{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T21:00:25Z","timestamp":1781643625052,"version":"3.54.5"},"reference-count":27,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,7,28]],"date-time":"2025-07-28T00:00:00Z","timestamp":1753660800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Human granulocytic anaplasmosis is an emerging tick-borne disease. Although Anaplasma phagocytophilum has been identified in vectors and animal reservoirs in Romania, evidence of human exposure has not yet been reported. This study aimed to generate initial evidence of human infection by evaluating A. phagocytophilum antibodies in individuals with recent tick exposure. We conducted a cross-sectional serosurvey between 2023 and 2024 at a tertiary care hospital in Bucharest, enrolling 80 participants 4 to 12 weeks following a tick bite. Serum IgG antibodies against A. phagocytophilum were detected using an indirect immunofluorescence assay, with a titer of \u22651:64 considered indicative of seropositivity. Eight (10%) participants tested positive for A. phagocytophilum IgG antibodies. Seropositivity was not significantly associated with demographics, geographical region, or clinical symptoms. However, fatigue and myalgia were more frequently seen in A. phagocytophilum IgG seropositive individuals. Notably, 43.8% of all participants reported erythema migrans, including five of the eight individuals with positive A. phagocytophilum IgG serology. This study provides the first serological evidence of human exposure to A. phagocytophilum in Romania. A 10% seroprevalence in this high-risk group suggests that anaplasmosis may be underrecognized. Clinicians should consider it in patients with tick exposure and compatible symptoms.<\/jats:p>","DOI":"10.3390\/microorganisms13081758","type":"journal-article","created":{"date-parts":[[2025,7,28]],"date-time":"2025-07-28T10:51:14Z","timestamp":1753699874000},"page":"1758","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Seroprevalence of Anaplasma phagocytophilum Antibodies Following Tick Bites: A Serosurvey in a Tertiary Care Hospital in Romania"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-7277-8499","authenticated-orcid":false,"given":"Cristina Alexandra","family":"Cheran","sequence":"first","affiliation":[{"name":"Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania"},{"name":"Department of Infectious Diseases, Bucharest Emergency University Hospital, 050098 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diana Gabriela","family":"Iacob","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania"},{"name":"Department of Infectious Diseases, Bucharest Emergency University Hospital, 050098 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Georgiana","family":"Neagu","sequence":"additional","affiliation":[{"name":"\u201cProf. Dr. Matei Bals\u201d National Institute of Infectious Diseases, 021105 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andreea Madalina","family":"Panciu","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania"},{"name":"\u201cProf. Dr. Matei Bals\u201d National Institute of Infectious Diseases, 021105 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6505-1699","authenticated-orcid":false,"given":"Adriana","family":"Hristea","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania"},{"name":"\u201cProf. Dr. Matei Bals\u201d National Institute of Infectious Diseases, 021105 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1186\/s13071-018-2756-1","article-title":"Molecular survey of neglected bacterial pathogens reveals an abundant diversity of species and genotypes in ticks collected from animal hosts across Romania","volume":"11","author":"Andersson","year":"2018","journal-title":"Parasites Vectors"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1186\/s13071-019-3852-6","article-title":"A review on the eco-epidemiology and clinical management of human granulocytic anaplasmosis and its agent in Europe","volume":"12","author":"Matei","year":"2019","journal-title":"Parasites Vectors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"106299","DOI":"10.1016\/j.actatropica.2021.106299","article-title":"Anaplasma phagocytophilum infection rates in questing and host-attached ticks: A global systematic review and meta-analysis","volume":"228","author":"Karshima","year":"2022","journal-title":"Acta Trop."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1007\/s10493-012-9568-3","article-title":"Ixodes ricinus is the dominant questing tick in forest habitats in Romania: The results from a countrywide dragging campaign","volume":"58","author":"Mihalca","year":"2012","journal-title":"Exp. Appl. Acarol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1196\/annals.1374.084","article-title":"Anaplasma phagocytophilum in ruminants in Europe","volume":"1078","author":"Woldehiwet","year":"2006","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Dumic, I., Jevtic, D., Veselinovic, M., Nordstrom, C.W., Jovanovic, M., Mogulla, V., Veselinovic, E.M., Hudson, A., Simeunovic, G., and Petcu, E. (2022). Human Granulocytic Anaplasmosis-A Systematic Review of Published Cases. Microorganisms, 10.","DOI":"10.3390\/microorganisms10071433"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1056\/NEJM199601253340401","article-title":"Direct cultivation of the causative agent of human granulocytic ehrlichiosis","volume":"334","author":"Goodman","year":"1996","journal-title":"N. Engl. J. Med."},{"key":"ref_8","first-page":"100830","article-title":"Worldwide meta-analysis on Anaplasma phagocytophilum infections in animal reservoirs: Prevalence, distribution and reservoir diversity","volume":"38","author":"Karshima","year":"2023","journal-title":"Vet. Parasitol. Reg. Stud. Rep."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"265","DOI":"10.4103\/0972-9062.364756","article-title":"Global status of Anaplasma phagocytophilum infections in human population: A 50-year (1970\u20132020) meta-analysis","volume":"60","author":"Karshima","year":"2023","journal-title":"J. Vector Borne Dis."},{"key":"ref_10","unstructured":"Spec, A., Escota, G., Chrisler, C., and Davies, B. (2019). Comprehensive Review of Infectious Diseases, Elsevier. [1st ed.]."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"669","DOI":"10.1016\/j.amjmed.2024.11.025","article-title":"Antibodies to Anaplasma phagocytophilum in Patients with Human Granulocytic Anaplasmosis Confirmed by Both Polymerase Chain Reaction and Culture","volume":"138","author":"Wormser","year":"2025","journal-title":"Am. J. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1093\/ajcp\/aqae126","article-title":"Culture and other direct detection methods to diagnose human granulocytic anaplasmosis","volume":"163","author":"Zentmaier","year":"2025","journal-title":"Am. J. Clin. Pathol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Zaj\u0105c, V., Bell-Sakyi, L., and W\u00f3jcik-Fatla, A. (2025). Use of Tick Cell Lines in Co-Infection Studies with a Preliminary Study of Co-Culture of Borrelia burgdorferi and Anaplasma phagocytophilum. Pathogens, 14.","DOI":"10.3390\/pathogens14010078"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"949","DOI":"10.7589\/JWD-D-20-00158","article-title":"Anaplasma phagocytophilum in Multiple Tissue Samples of Wild Carnivores in Romania","volume":"57","author":"Matei","year":"2021","journal-title":"J. Wildl. Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1186\/s13071-018-2791-y","article-title":"New records for Anaplasma phagocytophilum infection in small mammal species","volume":"11","author":"Matei","year":"2018","journal-title":"Parasites Vectors"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Bogdan, A.M., Ionita, M., and Mitrea, I.L. (2021). Serological Evidence of Natural Exposure to Tick-Borne Pathogens in Horses, Romania. Microorganisms, 9.","DOI":"10.3390\/microorganisms9020373"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Raileanu, C., Moutailler, S., Pavel, I., Porea, D., Mihalca, A.D., Savuta, G., and Vayssier-Taussat, M. (2017). Borrelia Diversity and Co-infection with Other Tick Borne Pathogens in Ticks. Front. Cell. Infect. Microbiol., 7.","DOI":"10.3389\/fcimb.2017.00036"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1016\/j.ttbdis.2016.12.013","article-title":"The risk of exposure to rickettsial infections and human granulocytic anaplasmosis associated with Ixodes ricinus tick bites in humans in Romania: A multiannual study","volume":"8","author":"Matei","year":"2017","journal-title":"Ticks Tick-Borne Dis."},{"key":"ref_19","unstructured":"(2023, March 27). DiaSorin Molecular Anaplasma phagocytophilum IFA IgG Assay (IF1450G) Package Insert\u2014Laboratory Specifications\u2014Available upon Request at MVZ Labor PD Dr. Volkmann und Kollegen GbR. Available online: https:\/\/laborvolkmann.de\/analysenspektrum\/HTML\/index.html."},{"key":"ref_20","first-page":"61","article-title":"Study on Tick Infestations of Small Ruminants in Southern Romania","volume":"69","author":"Dascalu","year":"2023","journal-title":"Sci. Work. Ser. C. Vet. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1016\/j.ijmm.2015.08.026","article-title":"Assessing the risk of human granulocytic anaplasmosis and lyme borreliosis after a tick bite in Bavaria, Germany","volume":"305","author":"Hautmann","year":"2015","journal-title":"Int. J. Med. Microbiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1007\/s00508-008-1000-y","article-title":"Serologic evidence of Anaplasma phagocytophilum infections in patients with a history of tick bite in central Slovakia","volume":"120","author":"Boldis","year":"2008","journal-title":"Wien. Klin. Wochenschr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/acr.24495","article-title":"Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 Guidelines for the Prevention, Diagnosis, and Treatment of Lyme Disease","volume":"73","author":"Lantos","year":"2021","journal-title":"Arthritis Care Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1186\/s13071-024-06449-5","article-title":"Incidence of symptomatic Borrelia burgdorferi sensu lato infection in Romania, 2018\u22122023","volume":"17","author":"Angulo","year":"2024","journal-title":"Parasites Vectors"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1016\/j.ttbdis.2015.03.010","article-title":"Anaplasma phagocytophilum in questing Ixodes ricinus ticks from Romania","volume":"6","author":"Matei","year":"2015","journal-title":"Ticks Tick-Borne Dis."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.cmi.2017.08.025","article-title":"To test or not to test? Laboratory support for the diagnosis of Lyme borreliosis: A position paper of ESGBOR, the ESCMID study group for Lyme borreliosis","volume":"24","author":"Dessau","year":"2018","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Panciu, A.M., Cheran, C.A., Militaru, E.D., R\u00eeciu, C.D., and Hristea, A. (2024). Serosurvey of Tick-Borne Encephalitis Virus Infection in Romania. Pathogens, 13.","DOI":"10.3390\/pathogens13030231"}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/8\/1758\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:17:16Z","timestamp":1760033836000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/8\/1758"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,28]]},"references-count":27,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2025,8]]}},"alternative-id":["microorganisms13081758"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms13081758","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,28]]}}}