BACKGROUND

Dengue fever (DF) is caused by dengue virus (DENV) and is primarily spread through bites of infected Aedes mosquitoes in tropical and subtropical regions, including Ethiopia. In the Afar region, DF is often misdiagnosed as malaria due to limited diagnostic capabilities. This study assessed the seroprevalence of DENV infection among febrile patients in healthcare facilities in the Afar region.

METHODS

A cross-sectional study was conducted from September 2022 to March 2023 in Amibara, Harunka and Awash Sebat city administration districts, involving febrile patients suspected of having malaria. Sociodemographic data, clinical features and blood samples were collected from participants after obtaining informed consent or assent. Following blood film examination for Plasmodium infection, sera were tested for anti-DENV IgM and IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Data were entered into Epi Data 3.1 and analyzed with Stata/SE 14.2. A p-value < 0.05 was considered significant.

RESULTS

A total of 411 febrile patients (55.5% female, aged 5-80 years, with a mean age of 27.3 ± 13.8 years) participated in the study. Among those tested for anti-DENV antibodies, 101/410 (24.6%) were positive for anti-DENV IgM, indicating an acute DENV infection, and 142/367 (38.7%) were positive for anti-DENV IgG, revealing previous exposure. Only 44/411 (10.7%) were positive for Plasmodium infection, while 18/410 (4.4%) were co-infected with malaria and acute DENV infection and 18/367 (4.9%) were positive for both malaria and previous exposure to DENV. Those diagnosed with malaria were nearly 2.5 times more likely to test positive for acute DENV infection than those without malaria (AOR = 2.37; 95% CI 1.14-4.92). The odds of positivity for previous exposure were about two times higher in females than in males (AOR = 2.24; 95% CI 1.32-3.26) and in government and private sector employees than in pastoralists and agro-pastoralists (AOR = 1.90; 95% CI 1.03-8.15), while patients aged 11-20 years had lower odds of previous exposure than those aged 5-10 years (AOR = 0.35; 95% CI 0.14-0.88). Experiencing muscle pain was associated with twice the odds of previous exposure (AOR = 1.90; 95% CI 1.04-3.49).

CONCLUSION

The study reveals a high seroprevalence of DENV infection among febrile patients in the study area, highlighting the need for routine diagnosis and management of DF in this setting. Improving vector control, disease surveillance and public awareness would be crucial for combating DF and other mosquito-borne diseases.