Lutte anti-dengue
Sur l'île de la Réunion, l'inquiétude grandit vis-à-vis de l'épidémie de dengue qui dure depuis déjà quatre ans. Depuis le décès de plusieurs personnes âgées de 30 à 50 ans, ainsi que d'un enfant de 12 ans, la forme hémorragique rarissime jusqu'à présent inquiète plus que le Covid.
Face à cette épidémie qui pourrait rappeler les heures sombres du chikungunya de 2005, les services de lutte antivectorielle de l'Agence Régionale de Santé de l'Océan Indien continuent d'être sur le qui-vive. Environ mille six cents cas sont à explorer chaque semaine, un chiffre habituellement plus proche des cinq cents durant l'été austral. L'équipe compte sur les renforts du SDIS et de la Protection Civile pour porter leurs effectifs de soixante-dix à environ deux cents personnes actuellement.
Giovanni Carpin est responsable du secteur Nord de l'île. Chaque fois qu'un patient est testé positif à la dengue en laboratoire d'analyses médicales, ses services sont alertés pour réaliser l'enquête autour du cas et pour mettre en place les mesures d'éradication. Pour lui, la propagation actuelle de l'épidémie est un échec des mesures préventives consistant à ne pas laisser la moindre source d'eaux stagnantes propice au développement des gites larvaires. Il coordonne les interventions sur site, qui allient sensibilisation de la population et usage de deltaméthrine pour éradiquer le foyer contaminant.
L'ARS dispose d'un laboratoire d'entomologie médicale. Maillon essentiel dans la lutte antivectorielle, Guillaume Dupuy étudie l'évolution des populations de moustiques et de larves sur l'île. Douze espèces sont recensées, mais uniquement deux sont responsables de la propagation de la dengue : Aedes albopictus, Aedes aegypti. Si la deltaméthrine est le seul produit autorisé par l'Union Européenne, il s'assure que les moustiques ne développent pas de résistances à l'insecticide.
Mais la sensibilité grandissante de la population aux problématiques écologiques et le risque d'inefficacité future du produit donnent au service de nouveaux défis à relever. Ils ont fait le choix de n'utiliser la deltaméthrine qu'en curatif, ainsi ils n'agissent qu'au domicile d'une personne touchée et dans les 80 à 100 mètres environnants.
Si la situation continue de se dégrader, ils devront reprendre les pulvérisations nocturnes, avec les risques qu'elles comportent pour tous les êtres vivants à sang froid qui ne résistent pas. En parallèle, ils travaillent avec deux organismes pour développer d'autres techniques de lutte passant par le largage de moustiques males stérilisés. Seules les femelles, qui ne peuvent être fécondées qu'une seule fois, transmettent la dengue. Si elles sont fécondées par ces moustiques stériles, elles n'auront pas de descendance. La piste est prometteuse, et les premiers largages par drones viennent d'avoir lieu sur la commune de Saint-Joseph.
Fight against dengue
On Reunion Island, there is growing concern about the dengue epidemic which has been going on for four years now. Since the death of several people aged between 30 and 50 years old, as well as a 12 year old child, the hemorrhagic form, which has been very rare until now, is more worrying than Covid.
Faced with this epidemic, which could recall the dark hours of chikungunya in 2005, the vector control services of the Regional Health Agency of the Indian Ocean continue to be on the alert. About one thousand six hundred cases are to be explored each week, a figure usually closer to five hundred during the southern summer. The team is counting on reinforcements from the SDIS and the Protection Civile to increase their staff from seventy to about two hundred people at present.
Giovanni Carpin is responsible for the northern sector of the island. Each time a patient is tested positive for dengue in a medical laboratory, his services are alerted to investigate the case and to implement eradication measures. For him, the current spread of the epidemic is a failure of the preventive measures consisting in not leaving the slightest source of stagnant water conducive to the development of larval gites. He coordinates the interventions on site, which combine public awareness and use of deltamethrin to eradicate the contaminating focus.
The ARS has a medical entomology laboratory. Guillaume Dupuy is an essential link in the fight against vector-borne diseases and studies the evolution of mosquito populations and larvae on the island. Twelve species have been identified, but only two are responsible for the spread of dengue: Aedes albopictus and Aedes aegypti. If deltamethrin is the only product authorized by the European Union, it ensures that mosquitoes do not develop resistance to the insecticide.
But the growing sensitivity of the population to ecological issues and the risk of future ineffectiveness of the product give the service new challenges to face. They have chosen to use deltamethrin only as a curative treatment, so they only act in the home of an affected person and in the surrounding 80 to 100 meters.
If the situation continues to deteriorate, they will have to resume night spraying, with the risks that this entails for all cold-blooded living beings that do not resist. At the same time, they are working with two organizations to develop alternative control techniques involving the release of sterilized male mosquitoes. Only females, which can only be fertilized once, transmit dengue. If they are fertilized by these sterile mosquitoes, they will not have offspring. The track is promising, and the first drops by drones have just taken place in the commune of Saint-Joseph.On the island of Reunion, there is growing concern about the dengue epidemic which has been going on for four years now. Since the death of several people aged between 30 and 50 years old, as well as a 12 year old child, the hemorrhagic form, which has been very rare until now, is more worrying than Covid.
Faced with this epidemic, which could recall the dark hours of chikungunya in 2005, the vector control services of the Regional Health Agency of the Indian Ocean continue to be on the alert. About one thousand six hundred cases are to be explored each week, a figure usually closer to five hundred during the southern summer. The team is counting on reinforcements from the SDIS and the Protection Civile to increase their staff from seventy to about two hundred people at present.
Giovanni Cartin is responsible for the northern sector of the island. Each time a patient is tested positive for dengue in a medical laboratory, his services are alerted to investigate the case and to implement eradication measures. For him, the current spread of the epidemic is a failure of the preventive measures consisting in not leaving the slightest source of stagnant water conducive to the development of larval gites. He coordinates the interventions on site, which combine public awareness and use of deltamethrin to eradicate the contaminating focus.
The ARS has a medical entomology laboratory. Guillaume Dupuy is an essential link in the fight against vector-borne diseases and studies the evolution of mosquito populations and larvae on the island. Twelve species have been identified, but only two are responsible for the spread of dengue: Aedes albopictus and Aedes aegypti. If deltamethrin is the only product authorized by the European Union, it ensures that mosquitoes do not develop resistance to the insecticide.
But the growing sensitivity of the population to ecological issues and the risk of future ineffectiveness of the product give the service new challenges to face. They have chosen to use deltamethrin only as a curative treatment, so they only act in the home of an affected person and in the surrounding 80 to 100 meters.
If the situation continues to deteriorate, they will have to resume night spraying, with the risks that this entails for all cold-blooded living beings that do not resist. At the same time, they are working with two organizations to develop alternative control techniques involving the release of sterilized male mosquitoes. Only females, which can only be fertilized once, transmit dengue. If they are fertilized by these sterile mosquitoes, they will not have offspring. The track is promising, and the first drops by drones have just taken place in the commune of Saint-Joseph.
Translated with www.DeepL.com/Translator (free version)