Peripheral nerve injury associated with JEV infection in high endemic regions, 2016-2020: a multicenter retrospective study in China

Abstract

Previously, we reported a cohort of Japanese encephalitis (JE) patients with Guillain-Barré syndrome. However, the evidence linking Japanese encephalitis virus (JEV) infection and peripheral nerve injury (PNI) remains limited, especially the epidemiology, clinical presentation, diagnosis, treatment, and outcome significantly differ from traditional JE. We performed a retrospective and multicenter study of 1626 patients with JE recorded in the surveillance system of the Chinese Center for Disease Control and Prevention, spanning the years 2016-2020. Cases were classified into type 1 and type 2 JE based on whether the JE was combined with PNI or not. A comparative analysis was conducted on demographic characteristics, clinical manifestations, imaging findings, electromyography data, laboratory results, and treatment outcomes. Among 1626 laboratory confirmed JE patients, 230 (14%) were type 2 mainly located along the Yellow River in northwest China. In addition to fever, headache, and disturbance of consciousness, type 2 patients experienced acute flaccid paralysis of the limbs, as well as severe respiratory muscle paralysis. These patients presented a greater mean length of stay in hospital (children, 22 years [range, 1-34]; adults, 25 years [range, 0-183]) and intensive care unit (children, 16 years [range, 1-30]; adults, 17 years [range, 0-102]). The mortality rate was higher in type 2 patients (36/230 [16%]) compared to type 1 (67/1396 [5%]). The clinical classification of the diagnosis of JE may play a crucial role in developing a rational treatment strategy, thereby mitigating the severity of the disease and potentially reducing disability and mortality rates among patients.

Keywords: Japanese encephalitis virus; clinical classification; electromyography; endemic; peripheral nerve injury.

Figure 1.

Presentation of surveillance data and infectious outcomes. The confirmation of JE was achieved through the detection of IgM antibody and RT-PCR assay in blood or cerebrospinal fluid samples. Abbreviations: JE, Japanese encephalitis; CNI, central nerve injury; JEV, Japanese encephalitis virus; PNI, peripheral nerve injury.

Figure 2.

Geographic and temporal representation of cases of JE. Panel A shows the cases of JE and PNI included in this report according to province; cases are only from the reporting hospitals and do not reflect all cases in each province. Panel B shows the time distribution of symptom onset among a subset of patients who were reported to the Chinese CDC surveillance system as having JE from 2016 to 2020. The numbers of total cases and laboratory-confirmed cases are provided. Cases of PNI are confirmed through signs and symptoms as well as clinical and laboratory tests. Abbreviations: PNI, peripheral nerve injury; JE, Japanese encephalitis; JEV, Japanese encephalitis virus.

Figure 3.

Suggestions for diagnosis and treatment of JEV infection. Abbreviations: JE, Japanese encephalitis; EMG, electromyography; NCV, nerve conduction velocity; CMAP, compound muscle action potential; CSF, cerebrospinal fluid; GBS, Guillain–Barré syndrome.