West Nile virus and malaria cases highlight need for enhanced surveillance and pest control

Beyond insect repellent sprays and mosquito nets, combating mosquito-borne diseases like malaria and West Nile fever requires more than just individual prevention efforts. Coordinated public health actions are essential to protect entire communities, according to Francesco Broccolo, a microbiologist at the University of Salento.

Broccolo noted that as of the latest bulletin from the Higher Institute of Health, Italy has registered 432 confirmed cases of West Nile virus infection and 17 deaths in 2026. The virus is now stably circulating in 17 regions. While the lethality of neuro-invasive forms has decreased compared to the same period in 2025, the virus's territorial spread is extensive. An increasing number of asymptomatic blood donors are being identified, indicating silent circulation of the virus.

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According to the latest bulletin from the Higher Institute of Health, from the beginning of 2026 in Italy there are 432 confirmed cases of West Nile virus infection and 17 deaths, with the virus now stably circulating in 17 Regions. The lethality of the neuro-invasive forms is decreasing compared to the same period in 2025, but the territorial diffusion is wide and surveillance intercepts an increasing number of asymptomatic blood donors, a sign of the silent circulation of the virus.

Regarding malaria, the situation remains one of imported cases, with approximately 700-800 cases per year, almost all contracted abroad, resulting in a couple of deaths annually. Although the expert considers it highly unlikely that malaria will become endemic in Italy again, rare cases linked to infected mosquitoes transported via aircraft or luggage serve as a reminder that the risk is not entirely eliminated.

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On the malaria front, the situation remains one of importation, with 700-800 cases per year, almost all contracted abroad, with a couple of deaths per year. At the moment, the expert believes it is very unlikely that the disease could become endemic again in our country, but 'the rare cases linked to infected mosquitoes transported by plane or in luggage (the so-called 'airport malaria') remind us that the risk is not zero'.

In response, Broccolo advocates for a broader strategy. This includes establishing an entomological surveillance network with mosquito traps to identify municipalities where viruses are circulating or where the first cases appear. An integrated One Health surveillance approach is also crucial, monitoring human cases, birds, and horses. Targeted disinfestation, guided by this data using larvicides and adulticides focused on outbreak areas, and the elimination of larval sources by removing stagnant water are vital.

Furthermore, ensuring the safety of blood and transplants, with screening for blood donors already in place for West Nile virus, is important. For malaria, the focus should be on travel medicine, including chemoprophylaxis, pre-travel consultations, and prompt diagnosis upon return.

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In this scenario, Broccolo continues, a broader strategy must be implemented that includes 'a network of entomological surveillance with mosquito traps, in order to identify the Municipalities where viruses circulate or the first sick people appear; integrated surveillance with a One Health perspective, which brings together human cases, birds and horses; targeted disinfestation guided by that data, with larvicides and adulticides concentrated on outbreaks; the fight against larval outbreaks, with the removal of stagnant waters; the safety of blood and transplants, with screening of donors already active for West Nile; and, on the malaria front, travel medicine, with chemoprophylaxis and pre-travel consultation and early diagnosis upon return'.