Mortality pattern and factors associated with prolonged hospital stay among admitted dengue fever patients during the ongoing war in Sudan: A hospital-based cross-sectional study

Abstract

Objective: To assess the prevalence of mortality and factors associated with prolonged length of hospital stay (LOS) among dengue fever (DF) patients who were admitted at Kassala Hospital, eastern Sudan, during the ongoing war.

Methods: This hospital-based cross-sectional study of 129 hospitalized DF patients was conducted in 2025. Data on sociodemographics, clinical outcomes (recovery or death), LOS, and hematological parameters were collected using standardized methods. Univariate and multivariate Poisson regression analyses were used to identify factors associated with prolonged LOS among the recovered patients.

Results: Of the 129 hospitalized patients, 67 (51.9%) were males and their median age was 32 years. The median LOS was 4 (interquartile range, IQR 3-6) days. Twelve patients (9.3%) died and they had significantly longer LOS, elevated white blood cell (WBC), and neutrophil counts compared to recovered patients. In multivariate analysis of recovered patients, higher WBC (adjusted risk ratio, aRR 1.020; 95% Cl 1.005-1.035), neutrophil (aRR 1.029; 95% Cl 1.008-1.050), and lymphocyte (aRR 1.044; 95% Cl 1.009-1.080) were positively associated with prolonged LOS. Other positive associations included being female sex (aRR 1.24; 95% Cl 1.05-1.46), married (aRR 1.29; 95% Cl 1.02-1.74), less educated (aRR 1.20; 95% Cl 1.01-1.44), being a local resident (non-internally displaced person) (aRR 1.44; 95% Cl 1.20-1.74), having dengue hemorrhagic fever (aRR 1.53; 95% Cl 1.27-1.85), and pre-existing morbidity (aRR 2.18; 95% Cl 1.71-2.78). Younger age (aRR 0.980; 95% Cl 0.980-0.990), and infection with DF serotype 2 (aRR 0.72; 95% Cl 0.61-0.86) or serotype 3 (aRR 0.51; 95% Cl 0.30-0.87) were negatively associated.

Conclusions: The mortality rate among hospitalized dengue patients was high. Among those who recovered, prolonged LOS was associated with various clinical and sociodemographic factors. These findings highlight the need for enhanced surveillance and targeted clinical management strategies for vulnerable dengue patients in conflict-affected settings.

Keywords

Dengue fever / Co-infection / Conflict / Length of hospital stay / White blood cell / Mortality / Sudan

Conflict of interest statement

The authors have no competing interests to declare.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Data availability

The data of the present study are available from the corresponding author upon reasonable request.

Ethics approval and consent from participants

All study procedures and data collection methods were conducted in strict accordance with the ethical principles outlined in the Declaration of Helsinki. The study received the ethics approval from the ethical board of the Health Research Ethics Committee, Ministry of health, Kassala state, Kassala, Sudan, under reference (No.28) on 20 May 2023. All participants (or their legal guardians for minors) signed a written informed consent form. The authors followed all measures to ensure the privacy and confidentiality of the participants, including excluding personal identifiers during data collection. All patients diagnosed by DF were treated in the same manner regardless of their participation.

Authors’ contributions

Conceptualization: AOM, TMA, AA, Data curation: AOM, TMA, AHK, AMA, Laboratory investigations and methodology: RWFO, WME, and SAAM. Data analysis and preparation of tables: AOM, Project administration and supervision: TMA, AOM, Funding acquisition: TMA, Writing the initial draft: AOM, AA, ASH, and TMA, Reviewing and editing the final draft: AAH, and ASH. All authors have reviewed and approved the final manuscript. All authors have read and agreed to the published version of the manuscript.

Publisher’s note

The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Edited by Lei Y, Pan Y, Zhang Q

Acknowledgements

We would like to thank the Research Funding Program-Research Chairs (ORF-RC-2025-0500), King Saud University, Riyadh, Saudi Arabia, for the overall funding and infrastructure support for our broader research initiative.

References

[1] World Health Organization. Dengue and severe dengue key facts. 2025; April. [Online]. Available from: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue. [Accessed on 15 July 2025].

[2] Wilder-Smith A, Ooi EE, Horstick O, Wills B. Dengue. Lancet 2019; 393: 350-363.

[3] Jahromi AS, Jokar M, Abdous A, Sharifi N, Abbasi T, Rahmanian V. Global systematic review and meta-analysis on knowledge, attitudes, and practices towards dengue fever among general population. Asian Pac J Trop Med 2024; 17(5): 191-207.

[4] Haider N, Hasan MN, Onyango J, Billah M, Khan S, Papakonstantinou D, et al. Global dengue epidemic worsens with record 14 million cases and 9 000 deaths reported in 2024. Int J Infect Dis 2025; 158: 107940.

[5] Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al. The global distribution and burden of dengue. Nature 2013; 496: 504-407.

[6] Zhang WX, Zhao TY, Wang CC, He Y, Lu HZ, Zhang HT, et al. Assessing the global dengue burden: Incidence, mortality, and disability trends over three decades. PLoS Negl Trop Dis 2025; 19: e0012932.

[7] Mwanyika GO, Mboera LEG, Rugarabamu S, Ngingo B, Sindato C, Lutwama JJ, et al. Dengue virus infection and associated risk factors in Africa: A systematic review and meta-analysis. Viruses 2021; 13: 536.

[8] Laserna A, Barahona-Correa J, Baquero L, Castañeda-Cardona C, Rosselli D. Economic impact of dengue fever in Latin America and the Caribbean: A systematic review. Rev Panam Salud Publica/Pan Am J Public Heal 2018; 42: e111.

[9] Bagahizel AM, Elkhatim HS. Assessment of the readiness and response toward the dengue fever outbreak (2019) in Sudan: A qualitative exploration. BMC Public Health 2023; 23: 2122.

[10] Mustafa MI, Makhawi AM. The reemergence of dengue virus in Sudan. J Infect Public Health 2023; 16: 1392-1395.

[11] Rahamtalla B, Medani I, Salih A, Hashim KN, Albasheer K, Munder O, et al. The impact of ongoing armed conflict on Sudan’s healthcare system: Narrative review. Discov Heal Syst 2025; 4: 49.

[12] Badri R, Dawood I. The implications of the Sudan war on healthcare workers and facilities: A health system tragedy. Confl Health 2024; 18: 22.

[13] World Health Organization. Sudan conflict and complex emergency: Public Health Situation Analysis (PHSA). 2025; March: 1-37. [Online]. Available from: https://cdn.who.int/media/docs/default-source/2021-dha-docs/20250310_phsa_sudan-conflict.pdf?sfvrsn=d1b69fc1_3#:~:text=Diseaseoutbreaks:Diseaseoutbreaksare,malaria%2Cmeasles%2Canddiphtheria. [Accessed on 13 May 2025].

[14] Elmukashfi H, Elobied S, Bushra M, Ahmed M, Ahmed ABM, Abdelrahman R, et al. Healthcare accessibility, utilization, and quality of life among internally displaced people during the Sudan war: A cross-sectional study. Confl Health 2025; 19: 11.

[15] Hassan IN, Abuassa N, Ibrahim M. The Sudan conflict: A catalyst for the spread of infectious diseases in displaced populations. Int J Infect Dis 2025; 151: 107326.

[16] Babekir A, Aalen L. When refuge is home: Sudan's war-affected IDPs in Gedarif State, Eastern Sudan. Bergen: Chr. Michelsen Institute (Sudan Working Paper SWP; 2024.

[17] Ahmed A, Eldigail M, Elduma A, Breima T, Dietrich I, Ali Y, et al. First report of epidemic dengue fever and malaria co-infections among internally displaced persons in humanitarian camps of North Darfur, Sudan. Int J Infect Dis 2021; 108: 513-516.

[18] Marou V, Vardavas CI, Aslanoglou K, Nikitara K, Plyta Z, Leonardi-Bee J, et al. The impact of conflict on infectious disease: A systematic literature review. Confl Health 2024; 18: 27.

[19] Ogony J, Menya D, Mangeni J, Ayodo G, Karanja S. Public health facility vulnerabilities, preparedness, and health outcomes for Plasmodium falciparum and dengue virus-infected children under years with acute febrile illnesses in Western Kenya. Front Public Heal 2025; 13: 1526558.

[20] Charani E, Cunnington AJ, Yousif AEHA, Seed Ahmed M, Ahmed AEM, Babiker S, et al. In transition: Current health challenges and priorities in Sudan. BMJ Glob Heal 2019; 4: e001723.

[21] Shahid Ansari M, Jain D, Harikumar H, Rana S, Gupta S, Budhiraja S, et al. Identification of predictors and model for predicting prolonged length of stay in dengue patients. Health Care Manag Sci 2021; 24: 786-798.

[22] Fonseca-Portilla R, Martínez-Gil M, Morgenstern-Kaplan D. Risk factors for hospitalization and mortality due to dengue fever in a Mexican population: A retrospective cohort study. Int J Infect Dis 2021; 110: 332-336.

[23] Iftikhar M, Shah MM, Khan WM, Uddin Z. Malaria and dengue co-infection: A comprehensive study in Peshawar, Pakistan. Cureus 2024; 16: e76401.

[24] Mallhi TH, Khan AH, Sarriff A, Adnan AS, Khan YH. Determinants of mortality and prolonged hospital stay among dengue patients attending tertiary care hospital: A cross-sectional retrospective analysis. BMJ Open 2017; 7: e016805.

[25] Khan S, Baki MA, Ahmed T, Mollah MAH. Clinical and laboratory profile of dengue fever in hospitalized children in a tertiary care hospital in Bangladesh. BIRDEM Med J 2020; 10: 200-203.

[26] Pooransingh S, Teelucksingh S, Dialsingh I. Dengue deaths: Associated factors and length of hospital stay. Adv Prev Med 2016; 2016: 6807674. doi: 10.1155/2016/6807674.Epub 2016 Jul 4.

[27] Khalil MAM, Tan J, Khalil MAU, Awan S, Rangasami M. Predictors of hospital stay and mortality in dengue virus infection-experience from Aga Khan University Hospital Pakistan. BMC Res Notes 2014; 7: 473.

[28] Kunti DPSA, Suryana K. Factors associated with prolonged length of stay in dengue hemorrhagic fever patients at Wangaya Hospital, Denpasar, Bali. Int J Adv Med 2024; 11: 328-332.

[29] Kaleem Z, Waris MH, Muneer R, Malik MN, Akram A, Ghazanfar S, et al. Predictors of hospital stay and prognostic factors for dengue infection in Holy Family Hospital, Rawalpindi. J Popul Ther Clin Pharmacol 2023; 30: 995-1000.

[30] de Sousa SC, da Silva TAM, Soares AN, Carneiro M, Barbosa DS, Bezerra JMT. Factors associated with deaths from dengue in a city in a metropolitan region in Southeastern Brazil: A case-control study. Rev Soc Bras Med Trop 2022; 55: e0043. doi: 10.1590/0037-8682-0043-2022.

[31] Sauceda-Acosta D, Almendares SPP, Cárcamo E, Zúniga-Gutiérrez M, Beltrán B, Rivera MF, et al. Risk factors for dengue mortality: A 7-year retrospective cohort in Honduras. BMC Infect Dis 2025; 25: 147.

[32] Amâncio FF, Heringer TP, De Oliveira CDCHB, Fassy LB, De Carvalho FB, Oliveira DP, et al. Clinical profiles and factors associated with death in adults with dengue admitted to intensive care units, Minas Gerais, Brazil. PLoS One 2015; 10: 1-16.

[33] Mahmood A, Haq A, Amin S, Rahim F, Noor M, Gul H, et al. Predictors of mortality in patients with dengue fever: Insights from a comparative analysis. Cureus 2023; 1: e36040.

[34] Abdallah TM, Ali AAA, Karsany MS, Adam I. Epidemiology of dengue infections in Kassala, Eastern Sudan. J Med Virol 2012; 84: 500-503.

[35] Cuschieri S. The STROBE guidelines. Saudi J Anaesth 2019; 13(Suppl 1): S31-S34.

[36] World Health Organization. Dengue hemorrhagic fever: Diagnosis, treatment and control. 2nd ed. Geneva, Switzerland: World Health Organization; 1997. [Online]. Available from: https://iris.who.int/handle/10665/41988. [Accessed on 29 June 2026].

[37] Eldigail MH, Abubaker HA, Khalid FA, Abdallah TM, Musa HH, Ahmed ME, et al. Association of genotype III of dengue virus serotype 3 with disease outbreak in Eastern Sudan, 2019. Virol J 2020; 17: 118.

[38] Desogi M, Ali M, Gindeel N, Khalid F, Abdelraheem M, Alnaby A, et al. First report of detection of dengue virus serotype 4 (DENV-4) in Sudan. East Mediterr Heal J 2023: 29(6): 436-441.

[39] Adam Bujang M, Baharum N, Mara T, Alam S. Sample size guideline for correlation analysis. Artic World J Soc Sci Res 2016; 3: 37-46.

[40] Lautika Sonkar LS, Prakash V, Verma D, Agarwal S. Evaluation of dengue and malaria co-infection in rohilkhand region of northern India. Int J Contemp Med Res 2019; 6: 6-9.

[41] Semahegn A, Adinew YM, Tiruneh GT, Argaw MD, Bekele B, Tesfaye M, et al. Gender disparities and barriers to access and use of essential health services in Ethiopia: Designing primary health care through gender lens. PLoS Glob Public Heal 2025; 5(6): e0004813.

[42] Xu JW, Liu H, Yaw B, Nbwi HS. The health beliefs, dengue knowledge and control behaviors among internally displaced persons versus local residents in Kachin Special Region II, Myanmar. PLoS Negl Trop Dis 2020; 14: e0008321.

[43] Rao MRK, Padhy RN, Das MK. Prevalence of dengue viral and malaria parasitic co-infections in an epidemic district, Angul of Odisha, India: An eco-epidemiological and cross-sectional study for the prospective aspects of public health. J Infect Public Health 2016; 9: 421-428.

[44] Siddig EE, Mohamed NS, Ahmed A. Severe coinfection of dengue and malaria: A case report. Clin Case Reports 2024; 12: e9079.

[45] Bower H, El Karsany M, Adam AAAH, Idriss MI, Alzain MA, Alfakiyousif MEA, et al. “Kankasha” in Kassala: A prospective observational cohort study of the clinical characteristics, epidemiology, genetic origin, and chronic impact of the 2018 epidemic of Chikungunya virus infection in Kassala, Sudan. PLoS Negl Trop Dis 2021; 15: e0009387.