Determinants and prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso: a hospital-based cross-sectional study.

BACKGROUND: Dengue fever (DF) is a significant public health concern in Burkina Faso, particularly in the Central Region, previously endemic for malaria. However, limited research has focused on dengue prevalence and associated factors among adult febrile patients in this region. This study aimed to estimate the prevalence of symptomatic dengue fever among adults and identify the sociodemographic and clinical determinants of the disease. METHODS: A seroepidemiological cross-sectional study was conducted in the Central Region of Burkina Faso, through a three-stage sampling. Five health facilities, one from each of the region five districts, were purposively selected. Febrile patients aged 16 and older, suspected of having dengue, were included in the study, after consenting. Bivariate analyses and multivariate binary logistic regression were done at a 5% confidence level. RESULTS: A total of 637 patients between the ages of 16 and 90 years were included. Most of the participants were females (58.71%). Most dengue cases resided in Arrondissement 4 (59.62%), or were present in the Arrondissement 4 at daytime during the previous days (51.92%). 52.90% of the participants knew of dengue. Dengue prevalence was estimated at 8.16% (95% CI: 6.16%-10.57%). The most frequent markers for dengue were immunoglobulins M detected in 4.40% (2.94%-6.29%), followed by Antigen NS1 at 4.24% (95% CI: 2.81%-6.11%). The Antigen NS1 marker was associated with myalgia (p = 0.024), vomiting (p < 0.001), hemorrhagic manifestations (p = 0.001), and anorexia (p < 0.001). Staying at Arrondissement 4 (vs staying at Saaba) during daytime (aOR = 2.36 95% CI: 1.03-5.45; p = 0.044) significantly increased the odds of dengue. Dengue cases were about 3 times more likely to have vomited (aOR = 2.99 95% CI: 1.58-5.64; p = 0.001). Participants knowing of dengue (aOR = 0.53 95% CI: 0.29-0.98; p = 0.042) and those coinfected with malaria (aOR = 0.28 95% CI: 0.14-0.57; p < 0.001) instead had reduced odds of dengue. CONCLUSION: The study revealed a relatively high prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso in 2022. These findings emphasize the need for continuous surveillance and targeted control measures. The low coinfection of dengue and malaria warrants further investigation.

Setting Dengue Fever Epidemic Thresholds Between 2016 and 2021 in the Central Health Region, Burkina Faso: An Ecological Study.

BACKGROUND: Dengue fever (DF) is endemic in Burkina Faso, with 70% of its burden supported by the Central Health Region. Then, a single confirmed case can no longer mean an epidemic. This study aimed at describing trends and setting epidemic thresholds of DF in the Central Health Region. DATA AND METHODS: An ecological study was conducted using monthly data from DF surveillance between 2016 and 2021. Three methods were applied to set alert and intervention thresholds of DF monthly incidence rate: mean [mean + 2 SD], median [3rd quartile] and cumulative sum (C-sum) [C-sum + 1.96 SD]. These thresholds were plotted with the monthly incidence rates for 2021. RESULTS: In total, 54,429 cases were reported between 2016 and 2021. Dengue cases increased biannually. The median annual incidence rate did not vary significantly across years [Kruskal-Wallis: χ2(5) = 9.825; p = 0.0803]. Within a year, the monthly incidence rate fell under 48.91 cases per 100,000 inhabitants between January and September and peaked in October or November. With the mean and C-sum methods, the 2021 monthly incidence rate remained below the intervention thresholds (Mean + 2 SD and C-sum + 1.96 SD). With the median method, the incidence rate exceeded the alert and intervention thresholds in July-September 2021. CONCLUSIONS: If the DF incidence varied within a year due to the seasons, it was relatively stable between 2016 and 2021. The mean and C-sum methods based on the mean were subject to extreme values, giving high thresholds. The median method seemed better for capturing the abnormal increase in dengue incidence.