As temperatures rise, mosquitoes resume their activity. This year, a widespread mild winter across China has brought an earlier‑than‑usual mosquito‑active season, raising risks of importation and local spread of mosquito‑borne infectious diseases including dengue fever, chikungunya fever and malaria. Mosquito prevention and control has become a priority for public health in this season. Let us start by understanding mosquitoes, adopt science‑based sustainable integrated vector management strategies, and build a health defense for ourselves and our families.
Recognize the Three Unwelcome Guests
Let us get acquainted with the three major culprits behind mosquito‑borne diseases.
Dengue fever is caused by the dengue virus and transmitted mainly through bites of Aedes mosquitoes (commonly known as tiger mosquitoes). It prevails across tropical and subtropical regions worldwide, exposing roughly half of the global population to infection risks. Typical symptoms include sudden high fever (up to 40°C), severe headache, retro‑orbital pain, generalized myalgia and arthralgia, nausea, vomiting and skin rash. Most patients experience mild or asymptomatic illness and recover within 1‑2 weeks. However, a small proportion may progress to severe dengue with serious hemorrhage, shock and even death. Patients reinfected with a different dengue virus serotype face higher risks of severe dengue.
Chikungunya fever is also transmitted by Aedes mosquitoes. Its symptoms overlap with dengue fever, making differential diagnosis challenging. Its hallmark manifestation is excruciating joint pain, predominantly affecting small joints such as wrists, ankles and fingers. Joint discomfort may linger for weeks or even months in some patients. While dengue features generalized muscular soreness, chikungunya is marked by severe small‑joint pain. Distinction relies on epidemiological history and etiological laboratory testing.
Malaria, colloquially known as ague, is transmitted by Anopheles mosquito bites and was once a devastating infectious disease threatening human health. It presents with paroxysmal cyclic episodes alternating among cold rigor phase, high‑fever phase and sweating phase: sudden chills and whole‑body shivering (lasting 1‑2 hours), followed by rapid temperature rise to 39℃‑40℃ accompanied by headache and myalgia, then profuse sweating and return to normal body temperature. Such paroxysms recur every 1‑2 days following a regular pattern. Though indigenous malaria has been eliminated in China, imported cases still occur annually. Returnees from Africa, Southeast Asia and other malaria‑endemic regions require special vigilance.
Watch Closely for These Warning Symptoms
Recognizing disease warning signals enables timely and appropriate responses. Below are core identification tips for the three mosquito‑borne illnesses.
Key signals of dengue fever: Sudden high fever (often above 39℃, some cases present biphasic fever), accompanied by severe headache, retro‑orbital pain, excruciating generalized muscle and bone‑joint pain (colloquially known as break‑bone fever), plus flushing over the face, neck and chest. After fever subsides, manifestations such as severe abdominal pain, persistent vomiting, tachypnea, gingival or nasal bleeding, hematemesis or melena, pale and clammy skin may indicate severe dengue; seek immediate medical care.
Key signals of chikungunya fever: Sudden high fever (usually above 39℃), with severe arthralgia chiefly affecting small joints including wrists, ankles, fingers and toes. Patients often describe the pain as knife‑like, so disabling that standing or holding a pen becomes difficult. Joint pain may persist weeks to months after fever resolves. Maculopapular rashes may develop on the trunk and extensor surfaces of limbs 2‑5 days after onset, sometimes accompanied by desquamation.
Key signals of malaria: Typical cyclic paroxysms cycling through chills‑rigors, high fever and profuse sweating. Each episode lasts several hours and recurs every 1‑2 days in a predictable rhythm. Rigors precede rapid temperature rise to 39℃‑40℃, followed by heavy sweating and return to baseline temperature. Severe malaria may present with confusion, coma, shock as well as hepatic and renal failure.
Special reminder: Early‑stage manifestations of dengue and chikungunya overlap significantly. Do not self‑medicate. Before dengue is ruled out, avoid non‑steroidal anti‑inflammatory drugs such as aspirin or ibuprofen to lower bleeding risk. Acetaminophen (paracetamol) is recommended for fever and pain relief.
Source‑oriented Eradication Prevails Over Insecticide Spraying
Many people only think of aerosol sprays and mosquito coils for mosquito control. Reliance solely on chemical agents fuels mosquito insecticide resistance, pollutes the environment and harms beneficial insects including bees. Sustainable integrated vector management is the internationally recognized scientific strategy, highlighting the following principles.
Environment‑based intervention: Eliminating mosquito breeding sites (stagnant water, garbage) represents the most fundamental, eco‑friendly measure with long‑lasting outcomes independent of chemical pesticides.
Rational chemical application: Apply insecticides in a targeted manner only when necessary; rotate formulations with different mechanisms of action to avoid resistance development.
Multi‑measure synergy: Combine physical control (window screens, mosquito nets, electric swatters), biological control (larvivorous fish feeding on mosquito larvae) and chemical control (insecticides, repellents).
Community‑wide participation: Patriotic Health Month encourages households to empty containers and overturn pots. Collective public engagement builds community‑wide protective barriers.
Surveillance and assessment: Regularly monitor mosquito density and insecticide resistance, dynamically adjust control strategies instead of adopting a one‑size‑fits‑all approach.
Four Steps for a Mosquito‑Free Home
Translated to daily‑life practice, mosquito‑proofing follows four core principles: Remove, Block, Eliminate, Inspect.
Step One: Remove stagnant water and destroy mosquito breeding grounds.
Mosquito eggs, larvae and pupae depend entirely on water. Eliminating stagnant water proves critical for mosquito prevention and suppression. At home, routinely inspect and drain water‑holding sites: flowerpot saucers, water buckets, air‑conditioner drip trays, idle containers and so forth. Adhere to the practice of overturning pots and cans and leaving no stagnant‑water corners. For hydroponic plants, replace water weekly and thoroughly scrub plant roots and container inner walls; alternatively switch to sand or ceramsite cultivation to cut off standing water. Households with courtyards shall regularly unclog drainage ditches. Store unused pots and cans upside‑down around premises to avoid rainwater accumulation. Timely dispose of or properly cover waste tires and other water‑retaining articles. At community level, renovate drainage channels, sewers and surroundings of waste bins; collect garbage on schedule and clear blockages.
Step Two: Block bites by installing physical barriers.
Physical protection represents the most fundamental and effective measure. Fit door and window screens indoors; use bed nets while sleeping to physically block mosquito entry. When outdoors, wear light‑colored long‑sleeve shirts and long trousers to minimize exposed skin. Apply repellent containing active ingredients such as DEET or IR3535 onto bare skin and garments. Aedes mosquitoes bite in daytime, peaking two hours after sunrise and two hours before sunset. Minimize outdoor stays amid dense mosquitoes under trees and grassland during these peak hours.
Step Three: Kill adult mosquitoes with targeted, science‑guided medication.
When adult mosquitoes appear indoors, deploy physical tools such as electric mosquito swatters or bug zappers for precise knockdown. You may also rationally use insecticidal products including liquid vaporizer mats, mosquito‑repellent mats and aerosol sprays. Always follow package instructions and avoid over‑application. Rotate products with different active ingredients (e.g. pyrethroids and organophosphates) to prevent resistance caused by long‑term single‑agent use. Never misuse highly toxic or banned pesticides for mosquito elimination; refrain from dumping insecticides directly into water bodies to prevent water contamination and toxicity to fish and shrimp.
Step Four: Inspect hidden hazards and sustain monitoring & early warning.
Routinely inspect your household and surrounding premises for newly‑formed stagnant‑water spots and eliminate them promptly. Communities may conduct periodic mosquito‑density surveillance to guide science‑based control actions.
Practical Wisdom for Daily Mosquito Prevention
Mosquito protection relies not merely on thorough cleaning and insecticides, but also on small, consistent daily‑life practices.
Maintain environmental sanitation. Keep indoor‑outdoor premises tidy; clear discarded clutter and garbage to reduce mosquito resting habitats. Property management teams shall perform routine mosquito suppression in public zones to lower mosquito‑fly density. During mosquito‑borne‑disease epidemic seasons, communities may organize residents to sanitize neglected corners and curb mosquito breeding from the source.
Travel‑related protection. Residents planning trips to dengue‑ or chikungunya‑endemic regions (Southeast Asia, South America, Africa and southern Chinese provinces such as Guangdong) shall review destination epidemic information beforehand and prepare protective supplies: repellents, bed nets and light‑colored long‑sleeve garments. Choose accommodation fitted with door‑window screens while travelling. Avoid grassy or riparian sites teeming with mosquitoes during mosquito‑active peaks. Pregnant women are strongly advised against travelling to Zika‑virus‑endemic areas.
Post‑return health monitoring. Continue mosquito‑preventive measures upon returning from endemic zones and closely monitor personal health status for two weeks. Seek prompt medical consultation and proactively notify clinicians of travel history and mosquito‑bite exposure once fever, rash, arthralgia or other suspicious manifestations develop. Timely diagnosis, treatment and mosquito‑proof isolation prevent transmission to household contacts. Exercise heightened vigilance toward malaria: seek medical evaluation for fever or chills within one month after returning from endemic areas (within two years for long‑term expatriates).
Source: Health Popular Science Network