The risk of Guillain-Barre syndrome (GBS) after confirmed dengue infection is similar to that after infection with established viral or bacterial triggers such as influenza or Campylobacter jejuni, per a letter to the editor published this week in the New England Journal of Medicine.

The letter, by UK and Brazilian researchers, described an analysis of linked national databases with information on hospitalizations, dengue notifications, and deaths in Brazil in 2023 and 2024. 

Dengue is a fast-spreading mosquito-borne illness. GBS is a rare autoimmune disease in which the immune system attacks the peripheral nerves, which connect the brain and spinal cord to the rest of the body.

The team used a self-controlled case-series model to estimate GBS incidence rate ratios (IRRs) from a risk window of one to 42 days after dengue symptom onset compared with a control period of 43 days post-onset through December 2024. 

Of 5,055 hospitalizations for GBS, 147 included a dengue diagnosis; in 89 of those cases, hospitalization occurred within the risk window. The IRR during the risk window, compared with the control period, was 16.75.

Given the recent large-scale outbreaks of dengue in regions where dengue is endemic, dengue-related Guillain-Barre syndrome may represent a substantial and underrecognized component of the neurologic burden attributable to the disease.

The risk was greatest in the first two weeks, returning to baseline by 43 days. The attributable risk from one to 42 days was 35.5 excess GBS cases per million dengue infections. Therefore, the risk of GBS after dengue infection appears comparable to that of influenza (IRR, 16.6) and C jejuni (odds ratio, 3 to 41).

Studies in tropical regions such as Brazil, India, and Malaysia suggest that arboviral infections such as dengue may be more common GBS triggers than C jejuni and enteroviruses in those settings, the authors noted.

“Given the recent large-scale outbreaks of dengue in regions where dengue is endemic, dengue-related Guillain-Barre syndrome may represent a substantial and underrecognized component of the neurologic burden attributable to the disease,” they wrote. Clinicians in dengue-endemic areas should consider GBS in patients with progressive weakness during or shortly after dengue infection to enable early treatment, they added.