Mosquitoes and viruses, here are the most dangerous ones. “Dengue is not an emergency in Italy, but cases are increasing”

In the first thirteen weeks of 2024, Brazil has already surpassed the annual historical record of deaths from Dengue fever. As of April 8, the confirmed deaths caused by the disease were 1,116, never so many since the beginning of the historical series that began in 2000. A few days ago a case was confirmed in the Ravenna area, in a person who returned to Italy from Brazil. The Emilia Romagna Region, through the approval of the 2024 regional arbovirus surveillance and control plan by the Council, this year has decided to strengthen actions against Dengue and the potentially serious viral diseases that mosquitoes can transmit. However, Professor Francesco Cristini, head of the “Infectious Diseases” Operational Unit of the “Morgagni-Pierantoni” hospital in Forlì, is keen to reassure, “Dengue is not an emergency in Italy, and no critical scenario is envisaged, either clear. What is expected is a possible increase in cases, including indigenous ones, so we need to monitor carefully.”

Professor Cristini, what danger do mosquitoes represent?
“The mosquito responsible for the transmission of Dengue in Italy is the tiger mosquito, technically Aedes albopictus. This means that this mosquito is capable of transmitting the virus to humans, after having bitten an infected subject. Therefore the vector of the disease is already historically present in Italy. However, there is another mosquito, the Aedes aegypti, widespread in tropical and sub-tropical countries where the Dengue virus is endemic, which has a much higher transmission power, and if it arrived in Italy could significantly worsen the situation in our country.”

Is there an increase in diseases transmitted by these insects with climate change?
“The increase in cases of vector-borne infections (think of how many cases of Dengue occurred in the first months of this year in South America, especially in Brazil) depends on the spread of the latter, and the spread of mosquitoes, vectors of Dengue in the specific case, is closely linked to the seasons, the amount of rainfall and hot temperatures. It is expected that this year too we may have indigenous cases of Dengue, given the climate trend in recent years”.

Can cases of pathologies that were considered tropical become endemic?
“Dengue is precisely the paradigmatic example of this theme. Last year in Italy there were a number of indigenous cases of infection that had never been seen before, 82 cases. Until then almost all of the Italian cases were imported, and even now the majority of total cases are.”

What are the symptoms that can alert us?
“The main symptom of the disease is high fever, like almost all viral infections, associated with particularly intense osteoarticular pain, it is no coincidence that it is called bone-breaking fever. In addition to these symptoms, many others may be present, typical of many viruses, such as skin rash, sore throat, respiratory symptoms and headache. It is important to consider that many infections can also be asymptomatic, therefore not intercepted”.

Are there any particular critical issues for pregnant women?
“If a pregnant woman contracts dengue, the virus can also be transmitted to the fetus or during childbirth. But the rate of vertical transmission, i.e. that which occurs during pregnancy to the fetus, appears to be low. It is still an issue little known from a scientific point of view, but preterm birth and low birth weight of the newborn are the most frequent consequences described on the unborn child of Dengue contracted by the mother”.

In your opinion, is it necessary to anticipate the contrast measures to prevent the proliferation of mosquitoes?
“Dengue is not an emergency in Italy, and no critical scenario is foreseen, let’s be clear. What is expected is a possible increase in cases, even indigenous ones, for which we must monitor carefully. And it is well known that for diseases transmitted by vectors, vector control, i.e. disinfestation activities, is the most effective preventive measure possible and since the hot season is upon us, it is much better if we intervene in time. Our local administrations know this, as do the airport administrations, in line with ministerial recommendations on vector control”.

What should be done to avoid the risk of bites?
“What has always been done to protect oneself from mosquitoes. The use of repellents during the most infested seasons, and perhaps paying attention to one’s living and working environment, always keeping it dry. The flower saucers on the balconies of the house, the gardens left unkempt, any potential container of rainwater, deep puddles and so on, are precisely the sites where mosquitoes thrive.”