{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T20:59:33Z","timestamp":1791233973587,"version":"4.1.0"},"reference-count":28,"publisher":"Wildlife Disease Association","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Wildlife Diseases"],"published-print":{"date-parts":[[2026,7,3]]},"abstract":"<jats:p>Toxoplasma gondii\u2014the causative agent of toxoplasmosis\u2014is a zoonotic pathogen of warm-blooded hosts. Infection causes mild-to-severe symptoms, including lethargy, fever, muscle pain, abortion, ocular disease, and encephalitis. Toxoplasma affects many vertebrate species, although felids are the only known definitive hosts. Seroprevalence in wildlife is often assessed using cross-sectional data, but few studies have tracked individual-level infections through time. We present a 4-yr dataset from white-tailed deer (Odocoileus virginianus) with repeated sampling of individuals that highlights challenges associated with assigning serostatus to individuals. Using a modified agglutination test, we observed seroconversion from seronegative to seropositive within individuals, as expected. Although toxoplasmosis is known to be a chronic disease, we also found reversion from seropositive to seronegative. Accurate assignment of serostatus is necessary for evaluating effects of infection on behavioral and physiologic outcomes. However, longitudinal data from individuals whose titers oscillate around the positive threshold present novel challenges. Therefore, we discuss the implications for assigning serostatus for chronic toxoplasmosis infection for three proposed approaches: 1) ever positive, always positive; 2) negative until positive and then always positive; and 3) status by sampling period. Clarifying which approach is used to assign serostatus when analyzing longitudinal T. gondii data may enable more meaningful comparisons across systems and studies.<\/jats:p>","DOI":"10.7589\/jwd-d-25-00216","type":"journal-article","created":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T08:59:13Z","timestamp":1783069153000},"page":"708-714","source":"Crossref","is-referenced-by-count":0,"title":["Toxoplasma gondii: Challenges and Perspectives in Interpreting Longitudinal Seroprevalence Data for a Chronic Parasitic Infection"],"prefix":"10.7589","volume":"62","author":[{"given":"Kendall L.","family":"Bancroft","sequence":"first","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Connor J.","family":"Meyer","sequence":"additional","affiliation":[{"name":"W.A. Franke College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, Montana 59812, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emily J.","family":"Jenkins","sequence":"additional","affiliation":[{"name":"Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 0X1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul C.","family":"Cross","sequence":"additional","affiliation":[{"name":"U.S. Geological Survey, Northern Rocky Mountain Science Center, 2327 University Way, Bozeman, Montana 59715, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Randy W.","family":"DeYoung","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aaron M.","family":"Foley","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miranda L.","family":"Hopper","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin T.","family":"Lovasik","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Landon R.","family":"Schofield","sequence":"additional","affiliation":[{"name":"East Foundation, 200 Concord Plaza Drive, San Antonio, Texas 78216, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bryan D.","family":"Spencer","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael J.","family":"Cherry","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alynn M.","family":"Martin","sequence":"additional","affiliation":[{"name":"Caesar Kleberg Wildlife Research Institute, Texas A&M University\u2013Kingsville, 700 University Boulevard, Kingsville, Texas 78363, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"4415","reference":[{"key":"15","doi-asserted-by":"crossref","unstructured":"EJ Jenkins, A Simon, N Bachand, et al.  \"Trends Parasitol.\"  31, \"Wildlife parasites in a One Health world.\" 174 (2015)","DOI":"10.1016\/j.pt.2015.01.002"},{"key":"1","doi-asserted-by":"crossref","unstructured":"\u00c9 Bouchard, SA Elmore, RT Alisauskas, et al.  \"J Wildl Dis.\"  55, \"Transmission dynamics of Toxoplasma gondii in arctic foxes (Vulpes lagopus): A long-term mark-recapture serologic study at Karrak Lake, Nunavut, Canada.\" 619 (2018)","DOI":"10.7589\/2018-06-144"},{"key":"3","doi-asserted-by":"crossref","unstructured":"D Contopoulos-Ioannidis  and JG Montoya  \"Principles and practice of pediatric infectious diseases.\"  \"Toxoplasma gondii (toxoplasmosis).\" 1352 (2018)","DOI":"10.1016\/B978-0-323-40181-4.00273-5"},{"key":"4","doi-asserted-by":"crossref","unstructured":"JM Corpa, A Garc\u00eda-Quir\u00f3s, M Casares, et al.  \"Vet Parasitol.\"  193, \"Encephalomyelitis by Toxoplasma gondii in a captive fossa (Cryptoprocta ferox).\" 281 (2013)","DOI":"10.1016\/j.vetpar.2012.11.018"},{"key":"6","doi-asserted-by":"crossref","unstructured":"FM Dini, JGP Jacinto, D Cavallini, et al.  \"Parasitol Res.\"  123, \"Observational longitudinal study on Toxoplasma gondii infection in fattening beef cattle: serology and associated haematological findings.\" 169 (2024)","DOI":"10.1007\/s00436-024-08189-y"},{"key":"7","doi-asserted-by":"crossref","unstructured":"JP. Dubey,  \"Vet Parasitol.\"  22, \"A review of toxoplasmosis in cattle.\" 177 (1986)","DOI":"10.1016\/0304-4017(86)90106-8"},{"key":"8","doi-asserted-by":"crossref","unstructured":"JP. Dubey,  \"Toxoplasmosis of animals and humans.\"  (2021a)","DOI":"10.1201\/9781003199373"},{"key":"9","doi-asserted-by":"crossref","unstructured":"JP. Dubey,  \"Parasit Vectors.\"  14, \"Outbreaks of clinical toxoplasmosis in humans: Five decades of personal experience, perspectives and lessons learned.\" 263 (2021b)","DOI":"10.1186\/s13071-021-04769-4"},{"key":"11","doi-asserted-by":"crossref","unstructured":"JP Dubey, FHA Murata, CK Cerqueira-C\u00e9zar, et al.  \"Parasit Vectors.\"  14, \"Recent aspects on epidemiology, clinical disease, and genetic diversity of Toxoplasma gondii infections in Australasian marsupials.\" 301 (2021)","DOI":"10.1186\/s13071-021-04793-4"},{"key":"13","doi-asserted-by":"crossref","unstructured":"J. Flegr,  \"Curr Clin Microbiol Rep.\"  2, \"Neurological and neuropsychiatric consequences of chronic Toxoplasma infection.\" 163 (2015)","DOI":"10.1007\/s40588-015-0024-0"},{"key":"14","doi-asserted-by":"crossref","unstructured":"EA Fisk, EF Cassirer, KS Huggler, et al.  \"J Wildl Dis.\"  59, \"Abortion and neonatal mortality due to Toxoplasma gondii in bighorn sheep (Ovis canadensis).\" 37 (2023)","DOI":"10.7589\/JWD-D-22-00057"},{"key":"16","doi-asserted-by":"crossref","unstructured":"SK Johnson  and PTJ Johnson  \"Annu Rev Anim Biosci.\"  9, \"Toxoplasmosis: Recent advances in understanding the link between infection and host behavior.\" 249 (2021)","DOI":"10.1146\/annurev-animal-081720-111125"},{"key":"18","doi-asserted-by":"crossref","unstructured":"KE McGovern, CM Cabral, HW Morrison, et al.  \"Sci Rep.\"  10, \"Aging with Toxoplasma gondii results in pathogen clearance, resolution of inflammation, and minimal consequences to learning and memory.\" 7979 (2020)","DOI":"10.1038\/s41598-020-64823-6"},{"key":"19","doi-asserted-by":"crossref","unstructured":"CJ Meyer, KA Cassidy, EE Stahler, et al.  \"Commun Biol.\"  5, \"Parasitic infection increases risk-taking in a social, intermediate host carnivore.\" 1180 (2022)","DOI":"10.1038\/s42003-022-04122-0"},{"key":"20","doi-asserted-by":"crossref","unstructured":"M Nava, L Corlatti, N Formenti, et al.  \"Biol Lett.\"  19, \"Parasite-mediated manipulation? Toxoplasma gondii infection increases risk behaviour towards culling in red deer.\" 20230292 (2023)","DOI":"10.1098\/rsbl.2023.0292"},{"key":"22","doi-asserted-by":"crossref","unstructured":"F Robert-Gangneux  and M-L Dard\u00e9  \"Clin Microbiol Rev.\"  25, \"Epidemiology of and diagnostic strategies for toxoplasmosis.\" 264 (2012)","DOI":"10.1128\/CMR.05013-11"},{"key":"23","doi-asserted-by":"crossref","unstructured":"S Salom\u00e8, C Grieco, PF Barra, et al.  \"Ital J Pediatr.\"  48, \"Specific antibody titer decay in neonates prenatally exposed to Toxoplasma gondii and their mothers.\" 63 (2022)","DOI":"10.1186\/s13052-022-01261-2"},{"key":"24","doi-asserted-by":"crossref","unstructured":"RM Shaapan, FA El-Nawawi, MAA Tawfik,  \"Vet Parasitol.\"  153, \"Sensitivity and specificity of various serological tests for the detection of Toxoplasma gondii infection in naturally infected sheep.\" 359 (2008)","DOI":"10.1016\/j.vetpar.2008.02.016"},{"key":"25","doi-asserted-by":"crossref","unstructured":"AC Steere, G McHugh, N Damle, et al.  \"Clin Infect Dis.\"  47, \"Prospective study of serologic tests for Lyme disease.\" 188 (2008)","DOI":"10.1086\/589242"},{"key":"26","doi-asserted-by":"crossref","unstructured":"Y. Suzuki,  \"Parasitol Int.\"  81, \"A pathway to cure chronic infection with Toxoplasma gondii through immunological intervention.\" 102259 (2021)","DOI":"10.1016\/j.parint.2020.102259"},{"key":"27","doi-asserted-by":"crossref","unstructured":"JA Vargas-Villavicencio, I Ca\u00f1edo-Solares, D Correa,  \"Microorganisms.\"  10, \"Anti-Toxoplasma gondii IgM long persistence: What are the underlying mechanisms?\" 1659 (2022)","DOI":"10.3390\/microorganisms10081659"},{"key":"28","doi-asserted-by":"crossref","unstructured":"JP Webster  and GA McConkey  \"Folia Parasitol.\"  57, \"Toxoplasma gondiialtered host behaviour: Clues as to mechanism of action.\" 95 (2010)","DOI":"10.14411\/fp.2010.012"},{"key":"17","doi-asserted-by":"crossref","unstructured":"Z Kol\u00f6ren, CK Cerqueira-C\u00e9zar, FHA Murata, et al.  \"J Parasitol.\"  105, \"High seroprevalence but low rate of isolation of Toxoplasma gondii from wild elk (Cervus canadensis) in Pennsylvania.\" 890 (2019)","DOI":"10.1645\/19-110"},{"key":"21","doi-asserted-by":"crossref","unstructured":"A Olsen, L Alban, M Denwood, et al.  \"Vet Parasitol.\"  295, \"A longitudinal study of Toxoplasma gondii seroconversion on four large Danish sow farms.\" 109460 (2021)","DOI":"10.1016\/j.vetpar.2021.109460"},{"key":"5","doi-asserted-by":"publisher","unstructured":"D Denk, S De Neck, S Khaliq, et al.  \"Animals.\"  12, \"Toxoplasmosis in zoo animals: A retrospective pathology review of 126 cases.\" 619 (2022)","DOI":"10.3390\/ani12050619"},{"key":"10","doi-asserted-by":"crossref","unstructured":"JP Dubey  and JL Jones  \"Int J Parasitol.\"  38, \"Toxoplasma gondii infection in humans and animals in the United States.\" 1257 (2008)","DOI":"10.1016\/j.ijpara.2008.03.007"},{"key":"12","doi-asserted-by":"crossref","unstructured":"S Fernandes, P Brilhante-Sim\u00f5es, T Coutinho, et al.  \"J Vet Diagn Invest.\"  31, \"Comparison of indirect and modified agglutination tests for detection of antibodies to Toxoplasma gondii in domestic cats.\" 774 (2019)","DOI":"10.1177\/1040638719868753"},{"key":"2","doi-asserted-by":"crossref","unstructured":"RA Casagrande, HFJ Pena, AD Cabral, et al.  \"Int J Parasitol Parasites Wildl.\"  4, \"Fatal systemic toxoplasmosis in Valley quail (Callipepla californica).\" 264 (2015)","DOI":"10.1016\/j.ijppaw.2015.04.003"}],"container-title":["Journal of Wildlife Diseases"],"original-title":[],"deposited":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T20:43:10Z","timestamp":1791232990000},"score":1,"resource":{"primary":{"URL":"https:\/\/bioone.org\/journals\/journal-of-wildlife-diseases\/volume-62\/issue-3\/JWD-D-25-00216\/Toxoplasma-gondii--Challenges-and-Perspectives-in-Interpreting-Longitudinal-Seroprevalence\/10.7589\/JWD-D-25-00216.full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,3]]},"references-count":28,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,7,1]]}},"URL":"https:\/\/doi.org\/10.7589\/jwd-d-25-00216","relation":{},"ISSN":["0090-3558","1943-3700"],"issn-type":[{"value":"0090-3558","type":"print"},{"value":"1943-3700","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,3]]}}}