Childhood acute flaccid myelitis, including the first confirmed cases of enterovirus D68 myelitis, in Singapore and Southeast Asia

Abstract

Aim

We report the epidemiology, treatment and outcomes of acute flaccid myelitis (AFM), including the first two cases of enterovirus (EV) D68 myelitis, in Singapore.

Methods

Retrospective observational study from a paediatric hospital in Singapore, from January 2012 to December 2022. Clinical, laboratory, neuroimaging and outcome data were analysed.

Results

Eight patients were identified (all male). Median age at presentation was 3 (interquartile range (IQR) 2.2–10.0) years. Seven (87.5%) patients were clustered in two time periods (July 2018–January 2019 and April–August 2022). Presenting features were a preceding febrile respiratory illness (n = 6) or hand-foot-and-mouth disease (n = 2), upper limb weakness (n = 5, 62.5%) and neurogenic bladder (3, 37.5%), while the spinal cord lesions were predominantly in the cervical region (7, 87.5%). Five (62.5%) and six (75.0%) patients had elevated cerebrospinal fluid (CSF) white cells (median 7.5/mm³ (IQR 2.8–40.3)) and protein (median 0.6 g/L (IQR 0.4–0.7)), respectively. CSF was negative for pathogens. Two (50%) of four patients with EV detected in respiratory/rectal swabs had EVD68 (2022 cluster). All received intravenous methylprednisolone, six (75%) had additional intravenous immunoglobulin and either plasma exchange therapy (n = 1) or intravenous tocilizumab (n = 1). Median modified Rankin Scale (mRS) at acute illness was 4 (IQR grades 3–5), with an improvement (median 2 (IQR 1.8–2.3) mRS grades) on follow-up (median duration 3.7 (IQR 1.4–4.1) years). One patient (12.5%) had a full recovery and seven (87.5%) have moderate disability (mRS 2–3).

Conclusion

Disability risk in AFM is high despite aggressive immunotherapy. We report the first two confirmed cases of EV D68 AFM in Singapore and Southeast Asia.