06/10/2026
📣⚕️Health Promotion Education ✍️
🥵☀️El Niño can affect Dengue transmission, but the relationship is complex. Its main effect is through changes in temperature, rainfall, water storage, and mosquito behavior.
*How EL NINO can affect DENGUE:
1. Higher temperatures → faster mosquito development.
>Aedes aegypti develops faster in warmer conditions.
>Mosquitoes may bite more frequently.
The dengue virus can replicate faster inside the mosquito, potentially shortening the time before the mosquito becomes infectious.
2. Water scarcity → more household water storage.
>During drought or water interruptions, communities may store water in containers.
>Uncovered or poorly managed containers can become breeding sites for Aedes mosquitoes.
This can paradoxically increase dengue risk even when rainfall is low.
3. Changes in rainfall → changes in breeding sites
>Moderate rainfall can create numerous small collections of water suitable for Aedes breeding.
>Extremely dry conditions may initially reduce natural breeding sites, but human water-storage practices can compensate for this reduction.
4. Longer or hotter transmission windows
>Warmer conditions can increase mosquito survival and viral transmission within suitable ranges.
>If El Niño produces prolonged warm periods followed by rainfall, dengue transmission can increase.
5. Effects are location-specific.
>El Niño does not automatically mean more dengue everywhere.
>The effect depends on local temperature, rainfall patterns, water availability, urbanization, sanitation, mosquito density, and population immunity.
The important public-health message:
☝️📣El Niño can shift Dengue risk rather than simply increase it.
📣📣📣A useful way to explain it is:
“When water becomes scarce, people store water. When temperatures rise, mosquitoes become more efficient. Together, these conditions can create a favorable environment for dengue transmission.”
☝️☝️El Niño should therefore trigger intensified vector surveillance, water-container inspection, source reduction, community risk communication, and early detection of cases, rather than focusing only on rainfall.
***📣Key point:
>NO RAIN does NOT necessarily mean NO Dengue.
>During El Niño, water-storage containers can become important breeding sites ☝️🪣🏺⚱️🫖🍯🚽
DOH Bicol CHD Department of Health (Philippines) Department of Health Catanduanes PHO Catanduanes Doc Aly T. Romano Susan Manlagnit Flores
