lobomycosis is a chronic mycotic disease of the skin and subdermal tissues caused by the yeast-like organism Lacazia loboi, which affects humans and Delphinidae. Cases of lobomycosis and lobomycosis-like disease (LLD), a disease very similar to lobomycosis but for which a histological diagnostic is missing, have been reported in small cetaceans from the Americas and Europe. Here we report on LLD in Indo-Pacific bottlenose dolphins Tursiops aduncus from the tropical lagoon of Mayotte, between Mozambique and Madagascar. From July 2004 to June 2008, boat surveys were conducted in Mayotte waters. At least 71 adult dolphins were photo-identified. Six (5 males, 1 female) had multiple raised, greyish nodules on the dorsal fin, head, flanks, belly, back and tailstock that suggested LLD. The lesions were extensive in some cases. The calf of the positive female was also affected. LLD has been present in this community since at least 1999. As sampling was not possible, the aetiology of the disease could not be explored. The emergence of LLD in Mayotte may be related to degradation of the coastal environment associated with rapid urbanization, expanding agriculture and increased release of untreated freshwater runoffs. Other skin lesions included scars, healing wounds, whitish lesions and lumps.KEY WORDS: Indo-Pacific bottlenose dolphin · Tursiops aduncus · Skin diseases · Lobomycosis · Mayotte · Indian Ocean Resale or republication not permitted without written consent of the publisherDis Aquat Org 84: [151][152][153][154][155][156][157] 2009 sion (Migaki et al. 1971. In South America, a disease very similar to lobomycosis, but for which a histological diagnostic is missing, was recently reported in coastal T. truncatus from Colombia, Ecuador, Peru and Brazil as well as in S. guianensis from the Paranaguá estuary, Brazil (Van Bressem et al. 2007, 2009, Moreno et al. 2008). Lobomycosis and lobomycosis-like disease (LLD) have been mostly observed in tropical and equatorial areas, such as Florida and Texas in the US and Peru, Ecuador, Columbia, Venezuela, Surinam and Brazil in South America. The habitat of the pathogen is believed to be aquatic or associated with soil and vegetation. T. truncatus from the Indian River Lagoon, Florida, affected by lobomycosis, were found to have a significant impairment in adaptive immunity possibly related to chronic exposure to environmental stressors ). The T. truncatus communities from South America presenting LLD inhabited biologically and chemically polluted waters surrounding large ports and cities (Van Bressem et al. 2007).The Indo-Pacific bottlenose dolphin Tursiops aduncus is only found in the warm temperate to tropical Indo-Pacific Ocean, from South Africa in the west to southern Japan and central Australia in the east (Jefferson et al. 2008). It is the second most common cetacean species in the coastal waters of the inner lagoon of Mayotte (Comoros archipelago, northeast Mozambique Channel, SW Indian Ocean; Kiszka et al. 2007). Recent investigations have indicated that...

No abstract

No abstract