American Association of Zoo Veterinarians Infectious Disease Manual Chrysosporium anamorph of Nannizziopsis vriesii: Nannizziopsis, Paranannizziopsis, and Ophiodiomyces ophidiicola (Under reclassification) Animal Transmission Clinical Severity Treatment Prevention Zoonotic Group(s) Signs and Control Affected Reptiles -Direct Variable Mild to Itraconazole; Proper No direct -Indirect (via dermatitis; severe but Voriconazole, disinfection of transmission fomites and Cellulitis high Terbinafine housing areas; from environmental and edema mortality (nebulization/ avoid animals contamination) may be is possible SQ implants/ contaminated reported but present. injection) fomites; humans can Internal prevent be infected organ contact with invasion infected with O. animals ophidiicola Fact Sheet compiled by: E. Marie Rush Sheet completed on: updated 1 May 2018 Fact Sheet Reviewed by: Bonnie Raphael, Tim Georoff Susceptible animal groups: Reptiles Causative organism: Nannizziopsis spp., Ophidiomyces spp., Paranannizziopsis spp. Formerly, this grouping was Chrysosporium anamorph of Nannizziopsis vriesii (CANV) fungus. Recent taxonomic publications have identified new epidemiological information about these fungi grouped under the CANV appellation. While Nannizziopsis vriesii does produce a Chrysosporium anamorph in culture, all CANV-like isolates differ so that an overarching CANV appellation is discouraged. For example, the “CANV” isolates that caused fatal disease in tentacled snakes have been reclassified as two species of Paranannizziopsis, which has not been isolated from other reptile species. Paranannizziopsis includes four species that infect squamates and tuataras. Ophidiomyces (belonging to the Order Onygenales) is a potent pathogen of snakes and associated with “Snake Fungal Disease,” but it has not yet been recovered from ill lizards or crocodiles so may not be a threat to these taxa. Nannizziopsis guarroi is the main causative agent of “Yellow Fungus Disease,” a common infection in bearded dragons, green iguanas, and other lizards. Classically dermatomycoses in reptiles are linked with stress and substandard husbandry in captive animals however experimental challenge of veiled chameleons (Chamaeleo calyptratus) with Nannizziopsis dermatitidis confirmed the organism can act as a primary pathogen. Zoonotic potential: While it is not directly transmitted from animals to humans, infection has been reported in two human cases where pre-existing immunosuppression was present. There are multiple subspecies of reptile infective organisms. Human species of these organisms have not been recovered in reptiles. Distribution: Worldwide. Incubation period: 2-5 weeks Clinical signs: Infection is often through a breach in the skin. Ophidiopmyces is the likely causative agent of “Snake Fungal Disease”, however the two have not always been found in tandem. Slow progression occurs from dry, hyperkeratotic plaques or vesicles to exudative lesions with excessive crusting that may later darken and slough. Snakes with Ophidiomyces, may have increased ecdysis frequency, abnormal resting in areas of the enclosure and anorexia. Skin may have fissures or thickening and upon pressure or incision into these areas, exudate may be expelled. Cellulitis can present concurrently. In advanced disease, general debilitation of the animal may be noted and deeper tissues – including muscle and bone – become affected. Hemogram and chemistry panels may be normal during this infection. In pygmy rattlesnakes, corticosterone levels were proportionately increased in direct correlation with severity of clinical SFD, recapture, decreased reproduction in females and decreased body condition score. Clinical signs correlated American Association of Zoo Veterinarians Infectious Disease Manual Chrysosporium anamorph of Nannizziopsis vriesii: Nannizziopsis, Paranannizziopsis, and Ophiodiomyces ophidiicola (Under reclassification) with decreased environmental temperatures have been established for SFD. Paranannizziopsis australasiensis has been reported in a tuatara with clinical signs and positive testing on PCR. Post mortem, gross, or histologic findings: Initially, there will be hyphae proliferating in the epidermis (stratum corneum) with subsequent deeper invasion in most cases. Progression to liquefactive necrosis of the epidermis with or without granulomatous inflammation of the dermis is noted over time. Terminal chains of arthroconidia may be seen on hyphae, and with Ophidiomyces, granulocytic change at sites of microinvasion. Diagnosis: Clinical signs are suggestive. Fungal culture of the organism on Mycosel™ Agar with incubation at 25-28°C. Histopathology can be performed. PAS stained sections of tissues will reveal hyphae in the keratin layer, epidermis, dermis and occasionally skeletal muscle layers depending on severity of disease. Fungus can be identified by PCR. Although Taqman RT PCR and PCR are considered the most sensitive and specific of the diagnostic tests, not all tissues may be positive, even if grossly visible lesions are present. In a study with O. ophiodiicola, 98% of culture positive (and 40% of culture negative) snakes were found to be positive on RT-PCR. Of these snakes, 20 showed clinical signs and 16 had no clinical signs of infection. This study suggests that some asymptomatic snakes (~6%) may harbor low levels of fungus, and PCR paired with histopathology is recommended for definitive diagnosis. Massasaugas in Illinois with Ophiodiomyces showed changes in WBC counts, lymphocytes and basophils noted retrospectively over peak years. Material required for laboratory analysis: Frozen and formalin-fixed representative tissue samples from multiple organ systems (including skin, muscle, and bone) of necropsy specimens. Biopsies from live animals should be divided and submitted chilled for culture and fixed for histopathology. Relevant diagnostic laboratories: Most diagnostic laboratories are capable of culturing of this organism. Pre-emptive contact with microbiologist prior to sample submission greatly increases the chance of diagnosis. Treatment: Itraconazole and voriconazole can be used systemically. Terbinafine (10mg/kg PO SID x 7 days; pulse repeat Q3wk until one-week past resolution of signs) pulsed with itraconazole or voriconazole. In a study with timber rattlesnakes and massasaugas, voriconazole via SQ pump led to adequate levels in timber rattlesnakes, but not massasaugas. Levels post injection in cottonmouths were maintained for 12-24 hours. Cloacal administration in cottonmouths did not reach adequate levels, and several snakes died after a single injection without further treatment. In cottonmouths, terbinafine reached peak concentrations at 0.5-4 hours post nebulization, and on day 1using subcutaneous implants (which maintained therapeutic levels for over 6 weeks). Although topical disinfection of skin lesions with chlorhexidine solution may be helpful, alone it is not likely to be successful so combined approach is needed. Cutaneous lesions can be debrided aggressively along with topical antifungal and antibacterial dressings. Mycetomas should be considered for surgical excision in addition to systemic treatment. Prognosis for deeper structure involvement (e.g., bone) is guarded to poor. Prevention and control: Optimization of husbandry conditions is critical for most reptiles to prevent disease as the problem is exacerbated by suboptimal husbandry. Housing areas should be thoroughly disinfected between individuals and any porous material from the enclosures should be discarded if unable to be sterilized or properly disinfected (i.e. substrate, drift wood furniture, etc). Proper quarantine measures for new animals should be followed. Separation of infected animals from healthy animals should be done until infection is completely cleared, based on biopsies and culture. Suggested disinfectant for housing facilities: Bleach and chlorhexidine for CANV. For Ophidiomyces: 3% bleach for at least 2 minutes, 70% ethanol, 0.16% Roccal®-D for 10 minutes, Lysol® products, CLR® bath and kitchen cleaner (5-10% lactic acid), Process NPD® or Formula 409® household cleaners. Chlorhexidine, Simple Green® and spectracide are NOT effective for Ophidiomyces. Ten minutes of contact time is recommended for most cleaners to reach optimal spore removal. Notification: None required American Association of Zoo Veterinarians Infectious Disease Manual Chrysosporium anamorph of Nannizziopsis vriesii: Nannizziopsis, Paranannizziopsis, and Ophiodiomyces ophidiicola (Under reclassification) Measures required under the Animal Disease Surveillance Plan: None required Measures required for introducing animals to infected animal: It is not recommended to introduce non- infected animals to infected animals until confirmation that infection is completely cleared based on culture of biopsy of the originally affected areas. Conditions for restoring disease-free status after an outbreak: It must be assured no residual carrier animals in remaining group of animals. Experts who may be consulted: Jean A. Paré, DMV, DVSc, DACZM Associate Veterinarian Global Health Program Wildlife Conservation Society 2300 Southern Boulevard Bronx, NY, 10460, USA Tel: 718-741-1174 Fax: 718-220-7126 Email: [email protected] Matt Allender, DVM, MS, PhD, Dipl. ACZM Director, Wildlife Epidemiology Lab Assistant Professor College of Veterinary Medicine University of Illinois 3846 VMBSB 2001 S. Lincoln Ave., Urbana, IL 61802 Tel: 217-265-0320 Email: [email protected] References: 1. Abarca ML, Martorell