Changhua County health officials expanded mosquito-control perimeters after three asymptomatic residents tested positive among 131 people screened near two confirmed local dengue cases living 110 meters apart, Liberty Times reported Saturday.
Screening timeline
The county tested 20 residents on Oct. 1 with negative results, then drew 131 more blood samples on Oct. 2. Three returned positive without fever, prompting Director Yeh Yen-po to keep them under observation while crews enlarged dirty-site inspections in Changhua City's Dongxing and Minquan neighborhoods.
Vector control enforcement
Teams flagged 12 cluttered lots—empty homes, parking puddles—and fined eight owners NT$3,000 to NT$15,000 for failing to clear breeding water. Daily penalties continue until fixes are verified. Mei-Hua Liu's desk notes asymptomatic positives complicate fever-based triage at clinics; NS1 rapid tests at airports caught Taiwan's ninth imported case in Tainan the same week.
Gene sequencing next
Authorities sent samples for viral genealogy to confirm whether the Changhua pair shares one chain of transmission. The county's last cluster was 2023; three years of quiet do not guarantee immunity because Ae. aegypti pockets persist in urban courtyards.
What residents should do
Empty containers, apply approved repellents during dawn and dusk patrols, and report stagnant water on the 1925 hotline. Hospital emergency departments ask travelers with fever within two weeks of Southeast Asia trips to disclose flight history before sitting in waiting rooms.
Imported pressure
CDC tallies show Vietnam, Indonesia, and the Philippines as top import sources. Changhua's local cluster is small against 167 imported cases, but local transmission triggers faster neighborhood sweeps because mosquitoes do not stamp passports.
School proximity
County education officials said campuses within the expanded perimeter will hold outdoor PE classes only after larvicide sweeps. Parents received SMS templates in Taiwanese and Mandarin explaining symptom watch lists even for children without fever.
Hospital capacity
Regional hospitals reserved isolation rooms for confirmed cases while urging mild fevers to use clinic triage lines first. Blood banks said dengue screening has not affected donation drives scheduled for Double Ten weekend.