JMIR Publications

ABSTRACT

Background:

Acute flaccid paralysis is a clinical syndrome characterized by the rapid onset of lower motor neuron weakness and remains an important global public health concern.

Objective:

This study assessed the epidemiological characteristics and environmental risk factors associated with acute flaccid paralysis in Taiwan from 2006 to 2020 using surveillance data from the Taiwan Centers for Disease Control (TCDC).

Methods:

Acute flaccid paralysis-related data reported to the National Infectious Diseases Statistics System between 1 January 2006 and 31 December 2020 were analyzed. Variables included age, sex, area of residence, and season of occurrence. Associations with meteorological and air pollution factors were evaluated.

Results:

A total of 719 cases with acute flaccid paralysis were identified, including 715 (99.4%) local and four (0.6%) imported cases. The average annual incidence rate ranged from 0.6 to 2.1 per 1,000,000 population. Significant differences were observed across age groups, seasonal patterns, and areas of residence (p < 0.001, p < 0.001, p = 0.032, respectively). The male-to-female ratio was approximately 1.5:1. Children younger than 5 years accounted for the largest proportion of cases. The cases occurred year-round, with peaks in winter and spring, and were most frequently reported in southern Taiwan. No significant differences by age group, season, or area of residence were observed when cases were stratified by sex. In contrast, significant differences by season and residence were identified across age groups (p = 0.004 and p = 0.003, respectively). Multiple linear regression analysis showed no significant associations between acute flaccid paralysis incidence and temperature, precipitation, relative humidity, or mean pressure. However, acute flaccid paralysis cases were positively associated with particulate matter ≤10 µm (B value = 0.177, p = 0.028) and negatively associated with SO2 concentration (B value = -3.092, p < 0.001).

Conclusions:

This study provides the first comprehensive analysis of laboratory-confirmed acute flaccid paralysis cases in Taiwan using long-term TCDC surveillance data. The findings highlight the importance of extended surveillance, environmental assessment, and geographically comprehensive analyses to better understand acute flaccid paralysis patterns and support prevention and control strategies in Taiwan.