Lobomycosis-like disease and other skin conditions in Indo-Pacific bottlenose dolphins Tursiops aduncus from the Indian Ocean

Abstract

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...

Cutaneous nodules in Irrawaddy dolphins: an emerging disease in vulnerable populations

“…In Chilika, prevalence was significantly higher (p = 0. well et al 1975, Kiszka et al 2009, Reif et al 2009, Van Bressem et al 2009b. In some small communities of inshore and estuarine populations, these pathologies are highly prevalent, may progress to cover extensive body areas and have been associated with the death or disappearance of severely affected individuals, including calves (Simões-Lopes et al 1993, Van Bressem et al 2007a, Kiszka et al 2009, Daura-Jorge & Simões-Lopes 2011. However, their impact on the long-term viability of affected communities is still vastly unknown.…”

Lacaziosis in bottlenose dolphins Tursiops truncatus along the coastal Atlantic Ocean, Florida, USA

“…However, a reported laboratory accident in which human lacaziosis was acquired from experimentally infected mice (Rosa et al 2009) and successful serial passage of Lacazia loboi in mice by footpad injection (Belone et al 2002) support the concept of horizontal transmission under highly unusual circumstances that could include mother to calf transmission (Kiszka et al 2009) and accidental inoculation. The preponderance of evidence suggests that the infection is acquired from the local environment in both humans (Rodriguez-Toro 1998) and dolphins (Reif et al 2006).…”

“…Recent reports have described confirmed or presumed lacaziosis (lacaziosis-like disease, LLD, based on photographic assessment; Van Bressem et al 2007) in Delphinidae from coastal areas around the world including Ecuador, Peru, and Columbia (Van Bressem et al 2007), Brazil (Van Bressem et al 2007), Venezuela (Bermudez et al 2009), and Mayotte in the Indian Ocean (Kiszka et al 2009). With a single, notable exception, all cases of lacaziosis reported in United States waters up to this point have been in coastal or estuarine bottlenose dolphins.…”

Cutaneous Lesions in Cetaceans: An Indicator of Ecosystem Status?

“…Chronic mycotic disease of the skin and subdermal tissues in Indo-Pacific bottlenose dolphins (Tursiops aduncus), caused by the fungus Lacasia loboi, was reported in 2009 [41]. These dolphins lived in the tropical lagoon of Mayotte, situated in the Indian Ocean between Mozambique and Madagascar, and were characterized by numerous raised, greyish nodules on the head, flanks, dorsal fin, belly, back and tail.…”

“…The yeast-like, dimorphic fungus, Lacazia loboi (formerly known as Laboa loboi) causes invasive cutaneous lesions in dolphins and humans [58], known as lobomycosis, lacaziosis or keloidal blastomycosis [41,59,62]. The first case of keloidal blastomycosis was described in 1931 in a human patient from the Amazon valley [63].…”