{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T00:32:52Z","timestamp":1792801972013,"version":"4.5.0"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,4,16]],"date-time":"2025-04-16T00:00:00Z","timestamp":1744761600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Crimean\u2013Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease characterized by a high case fatality rate of ~30%. CCHF is endemic in Kyzylorda Oblast, Kazakhstan, which has a population of 800,000, with approximately 10 cases reported annually. In 2022, by end of July, 15 cases had been reported. We conducted an investigation to identify the risk factors associated with CCHF and to recommend preventive measures.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We conducted a case\u2013control study. Case-patients were defined as individuals hospitalized between April and July 2022, showing signs consistent with CCHF and having a history of exposure\u2014contact with ticks or animals and sudden onset of unexplained bleeding\u2014within 2\u202fweeks before the onset of illness. Confirmed case-patients additionally tested positive for CCHF-using both polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) for both immunoglobulin M (IgM) and immunoglobulin G (IgG) tests. For every case-patient, two people from neighboring households were selected as controls. We used logistic regression to assess the factors associated with CCHF. Ticks collected from animals residing on the case-patient\u2019s property were tested for CCHF. We also reviewed public environmental and livestock data.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We studied 17 suspected, 7 probable, and 14 confirmed case-patients, along with 71 controls. Case-patients were predominantly male (74%), 47% were livestock workers and 37% were agricultural workers. Among the 14 confirmed CCHF case patients, 4 died from the illness (case fatality rate: 29%). Among the all case-patients, 100% reported weakness, 97% headaches, and 84% fevers. Over half (53%) of case-patients reported ticks on their bodies and clothing \u22642\u202fweeks before the onset of the illness compared to 1% of controls (<jats:italic>p<\/jats:italic>\u202f&amp;lt;\u202f0.001). Nearly half (47%) of the case-patients visited or lived in a high-risk area for tick bites \u22642\u202fweeks before the onset of the illness compared to 6% of controls (<jats:italic>p<\/jats:italic>\u202f&amp;lt;\u202f0.001). Livestock and agricultural workers had higher odds of CCHF compared to those not in these professions (odds ratios and 95% confidence interval [CI]: 3.0 [1.3\u20137.2] and 4.0 [1.5\u201310.5], respectively). Among the 55 control persons tested for CCHF, 1 (2%) tested IgG-positive. Of 163 ticks tested, 0.6% were PCR positive. In 2022, Kyzylorda had increased livestock numbers, above-average temperatures in February and March, and a delayed acaricidal treatment for livestock and pastures.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>We found a high occupational risk for CCHF. The prevalence of CCHF in ticks in our study was 0.6%, which is consistent with regional tick surveillance data. Increased tick control measures and personal protective measures for people with occupational exposure to ticks may help reduce cases.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fpubh.2025.1519261","type":"journal-article","created":{"date-parts":[[2025,4,16]],"date-time":"2025-04-16T05:28:51Z","timestamp":1744781331000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Outbreak of Crimean-Congo hemorrhagic fever in Kyzylorda region, Kazakhstan, March\u2013July 2022"],"prefix":"10.3389","volume":"13","author":[{"given":"Saya","family":"Gazezova","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Malika","family":"Gabdullina","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gulzhan","family":"Ayapova","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dilyara","family":"Nabirova","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle","family":"Waltenburg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manar","family":"Smagul","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lena","family":"Kasabekova","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Umirbek","family":"Ussenov","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberta","family":"Horth","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,4,16]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1016\/j.antiviral.2013.07.006","article-title":"Crimean-Congo hemorrhagic fever: history, epidemiology, pathogenesis, clinical syndrome and genetic diversity","volume":"100","author":"Bente","year":"2013","journal-title":"Antivir Res"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"463","DOI":"10.1038\/s41579-023-00871-9","article-title":"Crimean\u2013Congo haemorrhagic fever virus","volume":"21","author":"Hawman","year":"2023","journal-title":"Nat Rev Microbiol"},{"key":"ref3","article-title":"Learning objectives \u2022 Describe signs, symptoms, and transmission of Crimean-Congo Haemorrhagic Fever (CCHF) \u2022 List 4 preventive and control measures","year":"2018"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"203","DOI":"10.1016\/S1473-3099(06)70435-2","article-title":"Crimean-Congo haemorrhagic fever","volume":"6","author":"Erg\u00f6n\u00fcl","year":"2006","journal-title":"Lancet Infect Dis"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"70","DOI":"10.1016\/j.coviro.2018.12.002","article-title":"Crimean-Congo hemorrhagic fever and expansion from endemic regions","volume":"34","author":"Spengler","year":"2019","journal-title":"Curr Opin Virol"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"tpmd211092","DOI":"10.4269\/AJTMH.21-1092","article-title":"Prevalence of Crimean-Congo hemorrhagic fever virus among livestock and ticks in Zhambyl region, Kazakhstan, 2017","volume":"106","author":"Bryant-Genevier","year":"2022","journal-title":"Am J Trop Med Hyg"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.3390\/PATHOGENS11080841","article-title":"The prevalence and genetic variants of the CCHF virus circulating among ticks in the southern regions of Kazakhstan","volume":"11","author":"Sultankulova","year":"2022","journal-title":"Pathogens"},{"key":"ref8","article-title":"Guidance on regulations for the transport of infectious substances 2013\u20132014","volume-title":"WHO\/HSE\/GCR\/2012.12","year":"2012"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"864","DOI":"10.3201\/EID3005.231648","article-title":"Crimean-Congo hemorrhagic fever virus for clinicians\u2014diagnosis, clinical management, and therapeutics","volume":"30","author":"Frank","year":"2024","journal-title":"Emerg Infect Dis"},{"key":"ref10","year":"2022"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"75","DOI":"10.1016\/J.IJREGI.2023.11.018","article-title":"Alarming update on incidence of Crimean-Congo hemorrhagic fever in Iraq in 2023","volume":"10","author":"Atwan","year":"2024","journal-title":"IJID Regions"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"1319","DOI":"10.3201\/EID3007.230810","article-title":"Looking beyond the Lens of Crimean-Congo hemorrhagic fever in Africa - 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