Andalucía reports earliest-ever dengue import of the season

title: "Andalucía reports earliest-ever dengue import of the season" date: "2026-04-10" author: "Mosticare Editorial" authorRole: "Science Editor · Mosticare" mins: 5 region: "Spain" alert: "Import" excerpt: "A confirmed dengue import in Cordoba province on 8 April sets a new early-season record for mainland Spain. The index case returned from Colombia; entomological investigation finds Aedes albopictus breeding sites within 200 metres." sources:

• text: "Red Nacional de Vigilancia Epidemiológica · Boletín 14/2026" href: "https://www.isciii.es"
• text: "ECDC · Dengue multi-country, Rapid Risk Assessment, February 2026" href: "https://www.ecdc.europa.eu"
• text: "Vázquez et al. 2021 · Autochthonous dengue in Spain: epidemiology of nine seasons" href: "https://doi.org/10.1093/cid/ciab276" correctionEmail: "corrections@mosticare.org"

Spain's Red Nacional de Vigilancia Epidemiológica has confirmed a dengue import in Cordoba province with a notification date of 8 April 2026. The index case, a 34-year-old with no underlying conditions, returned from Colombia on 3 April and developed symptoms two days later.

This is the earliest imported dengue case with contemporaneous Aedes albopictus vector activity recorded in mainland Spain. The previous earliest-season import with documented local vector presence was 24 April 2024 in Valencia.

Why imports matter in southern Spain

An imported case becomes an epidemiological event when the returning traveller is viraemic at the same time and place as a competent vector population. In Andalucía, Aedes albopictus trap catches are already running in April, not at peak summer densities, but at levels sufficient to sustain a short transmission chain if the introduction is in the right microhabitat.

Entomological investigation in the Cordoba case found Aedes albopictus breeding in two ornamental plant containers and a neglected water tank within 200 metres of the patient's home. The patient was symptomatic for three days before hospitalisation. All household contacts are under follow-up.

No secondary transmission has been confirmed. However, RNVE is treating this as a potential index event and has activated enhanced surveillance for the surrounding census area.

The seasonal context

Andalucía experienced its worst autochthonous dengue season on record in 2025, with 41 locally-acquired cases confirmed in Almería and Granada provinces between June and October. The 2025 season was attributed to unusually high summer temperatures, elevated Aedes albopictus densities following a wet winter, and a record number of imported viraemic travellers arriving from Latin America and Southeast Asia.

The 2026 season is beginning with higher importation pressure than any previous April: the current global dengue case count, driven primarily by a Brazil epidemic and elevated transmission across the Asia-Pacific, represents the highest recorded April baseline since systematic surveillance began.

The combination of early vector activity, high import pressure, and warm spring temperatures places Andalucía, Valencia, Murcia, and the Balearics in the highest pre-season risk category for autochthonous transmission in 2026.

What travellers returning to southern Spain should know

• Symptoms typically appear 4–14 days after the infective bite. Any fever within two weeks of return from a dengue-endemic region warrants a blood test.
• Dengue is not transmitted person-to-person. The risk to household contacts is from shared exposure to the same vector, not from contact with the patient.
• Physical protection during the symptomatic period matters: a viraemic patient in a mosquito-infested garden is an amplification risk for the neighbourhood.

Mosticare's threat map is tracking the Andalucía situation and will post updates as the entomological investigation concludes.