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

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.