Pollen and rodents, that’s why there are so many ticks: “With climate change they will increase, the peak? Expected for the first half of June “

TRENTO. Since the start of the year Tick-borne viral encephalitis infections have risen to 10 (Tbe) reported in Trentino. On the national level, however, between 2000 and 2020, there were 204 records found with the annual average of cases doubling. Hand in hand they are grown up Even the reports with regard to Lyme disease, which in the last 10 years have been almost 400.

As he explains Annapaola Rizzoli, Head of the Applied Ecology Unit of the Research and Innovation Center of the Edmund Mach Foundation, these parasites can transmit both viruses and bacteria to people and animals. The research unit coordinated by Rizzoli deals with study the mechanisms that lead to the emergence of zoonoses, that is, all those diseases transmitted by wild animals but which they have an impact on human health.

“The most common ones are precisely la borreliosi, otherwise known as Lyme disease, that is a bacterial infection which can affect the skin or, in more severe forms, the joints, the nervous system and internal organs; the rickettsiosi transmitted by some bacteria carried by ticks; e la Tbe, a viral disease that can cause nerve damage but it can be prevented through a vaccine that is distributed free of charge in Trentino ”.

As the data in recent years show these diseases are increasing, an increment that is tied double stranded with the tick population. Logically more these parasites proliferate more they grow up the possibilities that the diseases are transmitted to people.

But why are ticks on the rise and what determines the prosperity of these parasites? The answer comes directly from the Fem that through the Applied Ecology Unit chaired by Rizzoli elaborate also a series of mathematical models able to predict the years in which ticks will be most present and thus provide useful support tools for prevention strategies fielded by the health company.

Speaking of mathematical models, researchers from the Unit of Applied Ecology and the Unit of Environmental Botany found that measuring the amount of pollen airborne by some tree species, in particular beech, hornbeam and oak, it’s possible predict the trend of TB cases for the next two years.

“The pollen dispersed in the air – says Rizzoli – are theindicative of plant seed production which in turn represent a food resource very important for some wild rodents widely spread in the Trentino woods “. Among these we mention the yellow-necked wild mouse (Apodemus flavicollis) o the reddish vole (Myodes glareolus). “When these food resources are abundant, for the following year, we see population peaks in wild rodent populations which act from ‘reservoirs’ for ticks “.

In other words to a increased pollen in the air corresponds a increase in seed production, than in the following year it will lead to a demographic spike in rodent populations that consequently it will amplify the circulation of pathogens among the mint youth stadiums. All this will lead, two years later, to an increase in tick-borne diseases. Since the pollen quantities recorded during 2020 turned out to be very high, 2022 is turning out a year with particularly intense circulation of the virus.

“In general the increase in pollen production is mainly linked to climate change – observes Rizzoli – secondly to affect the tick population is the increase of the forested area. Consequently for the next few years we will have to expect more ticks and therefore more cases of diseases “. Not only that, because as the expert points out the period of activity of ticks is becoming longer. “For about thirty years we have noticed that these parasites are also active during the spring periods and in the hottest areas they can also be found between January and February “.

In Trentino the presence of ticks (Ixodes ricinus) becomes important starting in March with the peak which is expected right between the end of May and the first half of June. This species is widespread in all forest environments from the valley floor up to 1,200 meters of altitude. In light of this considerations succeed in to prevent the tick bites becomes the most efficient weapon to control the transmission of these serious diseases.