West Nile, virologist Parrella: 'Situation under control but no cure, the most fragile must be protected'

The situation is under control, but we cannot afford to underestimate it. As SIMIT, we consider it essential to keep the attention of the institutions, the medical profession and the population high. The effective approach to this infection is based on three pillars: epidemiological surveillance, early diagnosis and environmental prevention.

How to recognise symptoms in suspected cases?

The West Nile virus is not transmitted from person to person: the only vector is the infected mosquito, which in turn becomes infected mainly by feeding on the blood of migratory birds. Humans, once infected, are 'dead-end hosts', i.e. they do not participate in the epidemiological chain.

Diagnosis, therefore, requires a high degree of clinical attention. The symptoms, initially similar to those of a flu - fever, headache, skin rash, muscle aches - may evolve into tremors, confusion, drowsiness and neurological disorders. Promptness in suspecting the disease is crucial, especially in emergency rooms and with general practitioners. Most infections escape diagnosis precisely because they are mild or asymptomatic: severe cases are only the tip of the iceberg.

Is there a specific cure for the West Nile virus?

To date, there are no specific antivirals approved for West Nile. Treatment remains symptomatic and supportive, with the use of immunoglobulins or experimental antivirals in selected cases. Therefore, primary prevention is our first and most effective line of defence.

Are the prevention and surveillance plans developed by the ministry and regions sufficient?

The Ministry of Health circular of 21 July, with the strengthening of the clinical and environmental surveillance network, goes in the right direction. Collaboration between health authorities, regional infectious networks and local administrations is essential to monitor the evolution of the virus and intervene rapidly in outbreaks. The infectious disease network - strengthened after the Covid-19 emergency - is already active, and thanks to the awareness of colleagues, it was possible to diagnose the first cases in a timely manner, demonstrating the importance of continuous training of health workers.

More and more is being said about One Health, the interconnection of the health of people, animals and the environment. How important is collaboration between different sectors in addressing global health challenges? .

Alongside clinical surveillance, systematic and capillary environmental prevention is needed. Disinfestations, the use of larvicides and adulticides, and entomological monitoring are essential tools. Municipalities must intervene in places at risk - wetlands, stagnant water, green areas - but citizens must also do their part. Eliminating stagnant water in gardens, saucers and uncovered containers, using mosquito nets and repellents, protecting domestic environments: these are simple but effective gestures.

We are facing an evolving scenario: what is the impact of climate on the expansion of arboviruses? .

The return of West Nile is not an isolated episode. In recent years, we have witnessed the appearance, also in Italy, of other mosquito-borne viruses, such as dengue, chikungunya, Zika and Usutu. Some of these were once considered exclusively tropical. Today, due to changed climatic and environmental conditions, our country has become a favourable habitat. We must therefore broaden our gaze to the entire family of arboviruses, envisaging integrated prevention strategies, including veterinary surveillance and control of sentinel animals, such as horses and wild birds.