Arterial Hypertension and Skin Allergy Are Risk Factors for Progression from Dengue to Dengue Hemorrhagic Fever: A Case Control Study

Background: Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF. Methods: A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities. Results: There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years. Conclusions: Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue. Author Summary: Dengue is a virus disease that has already reached more than 100 countries worldwide, transmitted by Aedes mosquitos, mainly Aedes aegypti. It is estimated that annually nearly 96 million symptomatic cases and about 22,000 deaths occur. This virus most often manifests itself in the form of Dengue Fever (DF), which in some cases progresses to severe forms, also called Dengue Hemorrhagic Fever (DHF). However, the current knowledge does not allow early prediction of which cases of DF will progress to DHF. But it is important to know the factors Involved in this process so that physicians may intervene early to prevent progression and avoid deaths. One of the proposed explanations is that preexisting comorbidities would increase the risk of progression from DF to DHF. This study showed that cases of DF associated with hypertension or skin allergy are more likely to progress to DHF. Monitoring and early appropriate clinical management of these cases can save lives.