Outcome of Japanese Encephalitis Virus (JEV) Infection in Pediatric and Adult Patients at Mahosot Hospital, Vientiane, Lao PDR

Abstract

Although Japanese encephalitis virus (JEV) infection is an important cause of acute febrile illness in Lao PDR (Laos), patient outcome has not been evaluated. We prospectively followed up 123 JEV-infected patients (70 children < 15 years and 53 adults ≥ 15 years) admitted at Mahosot Hospital, Vientiane, from 2003 to 2013. Japanese encephalitis virus infection was diagnosed by the detection of anti-JEV IgM in cerebrospinal fluid and/or IgM seroconversion. Neurological sequelae were assessed using the Liverpool Outcome Score (LOS), total (maximum score = 75), and final (maximum score = 5). The median (interquartile range [IQR]) age of the patients was 12.0 (7.5–18.8) years, and 57% were male. The median (IQR) duration of patients’ follow-up was 4.5 (3.2–7.3) years. Of all patients, 10/123 (8.1%) died during hospitalization, and 13/123 (10.6%) died at home after discharge, giving a mortality of 18.7% (23/123) (33 [26.8%] patients were lost to follow-up). The frequency of neurological sequelae at the last follow-up was 61.2% (48.4% in adults and 69.4% in children, P = 0.135). The proportion of patients with severe and moderate functional impairment at the last follow-up was significantly higher in children (25%) than in adults (6.5%), P = 0.042. Half of the patients who were still alive at the last follow-up (67) and for whom LOS data were available (22) had improvements in their total and final LOS between discharge and the last follow-up. The total and final LOS at discharge were not significantly different between children and adults, but total LOS at the last follow-up was significantly higher in adults than in children (median [IQR]: 74.5 [73–75] versus 73.0 [73–75], P = 0.019).

Estimates of Japanese Encephalitis mortality and morbidity: A systematic review and modeling analysis

“…Refusal to participation, no contact information, relocation, and leave against medical advice were the top four reasons for the lost to follow up. 7 studies [ 28 , 54 , 56 , 77 , 80 , 94 , 96 ] had lost to follow up greater than 20%. Within these articles, 5 studies [ 28 , 54 , 56 , 77 , 80 ] had follow-up period greater than 1 year, one study [ 54 ] alerted refusal to participation due to poor health condition may generate bias to the study’s result.…”

“…7 studies [ 28 , 54 , 56 , 77 , 80 , 94 , 96 ] had lost to follow up greater than 20%. Within these articles, 5 studies [ 28 , 54 , 56 , 77 , 80 ] had follow-up period greater than 1 year, one study [ 54 ] alerted refusal to participation due to poor health condition may generate bias to the study’s result. Long travel distance and unwillingness to receive medical examination were the main refusal reasons for the rest of studies and might not affect the estimate ( S6 Table ).…”

Modelling Japanese encephalitis virus transmission dynamics and human exposure in a Cambodian rural multi-host system

“…However, the predicted average age at infection in the modeled villages was very low, (ranging from 2 to 11 years old). Since young children are more likely to develop severe forms after JEV infection, as well as severe sequelae [ 2 , 33 , 82 , 84 , 85 ], these results and the current knowledge we have about JEV circulation in Cambodia would justify to intensify child immunization.…”

Acute neurologic emerging flaviviruses

“…21 , 22 , 35 A recent 10-year prospective study of Lao patients with severe JEV found that one-fifth of patients died and two-thirds of survivors had neurological sequelae for a median duration of 4.5 years. 58 Importantly, these sequelae were more common in children than adults.…”