The cohort comprised 464 patients enrolled from England, France, and the Netherlands. Mean patient age was 63 years (range, 17-99 years). Eleven patients had evidence of current or recent HEV infection, all genotype 3, and seven had HEV RNA recovered from serum.

"This was just a pilot study," Dalton said. "Basically, we called it 'operation blunderbuss' because it was a bit of a blunt instrument; we decided to test all-comers presenting with non-traumatic acute neurology to secondary care and test for hepatitis E."

The researchers observed several neurological events among those with evidence of HEV, including cerebrovascular accident (n = 4), neuralgic amyotrophy (n = 3), seizure (n = 3), encephalitis (n = 1) and cranial nerve palsies (n = 1).

Lasting neurological outcomes included minor sensory deficit, residual visual field defect, residual functional deficits, residual tinnitus, residual right-sided weakness, residual left-sided weakness and minimal deficits at 6 months, among seven patients, respectively. Regarding the other four patients, one recovered, one recovered completely, one returned to work after 6 months, and one recovered with recurrence at 6 months.

According to the researchers, the prevalence of HEV viremia in the cohort was 1.5%, which was at least 10 times higher than the prevalence recently documented in blood donors in England (0.035%), France (0.045%) and the Netherlands (0.17%).

The three patients with neuralgic amyotrophy and HEV had detectable HEV viremia at presentation. All three patients had bilateral asymmetrical involvement in the brachial plexus, which was previously associated with neuralgic amyotrophy in patients with HEV.

"In all patients with neuralgic amyotrophy, all patients with Guillain-Barré syndrome,and all patients with encephalitis, they should have their hepatitis E status checked, irrespective of their liver blood test abnormalities," Dalton concluded. "In other patients with neurology, I think it would be wise to consider it because we have not completely pinned it down what conditions might be associated to an all-cause. I think in the first three conditions I mentioned, there is very good evidence for causality. Hepatitis E is not just a hepatotropic virus, it can cause neurologic injury, so beware." - by Talitha Bennett

Disclosure: Dalton reports he has received travel and accommodation costs and consultancy fees from GlaxoSmithKline, Wantai and Roche; travel, accommodation and lecture fees from Merck, Gilead and GFE Blut GmBh; travel and accommodation fees from the Gates Foundation and Médecins Sans Frontières; and a grant from BMA. Please see the full study for the other authors' relevant financial disclosures.