Angiostrongylus cantonensis Meningo-Encephalitis in Children-Heightened Awareness Needed During Prolonged Wet Weather Conditions.

Aim: Angiostrongylus cantonensis, the leading cause of eosinophilic meningoencephalitis, is well established in eastern Australia. Prolonged wet weather in Queensland during 2021-2022 coincided with anecdotal reports of increased neuroangiostrongyliasis cases, prompting an evaluation of paediatric cases from 2013 to 2022.

Methods: This retrospective observational study reviewed children (0-16 years) with cerebrospinal fluid (CSF) eosinophilia (≥ 10% of the total CSF leukocyte count) and/or A. cantonensis testing (serology or polymerase chain reaction) between 01/01/2013 and 31/12/2022, using statewide laboratory data and patient records.

Results: Eighty children were identified: 59 (74%) had CSF eosinophilia without A. cantonensis testing, 9 (11%) had CSF eosinophilia with A. cantonensis testing, and 12 (15%) had A. cantonensis testing without CSF eosinophilia. Neuroangiostrongyliasis was either proven or probable in seven children: five (71%) during 2021-2022, coinciding with prolonged wet weather. A significant positive correlation was observed between rainfall and case numbers (r = 0.88, p < 0.01). Median age of diagnosed children was 4 years (IQR 1.8-8.5, range 1.5-13 years) and five (71%) were male. Snail or slug exposure was reported in four (57%) children. All children presented with vomiting, and six also had a headache and focal neurology (86%). Abnormal neuroimaging was noted in six (86%) cases. Five children received corticosteroid therapy alone (71%), while two (29%) were managed conservatively. There were no deaths, but one child had persistent focal neurological abnormalities at discharge.

Conclusion: Awareness of A. cantonensis and exposure risks is crucial, especially during prolonged wet weather conditions. While most children in this study had good outcomes, this is not always the case.