Dear teachers and colleagues,
The Centers for Disease Control (CDC) would like to remind everyone that recent hot and rainy weather across various regions has created favorable conditions for mosquito breeding and disease transmission. With frequent travel during the summer vacation and increased movement among different areas, all counties and cities face the risk of dengue fever outbreaks. We urge everyone to diligently implement the "Search, Dump, Clean, Brush" measures: regularly inspect your surroundings for stagnant water and dispose of it; clean water containers weekly by scrubbing their inner walls or turning them upside down to prevent mosquito breeding. When engaging in outdoor activities, please wear light-colored long-sleeved clothing to prevent mosquito bites. Individuals with recent travel history to outbreak areas who experience symptoms such as fever, headache, eye pain, muscle and joint pain should seek medical attention promptly and inform healthcare providers of their travel and activity history. Please be vigilant for warning signs of dengue fever, including abdominal pain and tenderness, persistent vomiting, mucosal bleeding, drowsiness, and restlessness. For more information on dengue fever, please visit the CDC website (https://www.cdc.gov.tw) or call the toll-free epidemic prevention hotline 1922 (0800-001922).
We kindly ask all teachers and colleagues to assist in clearing unnecessary containers from personal workspaces and to empty unused vases and containers. Vases and water-holding containers must be cleaned weekly, ensuring to scrub the inner walls. Each academic and administrative unit is requested to designate personnel to regularly inspect public spaces.
Transmission methods: The main vector mosquitoes in Taiwan are Aedes aegypti and Aedes albopictus.

• Aedes aegypti: Recognizable by a pair of lyre-shaped lines on each side of the thorax and a yellow line in the middle, they prefer indoor artificial containers or human-made stagnant water.
• Aedes albopictus: Identified by a prominent white stripe in the middle of the thoracic shield, they prefer outdoor habitats.

Peak biting times are approximately 1-2 hours after sunrise and 2-3 hours before sunset. When engaging in outdoor activities during these periods, please take adequate self-protection measures.
Incubation period: The typical incubation period for dengue fever is 3 to 8 days (up to 14 days). During the period from one day before symptom onset to five days after, known as the "infectious period," mosquitoes that bite an infected person can acquire the dengue virus. The virus undergoes an 8-12 day incubation period within the mosquito, which then becomes capable of lifelong transmission. When this mosquito subsequently bites another person, it can transmit the dengue virus.
Symptoms: Symptoms vary among individuals; some may experience mild or no symptoms. Typical symptoms include sudden high fever (≧38°C), headache, eye pain, muscle and joint pains, and rash. In cases of sequential infections with different dengue virus types, the likelihood of severe clinical symptoms increases. Without timely medical treatment, mortality rates can exceed 20%. Symptoms that worsen on days 3-5 after onset, such as severe pain, seizures, unconsciousness, changes in consciousness, and blood pressure changes, should be closely monitored for signs of severe dengue fever.
Preventive measures:

1. For the general public at home:
   • Install screens on windows and doors, and use mosquito nets while sleeping.
   • Eliminate unnecessary containers and store vases and containers upside down when not in use.
   • Regularly inspect dark areas or basements and consider using mosquito traps.
2. Eliminate breeding sources with the four practices of "Search, Dump, Clean, Brush":
   • Regularly inspect for potential standing water indoors and outdoors.
   • Dispose of stagnant water and unused containers.
   • Thoroughly clean and scrub containers and utensils used.
   • Remove mosquito eggs and ensure that containers do not accumulate water again.
3. Measures for individuals infected with dengue fever:
   • Patients should prevent mosquito bites within 5 days after symptom onset by installing screens and nets.
   • Health authorities should conduct source elimination and evaluate the need for adult mosquito control measures based on relevant data.
   • Investigate the travel history (or locations visited) of patients in the two weeks before onset and one week after onset to confirm suspected cases.