This June 1st begins the campaign to control mosquitoes carrying the West Nile virus. The General Directorate of Public Health and Pharmaceutical Regulation of the Ministry of Health and Consumer Affairs of the Government of Andalusia has established a total of 125 Andalusian municipalities with up to five risk levels and with a region of the province of Cádiz, made up of five municipalities, with special monitoring. There are more than twenty towns in the province among those monitored municipalities, with four at level 4, the second highest.
In the instruction published by the Ministry for the “implementation of the actions of the surveillance and comprehensive vector control program for West Nile Fever (WNF) related to health protection”, consulted by Europa Press, two regions of special interest. The first of these is made up of the Cádiz municipalities of Tarifa, Barbate, Vejer de la Frontera, Benalup-Casas Viejas and Medina Sidonia.
The second of them is made up of the Sevillian towns of Coria del Río, La Puebla del Río, Palomares del Río, Almensilla and Bollullos de la Mitación. In these two regions – which are established either because the circulation of West Nile virus in mosquitoes, horses, birds and humans has been detected continuously for at least three years in a row; or due to its eco-environmental and epidemiological situation–
In addition to the measures established according to the risk level of the municipality, the health administration may demand an “intensification of verifications” carried out by public health agents (ASP) and awareness campaigns among schoolchildren and the adult population, as well as having health centers and pharmacies to recommend the use of repellents and protection measures among the population.
The Ministry of Health highlights the “intense surveillance” that is maintained in Andalusia regarding the Nile Virus, while pointing out the importance of the administrations involved working “jointly”. This year, the first cases of West Nile Virus Fever were detected in the month of April as a result of the intense rains recorded at that time of year.
Risk levels
This classification is due, explains the Board, to the “accumulated” information regarding the circulation of the West Nile Fever (WNF) virus in the different territories, the environmental conditions and the experience acquired during the execution of the program for the years 2021, 2022 and 2023 by the different administrations involved.
The highest risk level is five (detection and confirmation of at least one case in humans in the municipality in the current season, 2024) and the Sevillian town of Lebrija is now located there. At this level, health services can activate measures in blood transfusion and transplant centers and epidemiological actions appropriate to the situation according to the current epidemiological surveillance protocol.
At risk level 4 (evidence of circulation of the Nile virus in the municipality in mosquitoes, birds and horses in the current season or in the years 2022 and 2023 less than 1.5 kilometers from the population center or, at least, one case in humans in the season 2022/2023), there are 20 towns in Andalusia, of which nine are in Seville; five in Cádiz; three in Córdoba; two in Huelva and one in Jaén. In the risk 4, If there are cases in humans, the regional health services reinforce the information to health professionals, especially at the Primary Care level, as well as epidemiological surveillance. Mortality of horses and wild birds is controlled and controls are carried out on equine farms located within a radius of less than 1.5 kilometers from urban centers “when possible and so determined.”
Janl level 3 at risk, 37 Andalusian municipalities are in this campaign, of which 23 are in the province of Seville; seven from Cádiz; two from Córdoba and two from Málaga and three from Huelva.
In it Level 2, 33 towns are counted: thirteen from Huelva; nine from Seville; nine from Cádiz and two from Jaén.
And finally, in level 1, There are 34 municipalities, of which five are from Almería; three from Cádiz; four from Córdoba; eight from Huelva; seven from Malaga and seven from Seville.
Diseases that are “challenging”
The Department of Health and Consumer Affairs of the Government of Andalusia has developed an Andalusian Strategic Plan for the Surveillance and Control of Arthropod Vectors with an Impact on Health (PEVA), which provides, among other measures, for the preparation of space/time maps in which “identify how insect populations are doing and thus see and calculate in a very precise way what its impact is going to be on the population.
This plan seeks to prevent diseases spread by mosquitoes and other arthropod vectors with an impact on human health and advocates joint work with councils, city councils and local entities to address the possible proliferation of these animals. Diseases such as the Nile virus, dengue and malaria “are and will be a challenge in the coming decades“.
The geographical location of Andalusia, a passage from the African continent, makes it an area more vulnerable to the passage of these arthropod vectors. For this reason, the PEVA is “a fundamental tool” to improve the health of the Andalusian population through the surveillance and control of arthropod vectors with an impact on health. The Ministry of Health and Consumer Affairs coordinates all the administrations involved and joins the efforts of other organizations, based on the “best scientific evidence” provided by experts.
The information obtained or coming from different sources will serve to make appropriate decisions early and informing the necessary measures, for example, to local administrations, whose participation is necessary and fundamental, or preparing a risk map of the territory, among other actions. During 2023, for example, imported, confirmed and probable cases of dengue (47) or malaria (101) were declared in Andalusia, or autochthonous cases such as leishmaniasis (76) or West Nile fever (2), which caused a total of three deaths in the autonomous community to patients, in most cases, with previous pathologies, one for leishmaniasis (81-year-old man), one for malaria (68-year-old woman) and one for FNO (84-year-old woman).
The strategic objectives of the PEVA are to implement integrated surveillance systems, have an updated system for spatiotemporal characterization of the risk of transmission of diseases transmitted by arthropod vectors, or identify responsibilities of all the agents involved and establish coordination mechanisms between them.
Another strategic objective is to have specific programs for the surveillance and control of diseases transmitted by arthropod vectors. Currently there is a Comprehensive Vector Surveillance and Control Program for West Nile fever (WNF) in Andalusia, but thanks to the PEVA many other emerging or re-emerging pathologies will be covered. The PEVA also seeks to promote and facilitate research on arthropod vectors and the diseases they transmit, as well as to train and inform health professionals and citizens themselves.