Outcomes of lupus and rheumatoid arthritis patients with primary dengue infection: A seven-year report from Brazil.

Objective: We described the clinical profile and outcomes of patients with SLE and RA diseases reported to the Brazilian Health Information System with primary dengue infection.

Methods: Databases from the Brazilian Public Health Informatics System (SUS) were linked as the source of information. Three databases comprising different longitudinal information of lupus or rheumatoid arthritis (RA) patients under treatment and care through the Brazilian Health System were linked. Patients who had lupus ICD-9 code or RA ICD-9 code and their treatment approved by SUS were included in the study. In Study 1, we described the clinical characteristics of RA/lupus patients who had dengue infection. In Study 2, we compared RA/lupus patients with or without dengue for hospitalization rates after index dengue diagnosis for dengue-exposed or matching date for dengue-unexposed.

Results: We included 69 SLE and 301 RA patients with dengue. In the RA/lupus with dengue case series, hospitalization was found in 24.6% of lupus subjects and of 11.2% of RA subjects. It differed by geographic region (p = 0.03), gender (p = 0.05) and the use of azathioprine (p = 0.02). Dengue was the most frequent reason for hospitalization reported (43.0%). Hospitalization due to dengue was noted in 12 (42.9%) dengue-exposed patients (p = 0.02), while rheumatoid arthritis was reported as the cause of hospitalization in 22.2% of dengue-unexposed (p = 0.005). Five deaths were reported among the dengue-exposed and none among dengue-unexposed. Bacterial infection was the most frequent cause of death. We found that the dengue exposure was associated with an increased risk of hospitalization outcome in RA and lupus patients (RR = 6.2; 95% CI: 2.99-12.94).

Summary: We found that when comparing RA/lupus patients with or without dengue, dengue-exposed patients had an increased rates of hospitalization and death.