Respiratory illness and acute flaccid myelitis in the Tokai district in 2018

An outbreak of acute flaccid myelitis was chronologically correlated with an outbreak of severe respiratory illness in Japan in 2015. We hypothesized that increases in children hospitalized with severe respiratory illnesses might also be associated with increase in acute flaccid myelitis in autumn 2018.

We explored the temporal correlations between respiratory illness outbreaks and acute flaccid myelitis during autumn season between 2016 and 2018 using questionnaire surveys. One questionnaire explored the monthly numbers of children with acute flaccid myelitis, Guillain-Barré syndrome, and other acute flaccid paralyses. The other questionnaire explored the monthly numbers of children hospitalized with respiratory illnesses associated with wheezing. A correlation between the monthly numbers of children with acute flaccid myelitis and those with respiratory illness was analyzed using the Pearson correlation test.

Although the number of patients hospitalized with respiratory illness did not correlate with the number of those admitted with myelitis, increases in children aged 7-12 and 13-19 years requiring intensive care unit admission correlated temporally with an outbreak of acute flaccid myelitis.

An increase in intensive care unit admissions to treat respiratory disease occurred in association with a cluster of acute flaccid myelitis. An increase in the number of intensive care unit admissions due to respiratory illness may be a clue to expect the occurrence of acute flaccid myelitis.