{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T11:04:02Z","timestamp":1768215842089,"version":"3.49.0"},"reference-count":39,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,11]],"date-time":"2026-01-11T00:00:00Z","timestamp":1768089600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Eosinophilia is a valuable biomarker for estimating the likelihood of parasitic infection in immigrants from tropical or subtropical regions. This study aimed to evaluate the frequency and etiology of imported eosinophilia in patients attending the Tropical Medicine Unit (TMU) of Salamanca, Spain, between 2008 and 2023. A total of 773 immigrant patients were assessed: 450 (58.2%) from Africa, 306 (39.6%) from Latin America, and 17 (2.2%) from Asia. Eosinophilia was observed in 338 patients (43.7%), of whom 15 (4.4%) had noninfectious causes. Among the remaining 323 evaluated for infections, 171 (52.9%) presented with relative eosinophilia and 152 (47.1%) presented with absolute eosinophilia. A specific diagnosis was reached in 49.2% of the cases, most commonly filariasis (12.1%), strongyloidiasis (9.9%), and schistosomiasis (4.6%): 58 patients had coinfections. In conclusion, eosinophilia is common among migrants and represents a valuable biomarker for helminthiasis. Despite protocolized evaluation, nearly half of the cases remain undiagnosed. The most frequent etiologies were filariasis, strongyloidiasis, and schistosomiasis, with African patients having the highest probability of diagnosis. Improved diagnostic approaches, including tests for less common parasites, may reduce uncertainty and enhance clinical management.<\/jats:p>","DOI":"10.3390\/tropicalmed11010020","type":"journal-article","created":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T07:30:34Z","timestamp":1768203034000},"page":"20","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Imported Eosinophilia in Migrants from Endemic Areas in Spain"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-1106-2284","authenticated-orcid":false,"given":"Laura","family":"Ni\u00f1o-Puerto","sequence":"first","affiliation":[{"name":"Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bel\u00e9n","family":"Vicente","sequence":"additional","affiliation":[{"name":"Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5055-826X","authenticated-orcid":false,"given":"Juan","family":"Hern\u00e1ndez-Goenaga","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Internal Medicine and Microbiology, University Hospital of Salamanca, Biomedical Research Institute of Salamanca, Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4439-7877","authenticated-orcid":false,"given":"Javier","family":"Pardo Lled\u00edas","sequence":"additional","affiliation":[{"name":"IDIVAL (Instituto de Investigaci\u00f3n Valdecilla), Internal Medicine Service, Hospital Marqu\u00e9s de Valdecilla, University of Cantabria, 39005 Santander, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5981-8785","authenticated-orcid":false,"given":"Juan Luis","family":"Mu\u00f1oz Bellido","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Internal Medicine and Microbiology, University Hospital of Salamanca, Biomedical Research Institute of Salamanca, Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2230-1256","authenticated-orcid":false,"given":"Moncef","family":"Belhassen-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Internal Medicine and Microbiology, University Hospital of Salamanca, Biomedical Research Institute of Salamanca, Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0244-4740","authenticated-orcid":false,"given":"Antonio","family":"Muro","sequence":"additional","affiliation":[{"name":"Infectious and Tropical Diseases Research Group (e-INTRO), Biomedical Research Institute of Salamanca Research Centre for Tropical Diseases at the University of Salamanca (IBSAL-CIETUS), 37007 Salamanca, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.mcna.2019.08.005","article-title":"Approach to Patients with Eosinophilia","volume":"104","author":"Kuang","year":"2020","journal-title":"Med. Clin. N. Am."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1016\/j.pop.2016.07.010","article-title":"Eosinophilia","volume":"43","author":"Kovalszki","year":"2016","journal-title":"Prim. Care: Clin. Off. Pract."},{"key":"ref_3","unstructured":"P\u00e9rez-Arellano, J.L., and Muro-\u00c1lvarez, A. (2006). Conducta Diagn\u00f3stica y Terap\u00e9utica Ante Una Eosinofilia Importada. Jano Med. Humanidades, 17\u201323."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e43","DOI":"10.1097\/MD.0000000000000043","article-title":"Relevance of Eosinophilia and Hyper-IgE in Immigrant Children","volume":"93","author":"Muro","year":"2014","journal-title":"Medicine"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/j.jinf.2017.08.007","article-title":"The Changing Aetiology of Eosinophilia in Migrants and Returning Travellers in the Hospital for Tropical Diseases, London 2002\u20132015: An Observational Study","volume":"75","author":"Barrett","year":"2017","journal-title":"J. Infect."},{"key":"ref_6","first-page":"62","article-title":"[Diagnosis and Treatment of Imported Eosinophilia in Travellers and Immigrants: Recommendations of the Spanish Society of Tropical Medicine and International Health (SEMTSI)]","volume":"30","year":"2017","journal-title":"Rev. Esp. Quim."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1016\/j.eimc.2016.10.007","article-title":"Aproximaci\u00f3n Cl\u00ednica a La Eosinofilia Importada","volume":"34","year":"2016","journal-title":"Enferm. Infecc. Microbiol. Clin."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3428","DOI":"10.1016\/j.med.2018.06.007","article-title":"Protocolo Diagn\u00f3stico de La Afectaci\u00f3n Hematol\u00f3gica Importada","volume":"12","author":"Torres","year":"2018","journal-title":"Med.-Programa Form. M\u00e9dica Contin. Acreditado"},{"key":"ref_9","first-page":"617","article-title":"Eosinophilia Prevalence and Related Factors in Travel and Immigrants of the Network +REDIVI","volume":"35","author":"Monge","year":"2017","journal-title":"Enfermedades Infecc. Microbiol. Clin. (Engl. Ed.)"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1016\/j.tmaid.2015.04.004","article-title":"Evaluation of Eosinophilia in Immigrants in Southern Spain Using Tailored Screening and Treatment Protocols: A Prospective Study","volume":"13","author":"Cobo","year":"2015","journal-title":"Travel Med. Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.eimc.2015.11.019","article-title":"Helmintosis y Eosinofilia En Espa\u00f1a (1990\u20132015)","volume":"36","year":"2018","journal-title":"Enferm. Infecc. Microbiol. Clin."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Lanng, K., Margolinsky, R.V., Wejse, C., Kallestrup, P., and Hvass, A.M.F. (2025). IgE and Eosinophilia in Newly Arrived Refugees in Denmark: A Cross-Sectional Study of Prevalence and Clinical Management in Primary Care. Int. J. Environ. Res. Public Health, 22.","DOI":"10.3390\/ijerph22020180"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"ofae430","DOI":"10.1093\/ofid\/ofae430","article-title":"A Retrospective Longitudinal Study of Refugees With Eosinophilia at an Academic Center in the United States From 2015 to 2020","volume":"11","author":"Ding","year":"2024","journal-title":"Open Forum Infect. Dis."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"106328","DOI":"10.1016\/j.jinf.2024.106328","article-title":"UK Guidelines for the Investigation and Management of Eosinophilia in Returning Travellers and Migrants","volume":"90","author":"Thakker","year":"2025","journal-title":"J. Infect."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"100072","DOI":"10.1016\/j.mcpsp.2019.09.003","article-title":"Eosinophilia in Blood Donors","volume":"3","author":"Muro","year":"2020","journal-title":"Med. Cl\u00ednica Pr\u00e1ctica"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1086\/338026","article-title":"Diagnostic Significance of Blood Eosinophilia in Returning Travelers","volume":"34","author":"Schulte","year":"2002","journal-title":"Clin. Infect. Dis."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1587","DOI":"10.3201\/eid1210.060102","article-title":"Helminth-Related Eosinophilia in African Immigrants, Gran Canaria","volume":"12","author":"Pardo","year":"2006","journal-title":"Emerg. Infect. Dis."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1046\/j.1365-3156.1998.00209.x","article-title":"Utility of Antibodies against a 22 KD Molecule of Dirofilaria Immitis in the Diagnosis of Human Pulmonary Dirofilariasis","volume":"3","author":"Perera","year":"1998","journal-title":"Trop. Med. Int. Health"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1128\/CDLI.11.6.1165-1170.2004","article-title":"Utility of Schistosoma Bovis Adult Worm Antigens for Diagnosis of Human Schistosomiasis by Enzyme-Linked Immunosorbent Assay and Electroimmunotransfer Blot Techniques","volume":"11","author":"Pardo","year":"2004","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1080\/00365540601105806","article-title":"Application of an ELISA Test Using Schistosoma Bovis Adult Worm Antigens in Travellers and Immigrants from a Schistosomiasis Endemic Area and Its Correlation with Clinical Findings","volume":"39","author":"Pardo","year":"2007","journal-title":"Scand. J. Infect. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2048","DOI":"10.1128\/jcm.26.10.2048-2053.1988","article-title":"Identification of a 17-Kilodalton Fasciola Hepatica Immunodiagnostic Antigen by the Enzyme-Linked Immunoelectrotransfer Blot Technique","volume":"26","author":"Hillyer","year":"1988","journal-title":"J. Clin. Microbiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1001\/jama.2024.22530","article-title":"The 2024 Revision to the Declaration of Helsinki: Modern Ethics for Medical Research","volume":"333","author":"Brubaker","year":"2025","journal-title":"JAMA"},{"key":"ref_23","unstructured":"International Organization for Migration (2021). World Migration Report 2022, International Organization for Migration."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.tmaid.2015.06.001","article-title":"Immigration, Helminths and Eosinophilia: A Complex Triad","volume":"13","author":"Norman","year":"2015","journal-title":"Travel Med. Infect. Dis."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2279","DOI":"10.1111\/jdv.18408","article-title":"Tropical Parasitic Itch in Returned Travellers and Immigrants from Endemic Areas","volume":"36","author":"Ju","year":"2022","journal-title":"J. Eur. Acad. Dermatol. Venereol."},{"key":"ref_26","first-page":"44","article-title":"Manejo Pr\u00e1ctico de Una Eosinofilia","volume":"21","author":"Pardo","year":"2004","journal-title":"An. Med. Interna"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1018","DOI":"10.4269\/ajtmh.24-0855","article-title":"Giardiasis and Eosinophilia in Outpatients with Gastrointestinal Symptoms: A Case Series","volume":"113","author":"Vicente","year":"2025","journal-title":"Am. J. Trop. Med. Hyg."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e48","DOI":"10.1086\/528865","article-title":"Cryptic Parasite Infection in Recent West African Immigrants with Relative Eosinophilia","volume":"46","year":"2008","journal-title":"Clin. Infect. Dis."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Odhiambo, C., Oyaro, B., Odipo, R., Otieno, F., Alemnji, G., Williamson, J., and Zeh, C. (2015). Evaluation of Locally Established Reference Intervals for Hematology and Biochemistry Parameters in Western Kenya. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0123140"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.tmaid.2017.09.001","article-title":"Helminthic Infections in Returning Travelers and Migrants with Eosinophilia: Diagnostic Value of Medical History, Eosinophil Count and IgE","volume":"20","author":"Salzer","year":"2017","journal-title":"Travel Med. Infect. Dis."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.eimc.2015.11.001","article-title":"Estrategias de Cribado En Poblaci\u00f3n Inmigrante Reci\u00e9n Llegada a Espa\u00f1a","volume":"34","year":"2016","journal-title":"Enferm. Infecc. Microbiol. Clin."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1080\/20469047.2015.1109802","article-title":"Should Parasitic Disease Be Investigated in Immigrant Children with Relative Eosinophilia from Tropical and Sub-Tropical Regions?","volume":"37","author":"Muro","year":"2017","journal-title":"Paediatr. Int. Child. Health"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"750","DOI":"10.4269\/ajtmh.15-0583","article-title":"Infectious Diseases in Sub-Saharan Immigrants to Spain","volume":"94","author":"Maruri","year":"2016","journal-title":"Am. Soc. Trop. Med. Hyg."},{"key":"ref_34","first-page":"801","article-title":"Eosinophilia in Returning Travelers and Migrants","volume":"105","author":"Ehrhardt","year":"2008","journal-title":"Dtsch. Arztebl. Int."},{"key":"ref_35","first-page":"tax035","article-title":"6-Year Review of +Redivi: A Prospective Registry of Imported Infectious Diseases in Spain","volume":"24","author":"Molina","year":"2017","journal-title":"J. Travel Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.trstmh.2006.04.008","article-title":"Time Delays between Patient and Laboratory Selectively Affect Accuracy of Helminth Diagnosis","volume":"101","author":"Dacombe","year":"2007","journal-title":"Trans. R. Soc. Trop. Med. Hyg."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/j.iac.2015.05.003","article-title":"Eosinophilia in Infectious Diseases","volume":"35","author":"Nutman","year":"2015","journal-title":"Immunol. Allergy Clin. N. Am."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1046\/j.1365-3156.2003.01069.x","article-title":"Clinical Presentation and Diagnostic Sensitivity of Laboratory Tests for Strongyloides Stercoralis in Travellers Compared with Immigrants in a Non-Endemic Country","volume":"8","author":"Sudarshi","year":"2003","journal-title":"Trop. Med. Int. Health"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Miller, J.M., Binnicker, M.J., Campbell, S., Carroll, K.C., Chapin, K.C., Gonzalez, M.D., Harrington, A., Jerris, R.C., Kehl, S.C., and Leal, S.M. (2024). Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin. Infect. Dis., ciae104.","DOI":"10.1093\/cid\/ciae104"}],"container-title":["Tropical Medicine and Infectious Disease"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2414-6366\/11\/1\/20\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T07:57:35Z","timestamp":1768204655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2414-6366\/11\/1\/20"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,11]]},"references-count":39,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["tropicalmed11010020"],"URL":"https:\/\/doi.org\/10.3390\/tropicalmed11010020","relation":{},"ISSN":["2414-6366"],"issn-type":[{"value":"2414-6366","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,11]]}}}