https://zh.nguoilontuoi.com/post/dengue-fever-is-prevalent-in-a-community-1-000-people-were-investigated-on-april-1-of-which-100-people-were-confirmed-to-have-been-infected-with-dengue-fever-the-same-population-was-investigated-on-june-1-and-another-100-people-were-confirmed-to-be-infected-with-dengue-fever-the-prevalence-of-dengue-fever-in-this-community-is-as-follows