Aim: We report the epidemiology, treatment and outcomes of acute flaccid myelitis (AFM), including the first two cases of enterovirus D68 myelitis, in Singapore. Methods: Retrospective study from a tertiary paediatric hospital in Singapore, from January 2012 to December 2022. Clinical, laboratory, neuroimaging and outcome data were analysed. Results: 8 patients were identified (all male). Median age at presentation was 3 (range 1.5- 11.5) years. Seven (87.5%) patients were clustered in two time periods (July 2018-January 2019; April-August 2022). Presenting features were a preceding febrile respiratory illness (n=6) or hand-foot-and-mouth disease (n=2) followed by upper limb weakness (n=5, 62.5%), and neurogenic bladder (3, 37.5%). Neuroimaging showed grey matter lesions (7, 87.5%) in the cervical spinal cord. Five (62.5%) and 6 (75.0%) patients had elevated cerebrospinal fluid (CSF) white cells (median 7.5/mm3 (1-325)) and protein (median 0.6g/L (0.21-0.88)), respectively. CSF was negative for pathogens. Two of 4 patients (50%) with enterovirus detected in respiratory/rectal swabs had genotype D68 (2022 cluster). All received intravenous methylprednisolone whilst 6 had additional intravenous immunoglobulin (n=6) and either plasma exchange therapy (n=1) or intravenous tocilizumab (n=1). Median modified Rankin Scale (mRS) at acute illness was 3.9, with an improvement (median 2 (1-3) mRS grades) on follow-up (median duration 4.1 (1.0-5.2) years). One patient (12.5%) had a full recovery; the remaining 7 (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 enterovirus D68 AFM in Singapore and South East Asia.

Jillian Pakiam
KK Women and Children's Hospital
Singapore

Karen Nadua
KK Women and Children's Hospital
Singapore

Cui Lin
National Public Health Laboratory
Singapore

Sing Yee Hoh
KK Women and Children's Hospital
Singapore

Ling Ying Tan
KK Women and Children's Hospital
Singapore

Jia Hui Teo
KK Women and Children's Hospital
Singapore

Zhi Min Ng
KK Women and Children's Hospital
Singapore

Indra Ganesan
KK Women and Children's Hospital
Singapore

Chia Yin Chong
KK Women and Children's Hospital
Singapore

Terrence Thomas
KK Women and Children's Hospital
Singapore