Dengue Fever Prevention and Control Plan (2025 Edition)

Q&A on the Interpretation of the Dengue Fever Prevention and Control Plan (2025 Edition)

1. What is the background for the introduction of the Dengue Fever Prevention and Control Plan (2025 Edition)?

Dengue fever is a Category B infectious disease stipulated by the Law of the People's Republic of China on the Prevention and Treatment of Infectious Diseases. In response to the epidemiological characteristics of dengue fever both domestically and internationally in recent years, and incorporating the beneficial experiences accumulated by localities in epidemic response, the National Disease Control and Prevention Administration, in conjunction with the National Health Commission, has formulated the Dengue Fever Prevention and Control Plan (2025 Edition) (hereinafter referred to as the "Plan"). The Plan clarifies the overall requirements for prevention and control work and the classification of epidemic risk areas, as well as specific requirements for measures such as case reporting and management, epidemic response, laboratory testing, and prevention. It guides localities in conducting dengue fever prevention and control work more scientifically and effectively to protect public health.

2. What are the sources of infection and transmission routes for dengue fever? Which populations are susceptible?

Sources of Infection: Dengue fever patients, asymptomatic carriers, and virus-carrying non-human primates can all serve as sources of infection.

Transmission Routes: Dengue fever is primarily transmitted through the bite of Aedes mosquitoes carrying the dengue virus. In China, the main vectors are Aedes albopictus (Asian tiger mosquito) and Aedes aegypti (yellow fever mosquito). In rare cases, it can also be transmitted through blood transfusion and mother-to-child transmission.

Susceptible Populations: The population is generally susceptible. Infection confers lasting immunity against the same dengue virus serotype, but does not provide effective protection against different serotypes. Re-infection with a different serotype increases the risk of severe disease.

3. How does the Plan define dengue fever epidemic risk areas?

Considering factors such as the distribution and activity period of vector mosquitoes, the occurrence and scale of previous local epidemics, 31 provinces (autonomous regions, municipalities directly under the Central Government) and the Xinjiang Production and Construction Corps are classified into four categories of epidemic risk areas based on dengue fever transmission risk, from highest to lowest: Category I (6), Category II (11), Category III (8), and Category IV (7). This classification can be dynamically adjusted based on changes in transmission risk.

4. What regulations does the Plan specify for epidemic prevention and response?

Case Reporting and Management: Customs authorities promptly notify local CDC departments of inbound travelers potentially infected with dengue virus. Medical institutions report identified dengue fever cases via the online direct reporting system within 24 hours. Hospitalized cases are treated with mosquito-proof isolation as required by the Dengue Fever Diagnosis and Treatment Plan (2024 Edition). Local CDC agencies and community health service centers (township health centers) guide non-hospitalized dengue fever cases in self-management with mosquito-proof isolation and health monitoring.

Scientific Epidemic Response: Upon detection of dengue fever cases, risk areas are scientifically delineated. Based on the epidemic progression, graded and classified measures are implemented, including emergency vector mosquito monitoring and control, and emergency case surveillance and management. Epidemic information is effectively communicated to curb the spread and diffusion of the outbreak.

Deepening Patriotic Health Campaigns: Localities are to organize patriotic health campaigns, urging all departments to fulfill their responsibilities by integrating mosquito vector control requirements into routine environmental sanitation improvements, breeding site elimination, and vector control efforts.

Strengthening Health Education: Based on local dengue fever epidemic characteristics and targeting different population groups, scientific prevention and control knowledge should be disseminated through various channels to enhance public self-protection awareness and initiative to seek medical attention.

Strengthening Prevention and Control in Key Sites: Key locations such as medical institutions, construction sites, parks, tourist attractions, flower markets, and hotels in high-risk areas should enhance environmental sanitation within their premises and surrounding areas. Rural areas are encouraged to adopt context-appropriate mosquito control measures focused on eliminating and modifying breeding sites to effectively reduce vector mosquito density.

5. What specific requirements does the Plan have for dengue fever case management?

Hospitalized cases receive mosquito-proof isolation treatment: beds are equipped with mosquito nets, wards, duty rooms, and other rooms have screens installed on doors and windows, and mosquito elimination is conducted within the hospital grounds and surrounding environment. Non-hospitalized cases are required to practice self-isolation with mosquito prevention measures; medical institutions inform cases of relevant precautions during the isolation period. Dengue fever cases can be released from mosquito-proof isolation once their course of illness exceeds 5 days and their body temperature has naturally returned to normal for more than 24 hours.

6. What measures does the Plan outline for epidemic response and control?

Scientific Delineation of Risk Areas: During the dengue fever epidemic season in Category I, II, and III areas, or during the non-epidemic season in areas with local cases, based on individual epidemiological investigation results, three risk zones are delineated from highest to lowest transmission risk: the core zone, alert zone, and monitoring zone. The core zone is defined as a spatial area with a radius of no less than 100 meters centered on the case's residence, workplace, or places where they spent extended periods during their infectious period. The alert zone extends 200 meters outward from the core zone boundary.

Graded and Classified Epidemic Response: Based on the characteristics of dengue fever transmission and disease progression, epidemics are classified as imported cases, local sporadic cases, clustered outbreaks, or local outbreaks. Response follows the principle of "early detection, localized containment, strict measures, and thorough implementation" ("early, small, strict, real") with graded and classified response measures.

For imported cases, strengthen vector mosquito monitoring, actively implement mosquito prevention and elimination, and ensure case treatment and isolation management.

For local sporadic cases, scientifically delineate risk areas, rapidly reduce mosquito density, and initiate emergency case surveillance.

For clustered outbreaks, require risk area delineation within 1 day and initiate mosquito elimination work. Within the core zone, complete household surveys and interventions within 3 days, achieve comprehensive adult mosquito killing within 3 days, and bring mosquito density under control within 5 days.

For local outbreaks, focus efforts on curbing the peak and slowing the spread , reducing mosquito density, minimizing the risk of severe cases and deaths, and preventing medical resource strain and local establishment of the virus.

Emergency Vector Mosquito Monitoring and Control: When dengue fever confirmed cases appear during the active period of vector mosquitoes, emergency vector mosquito monitoring and control are initiated in Category I, II, and III areas. Emergency monitoring and control in the core and alert zones can be terminated when no new dengue fever cases occur for 24 consecutive days within the zones, and the Breteau Index (BI) in the core zone drops below 5, and the adult mosquito density measured by the double-layered mosquito net method is no higher than 0.9 mosquitoes/(net·hour).

Epidemic Information Sharing: Provincial-level CDC departments shall release dengue fever epidemic information and issue scientific health risk alerts according to the law. When inter-regional transmission occurs within a province, the CDC departments and relevant agencies in the involved areas shall strengthen information sharing and take prevention and control measures as early as possible. When inter-provincial transmission occurs, the CDC department in the province receiving imported cases shall promptly notify the CDC department in the case-exporting province to jointly conduct epidemic investigation and response.