Climate change has brought more cases of leishmaniasis

Leishmaniasis, which normally affects dogs, can also infect humans:cases have been increasing in the last 10 years and this could also depend on the climate which has increased the number of sandflies

ROME – From 2004 to 2022 they were registered in the Bologna area 154 cases of cutaneous and visceral leishmaniasis in humans.Leishmaniasis is a serious disease caused by a microscopic parasite and is transmitted to humans and dogs by the bite of an insect that feeds on blood:the sandfly or sandfly.Of the 154 cases in Bologna in 19 years (plus 18 from outside the province), 11 led to death, with a fluctuating trend, but increasing in the last 10 years.One was seen higher incidence in men compared to women, in the zero-two year age group and in those with a compromised immune system.And it turned out that a factor in the increase in cases is also due to climate change.This is what a study published in "Eurosurveillance", a European journal on surveillance, epidemiology, prevention and control of infectious diseases, tells us.

It was investigated the way in which Leishmaniasis has spread in humans over the last 20 years and the role that reservoir animals and environmental and climatic conditions played in this;all starting from the cases of Leishmaniasis counted in the territory of the Bologna Local Health Authority from 2004 to 2022.The study was carried out by professionals from the Local Health Authority, the Zooprophylactic Institute of Emilia-Romagna and Lombardy, and the Sant'Orsola Polyclinic, using elements of knowledge deduced from human, veterinary and entomological surveillance, as well as clinical and environmental aspects. and weather-climatic. What does the climate have to do with it?Very: recent years with hot summers and little rain have favored the increase in sandflies, the insects that transmit the disease by biting humans and animals.There are two forms of Leishmaniasis in humans:cutaneous (it can be cured in 100% of cases, even in the absence of therapy) and visceral (if not treated, it can be fatal).In dogs it is a lethal disease.

The study highlights that, compared with past epidemics, cases of Leishmaniasis have also occurred in the city and in the plains in recent years.And among the hypotheses formulated to explain the phenomenon, there is the movement of reservoir animals towards the north, also due to climate changes, in correspondence with the waterways and the railway network.The study also highlights one aspect
in the veterinary field:the dog, usually considered the main reservoir of the parasite responsible for the disease, as well as being also affected by canine leishmaniasis, may not have such a decisive role in its spread.In fact, in the years in which more human cases were recorded, there was no corresponding increase in dogs, based on the results of the 1,422 blood tests carried out in the last 11 years.The data is not yet considered sufficient, but the hypothesis is that the spread also depends on other animals reservoir of the infection, identified in the DNA of up to 6% of wild mammals and in particular in 10-13% of mice and rats.

There is currently no human vaccine against Leishmaniasis.The main preventive measure to reduce the risk of contracting the disease remains to avoid sand fly bites by using insect repellent products on the skin and clothes, particularly in the evening and at night, wearing covering clothes outdoors, in the garden or at park, especially in the evening; protect dogs with sandfly repellents, do not leave them outdoors at night and check them periodically for Leishmaniasis.Mosquito nets, insecticides and fans are other 'weapons' to keep sandflies away.They are very small insects (two-four millimeters, about a third of a mosquito), difficult to see with the naked eye.Their flight is silent, short and can be hindered by the wind.