A Retrospective Analysis of the Significance of Haemoglobin SS and SC in Disease Outcome in Patients With Sickle Cell Disease and Dengue Fever☆☆☆

BACKGROUND Little is known about the significance of haemoglobin genotype in dengue fever severity. This study was undertaken to determine the case fatality ratio and the impact of genotype in patients with sickle cell disease and confirmed dengue fever. METHODS This retrospective analysis included 40 patients with confirmed dengue and sickle cell disease, during the study period (2010-2012). FINDINGS There was a significantly higher case fatality ratio, 12.5% among patients with either haemoglobin SC disease or homozygous SS disease when compared to that of the general population 0.41% (p < 0.0001). The unadjusted odds of dying among those with haemoglobin SC disease compared with the group with homozygous SS disease was OR = 4.4 (95% CI 0.6 to 31.7). The predictors of mortality independent of sickle cell disease genotype were haemoglobin concentration at presentation OR = 0.57 (95% CI, 0.35 to 0.94) and the change in haemoglobin concentration from steady state OR = 0.59 (95% CI, 0.37 to 0.94). Adjusting for haemoglobin concentration at presentation increased the risk of death for the SC genotype relative to SS genotype OR = 13.4 (95% CI 1.1 to 160.3). INTERPRETATION The risk of fatal dengue may be higher among patients with a relatively mild genotype (haemoglobin SC).