New West Nile Fever Case in Macomer Triggers Prevention Measures

A confirmed case of West Nile virus has been identified in Macomer, Sardinia, prompting local authorities to activate emergency prevention measures after the patient tested positive on June 17, 2026. The Sardinian regional health agency (ASSL) has confirmed the diagnosis, marking the first locally acquired case in the province of Nuoro this year, while the patient’s travel history to Bosa—another area under heightened surveillance—has raised concerns about potential regional spread.

The Macomer mayor, Giuseppe Marras, issued an immediate ordinance on June 18, mandating intensified mosquito control operations, public awareness campaigns, and restrictions on outdoor gatherings in high-risk zones. The measures follow a pattern seen in other Italian regions, including Lombardy and Veneto, where West Nile virus cases have surged in recent weeks due to warmer temperatures and stagnant water accumulation.

According to the Italian National Institute of Health (ISS), West Nile virus transmission peaks between June and September, with mosquitoes becoming most active during dawn and dusk. The ISS reports that 80% of infections are asymptomatic, but severe cases—particularly in immunocompromised individuals—can lead to neuroinvasive disease with fatality rates as high as 10%. In 2025, Italy recorded 212 confirmed cases, up from 147 in 2024, with Sardinia accounting for 12 cases in 2025.

The Macomer patient, a 58-year-old man, had not traveled outside Sardinia in the two weeks prior to symptoms, suggesting local mosquito-borne transmission. Local health officials have traced his movements to Bosa, where he stayed from June 3 to June 10, overlapping with a separate case confirmed in Oristano on June 15. The Sardinian ASL has dispatched vector-control teams to both municipalities to eliminate breeding sites and deploy larvicide treatments in public spaces.

While the World Health Organization (WHO) classifies West Nile virus as a "priority pathogen," there is no vaccine or specific antiviral treatment. Prevention relies on avoiding mosquito bites: using EPA-approved repellents (such as DEET or picaridin), wearing long sleeves, and eliminating standing water. The European Centre for Disease Prevention and Control (ECDC) warns that climate change is expanding the virus’s range, with cases now reported in 30 EU countries.

Authorities emphasize that the risk to the general public remains low but urge residents to report unusual mosquito activity. The Macomer ordinance will remain in effect until further notice, with weekly updates on mosquito surveillance data expected from the ASL.

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Why is this case significant compared to previous outbreaks in Italy?
This year’s cases in Sardinia align with a broader upward trend in Italy, where the number of West Nile virus infections has doubled over the past two years. While northern regions like Lombardy typically see higher case counts due to larger urban populations, Sardinia’s cases—particularly in rural areas like Macomer—highlight how climate shifts are altering transmission patterns. In 2023, Sardinia reported only three cases, compared to 12 in 2025 and now a confirmed fourth in 2026. The ISS attributes this to increased mosquito populations linked to milder winters and higher rainfall.

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What prevention measures are authorities taking beyond standard advice?
Beyond the usual recommendations, the Macomer municipality has implemented targeted actions:

• Mosquito surveillance drones: Deployed in collaboration with the University of Cagliari to map high-risk zones using thermal imaging.
• Citizen reporting app: Residents can log stagnant water spots via a regional ASL platform, with response teams dispatched within 24 hours.
• Blood donation restrictions: Local hospitals have paused donations from asymptomatic individuals in Macomer and Bosa until June 30, per ISS guidelines.

The ASL has also partnered with agricultural cooperatives to treat irrigation ditches with biological larvicides, reducing breeding sites in rural areas where most cases originate.

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How does West Nile virus compare to other mosquito-borne diseases in Europe?
While West Nile virus is the most commonly reported arbovirus in Italy, it shares transmission pathways with usutu virus (which caused a deadly outbreak in birds in 2022) and dengue fever (limited to southern Europe). Key differences:

• West Nile: Primarily affects older adults; fatality rate ~1% in severe cases.
• Usutu: Rarely infects humans but has high mortality in birds.
• Dengue: More common in tropical regions; symptoms are flu-like but can progress to hemorrhagic fever.

The ECDC notes that West Nile virus is now endemic in Italy, meaning it circulates annually, unlike dengue, which is imported. However, all three viruses rely on the same Culex pipiens mosquito vector, making integrated surveillance critical.

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What should travelers to Sardinia know?
The ISS advises that while the risk to tourists remains "very low," visitors should:

• Avoid outdoor activities at dawn/dusk in rural or agricultural areas.
• Use EPA-approved repellents (e.g., 30% DEET or 20% picaridin).
• Seek accommodations with screened windows or air conditioning.

No travel restrictions have been imposed, but the Italian Ministry of Health is monitoring the situation and may adjust guidance if cases rise. The last travel-related West Nile case in Italy involved a German tourist in Tuscany in 2024, but local transmission—like in Macomer—poses a higher risk.

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What’s next for Macomer and Sardinia?
The ASL will release weekly epidemiological bulletins starting June 25, detailing mosquito density and human case trends. If additional cases emerge, authorities may expand restrictions to include:

• Mandatory window screens in residential areas.
• Temporary closures of public parks or sports fields during peak mosquito hours.
• Increased testing of blood donors and equine populations (horses are highly susceptible and act as early indicators).

The regional government has allocated €500,000 to vector control, with funds prioritized for Nuoro and Oristano provinces. Public health experts warn that without sustained efforts, the virus could become entrenched in Sardinia’s ecosystems, as seen in Greece and Spain.

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Key sources and updates:

• Italian National Institute of Health (ISS) [June 2026 West Nile surveillance report]
• Sardinian Regional Health Agency (ASSL) [Macomer ordinance, June 18, 2026]
• European Centre for Disease Prevention and Control (ECDC) [Arbovirus risk assessment, 2025]
• L’Unione Sarda, Rai News, Cronache Nuoresi [local reporting, June 17–18, 2026]