Anses published this Friday, September 13, a report on the probability of epidemics caused by the tiger mosquito occurring in France. On a scale of 0 to 9, the risk is between 6 and 7 according to experts. Explanations.
In 20 years, dengue, chikungunya and Zika have become the three main arboviruses, diseases transmitted by arthropod vectors, which are threatened by the tiger mosquito.
In its report published this Friday, September 13, the National Agency for Health Security estimates the probability of an epidemic due to the tiger mosquito occurring in France, as well as the economic and social impact of such a scenario.
Transmissions that escape the control device
While indigenous cases of the virus transmitted by the tiger mosquito in France have been contained with very localized outbreaks, “experts estimate that an epidemic of arbovirosis, all viruses combined, has a probability of occurring between 6 and 7 on a scale of 0 to 9 in the next five years,” says ANSES. “We speak of an epidemic from the moment when it is not possible to link all infected people to a focus. This means that transmissions escape the control system,” explains Émeline Barrès, from the Risk Assessment Directorate at ANSES and one of the two coordinators of the expertise.
As a reminder, the conditions for an epidemic are: the presence of the tiger mosquito in the territory, favorable climatic conditions (heat and precipitation), arrivals of infected people in Metropolitan France, insufficient effectiveness of measures to prevent and combat viruses.
66 cases of indigenous dengue fever recorded in 2022
In addition, current means of preventing and controlling arboviruses could quickly become incapable of proving effective in the face of an increase in cases. “Some of the stakeholders involved in monitoring and vector control that we interviewed during the expert assessment told us that they would have been overwhelmed if additional cases had occurred in recent years,” says Véronique Raimond, a health economist in the Social Sciences, Economics and Society Department of ANSES, the other coordinator of the expert assessment. In 2022 alone, 66 cases of indigenous dengue fever were recorded, the total number of the previous 10 years!
A very heavy monitoring and control protocol
The surveillance and control protocol consists of tracing all contacts of the infected person over the last 10 days as well as monitoring all the places where they have been in order to eliminate, if necessary, any tiger mosquitoes present. A very cumbersome protocol that requires significant human, financial and material resources. Anses therefore recommends adapting the resources to these new needs.
Drawing on the experience of the French Overseas Territories
As for the healthcare system, ANSES also points out a risk of tension in the event of a major epidemic, or even saturation of the healthcare system in the event of a double epidemic, as was the case in the Antilles in 2020, with two concurrent epidemics, dengue fever and Covid-19. To prepare for this, the health agency is calling for France to rely much more on the experience of the overseas departments and regions.
Please note: Anses is also counting on the mobilization of the population with individual actions, such as: emptying containers filled with water, covering rainwater collectors with a mosquito net, protecting yourself from mosquito bites, reporting to a health professional in the event of symptoms in an area where an arbovirus is circulating.
