In 2020, seven people died in Andalusia after being bitten by ‘Aedes japonicus’ mosquitoes, transmitters of the fever that is to be controlled.

Images of La Puebla del Río and Coria and the mosquito that causes Nile fever.

Preventing 100% new outbreaks of the Nile virus is very difficult, almost impossible. Just like it is be able to completely eradicate disease-carrying mosquitoes after biting an infected bird. It would take a lot of means, especially financial ones, and a lot of political will.

However, it is possible to implement vector control plans to reduce their reproduction, but they should begin to apply them now. Time is short. The Junta de Andalucía presented at the beginning of March a strategic plan in order to reduce diseases transmitted by mosquitoes or ticks. It entails the start-up a specific Nile fever vector control program.

It is already published in the Official Gazette of the Junta de Andalucía (BOJA), but the affected municipalities such as Coria del Río, La Puebla or Isla Mayor, coastal towns of the Guadalquivir with a large presence of mosquitoes, they see it unaffordable. They believe that most of the actions fall on them.

This stumbling block between the administrations, the lack of agreement, the bureaucracy and the spring weather they don’t help. Nor the rains that may occur in the coming weeks. On the contrary, give wings to these mosquitoes.

The experts of the CSIC and Lokímica, the company that was in charge of the disinsection in the affected areas last summer, agree that prevention should be started now.

The accounts are simple, the less quantity of these insects in urban areas, the less possibility of contagion, assures Jordi Figuerola, researcher at the EsDoñana Biological Association-Higher Council for Scientific Research (CSIC), in conversation with EL ESPAÑOL.

76 affected

What happened last summer still reverberates in the memory of many Andalusians. Between the months of August and September the simple bite of a mosquito changed life to more than 80 families in the provinces of Seville, Cádiz and Extremadura.

Seven people died and 76 were affected. Of them, many suffer serious consequences, such as a 14-year-old girl and another under four. Most of the victims are residents of the towns of La Puebla and Coria del Río.

Among other issues, the plan contemplates that the councils included in moderate, high or affected risk areas should be the ones to assume with municipales of surveillance and control both in its larval and adult stages. It really is a municipal competition. However, from the Coria del Río City Council they assure that This type of project requires a tender, which would entail several months of paperwork.

The problem also lies in non-urban areas. Last In September, the Board hired the services of the Lokímica company and began a disinsection campaign. He did it for an emergency situation as it was not a regional competition. In the surroundings of the Coria and La Puebla del Río areas, all kinds of machinery were used, including drones loaded with specific biocides to kill their larvae.

To work in these months, the Junta de Andalucía has created a technical coordination and control group in different areas such as environmental, livestock, wild and human epidemiological surveillance. The data obtained will make it possible to prepare a risk map of the whole of Andalusia, which will be updated every fortnight.

Position of the municipalities

When the outbreak occurred, the municipalities of Coria and La Puebla del Río fumigated urban areas and they have not stopped acting, but they assure that they do not have sufficient means. In addition, they criticize the little margin they have for their application. Precisely, the Andalusian plan pursues that, to strengthen the coordination and communication mechanisms between the agents and all the administrations involved.

Personnel spraying to combat the mosquito that causes the Nile virus.

Personnel spraying to combat the mosquito that causes the Nile virus.

Faced with this situation, the mayors have submitted a letter to the General Directorate of Public Health to hold a meeting and reach an agreement, but time is running out. According to researcher Jordi Figuerola In the month of April you must already be disinsecting which is the period of greatest risk.

Another stumbling block is the rice fields. These municipalities have, under their terms, more than 35,000 hectares of rice and it is the municipalities that must require the owner to keep them in good condition.

The Huelva service

Mayors abound in need of greater coordination. Precisely Figuerola and the Junta de Andalucía itself give an example the Mosquito Control Service of the Diputación de Huelva. The plan operates on 140,000 hectares and is in agreement with 12 municipalities.

The budget is close to three million euros and the provincial entity contributes 80%. The implementation of a service of these characteristics is considered essential by Seville and Cádiz. In Huelva no case of Nile fever was registered last summer and advised the Board on the action plan that it carried out in the affected towns.

The researcher Figuerola has 42 articles published on the presence of this fever and has advised the Junta de Andalucía in the preparation of this action plan – he is part of the working group. The CSIC has evidence of the circulation of this virus in Andalusia since 2006.

But last year there were a series of circumstances that caused these outbreaks that ended with seven human lives. Mosquito populations were much more abundant than in other years after heavy rains fell in May. This allowed a greater development of mosquito populations, coupled with the lack of control in urban areas.

A plane and an operator of the mosquito service of the Huelva Provincial Council.

A plane and an operator of the mosquito service of the Huelva Provincial Council.
Provincial Council of Huelva

The virus replicates in most birds, but not all mosquitoes are carriers. They are mainly two species, the Culex pipiens in urban areas and Culex small in rural and natural areas.

Without wishing to alert, Figuerola assures that under normal conditions nothing happens, but the objective is to prevent infected mosquitoes from reaching inhabited areas. “It is convenient that we begin to take it seriously“. However, human cases – 76 in total – are often the tip of the iceberg. It means that the number of infected birds will have been much higher.