What You Must Know About Mosquito-Borne Diseases: A Complete Guide from Hazards to Prevention

To many people, mosquitoes are just a minor nuisance that causes itchy bumps. However, they are actually among the most dangerous insects in the world: as "mobile viral vectors," mosquitoes can transmit dozens of diseases. These infectious diseases spread by mosquitoes are collectively referred to as "mosquito-borne diseases." In recent years, with global warming and increased human mobility, the spread range and risk of mosquito-borne diseases have continued to expand. Understanding their hazards, transmission patterns, and prevention methods has become a must-have health lesson for everyone.

I. Alarming Current Risk Situation: Mosquito-Borne Diseases Are Closer Than You Think

When talking about mosquito-borne diseases, many people think of malaria in Africa or dengue fever in Southeast Asia. In reality, however, their risks have long penetrated our daily lives. According to data from the World Health Organization (WHO), more than 700,000 people die from mosquito-borne diseases worldwide each year, with malaria accounting for the highest proportion. Meanwhile, the incidence rates of diseases such as dengue fever, Zika virus disease, and chikungunya fever are rising at an annual rate of 10%.

In China, mosquito-borne diseases also cannot be ignored. Every summer, local dengue fever cases occur in southern regions. In 2023, multiple clustered outbreaks were reported in Guangdong, Yunnan, and other provinces. Although China has achieved the goal of "malaria elimination," there is still a risk of imported cases. Additionally, epidemic encephalitis B (Japanese encephalitis, JE) remains a threatening hazard for children in rural and suburban areas. More notably, as global temperatures rise, mosquitoes that were originally active only in tropical and subtropical regions (such as the Aedes albopictus that transmits dengue fever) are spreading to temperate zones. This means that the "northward shift of mosquito-borne disease risks" has become a new trend.

II. 4 Mosquito-Borne Diseases to Be Most Vigilant About: Concealed Symptoms, Severe Hazards

Different mosquitoes transmit different diseases. For example, Anopheles mosquitoes transmit malaria, Culex mosquitoes transmit Japanese encephalitis, and Aedes mosquitoes transmit dengue fever and Zika virus disease. However, they all share one common feature: their early symptoms are easily confused with those of a cold, and delayed treatment may lead to serious consequences.

1. Dengue Fever: "Fever with Bone Pain" Is a Typical Sign

Transmitted by Aedes albopictus (commonly known as "tiger mosquitoes"), infected individuals usually experience high fever (over 39°C), headache, muscle aches (especially joint pain, known as "breakbone fever"), and skin rashes. Most patients recover within 1-2 weeks, but a small number may develop "dengue hemorrhagic fever," which causes symptoms such as gum bleeding, vomiting blood, and shock, with a relatively high mortality rate. Provinces such as Guangdong, Hainan, and Fujian in China are high-incidence areas for dengue fever, with the epidemic season lasting from June to October each year.

2. Malaria: Don’t Ignore "Periodic Chills and Fever"

Transmitted by Anopheles mosquitoes, the typical symptoms include periodic episodes of "chills → high fever → profuse sweating," each lasting several hours and recurring every other day or every two days. If not treated promptly, Plasmodium (the parasite causing malaria) will destroy red blood cells, leading to anemia and hepatosplenomegaly. In severe cases, it can invade the brain, causing "cerebral malaria," which results in coma and convulsions. The mortality rate is extremely high among children and people with low immunity. Currently, malaria cases in China are mainly imported, so people returning from Africa or Southeast Asia need to be particularly vigilant.

3. Epidemic Encephalitis B (Japanese Encephalitis, JE): Children Are a High-Risk Group

Transmitted by Culex tritaeniorhynchus, this disease is more common in summer and autumn, and children under 10 years old are susceptible to infection. Early symptoms include fever, headache, and vomiting, which may be followed by drowsiness and convulsions. Severe cases can lead to coma, and some patients may suffer from sequelae such as intellectual disability and limb paralysis even after recovery. There is currently no specific treatment for Japanese encephalitis, and vaccination against JE is the most effective preventive measure.

4. Zika Virus Disease: Extremely High Risks for Pregnant Women and Fetuses

Also transmitted by Aedes albopictus, most infected people have mild symptoms, such as low-grade fever, skin rashes, and joint pain—similar to "mild dengue fever." However, if a pregnant woman is infected, it may cause microcephaly in the fetus (abnormally small head size accompanied by intellectual disability). The 2015 Zika epidemic in Brazil caused global panic. Although there is no large-scale outbreak now, sporadic cases still occur in tropical regions. Women who are planning to become pregnant or are already pregnant should avoid traveling to high-risk areas.

Conclusion: Don't Let "Small Mosquitoes" Bring "Big Risks"​