Milan, 29 April. (Adnkronos Health) – Will malaria return to Italy? “The current conditions do not justify an immediate alarm”, because the Anopheles mosquitoes carriers of the infection “are there today, but they are too few to support the transmission cycle of the disease. However, if conditions were to arise that were favorable to an explosion of the population of these insects, then certainly we should address the question.” Therefore “keep your guard up”, is the warning of the biologist Paolo Gabrieli, professor of Zoology at the State University of Milan, a career dedicated to the study of arboviruses. After the Experimental Zooprophylactic Institute of Puglia and Basilicata discovered specimens of malaria mosquitoes in Puglia that had not been detected for over 50 years, the expert explains to Adnkronos Salute why “it is essential to continue to follow the behavior of these insects and control their proliferation”. Especially, he warns, with climate change underway.
Until the 1960s, Gabrieli recalls, Italy was a malarial country and a few Anopheles mosquitoes remained in the country. “We still have mosquitoes belonging to the so-called maculipennis complex, a group of 7-8 species very similar to each other – explains the scientist – which are potential vectors of malaria. They are widespread in various areas of the Peninsula, especially in the coastal areas of Central-Southern Italy and in the islands, where they were once at home, we are therefore currently experiencing what is called ‘anophelism without malaria'”. There are two reasons. The first is that “having the right mosquito is not enough for the disease to also exist”, the second is that the Italian anopheles “today are not enough”.
“In the transmission cycle of pathogens such as malaria – specifies Gabrieli, arguing the first point – mosquitoes only act as vectors. When they are born, they are generally healthy. In order to transmit the pathogen they must first become infected themselves and for this to happen there must be a reservoir of the disease that we don’t yet have in Italy if they bit an infected person returning from a malarial country, they could at most give rise to a few cases of local transmission, but certainly not a large-scale epidemic.” As for the second point, the biologist continues, it is linked to “a parameter that is called ‘mosquito vectorial capacity’. It is similar to the R0 of infectious diseases and allows us to understand how much a population of mosquitoes is capable of transmitting a specific illness”. This index “depends on many factors, but one of the most important is the actual probability that mosquitoes can encounter (and bite) humans. The less numerous Anopheles mosquitoes are, and today in Italy they are very few, and the less likely it is that the encounter with man takes place”. (continued)
