19.06.2021 – 13.48 – These days the media alarm, which terrifies those looking for asparagus, related to the presence of the so-called “mouse fever” which could be contracted on the Karst Plateau, in Friuli Venezia Giulia and around Trieste. This is not new. The problem, already appeared in 2002 and 2012, mainly affects Slovenia and Croatia and is probably linked to the current high reproductive intensity of the mice themselves, which is subject to strong annual variability.
It is an infection caused by viruses belonging to the family of Hantavirus. Reservoirs and sources of infection are wild and domestic rodents. The animal reservoir characterizes Hantavirus infections as typical zoonoses. Clinically, Hantavirus infections produce a heterogeneous group of acute-onset diseases. In the “classic” form these are characterized by fever, headache, abdominal and lumbar pain, photophobia and after three to five days a renal syndrome with proteinuria appears, followed by hypotension, multiple bleeding and, in the most severe and extremely rare cases, coma. The clinical picture does not seem to be confused with Covid-19, also because an accurate anamnesis reveals the consumption of freely harvested vegetables. Lethality for humans varies from 0.5 percent of mild forms to 15 percent of severe untreated forms.
Wild rodents disseminate the virus in the environment by means of their excreta (urine, faeces, saliva). Once infected, rodents shed the virus throughout their life. Man is an accidental host of these viral agents, and can become infected following the ingestion of contaminated food, mainly fruit and vegetables, with the manure of infected rodents. The incubation period of “mouse fever” can vary from a few days to a few months, but in the majority of cases it is 2-4 weeks. Apart from exceptional circumstances, Hantaviruses are not transmitted from person to person: there is, therefore, no period of contagiousness.
How they are prevented. Preventive measures are mainly based on mouse population control, as wild rodents (field mice) are the reservoir and source of infection for humans. Basically it is advisable to wash wild asparagus with the utmost care if the season is the right one and all the other vegetables that are collected during the excursions. Remember that cooking is always decisive. It is necessary to avoid collecting wild asparagus near the pipes and drains, where the presence of mouse colonies may be greater. In conclusion, wild asparagus, the so-called “bruscandoli”, if the season allows it, can and can be eaten normally, but you must first wash them thoroughly, select them and cook them well.
Fulvio Zorzut