How to deal with the spread of West Nile virus
How to deal with the spread of West Nile virus
To effectively combat the spread of West Nile virus, which is transmitted primarily by mosquitoes, such as the common mosquito (Culex pipiens Linnaeus, 1758), it is essential to follow an integrated approach that takes into account both public health and environmental protection. To this end, some guidelines for correct procedures are outlined.
First, it is necessary to act according to the principles of Integrated Health (human health, animal health, and environmental health) (One Health), developed by the WHO, FAO, and OIE within UNEP, through the One Health Joint Plan of Action (2022–2026).
To this end, a joint action plan must be developed in agreement between veterinarians, agronomists or forestry doctors, epidemiologists, and health authorities, through an action plan consisting of three activities:
1. Action Plan
1.a Monitoring of human and animal cases (especially birds and horses).
1.b. Monitoring mosquitoes for the presence of the virus (captures and analysis).
1.c. Mapping of at-risk areas.
2. Mosquito prevention and control (targeted larval and adulticide control)
– Larval control (priority and low environmental impact):
– Use of biological larvicides (e.g., Bacillus thuringiensis israelensis – Bti).
– Introduction of natural predators (where possible) such as larvivorous fish into ponds and canals.
– Environmental remediation: removal of stagnant water (covering drains, emptying plant saucers, cleaning gutters, etc.).
Only in confirmed and verified cases, according to the indications emerging from the Action Plan, the following actions should be taken:
– Adulticide control (limited and controlled), through insecticide applications, but only in cases of concrete risk to public health.
– Targeted, nighttime treatments, with authorized substances and in specific areas.
– Advance warning to the public and behavioral guidelines (keep windows closed, do not go outside during treatments).
3. Public information and involvement
Through educational campaigns on:
– How to reduce larval outbreaks in domestic environments.
– Individual protective behaviors (use of repellents, mosquito nets, light-colored, covering clothing).
– Reporting of critical sites (manholes, stagnant water).
4. Institutional coordination
Therefore, a Regional/Municipal Surveillance and Control Plan must be developed and implemented through:
– Collaboration between municipalities, local health authorities (ASL), regional environmental protection agencies (ARPA), park authorities or biodistricts (where applicable), and the Civil Protection Department.
– Compliance with national guidelines (e.g., National Plan for Prevention, Surveillance, and Response to WNV).
5. Monitoring and evaluation of actions
The effectiveness of larval/adulticide treatments must be verified by the personnel listed above.
Through:
– Environmental impact assessment (including on fauna useful as pollinators).
– Adaptation of measures based on the results.
6. Ecological and sustainable approach
This approach is necessary to minimize the use of chemical insecticides, which, without this approach, would have even more negative repercussions on human, wildlife, and environmental health in general.
In this regard, as mentioned, we must focus primarily on prevention, promoting ecosystem-based solutions: improving urban drainage, designing urban green spaces so as not to encourage stagnation, thus avoiding collateral damage to biodiversity (e.g., protecting bees and pollinators).
In this sense, the anthropization of natural areas, especially with the elimination of amphibians, reptiles, birds, bats, etc., is the primary factor increasing the presence of mosquitoes and other vectors of infectious diseases.
For this reason, simple mosquito treatment with insecticides (which are not at all selective) is the worst solution and the greatest cause of worsening future ecological conditions and, therefore, the virulence of future diseases.
Guido Bissanti
Photo source:
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