Por Redaccion 
The Ministry of Health and Consumption activates entomological surveillance of mosquitoes carrying the West Nile virus (WNV) during the first week of May. Alongside this, a social media campaign has been launched, involving all pharmacies in Andalusia, coordinated by CACOF (Andalusian Council of Official Pharmacists), recommending that the population enhance protection measures against this virus, especially among the vulnerable population with compromised immunity.
In this way, the General Directorate of Public Health and Pharmaceutical Regulation emphasizes the need to use registered topical mosquito repellents, cover most of the body with light-colored clothing, avoid strong odors (perfumes, scented soaps…) as they attract mosquitoes, and avoid going out at dawn and dusk, which are the times of highest mosquito activity.
Likewise, Health reminds of the need to strengthen domestic measures: install mosquito nets, use household insecticides/environmental repellents, or turn off unnecessary lights because light attracts mosquitoes.
Another crucial measure is to avoid creating stagnant water areas where mosquitoes breed, so it is recommended to properly maintain swimming pools, ponds, and washbasins and empty any accumulated water that may go unnoticed in gardens, pots, toys, or buckets.
In the case of livestock farms, it is also advised to regularly renew animal drinking troughs, avoid water from puddles on vehicle tracks or roads, water leaks from taps or broken pipes, as well as in watering troughs with leaks or poor renewal.
Authorized and registered repellents
The use of body repellents is a good option to protect exposed areas of the body from bites (neck, hands…), but they must be appropriate repellents for age and specific situation, so it is recommended to carefully read the labeling instructions; check that the repellent is authorized and registered (the registration number should appear on the packaging information); follow the application instructions and test it on a small area of the skin beforehand to avoid allergic reactions. The product should be applied to the hand to spread it on the skin, avoiding contact with eyes, mucous membranes, wounds, and sensitive areas. Special care should be taken when applying repellents in the case of children under three years old, pregnancy and lactation, and pre-existing health problems.
In general, repellents can be composed of DEET (N,N-diethyl-m-toluamide), Icaridin, Citriodiol, or PMD, IR 3535 (Ethyl butylacetylaminopropionate) and essential oils (geraniol, lavender…) at different concentrations. These ingredients have been shown to be effective and safe when used according to their instructions, although their effectiveness depends, among other factors, on the active ingredient and its concentration, ambient temperature, exposure to water or simultaneous use of sunscreens, and individual’s level of sweating.
The Ministry of Health and Consumption emphasizes that the repellent protects against bites, but does not kill the insect, so despite its use, the rest of the recommendations should also be followed. It also urges to heighten these protection measures during festivals and pilgrimages that will take place in the coming days in high-risk municipalities.
Infection with WNV is a zoonosis transmitted by mosquitoes of the Culex genus. The virus is transmitted between birds through the bites of infected mosquitoes, this being its natural cycle. Humans and other mammals can become infected collaterally, without new transmissions occurring from them. According to published risk assessments, around 80% of WNV infections in humans are asymptomatic. West Nile fever (WNF) is the most common clinical presentation. The elderly and immunocompromised individuals are at higher risk of developing West Nile neuroinvasive disease.
Increased traps and other measures
The Comprehensive Surveillance and Control Program for West Nile Fever Vectors for the 2025 season also expands entomological surveillance, based on mosquito trapping and virus detection through PCR, both in the number of traps and the covered territory and time. Thus, the number of traps increases from 27 to 120, all Andalusian provinces are included (all Andalusian municipalities have a risk level: low, medium, or high) and it starts in May, a month earlier than in 2024 and two months earlier than in 2023.
It also highlights the mobilization of all health promotion and prevention actors of the Ministry of Health and Consumption (Family nurses, school and community referents, RELAS -Local Health Action Network- and pharmacies) in high-risk municipalities and the establishment of a second reference laboratory in Andalusia, at the Virgen del Rocío University Hospital, which joins the one at the Virgen de las Nieves University Hospital, allowing for a greater capacity and speed in diagnostic response.
Furthermore, coordination with other administrations is strengthened 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 (over 400 agents deployed throughout the territory). The communication plan to the population is also improved, so that they become an active part of vector surveillance and control.
The aim of this program update is to increase support to municipalities and councils in preparing for vector control, early identification of virus arrival, mobilizing other health actors, and communicating and better supporting the population in case of an alert situation.