Parasite/Disease / Status prior to 2000 / Timeline / Locality / Hosts and impact / Dynamics / Cause(s) / Notes
MICROPARASITES
Viruses
Ranavirus1-7 / Identified in the early 1990s with mass mortalities suspected from the 1980s; associated with mass mortalities of larval amphibians on a local scale; widespread global distribution; mass die offs in Americas, Europe and Asia / Ongoing and new population declines / North America, England / Individual mortality on 5 continents; mass dies offs of larvae and failure of recruitment affect short term population structure; long term effects in terms of impacting biodiversity generally not known; evidence of long-term decline inRana temporaria in England; Ranidae most susceptible / Largely endemic with many strains; mass mortality events / Naïve host exposure through trade/transport of amphibians; sporadic local nature suggests a variety of sufficient causes; waning immunity could be important for outbreaks; likely emerging due to increased incidence, geography and host range, although some cases may be due to increased detection / Research on population impacts required; important but level of importance needs to be resolved; notifiable disease to the OIE (World Organisation for Animal Health)
Chelonidfibropapilloma associated herpesvirus8,9 / First recognised in 1930s; widespread / Ongoing / Regarded as significant cause of mortality in Florida and Hawaii / Associated with fibropapillomas and fibromas in marine turtles; recognized as a major chronic disease of juvenile greenturtles; considered the most significant cause ofstrandings and mortality in waters around Florida and Hawaii; appears to be associated with oncogenesis in certain circumstances / Wildlife and environmental
management agencies are particularly concerned due tothe potential population impact this disease could exerton otherwise threatened species / Suspected to operate under certain environmental conditionsand in synergy with immune system modulatorswhich may influence the persistence and severity of the lesions; no obvious reason for emergence / Uncertain importance
May be a snap-shot of long-term dynamics
Bacteria
Mycoplasma agassizii
Part of Upper Respiratory Tract Disease (URTD) in desert tortoises10 / URTD and desert tortoise declines recognised in 1980s; M. agassizii shown to be causative experimentally of URTD in 1994 / Thought to be ongoing / California and Nevada, USA / Desert tortoise Gopherusagasizzii;
associated with declines; thought partly responsible for declines of up to 68%. / Causal evidence moderate and mostly relies on extrapolation of outcomes of laboratory experimental infections to prevalence data which is correlated with declines / Likely multifactorial given apparent heterogeneity in effects of pathogen in the wild; other pathogens implicated in URTD; hypothesised to have emerged but no obvious reason; alternative hypotheses are possible / Uncertain importance
May not be currently emerging; outbreaks may be snap-shots of long-term dynamics
Fungi
Chytridiomycosis
Batrachochytriumdendrobatidis(Bd)11-17 / Identified as the cause of “enigmatic” amphibian declines in 1998; disease and pathogen described in 1998 and 1999; sudden severe declines began in 1970’s, ongoing into 1990’s, retrospectively diagnosed as most likely due to Bd / Ongoing; declines due to chytridiomycosis have continued until the present day / Global distribution; few disease free countries; declines in Australia, Americas, Spain,
Tanzania / Individual mortality in multiple amphibian species
Population declines and extirpation have occurred in greater than 200 species. Approximately 100 species have gone extinct / Highly virulent lineages have caused population declines
Less virulent lineages exist in areas where there have not been declines such as Asia and appear to be endemic / Spread of highly virulent Bd lineage(from Africa) to naïve populations through globalisation of amphibian trade and lack of biosecurity / Most spectacular loss of vertebrate biodiversity due to disease in recorded history; very important; notifiable disease to the OIE (World Organisation for Animal Health)
Batrachochytriumsalamandrivorans (Bs)18 / Not previously known / 2013 / Netherlands / Caused 96% decline in fire salamander (Salamandrasalamandra) population / Novel pathogen related to Bd discovered and causing impact / Spread through globalisation of amphibian trade and lack of biosecurity; may have originated from Asia
MACROPARASITES
Myxozoa
Cystodiscusaxonis sp. n. and Cystodiscusaustralis sp. n. (species of Myxosporea)19-21 / Emergence in 20th century based on absence in museum specimens prior to 1935; disease recognised in 1997 / Pathogens identified in 2012 / Widespread Australia / Individual mortality in multiple amphibian species / Population effects unknown / Hypothesised that cane toads are an amplifier host / Uncertain importance;
may not be currently emerging
Helminths
Sparganosis cestodeSpirometra erinacei22-23 / Infects cats and dogs globally; frequent spillover to others / Recognised in 2009 / Australia / Individual mortality of white lipped green tree frogs (Litoriainfrafrenata) and green tree frogs (Litoriacaerulea) / Lack of significant spatial or temporal patterns / Likely spillover from cats (definitive host) / May have emerged prior to 2000
Serpinema microcephalus24 / Broad natural host range in Europe and Asia / 2003 / Spain / Pancreatitis and morbidity in red eared sliders Trachemysscriptaelegans / Population effects unknown / Spread from native to exotic turtle; overcrowding, stress from non-native habitat hypothesised potentiating factors / May have emerged prior to 2000
Copepods
Parasitic copepod Lernaea cyprinacea25 / Opportunistic parasite of many freshwater fish and amphibians; cosmopolitan spread from Africa due to international fish translocations / 2006 / California, USA / Malformations in tadpoles and young of the year in Foothill yellow-legged frogs (Rana boylii) / No records in this species back to 1989; population effects unknown / Hypothesised increasing temperatures in summer and/or decreased daily discharge in a watershed. / May have emerged prior to 2000; may be a snap-shot of long-term dynamics

References

  1. Jancovich, J. K., et al. (2005). "Evidence for emergence of an amphibian iridoviral disease because of human-enhanced spread." Molecular Ecology 14(1): 213-224.
  2. Storfer, A., et al. (2007). "Phylogenetic concordance analysis shows an emerging pathogen is novel and endemic." Ecology Letters 10(11): 1075-1083.
  3. Picco, A. M. and J. P. Collins (2008). "Amphibian Commerce as a Likely Source of Pathogen Pollution." Conservation Biology 22(6): 1582-1589.
  4. Hemingway V, Brunner J, Speare R, Berger L. 2009. Viral and Bacterial Diseases in Amphibians. Pp 2969-2986 in: Amphibian Biology, Volume 8 Amphibian Decline: Disease, Parasites, Maladies, and Pollution. Edited by H Heatwole and JW Wilkinson, Surrey Beatty & Sons. NSW
  5. Gray, M. J., et al. (2009). "Ecology and pathology of amphibian ranaviruses." Diseases of Aquatic Organisms 87(3): 243-266.
  6. Teacher, A. G. F., et al. (2010). "Assessing the long-term impact of Ranavirus infection in wild common frog populations." Animal Conservation 13(5): 514-522.
  7. Hoverman, J. T., et al. (2011). "Phylogeny, Life History, and Ecology Contribute to Differences in Amphibian Susceptibility to Ranaviruses." Ecohealth 8(3): 301-319.
  8. Schumacher, J. (2006). "Selected infectious diseases of wild reptiles and amphibians." Journal of Exotic Pet Medicine 15(1): 18-24.
  9. Ariel, E. (2011). "Viruses in reptiles." Veterinary Research 42.
  10. Sandmeier et al. 2009 Upper respiratory tract disease (URTD) as a threat to desert tortoise populations: a reevaluation. Biological Conservation 142: 1255-1268.
  11. Berger, L., et al. (1998). "Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America." Proceedings of the National Academy of Sciences of the United States of America 95(15): 9031-9036.
  12. Longcore et al. (1999).Batrachochytrium dendrobatidis gen. et sp. nov., a Chytrid Pathogenic to Amphibians. Mycologia 91: 219–227.
  13. Nicholls et al. (1999).Cutaneous chytridiomycosis: an emerging disease?Proceedings of the American Association of Zoo Veterinarians 1998;269-271.
  14. Skerratt, L. F., et al. (2007). "Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs." Ecohealth 4(2): 125-134.
  15. Hyatt, A. D., et al. (2010). "Amphibian chytridiomycosis." Diseases of Aquatic Organisms 92(2-3): 89-91.
  16. Farrer, R. A., et al. (2011). "Multiple emergences of genetically diverse amphibian-infecting chytrids include a globalized hypervirulent recombinant lineage." Proceedings of the National Academy of Sciences of the United States of America 108(46): 18732-18736.
  17. Bai, C. M., et al. (2012). "Global and endemic Asian lineages of the emerging pathogenic fungus Batrachochytrium dendrobatidis widely infect amphibians in China." Diversity and Distributions 18(3): 307-318.
  18. Martel et al. 2013 Batrachochytriumsalamandrivoranssp. nov.causes lethal chytridiomycosis in amphibians PNAS 110: 15325–15329.
  19. Hartigan, A., et al. (2010). "Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia." Parasites & Vectors 3.
  20. Hartigan, A., et al. (2011). "A Suspected Parasite Spill-Back of Two Novel Myxidium spp. (Myxosporea) Causing Disease in Australian Endemic Frogs Found in the Invasive Cane Toad." Plos One 6(4).
  21. Hartigan, A., et al. (2012). "New species of Myxosporea from frogs and resurrection of the genus Cystodiscus Lutz, 1889 for species with myxospores in gallbladders of amphibians." Parasitology 139(4): 478-496.
  22. Berger, L., et al. (2009). "SEVERE SPARGANOSIS IN AUSTRALIAN TREE FROGS." Journal of Wildlife Diseases 45(4): 921-929.
  23. Young, S., et al. (2012). "Using community surveillance data to differentiate between emerging and endemic amphibian diseases." Diseases of Aquatic Organisms 98(1): 1-10.
  24. Hidalgo-Vila, J., et al. (2011). "Pancreatitis Associated with the Helminth Serpinema microcephalus (Nematoda: Camallanidae) in Exotic Red-Eared Slider Turtles (Trachemys scripta elegans)." Journal of Wildlife Diseases 47(1): 201-205.
  25. Kupferberg, S. J., et al. (2009). "Parasitic Copepod (Lernaea cyprinacea) Outbreaks in Foothill Yellow-legged Frogs (Rana boylii) Linked to Unusually Warm Summers and Amphibian Malformations in Northern California." Copeia(3): 529-537.