The latest forecast from the World Meteorological Organization (WMO) shows that the El Niño phenomenon may further intensify in the coming months and could develop into a strong El Niño. El Niño may cause global temperatures to rise further, alter atmospheric circulation and rainfall patterns, and increase the risk of extreme weather events; some regions may experience more concentrated rainfall, facing short‑duration heavy rain, torrential rain, severe floods, and inundation, while other areas may face drought and water shortages. International studies indicate that the high temperatures, warm winters, and abnormal rainfall associated with El Niño may affect the growth and reproduction of vector mosquitoes and increase the risk of dengue transmission. Rising temperatures may shorten the mosquito life cycle and accelerate breeding; high temperatures may also reduce the time required for dengue virus to replicate within mosquitoes to an infectious stage, increasing transmission opportunities. On the other hand, after heavy rain, torrential rain, or continuous rainfall, various standing‑water habitats can form indoors and outdoors, increasing mosquito breeding opportunities. Because El Niño favors dengue transmission, and mosquito‑borne disease outbreaks continue internationally during the peak summer travel season, the public is urged to implement mosquito‑preventive measures while abroad and to seek medical care promptly if symptoms appear after returning, to jointly prevent dengue.
CDC surveillance data show that as of July 6 this year, a total of 83 confirmed dengue cases have been reported, including 7 locally transmitted cases, all residing in Kaohsiung City; the remaining 76 were imported from Southeast and South Asian countries, with Indonesia (21 cases) the highest, followed by the Maldives (14 cases) and Vietnam (11 cases). The cumulative case count this year is lower than the same period in the previous year (2025) (91 cases). The global dengue situation remains severe; as of May this year, more than 1.44 million cases have been reported, primarily in the Americas, with Brazil having the highest number, followed by Bolivia and Colombia. In neighboring Asian countries such as Vietnam, Malaysia, Sri Lanka, Cambodia, Bangladesh, and Laos, recent outbreaks have risen, with case numbers higher than the same period last year, and multiple dengue virus serotypes co‑circulating. Given that it is the rainy season in Southeast Asia with frequent rainfall, the overall epidemic is expected to remain at a peak. Health authorities continue to closely monitor community vector mosquito densities and strengthen inspections and control measures in high‑risk areas.
The CDC explains that recent domestic weather has been persistently hot with frequent afternoon thunderstorms; post‑rain environmental cleanup is key to dengue control. The public should regularly inspect both indoor and outdoor areas, thoroughly remove standing‑water containers such as plant saucers, discarded tires, and stacked items, invert or properly store unused containers, and re‑inspect after rain, implementing the “inspect, invert, clean, brush” approach to prevent mosquito breeding.
The CDC reminds that the current climate is conducive to mosquito growth and activity. When outdoors, people are advised 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 occur, seek medical care promptly and inform the physician of travel history. Medical facilities are also urged to stay vigilant, inquire about TOCC (travel, occupation, contact, cluster history), use dengue NS1 rapid tests for early diagnosis and reporting, enabling health authorities to act quickly. Moreover, as the international dengue situation persists, travelers returning to the country should proactively inform airport quarantine personnel if they develop fever, headache, muscle or joint pain, rash, or other suspected dengue symptoms. For dengue information, please visit the CDC’s global website (https://www.cdc.gov.tw) for reference, or call the toll‑free epidemic prevention hotline 1922 (0800-001922).
Source: Centers for Disease Control
Data compiled: Infection Control Office
