Por Redaccion 
The General Directorate of Public Health and Pharmaceutical Regulation of the Ministry of Health and Consumption of the Andalusian Regional Government has declared alert areas in the neighborhoods of Retamar-El Toyo, with 11,000 inhabitants, and El Alquián, with 6,000 inhabitants, in the municipality of Almería after confirming the circulation of the West Nile virus (WNV) in mosquitoes captured in traps located in these areas. Likewise, it has raised the risk level from low to high for the entire municipality of Almería. This is the first declaration of an alert area and elevation of the risk level this season.
Health and Consumption sent the National Microbiology Center-Carlos III Institute in Madrid the samples of female mosquitoes collected on June 11 in El Retamar to confirm the positive for WNV that our laboratories had detected. The detection of these mosquitoes in a low-risk municipality confirms the working hypothesis of the Comprehensive Surveillance and Control Program of West Nile Fever Vectors for 2025 and reinforces the decisions made: no Andalusian municipality is exempt from the risk of WNV circulation and entomological surveillance precedes human surveillance.
The Ministry immediately conveyed the information and decision to the Almería City Council and convened a meeting for this Saturday attended by the Government Delegate of the Andalusian Regional Government, Aránzazu Martín; the Territorial Delegate of Health and Consumption, Juan de la Cruz Belmonte; the Mayor of Almería, María del Mar Vázquez; the Councilor for Environmental Sustainability and Energy, Antonio Urdiales, and the company Athisa, responsible for pest control and environmental health in the municipal area of Almería, which has been carrying out preventive treatments since April, to coordinate the joint action plan.
The meeting held at the Almería City Council was attended by the Government Delegate of the Junta, Aránzazu Martín; the Territorial Delegate of Health and Consumption, Juan de la Cruz Belmonte; the Mayor of Almería, María del Mar Vázquez; the Councilor for Environmental Sustainability and Energy, Antonio Urdiales, and the company Athisa, responsible for pest control and environmental health in the municipal area of Almería.
The declaration of the alert area, for a minimum period of four weeks or until no new cases are reported or the circulation of the virus in the mosquito vectors of this disease, birds, or equines in this territory is detected for an equivalent period, entails intensifying the three surveillances (entomological, animal, and human) in the area, activating promotion actions in schools and residences in the area, and reinforcing communication actions to the public through community pharmacies and nursing so that they adopt the necessary protection measures against WNV.
On the other hand, local administration must intensify the measures for the control and treatment of mosquito vectors of the disease during the period the area is on alert.
Update of the Comprehensive Surveillance and Control Program of FNO Vectors
The Ministry of Health and Consumption approved last February the update of the Comprehensive Surveillance and Control Program of West Nile Fever Vectors for the 2025 season, in which more than 250 professionals have participated including municipalities, provincial councils, scientific groups, Public Health inspectors, and companies, through meetings held between December and January of the past year.
This program establishes that all municipalities in Andalusia are included in some level of risk and, therefore, all have a need to control the virus because in the previous season it was found that mosquito species that are transmitters (culex) are present throughout the Andalusian territory. These risk levels have been reduced to three (low, medium, and high) to facilitate understanding by all stakeholders, including the population, as well as the prevention and control measures associated with each level. In total, there are 103 municipalities at high risk, 313 at medium risk, and 369 at low risk.
The medium and high levels correspond to territories where the circulation of the West Nile virus has already been evidenced. The high level corresponds to evidence of WNV circulation near populations in any of the last three seasons. In this way, all municipalities should incorporate mosquitoes into their existing pest control programs (rodents, cockroaches, processionary caterpillars), as well as conduct a diagnosis of potential larval sites within population centers or very close to them and keep them monitored (in the case of low and medium risk) and, in municipalities at high risk, these measures should be extended to the entire municipal territory, with special attention to larval sites or adult refuge within a distance of 1.5 km from populations.
In March, all municipalities were informed of their risk level and the Public Health inspectors (more than 400 deployed throughout Andalusia) contacted them to provide technical advice on the implementation of surveillance and control measures, which should cover the entire year with the aim of keeping mosquito populations as low as possible when the peak virus circulation season arrives, which is from June to October.
In addition, in the Special Monitoring Areas (La Janda in Cádiz and Bajo Guadalquivir in Seville), which account for over 95% of confirmed cases since 2021, the Ministry of Health and Consumption has also implemented surveillance of mild cases of WNV (non-neuroinvasive forms), where other pathogens have been ruled out, through PCR. 80% of infections in humans are asymptomatic. Approximately 20% of infected individuals present symptoms similar to the flu characterized by fever, headache, fatigue, myalgia, general discomfort, nausea, vomiting, and sometimes maculopapular rash and adenopathy. Less than 1% of those infected become seriously ill with neurological involvement (meningitis, encephalitis, or flaccid paralysis).
Similarly, the program expands entomological surveillance, based on mosquito trapping and virus detection through PCR, both in the number of traps and in the territory covered and in time. Thus, the number of traps has increased from 27 to 120, all Andalusian provinces are included, and it started in May, a month earlier than in 2024 and two months earlier than in 2023.
The program also improves the predictive model to assess the risk of WNV circulation, integrating the one designed by CSIC-Doñana, to which the Ministry’s own data has been added, including new variables such as land use, infected birds, or vector presence, among others.
It also highlights the mobilization of all stakeholders in health promotion and prevention by the Ministry of Health and Consumption (Family and Community nurses, RELAS -Local Health Action Network- and pharmacies) in high-risk municipalities and the creation of a second reference laboratory in Andalusia, at Virgen del Rocío University Hospital, in addition to the one at Virgen de las Nieves University Hospital, allowing for greater capacity and speed in diagnostic response.
Furthermore, coordination with other administrations is reinforced through working groups preparing for the season that started in winter; and support for municipalities through more visits by public health agents to affected municipalities since March. The communication plan to the population is also improved, so that they can be an active part of vector surveillance and control.
The objective of this program update is to increase assistance to municipalities and provincial councils to prepare for vector control; identify the early arrival of the virus; mobilize other health actors and communicate and better support the population in case of an alert situation.
Recommendations to the population
The Ministry of Health and Consumption has launched a social media campaign, in which all pharmacies in Andalusia also participate, coordinated by CACOF (Andalusian Council of Official Pharmacists), recommending that the population strengthen protection measures against this virus, especially among the vulnerable population with compromised immunity.
Thus, the General Directorate of Public Health and Pharmaceutical Regulation emphasizes the need to use registered mosquito repellents (comprising DEET (N,N-diethyl-m-toluamide), Icaridin, Citriodiol or PMD, IR 3535 (Ethyl butylacetylaminopropionate), and essential oils (geraniol, lavender…) at different concentrations and for topical use), cover most of the body with light-colored clothing and avoid strong odors (perfumes, scented soaps…) as they attract mosquitoes.
Health reminds of the need to reinforce domestic protection measures such as installing mosquito nets, using domestic insecticides/ambient repellents or turning off lights if they are not necessary, as light attracts mosquitoes. Another fundamental measure is to avoid creating stagnant water areas, where mosquitoes breed their larvae, so it is recommended to properly maintain pools, swimming pools, and washing areas and empty any accumulated and unnoticed water in gardens, pots, toys, or buckets.
In the case of livestock farms, it is also advised to regularly renew animal drinkers; avoid water from puddles on vehicle tracks or roads, water leaks from taps or broken pipes, drinkers with leaks or poor renewal.