Does Hydroxyurea Reduce Hospital Admissions in Patients With Both Sickle Cell Disease and Dengue Fever?

INTRODUCTION: The aim of this study was to evaluate the effect of hydroxyurea on reducing the number of hospitalizations for dengue fever in patients with sickle cell disease (SCD). METHODS: In this nested case-control study, conducted between January 1 and December 31, 2024, we included all pediatric and adult patients with SCD followed up at the Cayenne Sickle Cell Center, in French Guiana. RESULTS: Our study population consisted of 90 cases and 189 controls. A total of 51 patients (18%) were hospitalized for dengue fever because of the presence of warning signs. Patients receiving hydroxyurea were older (28 years [19-40] vs. 23 years [10-37], p < 0.001) and primarily of the SS phenotype (89% vs. 52 %, p < 0.001). Hospitalizations for dengue fever occurred exclusively in patients younger than 18 years (12 years [6-18], p < 0.001). Among the patients treated with hydroxyurea, 13% have been hospitalized for dengue fever compared to 21% for the controls. However, this difference was not statistically significant. Patients with severe dengue fever had a longer hospital stay, were more often admitted to intensive care, had more dengue hemorrhagic fever and dengue shock syndrome, and were more often transfused. We noted three deaths among the severe dengue patients, all with dengue shock syndrome and multi-organ failure in two SS patients and one SC patient. The fatality rate of dengue fever has been estimated to be 6%. DISCUSSION: This study showed a lower prevalence of dengue hospitalization in patients with SCD treated with hydroxyurea, suggesting an anti-dengue viral role for hydroxyurea. Further multicenter studies are required to confirm this hypothesis.