Parasitology Research

, Volume 117, Issue 5, pp 1453–1463 | Cite as

First report of Toxoplasma gondii sporulated oocysts and Giardia duodenalis in commercial green-lipped mussels (Perna canaliculus) in New Zealand

  • Alicia CoupeEmail author
  • Laryssa Howe
  • Elizabeth Burrows
  • Abigail Sine
  • Anthony Pita
  • Niluka Velathanthiri
  • Emilie Vallée
  • David Hayman
  • Karen Shapiro
  • Wendi D. Roe
Original Paper


Pollution of marine ecosystems with the protozoan parasites Toxoplasma gondii, Cryptosporidium spp. and Giardia duodenalis can be studied using bivalve shellfish as biosentinels. Although evidence suggests that these parasites are present in New Zealand coastal waters, the extent of protozoal pollution has not been investigated. This study used optimised molecular methods to detect the presence of Cryptosporidium spp., G. duodenalis and T. gondii in commercially sourced green-lipped mussel (Perna canaliculus), an endemic species found throughout coastal New Zealand. A nested polymerase chain reaction was validated for detection of T. gondii DNA and applied to 104 commercially sourced mussels. Thirteen mussels were positive for T. gondii DNA with an estimated true prevalence of 16.4% using Bayesian statistics, and the presence of T. gondii in mussels was significantly associated with collection during the summer compared with that in the winter (P = 0.003). Consumption of contaminated shellfish may also pose a health risk for humans and marine wildlife. As only sporulated T. gondii oocysts can be infectious, a reverse transcriptase-polymerase chain reaction was used to confirm presence of a sporozoite-specific marker (SporoSAG), detected in four mussels. G. duodenalis assemblage B, known to be pathogenic in humans, was also discovered in 1% mussels, tested by polymerase chain reaction (n = 90). Cryptosporidium spp. was not detected in the sampled mussel haemolymph. Results suggest that New Zealand may have high levels of coastal contamination with T. gondii, particularly in summer months, and that naturally exposed mussels can ingest and retain sporulated oocysts, further establishing shellfish consumption as a health concern.


Biosentinels Toxoplasma gondii Giardia duodenalis SporoSAG Perna canaliculus 



We thank Heather Fritz, Jeroen Saeij and David Arranz Solis for producing and generously providing T. gondii oocysts from the University of California, Davis. We are very grateful to Patricia Conrad, University California, Davis, for supporting collaboration with Massey University and also to Juan-Carlos Garcia Ramirez for providing scientific guidance on Giardia duodenalis in New Zealand.

Funding information

Funding for this work was provided by the New Zealand Department of Conservation, the Massey University Research Foundation, the Lewis Fitch Foundation, the Marian Cunningham Memorial Fund and the New Zealand Ministry of Health. We acknowledge the financial support received from the IVABS Doctoral Scholarship, Massey University and the New Zealand International Doctoral Research Scholarship, Education New Zealand.


  1. Abeywardena H, Jex AR, Nolan MJ et al (2012) Genetic characterisation of Cryptosporidium and Giardia from dairy calves: discovery of species/genotypes consistent with those found in humans. Infect Genet Evol 12:1984–1993PubMedCrossRefGoogle Scholar
  2. Adell AD, Smith WA, Shapiro K, Melli A, Conrad PA (2014) Molecular epidemiology of Cryptosporidium spp. and Giardia spp. in mussels (Mytilus californianus) and California sea lions (Zalophus californianus) from Central California. Appl Environ Microbiol 80:7732–7740PubMedPubMedCentralCrossRefGoogle Scholar
  3. Aksoy U, Marangi M, Papini R, Ozkoc S, Bayram Delibas S, Giangaspero A (2014) Detection of Toxoplasma gondii and Cyclospora cayetanensis in Mytilus galloprovincialis from Izmir Province coast (Turkey) by real time PCR/high-resolution melting analysis (HRM). Food Microbiol 44:128–135PubMedCrossRefGoogle Scholar
  4. Alves M, Xiao L, Sulaiman I, Lal AA, Matos O, Antunes F (2003) Subgenotype analysis of Cryptosporidium isolates from humans, cattle, and zoo ruminants in Portugal. J Clin Microbiol 41:2744–2747PubMedPubMedCentralCrossRefGoogle Scholar
  5. Thompson RCA (2004) The zoonotic significance and molecular epidemiology of Giardia and giardiasis. Vet Parasitol 126:15–35PubMedCrossRefGoogle Scholar
  6. Arkush KD, Miller MA, Leutenegger CM, Gardner IA, Packham AE, Heckeroth AR, Tenter AM, Barr BC, Conrad PA (2003) Molecular and bioassay-based detection of Toxoplasma gondii oocyst uptake by mussels (Mytilus galloprovincialis). Int J Parasitol 33:1087–1097PubMedCrossRefGoogle Scholar
  7. Aspinall TV, Joynson DHM, Guy E, Hyde JE, Sims PFG (2002a) The molecular basis of sulfonamide resistance in Toxoplasma gondii and implications for the clinical management of toxoplasmosis. J Infect Dis 185:1637–1643PubMedCrossRefGoogle Scholar
  8. Aspinall TV, Marlee D, Hyde JE, Sims PFG (2002b) Prevalence of Toxoplasma gondii in commercial meat products as monitored by polymerase chain reaction—food for thought? Int J Parasitol 32:1193–1199PubMedCrossRefGoogle Scholar
  9. Betancourt WQ, Duarte DC, Vásquez RC, Gurian PL (2014) Cryptosporidium and Giardia in tropical recreational marine waters contaminated with domestic sewage: estimation of bathing-associated disease risks. Mar Pollut Bull 85:268–273PubMedCrossRefGoogle Scholar
  10. Bowie WR, King AS, Werker DH, Isaac-Renton JL, Bell A, Eng SB, Marion SA (1997) Outbreak of toxoplasmosis associated with municipal drinking water. Lancet 350:173–177PubMedCrossRefGoogle Scholar
  11. Branscum AJ, Gardner IA, Johnson WO (2005) Estimation of diagnostic-test sensitivity and specificity through Bayesian modeling. Prev Vet Med 68:145–163PubMedCrossRefGoogle Scholar
  12. Brown TJ, Donaghy MJ, Keys EA, Ionas G, Learmonth JJ, McLenachan PA, Clarke JK (1999) The viability of Giardia intestinalis and Giardia muris cysts in seawater. Int J Environ Health Res 9:157–161CrossRefGoogle Scholar
  13. Brown TJ, Hastie JC, Kelly PJ et al (1992) Presence and distribution of Giardia cysts in New Zealand waters. N Z J Mar Freshwater Res 26:279–282CrossRefGoogle Scholar
  14. Chiang T-Y, Kuo M-C, Chen C-H, Yang JY, Kao CF, Ji DD, Fang CT (2014) Risk factors for acute Toxoplasma gondii diseases in Taiwan: a population-based case-control study. PLoS One 9:e90880PubMedPubMedCentralCrossRefGoogle Scholar
  15. Conrad PA, Atwill ER, Gardner IA, et al (2005) Cryptosporidium in bivalves as indicators of fecal pollution in the California coastal ecosystemGoogle Scholar
  16. Costa J-M, Bretagne S (2012) Variation of B1 gene and AF146527 repeat element copy numbers according to Toxoplasma gondii strains assessed using real-time quantitative PCR. J Clin Microbiol 50:1452–1454PubMedPubMedCentralCrossRefGoogle Scholar
  17. Dabritz HA, Atwill ER, Gardner IA, Miller MA, Conrad PA (2006) Outdoor fecal deposition by free-roaming cats and attitudes of cat owners and nonowners toward stray pets, wildlife, and water pollution. J Am Vet Med Assoc 229:74–81PubMedCrossRefGoogle Scholar
  18. Dabritz HA, Conrad PA (2010) Cats and Toxoplasma: implications for public health. Zoonoses Public Health 57:34–52PubMedCrossRefGoogle Scholar
  19. Dorai-Raj S (2014) binom: binomial confidence intervals for several parameterizations. R package version 1.1-1.
  20. Downey AS, Graczyk TK (2007) Maximizing recovery and detection of Cryptosporidium parvum oocysts from spiked eastern oyster (Crassostrea virginica) tissue samples. Appl Environ Microbiol 73:6910–6915PubMedPubMedCentralCrossRefGoogle Scholar
  21. Dubey JP, Jones JL (2008) Toxoplasma gondii infection in humans and animals in the United States. Int J Parasitol 38:1257–1278PubMedCrossRefGoogle Scholar
  22. Dubey JP, Lindsay DS, Speer CA (1998) Structures of Toxoplasma gondii tachyzoites, bradyzoites, and sporozoites and biology and development of tissue cysts. Clin Microbiol Rev 11:267–299PubMedPubMedCentralGoogle Scholar
  23. Dubey JP, Miller NL, Frenkel JK (1970) The Toxoplasma gondii oocyst from cat feces. J Exp Med 132:636–662PubMedPubMedCentralCrossRefGoogle Scholar
  24. Ene L, Marcotte TD, Umlauf A, Grancea C, Temereanca A, Bharti A, Achim CL, Letendre S, Ruta SM (2016) Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection. J Neuroimmunol 299:1–7PubMedPubMedCentralCrossRefGoogle Scholar
  25. Esmerini PO, Gennari SM, Pena HFJ (2010) Analysis of marine bivalve shellfish from the fish market in Santos city, São Paulo state, Brazil, for Toxoplasma gondii. Vet Parasitol 170:8–13PubMedCrossRefGoogle Scholar
  26. ESR (2017) The Institute of Environmental Science and Research Ltd. Notifiable Diseases in New Zealand: Annual Report 2016 Porirua, New Zealand. Available at:
  27. Farnworth MJ, Campbell J, Adams NJ (2010) Public awareness in New Zealand of animal welfare legislation relating to cats. N Z Vet J 58:213–217PubMedCrossRefGoogle Scholar
  28. Fayer R (2004) Cryptosporidium: a water-borne zoonotic parasite. Vet Parasitol 126:37–56PubMedCrossRefGoogle Scholar
  29. Fayer R, Dubey JP, Lindsay DS (2004) Zoonotic protozoa: from land to sea. Trends Parasitol 20:531–536PubMedCrossRefGoogle Scholar
  30. Fayer R, Graczyk TK, Lewis EJ, Trout JM, Farley CA (1998) Survival of infectious Cryptosporidium parvum oocysts in seawater and eastern oysters (Crassostrea virginica) in the Chesapeake Bay. Appl Environ Microbiol 64:1070–1074PubMedPubMedCentralGoogle Scholar
  31. Feng Y, Xiao L (2011) Zoonotic potential and molecular epidemiology of Giardia species and giardiasis. Clin Microbiol Rev 24:110–140PubMedPubMedCentralCrossRefGoogle Scholar
  32. Garcia-R JC, French N, Pita A et al (2017) Local and global genetic diversity of protozoan parasites: spatial distribution of Cryptosporidium and Giardia genotypes. PLoS Negl Trop Dis 11:e0005736PubMedPubMedCentralCrossRefGoogle Scholar
  33. Giangaspero A, Papini R, Marangi M, Koehler AV, Gasser RB (2014) Cryptosporidium parvum genotype IIa and Giardia duodenalis assemblage A in Mytilus galloprovincialis on sale at local food markets. Int J Food Microbiol 171:62–67PubMedCrossRefGoogle Scholar
  34. Gilbert S, Lake R, Hudson A, Cressy P (2007) Risk profile: Cryptosporidium spp. in shellfish. Institute of Environmental Science & Research Limited. Report prepared as part of a New Zealand Food Safety Authority contract for scientific services. Available at:
  35. Gómez-Couso H, Freire-Santos F, Amar CFL, Grant KA, Williamson K, Ares-Mazás ME, McLauchlin J (2004) Detection of Cryptosporidium and Giardia in molluscan shellfish by multiplexed nested-PCR. Int J Food Microbiol 91:279–288PubMedCrossRefGoogle Scholar
  36. Gómez-Couso H, Freire-Santos F, Martínez-Urtaza J, García-Martín O, Ares-Mazás ME (2003a) Contamination of bivalve molluscs by Cryptosporidium oocysts: the need for new quality control standards. Int J Food Microbiol 87:97–105PubMedCrossRefGoogle Scholar
  37. Gómez-Couso H, Freire-Santos F, Ortega-Iñarrea MR, Castro-Hermida JA, Ares-Mazás ME (2003b) Environmental dispersal of Cryptosporidium parvum oocysts and cross transmission in cultured bivalve molluscs. Parasitol Res 90:140–142PubMedCrossRefGoogle Scholar
  38. Gómez-Couso H, Méndez-Hermida F, Castro-Hermida JA, Ares-Mazás E (2005) Giardia in shellfish-farming areas: detection in mussels, river water and waste waters. Vet Parasitol 133:13–18PubMedCrossRefGoogle Scholar
  39. Graczyk TK, Thompson RC, Fayer R et al (1999) Giardia duodenalis cysts of genotype A recovered from clams in the Chesapeake Bay subestuary, Rhode River. Am J Trop Med Hyg 61:526–529PubMedCrossRefGoogle Scholar
  40. Hall CM, Adams NA, Bradley JS, Bryant KA, Davis AA, Dickman CR, Fujita T, Kobayashi S, Lepczyk CA, McBride EA, Pollock KH, Styles IM, van Heezik Y, Wang F, Calver MC (2016) Community attitudes and practices of urban residents regarding predation by pet cats on wildlife: an international comparison. PLoS One 11:e0151962PubMedPubMedCentralCrossRefGoogle Scholar
  41. Hartley WJ, Bridge PS (1975) A case of suspected congenital Toxoplasma encephalomyelitis in a lamb associated with a spinal cord anomaly. Br Vet J 131(4):380–384PubMedCrossRefGoogle Scholar
  42. Hohweyer J, Dumètre A, Aubert D et al (2013) Tools and methods for detecting and characterizing Giardia, Cryptosporidium, and Toxoplasma parasites in marine mollusks. J Food Prot 76:1649–1657PubMedCrossRefGoogle Scholar
  43. Homan WL, Gilsing M, Bentala H, Limper L, van Knapen F (1998) Characterization of Giardia duodenalis by polymerase-chain-reaction fingerprinting. Parasitol Res 84:707–714PubMedCrossRefGoogle Scholar
  44. Homan WL, Vercammen M, De Braekeleer J, Verschueren H (2000) Identification of a 200- to 300-fold repetitive 529 bp DNA fragment in Toxoplasma gondii, and its use for diagnostic and quantitative PCR. Int J Parasitol 30(1):69–75PubMedCrossRefGoogle Scholar
  45. Howe L, Hunter S, Burrows E, Roe W (2014) Four cases of fatal toxoplasmosis in three species of endemic New Zealand birds. Avian Dis 58:171–175PubMedCrossRefGoogle Scholar
  46. Hunt CL, Ionas G, Brown TJ (2000) Prevalence and strain differentiation of Giardia intestinalis in calves in the Manawatu and Waikato regions of North Island, New Zealand. Vet Parasitol 91:7–13PubMedCrossRefGoogle Scholar
  47. Ionas G, Learmonth JJ, Keys EA, Brown TJ (1998) Distribution of Giardia and Cryptosporidium in natural water systems in New Zealand—a nationwide survey. Water Sci Technol 38:57–60CrossRefGoogle Scholar
  48. Iwamoto M, Ayers T, Mahon BE, Swerdlow DL (2010) Epidemiology of seafood-associated infections in the United States. Clin Microbiol Rev 23:399–411PubMedPubMedCentralCrossRefGoogle Scholar
  49. James MR, Weatherhead MA, Ross AH (2001) Size-specific clearance, excretion, and respiration rates, and phytoplankton selectivity for the mussel Perna canaliculus at low levels of natural food. N Z J Mar Freshwater Res 35:73–86CrossRefGoogle Scholar
  50. Johnson DC, Reynolds KA, Gerba CP et al (1995) Detection of Giardia and Cryptosporidium in marine waters. Water Sci Technol 31:439–442CrossRefGoogle Scholar
  51. Jones JL, Dargelas V, Roberts J, Press C, Remington JS, Montoya JG (2009) Risk factors for Toxoplasma gondii infection in the United States. Clin Infect Dis 49:878–884PubMedCrossRefGoogle Scholar
  52. Jones JL, Dubey JP (2010) Waterborne toxoplasmosis … recent developments. Exp Parasitol 124:10–25PubMedCrossRefGoogle Scholar
  53. Karanis P, Aldeyarbi HM, Mirhashemi ME, Khalil KM (2013) The impact of the waterborne transmission of Toxoplasma gondii and analysis efforts for water detection: an overview and update. Environ Sci Pollut Res Int 20:86–99PubMedCrossRefGoogle Scholar
  54. Kerambrun E, Palos Ladeiro M, Bigot-Clivot A, Dedourge-Geffard O, Dupuis E, Villena I, Aubert D, Geffard A (2016) Zebra mussel as a new tool to show evidence of freshwater contamination by waterborne Toxoplasma gondii. J Appl Microbiol 120:498–508PubMedCrossRefGoogle Scholar
  55. King N, Lake R (2013) Bivalve shellfish harvesting and consumption in New Zealand, 2011: data for exposure assessment. N Z J Mar Freshw Res 47(1):62–72CrossRefGoogle Scholar
  56. Lal A, Baker MG, Hales S, French NP (2013) Potential effects of global environmental changes on cryptosporidiosis and giardiasis transmission. Trends Parasitol 29:83–90PubMedCrossRefGoogle Scholar
  57. Learmonth JJ, Ionas G, Pita AB, Cowie RS (2003) Identification and genetic characterisation of Giardia and Cryptosporidium strains in humans and dairy cattle in the Waikato Region of New Zealand. Water Sci Technol 47:21–26PubMedCrossRefGoogle Scholar
  58. Lemon J (2006) Plotrix: a package in the red light district of R. R-News 6(4):8–12Google Scholar
  59. Lindsay DS, Collins MV, Mitchell SM, Wetch CN, Rosypal AC, Flick GJ, Zajac AM, Lindquist A, Dubey JP (2004) Survival of Toxoplasma gondii oocysts in eastern oysters. J Parasitol 90:1054–1057PubMedCrossRefGoogle Scholar
  60. Li N, Xiao L, Wang L, Zhao S, Zhao X, Duan L, Guo M, Liu L, Feng Y (2012) Molecular surveillance of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi by genotyping and subtyping parasites in wastewater. PLoS Negl Trop Dis 6:e1809PubMedPubMedCentralCrossRefGoogle Scholar
  61. Lucy FE, Graczyk TK, Tamang L, Miraflor A, Minchin D (2008) Biomonitoring of surface and coastal water for Cryptosporidium, Giardia, and human-virulent microsporidia using molluscan shellfish. Parasitol Res 103:1369–1375PubMedCrossRefGoogle Scholar
  62. Marangi M, Giangaspero A, Lacasella V, Lonigro A, Gasser RB (2015) Multiplex PCR for the detection and quantification of zoonotic taxa of Giardia, Cryptosporidium and Toxoplasma in wastewater and mussels. Mol Cell Probes 29:122–125PubMedCrossRefGoogle Scholar
  63. Marquis ND, Record NR, Robledo JAF (2015) Survey for protozoan parasites in Eastern oysters (Crassostrea virginica) from the Gulf of Maine using PCR-based assays. Parasitol Int 64:299–302PubMedCrossRefGoogle Scholar
  64. Meneceur P, Bouldouyre M-A, Aubert D, Villena I, Menotti J, Sauvage V, Garin JF, Derouin F (2008) In vitro susceptibility of various genotypic strains of Toxoplasma gondii to pyrimethamine, sulfadiazine, and atovaquone. Antimicrob Agents Chemother 52:1269–1277PubMedPubMedCentralCrossRefGoogle Scholar
  65. Miller MA, Gardner IA, Kreuder C, Paradies DM, Worcester KR, Jessup DA, Dodd E, Harris MD, Ames JA, Packham AE, Conrad PA (2002) Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis). Int J Parasitol 32:997–1006PubMedCrossRefGoogle Scholar
  66. Miller MA, Miller WA, Conrad PA, James ER, Melli AC, Leutenegger CM, Dabritz HA, Packham AE, Paradies D, Harris M, Ames J, Jessup DA, Worcester K, Grigg ME (2008) Type X Toxoplasma gondii in a wild mussel and terrestrial carnivores from coastal California: new linkages between terrestrial mammals, runoff and toxoplasmosis of sea otters. Int J Parasitol 38:1319–1328PubMedCrossRefGoogle Scholar
  67. Miller WA, Atwill ER, Gardner IA, Miller MA, Fritz HM, Hedrick RP, Melli AC, Barnes NM, Conrad PA (2005a) Clams (Corbicula fluminea) as bioindicators of fecal contamination with Cryptosporidium and Giardia spp. in freshwater ecosystems in California. Int J Parasitol 35:673–684PubMedCrossRefGoogle Scholar
  68. Miller WA, Miller MA, Gardner IA, Atwill ER, Harris M, Ames J, Jessup D, Melli A, Paradies D, Worcester K, Olin P, Barnes N, Conrad PA (2005b) New genotypes and factors associated with Cryptosporidium detection in mussels (Mytilus spp.) along the California coast. Int J Parasitol 35:1103–1113PubMedCrossRefGoogle Scholar
  69. Monis PT, Mayrhofer G, Andrews RH, Homan WL, Limper L, Ey PL (1996) Molecular genetic analysis of Giardia intestinalis isolates at the glutamate dehydrogenase locus. Parasitology 112(1):1–2PubMedCrossRefGoogle Scholar
  70. Monis PT, Andrews RH, Mayrhofer G, Ey PL (2003) Genetic diversity within the morphological species Giardia intestinalis and its relationship to host origin. Infect Genet Evol 3:29–38PubMedCrossRefGoogle Scholar
  71. New Zealand Companion Animal Council Inc. (2016) Companion Animals in New Zealand 2016. Author, Auckland. Available at:
  72. Olson ME, Goh J, Phillips M, Guselle N, McAllister TA (1999) Giardia cyst and Cryptosporidium oocyst survival in water, soil, and cattle feces. J Environ Qual 28:1991–1996CrossRefGoogle Scholar
  73. Pashley TV, Volpe F, Pudney M, Hyde JE, Sims PFG, Delves CJ (1997) Isolation and molecular characterization of the bifunctional hydroxymethyldihydropterin pyrophosphokinase-dihydropteroate synthase gene from Toxoplasma gondii. Mol Biochem Parasitol 86(1):37–47PubMedGoogle Scholar
  74. Patel KK, Howe L, Heuer C, Asher GW, Wilson PR (2017) Evaluation of Western blot, ELISA and latex agglutination tests to detect Toxoplasma gondii serum antibodies in farmed red deer. Vet Parasitol 244:154–159PubMedCrossRefGoogle Scholar
  75. Peng MM, Matos O, Gatei W et al (2001) A comparison of Cryptosporidium subgenotypes from several geographic regions. J Eukaryot Microbiol Suppl 48:28S–31SCrossRefGoogle Scholar
  76. Putignani L, Mancinelli L, Del Chierico F et al (2011) Investigation of Toxoplasma gondii presence in farmed shellfish by nested-PCR and real-time PCR fluorescent amplicon generation assay (FLAG). Exp Parasitol 127:409–417PubMedCrossRefGoogle Scholar
  77. R Core Team (2017) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria URL Google Scholar
  78. Radke JR, Gubbels M-J, Jerome ME, Radke JB, Striepen B, White MW (2004) Identification of a sporozoite-specific member of the Toxoplasma SAG superfamily via genetic complementation. Mol Microbiol 52:93–105PubMedCrossRefGoogle Scholar
  79. Read CM, Monis PT, Thompson RCA (2004) Discrimination of all genotypes of Giardia duodenalis at the glutamate dehydrogenase locus using PCR-RFLP. Infect Genet Evol 4:125–130PubMedCrossRefGoogle Scholar
  80. Ribeiro LA, Santos LKNSS, Brito PA Jr et al (2015) Detection of Toxoplasma gondii DNA in Brazilian oysters (Crassostrea rhizophorae). Genet Mol Res 14:4658–4665PubMedCrossRefGoogle Scholar
  81. Robertson LJ (2007) The potential for marine bivalve shellfish to act as transmission vehicles for outbreaks of protozoan infections in humans: a review. Int J Food Microbiol 120:201–216PubMedCrossRefGoogle Scholar
  82. Roe WD, Howe L, Baker EJ, Burrows L, Hunter SA (2013) An atypical genotype of Toxoplasma gondii as a cause of mortality in Hector’s dolphins (Cephalorhynchus hectori). Vet Parasitol 192:67–74PubMedCrossRefGoogle Scholar
  83. Roe WD, Michael S, Fyfe J, Burrows E, Hunter SA, Howe L (2017) First report of systemic toxoplasmosis in a New Zealand sea lion (Phocarctos hookeri). N Z Vet J 65:46–50PubMedCrossRefGoogle Scholar
  84. Ryan U, Cacciò SM (2013) Zoonotic potential of Giardia. Int J Parasitol 43:943–956PubMedCrossRefGoogle Scholar
  85. Safi KA, Gibbs MM (2003) Importance of different size classes of phytoplankton in Beatrix Bay, Marlborough Sounds, New Zealand, and the potential implications for the aquaculture of the mussel, Perna canaliculus. N Z J Mar Freshwater Res 37:267–272CrossRefGoogle Scholar
  86. Scholes P, Greening G, Campbell D, Sim J, Gibbons-Davies J, Dohnt G, et al. (2009) Microbiological quality of shellfish in estuarine areas. Joint agency research report. Available at:
  87. Shapiro K, Miller M, Mazet J (2012) Temporal association between land-based runoff events and California sea otter (Enhydra lutris nereis) protozoal mortalities. J Wildl Dis 48:394–404PubMedCrossRefGoogle Scholar
  88. Shapiro K, VanWormer E, Aguilar B, Conrad PA (2015) Surveillance for Toxoplasma gondii in California mussels (Mytilus californianus) reveals transmission of atypical genotypes from land to sea. Environ Microbiol 17:4177–4188PubMedCrossRefGoogle Scholar
  89. Shumway SE, Cucci TL, Newell RC, Yentsch CM (1985) Particle selection, ingestion, and absorption in filter-feeding bivalves. J Exp Mar Bio Ecol 91:77–92CrossRefGoogle Scholar
  90. Smith HV, Nichols RAB (2010) Cryptosporidium: detection in water and food. Exp Parasitol 124:61–79PubMedCrossRefGoogle Scholar
  91. Snel SJ, Baker MG, Kamalesh V et al (2009) A tale of two parasites: the comparative epidemiology of cryptosporidiosis and giardiasis. Epidemiol Infect 137:1641–1650PubMedCrossRefGoogle Scholar
  92. Staggs SE, Keely SP, Ware MW, Schable N, See MJ, Gregorio D, Zou X, Su C, Dubey JP, Villegas EN (2015) The development and implementation of a method using blue mussels (Mytilus spp.) as biosentinels of Cryptosporidium spp. and Toxoplasma gondii contamination in marine aquatic environments. Parasitol Res 114:4655–4667PubMedCrossRefGoogle Scholar
  93. Su C, Shwab EK, Zhou P et al (2010) Moving towards an integrated approach to molecular detection and identification of Toxoplasma gondii. Parasitology 137:1–11PubMedCrossRefGoogle Scholar
  94. Sugden K, Moffitt TE, Pinto L, Poulton R, Williams BS, Caspi A (2016) Is Toxoplasma gondii infection related to brain and behavior impairments in humans? Evidence from a population-representative birth cohort. PLoS One 11:e0148435PubMedPubMedCentralCrossRefGoogle Scholar
  95. Sukthana Y (2006) Toxoplasmosis: beyond animals to humans. Trends Parasitol 22:137–142PubMedCrossRefGoogle Scholar
  96. Tenter AM, Heckeroth AR, Weiss LM (2000) Toxoplasma gondii: from animals to humans. Int J Parasitol 30:1217–1258PubMedPubMedCentralCrossRefGoogle Scholar
  97. Till D, McBride G, Ball A, Taylor K, Pyle E (2008) Large-scale freshwater microbiological study: rationale, results and risks. J Water Health 6:443–460PubMedCrossRefGoogle Scholar
  98. Toze S (1999) PCR and the detection of microbial pathogens in water and wastewater. Water Res 33:3545–3556CrossRefGoogle Scholar
  99. Travaillé E, La Carbona S, Gargala G et al (2016) Development of a qRT-PCR method to assess the viability of Giardia intestinalis cysts, Cryptosporidium spp. and Toxoplasma gondii oocysts. Food Control 59:359–365CrossRefGoogle Scholar
  100. VanWormer E, Carpenter TE, Singh P, Shapiro K, Wallender WW, Conrad PA, Largier JL, Maneta MP, Mazet JAK (2016) Coastal development and precipitation drive pathogen flow from land to sea: evidence from a Toxoplasma gondii and felid host system. Sci Rep 6:29252PubMedPubMedCentralCrossRefGoogle Scholar
  101. VanWormer E, Fritz H, Shapiro K, Mazet JAK, Conrad PA (2013/5) Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface. Comp Immunol Microbiol Infect Dis 36:217–231PubMedCrossRefGoogle Scholar
  102. VanWormer E, Miller MA, Conrad PA, Grigg ME, Rejmanek D, Carpenter TE, Mazet JAK (2014) Using molecular epidemiology to track Toxoplasma gondii from terrestrial carnivores to marine hosts: implications for public health and conservation. PLoS Negl Trop Dis 8:e2852PubMedPubMedCentralCrossRefGoogle Scholar
  103. Venables WN, Ripley BD (2002) Modern applied statistics with S, Fourth edn. Springer, New York IBSN 0-387-95457-0CrossRefGoogle Scholar
  104. Verant ML, d’Ozouville N, Parker PG, Shapiro K, VanWormer E, Deem SL (2014) Attempted detection of Toxoplasma gondii oocysts in environmental waters using a simple approach to evaluate the potential for waterborne transmission in the Galápagos Islands, Ecuador. EcoHealth 11:207–214PubMedCrossRefGoogle Scholar
  105. Villegas EN, Augustine SAJ, Villegas LF, Ware MW, See MJ, Lindquist HDA, Schaefer FW III, Dubey JP (2010) Using quantitative reverse transcriptase PCR and cell culture plaque assays to determine resistance of Toxoplasma gondii oocysts to chemical sanitizers. J Microbiol Methods 81:219–225PubMedCrossRefGoogle Scholar
  106. Ware MW, Augustine SAJ, Erisman DO, See MJ, Wymer L, Hayes SL, Dubey JP, Villegas EN (2010) Determining UV inactivation of Toxoplasma gondii oocysts by using cell culture and a mouse bioassay. Appl Environ Microbiol 76:5140–5147PubMedPubMedCentralCrossRefGoogle Scholar
  107. Webster JP, Kaushik M, Bristow GC, McConkey GA (2013) Toxoplasma gondii infection, from predation to schizophrenia: can animal behaviour help us understand human behaviour? J Exp Biol 216:99–112PubMedPubMedCentralCrossRefGoogle Scholar
  108. Wells B, Shaw H, Innocent G, Guido S, Hotchkiss E, Parigi M, Opsteegh M, Green J, Gillespie S, Innes EA, Katzer F (2015) Molecular detection of Toxoplasma gondii in water samples from Scotland and a comparison between the 529bp real-time PCR and ITS1 nested PCR. Water Res 87:175–181PubMedCrossRefGoogle Scholar
  109. West DM (2002) Ovine abortion in New Zealand. N Z Vet J 50:93–95PubMedCrossRefGoogle Scholar
  110. Willis JE, McClure JT, Davidson J, McClure C, Greenwood SJ (2013) Global occurrence of Cryptosporidium and Giardia in shellfish: should Canada take a closer look? Food Res Int 52:119–135CrossRefGoogle Scholar
  111. Winkworth CL, Matthaei CD, Townsend CR (2008) Prevalence of Giardia and Cryptosporidium spp in calves from a region in New Zealand experiencing intensification of dairying. N Z Vet J 56:15–20PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Alicia Coupe
    • 1
    Email author
  • Laryssa Howe
    • 1
  • Elizabeth Burrows
    • 1
  • Abigail Sine
    • 1
  • Anthony Pita
    • 2
  • Niluka Velathanthiri
    • 2
  • Emilie Vallée
    • 1
  • David Hayman
    • 2
  • Karen Shapiro
    • 3
    • 4
  • Wendi D. Roe
    • 1
  1. 1.Institute of Veterinary, Animal and Biomedical Sciences, College of SciencesMassey UniversityPalmerston NorthNew Zealand
  2. 2.Molecular Epidemiology and Public Health Laboratory, Hopkirk Research InstituteMassey UniversityPalmerston NorthNew Zealand
  3. 3.One Health Institute, School of Veterinary MedicineUniversity of CaliforniaDavisUSA
  4. 4.Department of Pathology, Microbiology and Immunology, School of Veterinary MedicineUniversity of CaliforniaDavisUSA

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