Clean Up After Heavy Rain, Remove Standing Water, and Seek Prompt Care for Dengue Symptoms

The Centers for Disease Control (hereafter referred to as the CDC) stated today (the 16th) that recent heavy rain across the country, driven by the plum‑rain front and southwest winds, has led to intense rainfall nationwide, and the hot temperatures favor the breeding of vector mosquitoes. Moreover, local clusters of dengue fever cases have already emerged domestically, increasing the risk of epidemic spread; the CDC urges the public to proactively eliminate standing‑water containers inside and outside homes to reduce vector mosquito breeding. The CDC explained that as of June 15, the local dengue fever cluster at a hospital in Kaohsiung City totaled six cases, with no new cases added. The confirmed patients were all contacts in the same ward during the hospitalization of the index case, and viral genome sequencing showed that the virus matched that of an imported case from Vietnam (symptom onset June 1); there is currently no evidence of outward spread, and monitoring is planned through July 12. In addition, the CDC’s rapid response team continues to dispatch personnel to assess control effectiveness and evaluate risks in surrounding communities, with a cumulative 24 person‑days of deployment to date; health authorities have also carried out inspections and removal of breeding sources in hospitals and communities, chemical control, and environmental cleanup, and have expanded testing to staff in the affected areas, current inpatients, and previously discharged patients, testing more than 1,400 individuals, all of whom were negative except for the aforementioned confirmed case. CDC surveillance data show that up to June 15 this year, there have been a total of 75 confirmed dengue cases, including seven locally acquired cases, all residing in Kaohsiung City; the remaining 68 were imported, all from Southeast and South Asian countries, with Indonesia accounting for the most (21 cases), followed by the Maldives (14) and Vietnam (9). The total number of cases this year is comparable to the same period in 2025 (79 cases) and lower than the same period in 2024 (274 cases). Regarding the international situation, the global dengue epidemic continues, with over 1.02 million cases reported worldwide as of April this year, primarily in the Americas, especially Brazil, Bolivia and Colombia. In neighboring Asian countries such as Vietnam, Malaysia and Sri Lanka, recent case numbers have risen, and Vietnam, Sri Lanka, Laos, Cambodia, the Maldives and Timor‑Leste have reported higher case counts this year than the same period last year. The CDC notes that after a dengue vector mosquito feeds, it seeks water to lay eggs, and both larvae (nymphs) and pupae develop in water. The public should proactively inspect indoor and outdoor environments, implementing the “inspect, dump, clean, brush” approach: remove unnecessary items, regularly scrub containers that must be kept and store them upside down after use; after rainfall, be sure to re‑inspect the surroundings of the home and any indoor areas for standing water, and dump any water found. Eliminating breeding sites removes the vector mosquitoes and reduces the risk of dengue and other mosquito‑borne diseases. The CDC reminds that dengue activity continues in neighboring Southeast and South Asian countries. Travelers returning to the country who have possible dengue symptoms should inform airport quarantine personnel. When engaging in outdoor activities, it is recommended to wear light‑colored long‑sleeved clothing and use government‑approved insect repellents containing effective ingredients such as DEET, picaridin, or IR‑3535. If fever, headache, retro‑orbital pain, muscle or joint pain, or other suspected dengue symptoms appear, seek medical care promptly and inform the physician of travel history. Medical facilities are urged to stay vigilant, consistently inquire about TOCC (Travel, Occupation, Contact, Cluster) history, use dengue NS1 rapid tests as appropriate for diagnosis, and report cases early to enable health authorities to implement control measures. For dengue information, visit the CDC website (https://www.cdc.gov.tw) or call the toll‑free epidemic prevention line 1922 (0800‑001922).

Source: Centers for Disease Control

Data compiled by: Surveillance Office