Given the current epidemiological situation, which is affecting some European countries and all the regions of the Po Valley, the Veneto Region, in addition to all the ordinary actions envisaged by the National and Regional Plan already implemented since the beginning of the vector season, has prepared the launch of the Extraordinary Plan to combat the spread of West Nile Virus. The Plan, shared with the Ministry of Health and the Higher Institute of Health, provides for a series of interventions to be implemented in the first 10 days of September, with the aim of reducing new infections in the population most at risk. A risk assessment map will allow to direct the interventions that will be concentrated in the territories where the greatest number of cases could occur in the coming weeks, on the basis of epidemiological surveillance data collected by the Region, the ULSS and the Experimental Zooprophylactic Institute of Venezie.
“Compared to 2018, the year in which a high number of cases had occurred, this year the situation affects some areas more for which some extraordinary targeted interventions are necessary. The actions of this plan, which insert and update the regional strategy, have been implemented in the current scenario as the targeted use of adulticides represents a measure that national and international bodies recommend only when there is epidemiological evidence that ordinary interventions do not highlight. an optimal result in controlling the spread of the virus. In fact, the Veneto Region had already foreseen the possibility of resorting to extraordinary interventions by identifying, starting from 2019, the availability of a disinfestation service for health emergencies) “.
What the extraordinary plan provides
– the further enhancement of laboratory diagnostics in order to allow the timely identification and confirmation of cases
– the identification of the municipalities in which the greatest number of cases could occur in the coming weeks through the adoption of a new integrated risk assessment tool. This tool provides for the subdivision into risk areas (white, yellow, orange, red) on the basis of epidemiological surveillance data and the planning of targeted interventions according to the assigned risk (fig. 1)
– extraordinary larvicidal interventions in medium and high risk municipalities (orange and red areas)
– extraordinary adulticidal interventions in sensitive sites (e.g. public parks, social and health facilities, hospitals, etc.) of high-risk municipalities (red areas) or in medium-risk municipalities (orange areas) in close urban continuity with the municipalities high risk (red areas)
– further communication interventions aimed at increasing the perception of risk in the population, favoring the adoption of individual protection measures and suitable measures to combat the vector in the context of public and private areas
– intensification of the control of the effectiveness of the treatments carried out
– epidemiological analysis with evaluation and monitoring of the adopted Plan
– Identification of “buffer” or “Buffer” areas, that is territorial areas that are classified as medium risk but which occur in urban continuity or frequentation with those at high risk, also in these the measures envisaged for high risk areas are applied in order to widen the protection from infected vectors as much as possible.
The current situation
For several years, the West Nile virus has been circulating every summer in the territory of the Veneto Region and other regions of northern Italy. West Nile is a virus that is transmitted by the common mosquito (not the tiger mosquito) that mainly bites from dusk to dawn. This virus is not spread from person to person. The disease can manifest itself with fever, headache, joint pain and in some cases (less than 1 in 100), it can involve the central nervous system with serious consequences.
In recent weeks, several cases of West Nile infection have occurred and the virus has been found in mosquitoes in many municipalities in the Veneto region (for details, see the consultation of the Arbovirus Surveillance Bulletin – Year 2022 n.7 of 26/08 / 2022). The concentration of even serious human cases and the high presence of viruses in mosquitoes indicate that this year the virus is circulating a lot on the regional territory.
The environmental and climatic situation of summer 2022 is, in fact, determining a very favorable context for viral circulation for the following reasons:
– the lack of rain has caused the slowing of the flow of water in rivers and canals and the formation of stagnations which are the ideal environment for mosquitoes;
– mosquitoes, finding less water in sparsely inhabited areas, approach homes where they find more easily stagnations where they can reproduce;
-the climate and spring temperatures allowed mosquitoes to start reproducing very early in the spring.
-It is therefore very important that everyone takes appropriate measures to prevent mosquito bites and to avoid the spread and growth of mosquitoes.
How to protect yourself
Older people or people with concomitant conditions are those at greatest risk for severe forms of West Nile. For this reason it is important that all these people adopt useful behaviors to prevent mosquito bites and that treatments against mosquito larvae (eg larvicidal tablets in manholes) are also implemented in all private homes and in particular in those where they live. frail people.
Avoid the proliferation of mosquitoes:
– do not abandon objects and containers of any nature and size in which rainwater can collect (jars, bins, basins, watering cans, tires, etc.)
– daily empty any commonly used container with the presence of water and, where possible, turn them upside down;
– hermetically cover (also through tight mesh nets) the immovable water containers (bins, cisterns);
– carry out a correct disinfestation of the larvae in manholes, drains, ditches, with suitable larvicidal products and with repetitions of the treatments according to the provisions of the product sheet used.
Avoid mosquito bites to avoid contracting the virus:
– outdoors wear light colored clothing, light, as covering as possible (long sleeves and long pants);
– from 2 years of age use repellents based on DEET or Icaridina, to be applied directly to the skin, repeating the treatment with appropriate frequency, following the instructions on the package. Repellent products should not be applied to mucous membranes (lips, mouth), eyes, abraded skin, while they can instead be used on clothes to increase their protective effect.
-for children under two years use repellents based on Paramatandiol (PMD, Citrodiol)
-application to doors and windows of close-meshed mosquito nets, in addition to the use of electro-emanating devices of liquid insecticides or plates.
Why hasn’t an Extraordinary Plan been made first?
Because unforeseeable factors contributed to the epidemiological situation we are observing, such as the persistence of the drought that brought the vector closer to man, the presence of birds, which constitute the reservoir of the virus, more infected than in other years and the contemporary circulation of two virus subtypes. In addition to the planned larvicidal disinfestation, adulticidal disinfestation targeted around the clusters (2 cases within 2 Km) were immediately applied.
International literature such as ECDC recommends that in situations of high risk in which the larvicidal treatments integrated with all the ordinary interventions have failed in larval control or in any case have shown partial efficacy in vector reduction, to integrate the approach with others. contrast methods, primarily the adulticidal intervention, to which must be added in an integrated approach the strengthening of adulticides, the strengthening of surveillance, behavioral measures and, lastly, the empowerment of private citizens in the aforementioned behaviors.
In this emergency phase, in the areas of high and medium risk, the possibility of using the larvicides also in all private areas will be made available by the Municipalities and the Uls Companies.