{ "abstract": "Background: Dengue emerged as a new public health threat in the Rohingya refugee camps in Cox’s Bazar, Bangladesh, in 2021 and expanded into large-scale upsurges in subsequent years. Evidence on dengue epidemiology and clinical presentation in protracted refugee settings remains limited, despite the need for stronger outbreak preparedness and case management in these contexts. Objectives: To describe the epidemiological, clinical, and diagnostic characteristics of the dengue upsurge among Rohingya refugees and surrounding host communities in Cox’s Bazar, Bangladesh, and to identify predictors of inpatient admission and diagnostic positivity patterns. Methods: This retrospective observational study used anonymized surveillance data from the International Organization for Migration (IOM) dengue patient database. Rapid diagnostic test (RDT)–confirmed dengue cases identified across 36 IOM-supported health facilities in Ukhiya and Teknaf between 1 October 2021 and 31 December 2024 were included. Demographic, epidemiological, clinical, and laboratory variables were summarized using descriptive statistics. Weekly case counts were aggregated by epidemiological week and calendar year, and epidemic growth and decay phases were modelled using phase-specific Poisson regression. Multivariable logistic regression was used to identify factors associated with inpatient admission, while separate models examined associations between delay in presentation and RDT positivity patterns, adjusting for age and sex. Results: A total of 35,581 RDT-confirmed dengue cases were reported, of which 90.2% occurred among Rohingya refugees. The median age was 17 years (IQR 7–30), and 46.0% of cases were among children aged 0–14 years. Annual caseload increased from 1,011 in 2021–11,752 in 2022, 10,669 in 2023 and 12,149 in 2024, with seasonal peaks during the monsoon period and progressively later peaks and longer epidemic tails over time. Poisson models showed decreasing growth rates across years (r = 0.449 in 2021 to r = 0.091 in 2024) with increasing doubling times, while decay rates remained broadly comparable (halving time ~4.4–6.0 weeks). Overall, 8.0% of cases required inpatient admission, 1.3% were referred, and four deaths were reported (case fatality <0.1%). In multivariable analysis, inpatient admission was associated with older age (≥60 vs 0–14: aOR 2.48), delayed presentation (aOR 1.06 per day), refugee status (aOR 1.43), fever ≥38°C at presentation (aOR 1.13), presence of any WHO warning sign (aOR 28.87), and chronic co-morbidity (aOR 6.63). Males had lower odds of admission than females (aOR 0.87). Conclusion: Sustained dengue preparedness is required in Cox’s Bazar, including strengthened surveillance, community-based early referral, targeted monitoring of high-risk groups, environmental vector control, and phase-appropriate use of NS1 and IgM/IgG diagnostics to reduce missed diagnoses and prevent progression to severe disease. These findings highlight the need for a policy shift from episodic outbreak response toward sustained dengue preparedness in humanitarian settings, including strengthened surveillance systems, integrated diagnostic strategies, community-based early referral, and coordinated vector control interventions. Author summary: Dengue has emerged as an important public health threat in the Rohingya refugee camps and surrounding host communities in Cox’s Bazar, Bangladesh. However, evidence describing dengue epidemiology and clinical presentation in refugee settings remains limited. We analyzed routinely collected surveillance data from 35,581 rapid diagnostic test-confirmed dengue cases attending 36 IOM-supported health facilities between October 2021 and December 2024. Dengue cases increased substantially after the initial outbreak in 2021, with seasonal peaks occurring during and after the monsoon period. Children represented a large proportion of reported cases, while older age, delayed presentation, chronic co-morbidities, and clinical warning signs were associated with inpatient admission. Diagnostic positivity also varied according to the timing of presentation, reflecting the expected transition from early NS1 antigen detection to later antibody detection. These findings demonstrate the growing operational burden of dengue in this prolonged humanitarian setting. Strengthening surveillance, early referral, diagnostic capacity, vector control, and preparedness may help humanitarian health systems identify cases earlier and respond more effectively to future dengue outbreaks.", "abstract_shown": true, "affiliations": [ "Migration Health Division (MHD), International Organization for Migration (IOM), Cox’s Bazar, Bangladesh", "Migration Health Research Unit, Regional Office for Asia and the Pacific, International Organization for Migration (IOM), Bangkok, Thailand", "World Health Organization, Cox’s Bazar, Bangladesh", "Civil Surgeon Office, Cox’s Bazar, Bangladesh", "Refugee Relief & Repatriation Commissioner Office, Cox’s Bazar, Bangladesh", "Cox’s Bazar Medical College, Cox’s Bazar, Bangladesh" ], "article_type": "Research Article", "arxiv": null, "author_total": 17, "authors": [ { "affs": [ 0 ], "name": "Charls Erik Halder", "orcid": "0000-0003-4862-7745" }, { "affs": [ 0 ], "name": "Md Abeed Hasan" }, { "affs": [ 0 ], "name": "Emmanuel Roba Soma" }, { "affs": [ 0 ], "name": "James Charles Okello" }, { "affs": [ 0 ], "name": "Md Mostafizur Rahman" }, { "affs": [ 0 ], "name": "Partha Pratim Das" }, { "affs": [ 0 ], "name": "U. Maung Prue" }, { "affs": [ 0 ], "name": "Dickson Wafula Barasa" }, { "affs": [ 0 ], "name": "Md Atiquzzaman" }, { "affs": [ 0 ], "name": "Md Sobuz Hosen" }, { "affs": [ 0 ], "name": "Saddam Hossain Shagar" }, { "affs": [ 1 ], "name": "Elizabeth Yie Chuen Chong" }, { "affs": [ 2 ], "name": "Debashish Paul" }, { "affs": [ 2 ], "name": "S. M. Niaz Mowla" }, { "affs": [ 3 ], "name": "Mohammadul Hoque" }, { "affs": [ 4 ], "name": "Abu Toha MHR Bhuiyan" }, { "affs": [ 5 ], "name": "Md Farhad Hussain" } ], "bibtex": "https://research.draconitic.com/paper/053krhry5sdvk.bib", "cited_by": 0, "doi": "10.1371/journal.pntd.0014198", "fulltext_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014198", "id": "053krhry5sdvk", "issns": [ "1935-2735", "1935-2727" ], "landing_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014198", "language": "en", "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Asia" ], [ "heading", "Bangladesh" ], [ "heading", "Demography" ], [ "heading", "Dengue Fever" ], [ "heading", "Diagnostic Medicine" ], [ "heading", "Epidemiology" ], [ "heading", "Geographical Locations" ], [ "heading", "Health Care" ], [ "heading", "Health Care Facilities" ], [ "heading", "Infectious Diseases" ], [ "heading", "Inpatients" ], [ "heading", "Medical Conditions" ], [ "heading", "Medical Risk Factors" ], [ "heading", "Medicine and Health Sciences" ], [ "heading", "Neglected Tropical Diseases" ], [ "heading", "Patients" ], [ "heading", "People and Places" ], [ "heading", "Refugees" ], [ "heading", "Research Article" ], [ "heading", "Tropical Diseases" ], [ "heading", "Viral Diseases" ], [ "openalex", "2739|Mosquito-borne diseases and control" ], [ "plos", "/Medicine and health sciences/Diagnostic medicine" ], [ "plos", "/Medicine and health sciences/Epidemiology" ], [ "plos", "/Medicine and health sciences/Epidemiology/Medical risk factors" ], [ "plos", "/Medicine and health sciences/Health care/Health care facilities" ], [ "plos", "/Medicine and health sciences/Health care/Patients/Inpatients" ], [ "plos", "/Medicine and health sciences/Medical conditions/Infectious diseases/Viral diseases/Dengue fever" ], [ "plos", "/Medicine and health sciences/Medical conditions/Tropical diseases/Neglected tropical diseases/Dengue fever" ], [ "plos", "/People and places/Demography/Refugees" ], [ "plos", "/People and places/Geographical locations/Asia/Bangladesh" ] ], "openalex": "W7223319511", "pdf_url": "https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0014198&type=printable", "pmcid": "PMC13719038", "pmid": "42912829", "published": "2026-10-23", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/053krhry5sdvk.ris", "sources": [ { "first_seen": "2026-10-30T12:17:23Z", "native_id": "10.1371/journal.pntd.0014198", "source": "plos", "url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014198" }, { "first_seen": "2026-11-02T12:22:57Z", "native_id": "PMC13719038", "source": "pmc", "url": "https://doi.org/10.1371/journal.pntd.0014198" } ], "subjects": [ { "field": "medicine", "origin": "plos:epidemiology", "subfield": "epidemiology-public-health" }, { "field": "medicine", "origin": "plos:infectious diseases", "subfield": "infectious-disease" } ], "title": "Epidemiological, clinical, and diagnostic characteristics of a large-scale upsurge of dengue in the rohingya refugee camps and host communities in Cox’s Bazar, Bangladesh, 2021 to 2024: A retrospective study", "title_text": "Epidemiological, clinical, and diagnostic characteristics of a large-scale upsurge of dengue in the rohingya refugee camps and host communities in Cox’s Bazar, Bangladesh, 2021 to 2024: A retrospective study", "type": "peer-reviewed", "updated_at": "2026-11-02T12:22:57Z", "url": "https://research.draconitic.com/paper/053krhry5sdvk", "venue": "PLOS Neglected Tropical Diseases", "versions": [] }