Incidence of dementia after dengue fever: Results of a longitudinal population-based study

Abstract

Objective: To investigate the epidemiological relationship between dengue fever and the subsequent development of dementia.

Methods: Using nationwide Taiwan registries from the National Health Insurance Research (NHIRD), we identified adults aged over 40 years who received a dengue fever diagnosis from 1 January 2000 to 31 December 2012 and who did not have a history of dementia. We used a propensity score match (PSM) to balance the baseline characteristics between groups. All eligible adults were sorted into either the dengue group or non-dengue group at a ratio of 1:4, matching by age, sex, index years, income level, and relevant comorbidities. Using Cox regression with proportional hazards models, we estimated the risk of dementia. The study period started from 1 January 2000 to 31 December 2013. We conducted sensitivity analyses to cross-validate study results.

Results: With a median of 8.01 years of follow-up, patients in the dengue group were more at risk of developing dementia than the non-dengue group. The estimated cumulative incidence of dementia was 7.21% in the dengue group and 4.03% in the non-dengue group (adjusted hazard ratio (aHR), 1.71; 95% CI, 1.03 to 2.83). Sensitivity analyses yielded consistent findings. We excluded any stroke cases before the end of the study, and subgroup analysis by follow-up time showed that the dengue group has a significantly higher risk of new-onset dementia >6 years after the index date (aHR 3.24; 95% CI, 1.42 to 7.37). The P value for interaction was significant (<.0001).

Conclusions: This study demonstrated a significantly higher risk of dementia in patients with dengue fever in Taiwan than in those without dengue fever.