Risk of Guillain–Barre Syndrome Rises After Dengue Infection

Dengue infection was associated with an elevated risk of Guillain-Barré syndrome (GBS) up to 6 weeks after symptom onset, data from Brazil showed.

In a self-controlled case series, the risk of GBS was highest in the first 2 weeks and returned to baseline by day 43, reported Thiago Cerqueira‑Silva, MD, PhD, of the London School of Hygiene and Tropical Medicine, and co-authors.

The attributable risk resulted in 35.5 excess GBS cases (95% CI 34.3-36.3) per million laboratory-confirmed dengue infections, Cerqueira‑Silva and colleagues wrote in correspondence to the New England Journal of Medicine.

Dengue is the fastest-spreading mosquito-borne disease globally. In the Americas region, 13 million cases and 8,200 deaths were reported in 2024, according to the CDC. In the continental U.S., the number of new dengue cases in 2024 topped 3,500.

GBS is an acquired demyelinating polyneuropathy with an axonal variant, often beginning in the lower extremities and ascending over time with loss of reflexes. It sometimes leads to paralysis.

The risk of dengue-related GBS has not been quantified in a large-scale study, Cerqueira‑Silva noted.

“In the literature, there are multiple case reports about GBS following dengue. However, GBS is a very rare condition, and only with very large numbers would it be possible to assess this association formally,” he told MedPage Today. “We evaluated this association using data from Brazil, which registered more than 6 million dengue cases in 2024.”

Cerqueira‑Silva and colleagues assessed information about hospitalizations, dengue cases, and mortality in Brazilian national databases in 2023 and 2024. They used a self-controlled case series model to estimate the incidence rate ratio (IRR) of GBS 1 to 42 days after dengue symptom onset versus the control period (day 43 through December 2024).

The researchers identified 5,055 hospitalizations for GBS. Of these, 147 included a documented dengue infection, and hospitalization occurred within the risk window (1 to 42 days after symptom onset) in 89 cases. From day 1 to day 42, the IRR was 16.75 (95% CI 10.97-25.55, P<0.001) compared with the control period.

Sensitivity analyses that examined cases of dengue infection confirmed by testing or diagnosed clinically showed consistent findings. Positive control outcomes (stroke and acute myocardial infarction) showed expected associations, and negative control outcomes (foot and shoulder fractures) showed no association, supporting internal validity.

The findings have important clinical implications, the researchers observed. “Clinicians in areas where dengue is endemic should suspect GBS in patients who present with progressive weakness during or shortly after dengue infection,” they wrote.

“Recognizing symptoms early allows for timely immunotherapy (intravenous immune globulin or plasmapheresis), which halts disease progression and improves recovery,” they added. “From a public health perspective, our results further strengthen the case for dengue vaccination programs.”

Much literature shows Campylobacter jejuni infection as a main driver of GBS, Cerqueira‑Silva pointed out.

“Our study highlights that common infections in tropical areas may carry similar risks and probably are most important in the context of those areas, as other arbovirus infections — such as Zika and chikungunya — have also been associated with increased risk of GBS,” he said. “In this context, doctors should pay special attention to patients with neurological symptoms following dengue and other arbovirus infections.”