{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T15:38:01Z","timestamp":1787067481630,"version":"build-2736575974"},"reference-count":55,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,10,14]],"date-time":"2020-10-14T00:00:00Z","timestamp":1602633600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Leptospirosis in New Zealand has been strongly associated with animal-contact occupations and with serovars Hardjo and Pomona. However, recent data suggest changes in these patterns, hence, serovar-specific epidemiology of leptospirosis from 1999 to 2017 was investigated. The 19-year average annual incidence is 2.01\/100,000. Early (1999\u20132007) and late (2008\u20132017) study period comparisons showed a significant increase in notifications with serovar Ballum (IRR: 1.59, 95% CI: 1.22\u20132.09) in all cases and serovar Tarassovi (IRR: 1.75, 95% CI: 1.13\u20132.78) in Europeans and a decrease in notifications with serovars Hardjo and Pomona in all cases. Incidences of Ballum peaked in winter, Hardjo peaked in spring and Tarassovi peaked in summer. Incidence was highest in M\u0101ori (2.24\/100,000) with dominant serovars being Hardjo and Pomona. Stratification by occupation showed meat workers had the highest incidence of Hardjo (57.29\/100,000) and Pomona (45.32\/100,000), farmers had the highest incidence of Ballum (11.09\/100,000) and dairy farmers had the highest incidence of Tarassovi (12.59\/100,000). Spatial analysis showed predominance of Hardjo and Pomona in Hawke\u2019s Bay, Ballum in West Coast and Northland and Tarassovi in Waikato, Taranaki and Northland. This study highlights the serovar-specific heterogeneity of human leptospirosis in New Zealand that should be considered when developing control and prevention strategies.<\/jats:p>","DOI":"10.3390\/pathogens9100841","type":"journal-article","created":{"date-parts":[[2020,10,14]],"date-time":"2020-10-14T21:24:39Z","timestamp":1602710679000},"page":"841","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Diverse Epidemiology of Leptospira Serovars Notified in New Zealand, 1999\u20132017"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1721-0808","authenticated-orcid":false,"given":"Shahista","family":"Nisa","sequence":"first","affiliation":[{"name":"Molecular Epidemiology and Public Health Laboratory, Hopkirk Research Institute, School of Veterinary Science, Massey University, Palmerston North 4474, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9986-6212","authenticated-orcid":false,"given":"David","family":"Wilkinson","sequence":"additional","affiliation":[{"name":"New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North 4474, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7708-2919","authenticated-orcid":false,"given":"Olivia","family":"Angelin-Bonnet","sequence":"additional","affiliation":[{"name":"School of Fundamental Sciences, College of Sciences, Massey University, Palmerston North 4474, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shevaun","family":"Paine","sequence":"additional","affiliation":[{"name":"Institute of Environmental Science and Research, Wellington 5022, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karen","family":"Cullen","sequence":"additional","affiliation":[{"name":"Institute of Environmental Science and Research, Wellington 5022, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6462-4769","authenticated-orcid":false,"given":"Jackie","family":"Wright","sequence":"additional","affiliation":[{"name":"Institute of Environmental Science and Research, Wellington 5022, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1865-1536","authenticated-orcid":false,"given":"Michael","family":"Baker","sequence":"additional","affiliation":[{"name":"Department of Public Health, University of Otago, Wellington 6021, New Zealand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7814-4341","authenticated-orcid":false,"given":"Jackie","family":"Benschop","sequence":"additional","affiliation":[{"name":"Molecular Epidemiology and Public Health Laboratory, Hopkirk Research Institute, School of Veterinary Science, Massey University, Palmerston North 4474, New Zealand"},{"name":"Global Leptospirosis Environmental Action Network, World Health Organization, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.vetmic.2009.03.012","article-title":"Leptospira and leptospirosis","volume":"140","author":"Adler","year":"2010","journal-title":"Vet. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Costa, F., Hagan, J.E., Calcagno, J., Kane, M., Torgerson, P., Martinez-Silveira, M.S., Stein, C., Abela-Ridder, B., and Ko, A.I. (2015). Global morbidity and mortality of leptospirosis: A systematic review. PLoS Negl. Trop. Dis., 9.","DOI":"10.1371\/journal.pntd.0003898"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Torgerson, P.R., Hagan, J.E., Costa, F., Calcagno, J., Kane, M., Martinez-Silveira, M.S., Goris, M.G.A., Stein, C., Ko, A.I., and Abela-Ridder, B. (2015). Global burden of leptospirosis: Estimated in terms of disability adjusted life years. PLoS Negl. Trop. Dis., 9.","DOI":"10.1371\/journal.pntd.0004122"},{"key":"ref_4","first-page":"65","article-title":"Leptospirosis in humans","volume":"387","author":"Haake","year":"2015","journal-title":"Curr. Top. Microbiol. Immunol."},{"key":"ref_5","first-page":"102","article-title":"Leptospirosis in three workers on a dairy farm with unvaccinated cattle","volume":"130","author":"Benschop","year":"2017","journal-title":"N. Z. Med. J."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Goris, M.G.A., Kikken, V., Straetemans, M., Alba, S., Goeijenbier, M., Van Gorp, E.C.M., Boer, K.R., Wagenaar, J.F.P., and Hartskeerl, R.A. (2013). Towards the burden of human leptospirosis: Duration of acute illness and occurrence of post-leptospirosis symptoms of patients in The Netherlands. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0076549"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1016\/S1473-3099(03)00830-2","article-title":"Leptospirosis: A zoonotic disease of global importance","volume":"3","author":"Bharti","year":"2003","journal-title":"Lancet Infect. Dis."},{"key":"ref_8","first-page":"e000144","article-title":"Deciphering the unexplored Leptospira diversity from soils uncovers genomic evolution to virulence","volume":"4","author":"Thibeaux","year":"2018","journal-title":"Microb. Genom."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Vincent, A.T., Schiettekatte, O., Goarant, C., Neela, V.K., Bernet, E., Thibeaux, R., Ismail, N., Khalid, M.K.N.M., Amran, F., and Masuzawa, T. (2019). Revisiting the taxonomy and evolution of pathogenicity of the genus Leptospira through the prism of genomics. PLoS Negl. Trop. Dis., 13.","DOI":"10.1371\/journal.pntd.0007270"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1038\/nrmicro.2017.5","article-title":"Virulence of the zoonotic agent of leptospirosis: Still terra incognita?","volume":"15","author":"Picardeau","year":"2017","journal-title":"Nat. Rev. Genet."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Dunay, S.N., Bass, J., and Stremick, J. (2016). Leptospirosis: A global health burden in review. Emerg. Med. Open Access, 6.","DOI":"10.4172\/2165-7548.1000336"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1111\/1753-6405.12946","article-title":"Leopold kirschner, Edward Sayers, and Neil Bru\u00e8re: The initial descriptions of leptospirosis in New Zealand","volume":"44","author":"Whitcombe","year":"2019","journal-title":"Aust. N. Z. J. Public Health"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1080\/00480169.2002.36270","article-title":"Fifty years of leptospirosis research in New Zealand: A perspective","volume":"50","author":"Marshall","year":"2002","journal-title":"N. Z. Vet. J."},{"key":"ref_14","first-page":"27","article-title":"Vaccination of dairy cattle against leptospirosis as a means of preventing human infections","volume":"23","author":"Marshall","year":"1996","journal-title":"Surveillance"},{"key":"ref_15","first-page":"15","article-title":"Porcine leptospirosis in New Zealand","volume":"24","author":"Fairly","year":"1997","journal-title":"Surveillance"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1017\/S0950268801006392","article-title":"Changing epidemiology of human leptospirosis in New Zealand","volume":"128","author":"Thornley","year":"2002","journal-title":"Epidemiol. Infect."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/j.actatropica.2018.08.021","article-title":"Update on the status of leptospirosis in New Zealand","volume":"188","author":"Bruce","year":"2018","journal-title":"Acta Trop."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2095","DOI":"10.1017\/S0950268814002477","article-title":"Risk of infection and associated influenza-like disease among abattoir workers due to two Leptospira species","volume":"143","author":"Dreyfus","year":"2015","journal-title":"Epidemiol. Infect."},{"key":"ref_19","first-page":"13","article-title":"A cluster of three cases of leptospirosis in dairy farm workers in New Zealand","volume":"127","author":"McLean","year":"2014","journal-title":"N. Z. Med. J."},{"key":"ref_20","first-page":"39","article-title":"Sero-prevalence of leptospirosis in workers at a New Zealand slaughterhouse","volume":"122","author":"Benschop","year":"2009","journal-title":"N. Z. Med. J."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1080\/09603120601124181","article-title":"Chemical exposure among NZ farmers","volume":"17","author":"Firth","year":"2007","journal-title":"Int. J. Environ. Health Res."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Smythe, L.D., Smith, I.L., Smith, G.A., Dohnt, M.F., Symonds, M.L., Barnett, L.J., and McKay, D.B. (2002). A quantitative PCR (TaqMan) assay for pathogenic Leptospira spp. BMC Infect. Dis., 2.","DOI":"10.1186\/1471-2334-2-13"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"104727","DOI":"10.1016\/j.prevetmed.2019.104727","article-title":"Emerging Leptospira strain poses public health risk for dairy farmers in New Zealand","volume":"170","author":"Yupiana","year":"2019","journal-title":"Prev. Vet. Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1111\/zph.12317","article-title":"Seroprevalence and risk factors for leptospira seropositivity in beef cattle, sheep and deer farmers in New Zealand","volume":"64","author":"Sanhueza","year":"2016","journal-title":"Zoonoses Public Health"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1136\/oemed-2014-102457","article-title":"Risk factors for new infection with Leptospira in meat workers in New Zealand","volume":"72","author":"Dreyfus","year":"2014","journal-title":"Occup. Environ. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1080\/00480169.1980.34774","article-title":"Leptospira interrogans serovar balcanica in cattle","volume":"28","author":"Mackintosh","year":"1980","journal-title":"N. Z. Vet. J."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"345","DOI":"10.7589\/0090-3558-14.3.345","article-title":"The serologic and cultural prevalence of leptospira interrogans serovar balcanica in possums (trichosurus vulpecula) in New Zealand","volume":"14","author":"Hathaway","year":"1978","journal-title":"J. Wildl. Dis."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Mwachui, M.A., Crump, L., Hartskeerl, R., Zinsstag, J., and Hattendorf, J. (2015). Environmental and behavioural determinants of leptospirosis transmission: A systematic review. PLoS Negl. Trop. Dis., 9.","DOI":"10.1371\/journal.pntd.0003843"},{"key":"ref_29","first-page":"30","article-title":"Is wildlife a source of Leptospira infection in livestock in New Zealand","volume":"Volume 332","author":"Moinet","year":"2017","journal-title":"Proceedings of the Society of Dairy Cattle Veterinarians of the NZVA Annual Conference\u20142017 Proceedings of the Society of Dairy Cattle Veterinarians Annual Conference"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1017\/S0950268813001775","article-title":"Leptospirosis in Ireland: Annual incidence and exposures associated with infection","volume":"142","author":"Garvey","year":"2013","journal-title":"Epidemiol. Infect."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1048","DOI":"10.3201\/eid1107.041172","article-title":"Leptospirosis in Germany, 1962\u20132003","volume":"11","author":"Jansen","year":"2005","journal-title":"Emerg. Infect. Dis."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1023\/A:1007658607963","article-title":"Epidemiological trend of human leptospirosis in Italy between 1994 and 1996","volume":"16","author":"Ciceroni","year":"2000","journal-title":"Eur. J. Epidemiol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.ijid.2005.02.010","article-title":"Trends in leptospirosis epidemiology in France. Sixty-six years of passive serological surveillance from 1920 to 2003","volume":"10","author":"Baranton","year":"2006","journal-title":"Int. J. Infect. Dis."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2167","DOI":"10.1007\/s10096-012-1551-8","article-title":"Long-term trends in the epidemiology of human leptospirosis (Slovak Republic, 1954\u20132006)","volume":"31","author":"Bakoss","year":"2012","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.jmii.2013.03.001","article-title":"Laboratory diagnosis of leptospirosis: A challenge","volume":"46","author":"Musso","year":"2013","journal-title":"J. Microbiol. Immunol. Infect."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1093\/biosci\/biv012","article-title":"Predator-free New Zealand: Conservation country","volume":"65","author":"Russell","year":"2015","journal-title":"Bioscience"},{"key":"ref_37","unstructured":"(2020, September 04). Statistics New Zealand, Available online: https:\/\/www.stats.govt.nz\/indicators\/livestock-numbers#:~:text=The%20largest%20number%20of%20dairy,5%20million%20to%203.6%20million).&text=Total%20cattle%20have%20increased%20from,and%203.6%20million%20beef%20cattle)."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.tmaid.2009.12.002","article-title":"Leptospirosis: An emerging disease in travellers","volume":"8","author":"Lau","year":"2010","journal-title":"Travel Med. Infect. Dis."},{"key":"ref_39","unstructured":"(2020, March 04). Communicable Disease Control Manual, Available online: https:\/\/www.health.govt.nz\/our-work\/diseases-and-conditions\/communicable-disease-control-manual\/leptospirosis#casedef."},{"key":"ref_40","unstructured":"(2020, March 04). Ethnicity Code Tables, Available online: https:\/\/www.health.govt.nz\/nz-health-statistics\/data-references\/code-tables\/common-code-tables\/ethnicity-code-tables."},{"key":"ref_41","unstructured":"(2020, March 04). Statistics New Zealand, Available online: https:\/\/www.stats.govt.nz\/topics\/census."},{"key":"ref_42","unstructured":"(2020, January 31). District Health Board Boundaries. Available online: https:\/\/koordinates.com\/layer\/4324-nz-district-health-boards-2012\/."},{"key":"ref_43","unstructured":"StataCorp (2015). Stata Statistical Software: Release 14, StataCorp LP."},{"key":"ref_44","unstructured":"R Core Team (2020). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing."},{"key":"ref_45","unstructured":"Wickham, H., and Fran\u00e7ois, R. (2020, October 09). Dplyr: A Grammar of Data Manipulation. Available online: https:\/\/CRAN.R-project.org\/package=dplyr."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1686","DOI":"10.21105\/joss.01686","article-title":"Welcome to the Tidyverse","volume":"4","author":"Wickham","year":"2019","journal-title":"J. Open Source Softw."},{"key":"ref_47","unstructured":"Wickham, H. (2020, October 09). Forcats: Tools for Working with Categorical Variables (Factors); R Package Version 0.5.0. Available online: https:\/\/CRAN.R-project.org\/package=forcats."},{"key":"ref_48","unstructured":"Stevenson, M., Nunes, T., Sanchez, J., Thornton, R., Reiczigel, J., Robison-Cox, J., and Sebastiani, P. (2020, October 09). EpiR: An. R Package for the Analysis of Epidemiological Data. 2013. Available online: https:\/\/CRAN.R-project.org\/package=epiR."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Wickham, H. (2016). Ggplot2: Elegant Graphics for Data Analysis, Springer.","DOI":"10.1007\/978-3-319-24277-4_9"},{"key":"ref_50","unstructured":"Keitt, T., Bivand, R., Pebesma, E., and Rowlingson, B. (2020, October 09). Rgdal: Bindings for the Geospatial Data Abstraction Library; R package Version 0.6-27. Available online: https:\/\/CRAN.R-project.org\/package=rgdal."},{"key":"ref_51","unstructured":"Auguie, B. (2020, October 09). GridExtra: Miscellaneous Functions for \u201cGrid\u201d Graphics; R Package Version 2.3. Available online: https:\/\/www.R-project.org\/."},{"key":"ref_52","unstructured":"Urbanek, S. (2020, October 09). Png: Read. and Write PNG Images; R Package Version 0.1-7. Available online: https:\/\/CRAN.R-project.org\/package=png."},{"key":"ref_53","unstructured":"Baquero, O.S. (2020, October 09). Ggsn: North. Symbols and Scale Bars for Maps Created with \u2019ggplot2\u2019 or \u2019ggmap\u2019; R Package Version. Available online: https:\/\/github.com\/oswaldosantos\/ggsn."},{"key":"ref_54","unstructured":"Becker, R.A., Wilks, A.R., Brownrigg, R., Minka, T.P., and Deckmyn, A. (2020, October 09). Maps: Draw Geographical Maps; R Package Version 3.3.0. Available online: https:\/\/CRAN.R-project.org\/package=maps."},{"key":"ref_55","unstructured":"Bivand, R., and Lewin-Koh, N. (2020, October 09). Maptools: Tools for Handling Spatial Objects; R Package Version 0.9-9. Available online: https:\/\/CRAN.R-project.org\/package=maptools."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/9\/10\/841\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:21:18Z","timestamp":1760178078000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/9\/10\/841"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,10,14]]},"references-count":55,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2020,10]]}},"alternative-id":["pathogens9100841"],"URL":"https:\/\/doi.org\/10.3390\/pathogens9100841","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,14]]}}}