First autochthonous dengue outbreak in Italy, August 2020

Area of Science:

• * Infectious Diseases
• * Medical Entomology
• * Public Health

Background:

• * The coronavirus disease (COVID-19) pandemic presented unique challenges for managing other infectious diseases.
• * Italy has endemic populations of the Aedes albopictus mosquito, a known vector for several arboviruses.
• * Imported infectious diseases pose a risk in regions with competent local vectors.

Purpose of the Study:

• * To report the first outbreak of autochthonous dengue virus type 1 in Italy.
• * To emphasize the importance of surveillance for imported febrile illnesses during the COVID-19 pandemic.
• * To highlight the role of Aedes albopictus in local dengue transmission.

Main Methods:

• * Case detection within a family cluster in Vicenza Province, North-East Italy.
• * Identification of dengue virus type 1.
• * Tracing the primary case to an importation from West Sumatra, Indonesia.

Main Results:

• * Five locally acquired cases of dengue virus type 1 were confirmed in August 2020.
• * The outbreak was linked to a single imported case.
• * This marked the first documented instance of autochthonous dengue transmission in Italy.

Conclusions:

• * Autochthonous dengue transmission is a reality in Italy, even during the COVID-19 pandemic.
• * Vigilant screening of febrile travelers from endemic regions is critical in areas with established Aedes albopictus populations.
• * Integrated disease surveillance is essential for preventing and controlling arboviral outbreaks.