Distribution of subjects according to the infection state within each age and sex category and comparisons of these distributions between infection state categories.

Distributions by age categories were compared using the Fisher’s exact test, and distributions by sex were compared using the χ2 test.

按年龄分组的分布情况采用费希尔精确检验（Fisher’s exact test）进行组间比较，按性别划分的分布情况则采用卡方检验（χ2 test）进行组间比较。