Belonging to the Hantaviridae family (whose main genus is now referred to as Orthohantavirus), these pathogens are RNA viruses found in both the Old and the New World. Their geographic distribution also determines the type of disease they can cause in humans: in the New World (the Americas), they are responsible for severe respiratory illnesses known as Hantavirus Pulmonary Syndromes. In the Old World (Europe and Asia), they instead cause hemorrhagic fevers with renal syndrome, which differ in nature and clinical progression.

Infection occurs almost exclusively through the inhalation of viral particles present in the excreta (feces, urine, and saliva) of infected rodents, which become airborne especially in enclosed or dusty environments.

The outbreak that affected the South American ship was caused by a specific viral strain: the Andes virus. Found exclusively in South America, this pathogen has a distinctive feature that makes it unique among hantaviruses: it is the only one for which human-to-human transmission has been documented.

This virus is carried by a native South American rodent, Oligoryzomys longicaudatus (commonly known as the long-tailed pygmy rice rat). Since this animal lives only in the South American continent, mainly in agricultural areas, the likelihood that one or more individuals could board a ship and survive a transoceanic journey on commercial vessels—and then successfully establish themselves in our country—is considered extremely low.

If the Andes virus is not a cause for concern—at least regarding transmission from its natural reservoir—it is important to note that other hantavirus species are also present in the Old World. They are particularly widespread in Asia and in central and northern Europe; among the most well-known in Europe are the Puumala virus, Tula virus, and Dobrava-Belgrade virus.

Hantaviruses have also been detected in Italy, with some documented human infection cases. However, knowledge about their spread and actual prevalence in our country is still limited, although research groups have been conducting dedicated studies for several years.

What we know for certain is that the reservoir of hantavirus species present in Italy is not made up of urban rodents, but rather of forest-dwelling rodents, particularly the bank vole (Clethrionomys glareolus) and the yellow-necked mouse (Apodemus flavicollis).

These small mammals live in woodland environments. As a result, the risk of human contact occurs mainly in interface areas between forests and small inhabited sites, such as country houses, mountain huts, wood sheds, or rural buildings located near or within wooded areas. The role of synanthropic rodents (such as the brown rat, black rat, or house mouse) in the transmission of the hantavirus species typically found in Italy appears to be entirely secondary.

In light of this information, there appears to be no need to implement emergency measures or specific management campaigns driven by concerns about the Andes virus.

However, prevention remains the primary measure with regard to the viral species present in Italy. Routine and consistent rodent management in the vicinity of homes, workplaces, and gathering areas is a fundamental public health practice. The goal is not to control wildlife in forests, but rather to prevent rodents from finding shelter and food inside or near human buildings.

To achieve this, several practical precautions are essential: cracks and openings should be sealed, waste must be properly managed, and indoor spaces should be thoroughly ventilated before being occupied. In the presence of rodent droppings, it is crucial to avoid dry sweeping dusty floors, as this can disperse contaminated particles into the air; instead, wet cleaning methods should be preferred. Additionally, when working in enclosed areas heavily frequented by rodents and with abundant droppings, the use of a protective mask is strongly recommended.

Hantaviruses certainly deserve attention, but it should not be forgotten that rodents are known carriers of many other pathogens. Proper environmental prevention and effective pest management in the places we use daily remain, as always, the most reliable protective shield for safeguarding public health.