Guangzhou has entered the peak season for dengue fever, according to the Guangzhou Center for Disease Control and Prevention (Guangzhou CDC) on August 12. The virus is transmitted not only by symptomatic patients but also by asymptomatic carriers.
Dengue fever, the most common mosquito-borne disease worldwide, is an acute infectious disease caused by the dengue virus and transmitted through the bites of Aedes species mosquitoes. In Guangdong Province, cases typically begin to rise gradually from May, with the peak period occurring between August and November.
The Guangzhou CDC explains that dengue fever primarily spreads through an "Aedes mosquito-human-Aedes mosquito" cycle. Infected individuals and asymptomatic carriers serve as major sources of infection. Patients are infectious during the viremic period, which spans from one day before symptom onset to five days after. If bitten by a female Aedes mosquito during this period, transmission can occur.
Dengue fever spreads through an "Aedes mosquito-human-Aedes mosquito" cycle. (The picture is generated by AI.)
Studies show that although asymptomatic carriers of dengue fever have lower viremia levels than symptomatic patients, they represent a larger proportion of infections and significantly contribute to the spread of outbreaks.
After a female Aedes mosquito bites an asymptomatic carrier, the virus replicates and becomes infectious within the mosquito during an "extrinsic incubation period" of approximately 8–10 days. Once the mosquito bites another person, it can transmit the virus.
There are four distinct serotypes of the dengue virus. Infection with one serotype confers lifelong immunity to that specific type but provides no cross-protection against others. A secondary infection with a different serotype carries a significantly higher risk of severe disease progression, potentially leading to life-threatening complications.
The Guangzhou CDC reminds residents to remove standing water around homes and public areas and to use insect protection outdoors to prevent infection.
Reporter | Luo Shuxin (intern), Chen Jinxia
Editor | Hu Nan, James, Shen He
