“Larvicidal treatments fundamental for prevention”

Reports of suspected cases of Dengue in Italy are increasing. The latest in chronological order concerned a patient arriving at the San Martino hospital in Genoa from Argentina and a man at the ATS in Brescia, but they were also recorded in Busto Arsizio, in the province of Varese, and in Veneto.

The Ministry of Health has issued three circulars which aim to raise the alert on Dengue in airports, ports and also in local medicine.

But what exactly is dengue fever, known simply as dengue? It is a tropical infectious disease caused by the Dengue virus. It is transmitted to humans through the bites of mosquitoes which, in turn, bite an infected person. There is therefore no direct contagion between humans, even if humans are the main host of the virus.

It presents with fever, headache, muscle and joint pain, as well as the characteristic skin rash similar to that of measles. In a small percentage of cases, however, a hemorrhagic fever develops, which implies more severe conditions.

Doctor Guido Marinoni, president of the Bergamo Medical Association, notes: “The scientific communicator Roberta Villa in her new book, ‘Counterglossary of medicine’, explained that at the end of the summer of 2023 the tiger mosquito also caused, for the first time in Italy, a small indigenous outbreak (11 cases) of dengue. This disease also seems to take its name, through Spanish, from a Swahili word, ki denga pepo, which would mean something like ‘cramp-like convulsions caused by an evil spirit’. Like Chikungunya, this virus also causes, in addition to fever, headache, any skin manifestations, very severe pain that can resolve within a few weeks or persist for months or years. This is why the disease is also called ‘bone-breaking fever’. Up to 400 million people are infected with the dengue virus every year, although only around a hundred of them develop symptoms, which can sometimes even be haemorrhagic in nature.”

“To reduce the risks – adds Dr. Marinoni – it is essential to carry out larvicidal treatments, aimed at counteracting the proliferation of these insects. The various campaigns organized in the area by the various competent bodies are therefore important. Even individual measures such as avoiding keeping water in saucers and containers in the garden or on the terrace helps because small stagnant water constitute a habitat for the tiger mosquito”.

Dengue affects humans but, as far as we know, not animals. The veterinary profession, however, was also involved by the Ministry of Health in disseminating prevention measures to the public through a circular dated 15 November 2023 from the General Directorate of Animal Health and Veterinary Medicines. The doctor explains it Stefano Faverzanipresident of the Order of Veterinary Doctors of the province of Bergamo, who observes: “In this document it is also recommended that Veterinary Doctors disseminate information, also through direct communication to the client, in clinics, veterinary or university clinics”.

“The Ministry of Health – continues Dr. Faverzani – reports gatherings for sporting events, especially when these take place in areas at risk due to the presence of the vector, close to areas where the multiplication of mosquitoes occurs the most, or on the occasion of daily walks of pets especially near green patches, marshy areas and watercourses”.

It is essential to combat the proliferation of these insects. The president of the Order of Veterinary Doctors of the province of Bergamo notes: “Among the recommended measures there is the use of “topical repellents” and adequate and protective clothing but also “the implementation of authorized forms of environmental control” , effective against both larval and adult mosquitoes, to be implemented “before sporting events or in the situations of establishments (referred to in Reg. 2016/429) or structures most at risk”. The Ministry recommends relying on authorized companies that carry out checks on their equipment and the use of authorized disinfestants”.

Finally, Dr. Faverzani concludes: “I can add that although dengue is not a disease of domestic animals, these prevention rules are also important for our animals (dogs and cats) to which the same species of mosquito (Aedes) can transmit other diseases such as heartworm disease (from Dirofilaria Immitis and subcutaneous heartworm disease (from Dirofilaria Repens). These are parasitic diseases (therefore not viral like Dengue, from Arbovirus) and since it can be complicated to apply effective repellents against mosquitoes (dogs and cats have hair…), for these diseases prophylaxis is also available with drugs that prevent the development of parasites in the animal’s body. It is very important that owners follow the advice of the veterinary surgeon on the correct way to protect their pet” .