Dengue, chikungunya, and Zika are classic tropical diseases caused by arboviruses. They are regularly brought into France by travelers (imported cases), where they can be transmitted by the Asian tiger mosquito (Aedes albopictus). The active season for the mosquitoes that transmit these diseases began on May 1, while a sharp increase in imported dengue cases has been observed in France since 2023. In this context, Santé publique France reiterates the essential role of healthcare professionals in the prevention and control of arboviral diseases. Indeed, informing patients—including travelers—about prevention measures, early diagnosis, and reporting of these diseases helps reduce the risk of local transmission chains (autochthonous cases). For this reason, Santé publique France is providing a practical guide for healthcare professionals that outlines these elements and the key prevention messages to convey to individuals with dengue, chikungunya, or Zika.

Healthcare professionals: a central role in the system

Healthcare professionals play an important role at several levels in the arbovirus surveillance and control system, particularly by:

• disseminating messages on personal prevention to their patients, including best practices for avoiding mosquito bites;

• diagnosing and treating patients with these infections;

• reporting cases to regional health agencies (ARS), which enables investigations to be launched and guides mosquito control measures.

In the event of local outbreaks, these reports also enable the implementation of measures to secure products of human origin.

How do you report these diseases?

Chikungunya, dengue, and Zika are notifiable diseases and must be reported year-round. The CERFA forms to be completed can be downloaded from our website for dengue, chikungunya, and Zika.

Between May and November, the tiger mosquito is particularly active across much of mainland France, and enhanced surveillance is implemented. During this period, early reporting of cases is essential to reduce the risk of local transmission.

• Learn more about reporting cases of dengue, chikungunya, and Zika

What is the situation in mainland France?

The risk of local transmission in mainland France is real, and outbreaks are identified every year. Furthermore, an increase in transmission has been detected over the past two years.

In 2024, this risk is all the more significant given that the number of identified imported cases is unprecedented, largely due to the ongoing dengue epidemic in the French West Indies.

Weekly updates are published on our website, allowing you to track changes in the number of cases.