Mosquito, Bird and Human Surveillance of West Nile and Usutu Viruses in Emilia-Romagna Region (Italy) in 2010

<div><h3>Background</h3><p>In 2008, after the first West Nile virus (WNV) detection in the Emilia-Romagna region, a surveillance system, including mosquito- and bird-based surveillance, was established to evaluate the virus presence. Surveillance was improved in following years by extending the monitoring to larger areas and increasing the numbers of mosquitoes and birds tested.</p> <h3>Methodology/Principal Findings</h3><p>A network of mosquito traps, evenly distributed and regularly activated, was set up within the surveyed area. A total of 438,558 mosquitoes, grouped in 3,111 pools and 1,276 birds (1,130 actively sampled and 146 from passive surveillance), were tested by biomolecular analysis. The survey detected WNV in 3 <em>Culex pipiens</em> pools while Usutu virus (USUV) was found in 89 <em>Cx. pipiens</em> pools and in 2 <em>Aedes albopictus</em> pools. Two birds were WNV-positive and 12 were USUV-positive. Furthermore, 30 human cases of acute meningoencephalitis, possibly caused by WNV or USUV, were evaluated for both viruses and 1,053 blood bags were tested for WNV, without any positive result.</p> <h3>Conclusions/Significance</h3><p>Despite not finding symptomatic human WNV infections during 2010, the persistence of the virus, probably due to overwintering, was confirmed through viral circulation in mosquitoes and birds, as well as for USUV. In 2010, circulation of the two viruses was lower and more delayed than in 2009, but this decrease was not explained by the relative abundance of <em>Cx. pipiens</em> mosquito, which was greater in 2010. The USUV detection in mosquito species confirms the role of <em>Cx. pipiens</em> as the main vector and the possible involvement of <em>Ae. albopictus</em> in the virus cycle. The effects of meteorological conditions on the presence of USUV-positive mosquito pools were considered finding an association with drought conditions and a wide temperature range. The output produced by the surveillance system demonstrated its usefulness and reliability in terms of planning public health policies.</p> </div

Evidence of Simultaneous Circulation of West Nile and Usutu Viruses in Mosquitoes Sampled in Emilia-Romagna Region (Italy) in 2009

BACKGROUND: In recent years human diseases due to mosquito-borne viruses were increasingly reported in Emilia-Romagna region (Italy), from the chikungunya virus in 2007 to the West Nile virus (WNV) in 2008. An extensive entomological survey was performed in 2009 to establish the presence and distribution of mosquito arboviruses in this region, with particular reference to flaviviruses. METHODOLOGY/PRINCIPAL FINDINGS: From May 6 to October 31, a total of 190,516 mosquitoes were sampled in georeferenced stations, grouped in 1,789 pools according date of collection, location, and species, and analyzed by reverse transcription polymerase chain reaction (RT-PCR) to detect the presence of RNA belong to Flavivirus genus. WNV was detected in 27 mosquito pools, producing sequences similar to those of birds and human strains obtained in 2008 outbreak, pointed out the probable virus overwintering. Isolation of WNV was achieved from one of these pools. Moreover 56 pools of mosquitoes tested positive for Usutu virus (USUV). Most PCR positive pools consisted of Culex pipiens, which also was the most analyzed mosquito species (81.4% of specimens); interestingly, USUV RNA was also found in two Aedes albopictus mosquito pools. Simultaneous circulation of WNV and USUV in the survey area was highlighted by occurrence of 8 mosquito WNV- and USUV-positive pools and by the overlaying of the viruses "hot spots", obtained by kernel density estimation (KDE) analysis. Land use of sampled stations pointed out a higher proportion of WNV-positive Cx. pipiens pool in rural environments respect the provenience of total sampled pool, while the USUV-positive pools were uniformly captured in the different environments. CONCLUSIONS/SIGNIFICANCE: Obtained data highlighting the possible role of Cx. pipiens mosquito as the main vector for WNV and USUV in Northern Italy, and the possible involvement of Ae. albopictus mosquito in USUV cycle. The described mosquito-based surveillance could constitute the foundation for a public health alert system targeting mosquito borne arboviruses

Advanced control systems for single compressor chiller units

n this paper the problem of designing advanced control systems for increasing the performances of low capacity HVAC system with single scroll compressor is addressed. In particular, a simulation environment based on Matlab/Simulink that has been validated on a state-of-the-art experimental facility and used to design an adaptive controller for single scroll compressor, packaged air-cooled water chillers is presented. The capability of the controller to substantially increase the energy performance of the system, as well as to achieve excellent regulation performances in process applications is demonstrated

Effects of the Weather on the Seasonal Population Trend of <i>Aedes albopictus</i> (Diptera: Culicidae) in Northern Italy

Background: Aedes albopictus, the Asian tiger mosquito, has become a prevalent pest in Italy, causing severe nuisance and posing a threat of transmission of arboviruses introduced by infected travelers. In this study, we investigated the influence of weather parameters on the seasonal population density of Aedes albopictus. Methods: A Bayesian approach was employed to identify the best meteorological predictors of species trend, using the eggs collected monthly from 2010 to 2022 by the Emilia-Romagna regional monitoring network. Results: The findings show that the winter–spring period (January to May) plays a crucial role in the size of the first generation and seasonal development of the species. Conclusions: A temperate winter and a dry and cold March, followed by a rainy and hot spring and a rainy July, seem to favor the seasonal development of Ae. albopictus

Quantitative monitoring of Aedes albopictus in Emilia-Romagna, Northern Italy: cluster investigation and geostatistical analysis

Abstract The Aedes albopictus (Skuse) (Diptera Culicidae) control program currently applied in the Emilia-Romagna region (Northern Italy) is based on the use of ovitraps as a tool for mosquito population density estimation. During the favourable season 2008 (MayOctober), 2,741 ovitraps were activated in the urban areas of 242 municipalities according to standard criteria and were checked weekly. The universal kriging interpolation was used to estimate the seasonal abundance of the species at unsampled locations, and spatial cluster analysis was used to identify particular areas that had statistically significant high or low mosquito density. The overall data pattern was highly clustered and autocorrelated, and the choropleth and LISA cluster maps showed high egg density in the North, North-East and in the South-West areas of the region. The cross-validation statistics and results showed that the predicted values were reasonable for map production. The characterization of large geographic areas with high or low abundance of Ae. albopictus may provide information both on the environmental variables that promote species dispersion, and on the epidemic diseases risk, essential to develop effective disease surveillance programs, particularly for Chikungunya and Dengue

Quality control and data validation procedure in large-scale quantitative monitoring of mosquito density. The case of Aedes albopictus in Emilia-Romagna region, Italy

The risk of local transmission of chikungunya, dengue, and Zika viruses from viremic travelers arriving from affected areas is a real possibility in southern Europe, due to the large presence of the vector Aedes albopictus. The first chikungunya outbreak in Europe occurred in the Emilia-Romagna region, Italy, in 2007, prompting the regional public health department to implement an Ae. albopictus monitoring and control plan. This paper presents the procedure developed for the quality control of the data collected by the regional ovitrap monitoring network. The quality control procedure consists of four successive steps; the first step is data acquisition and the second is an automatic data processing step, while skilled technicians according to specific procedures perform the third and fourth steps by checking the exact position of the ovitraps and by conducting human landing collections, respectively. The paper also presents the results of this quality control procedure applied to the data collected through the large-scale Ae. albopictus monitoring operation performed in Emilia-Romagna in 2015

Field Performance Assessment of Irradiated Aedes albopictus Males Through Mark–Release–Recapture Trials With Multiple Release Points

International audienceMark–release–recapture (MRR) trials have been conducted in Northern Italy to evaluate the capacity of radio-substerilized Aedes albopictus males to survive, disperse, and engage in mating in the field. Two MRR sessions with the human landing collection method (HLC) were conducted with the simultaneous release of irradiated males marked with four different pigment colors. The survival and dispersal rates seem to be influenced more by environmental factors such as barriers, shading, and vegetation rather than weather parameters. In this study, we confirmed a positive linear relationship between the sterile adult male’s daily survival rate and the relative humidity previously reported in similar experimental conditions and a different dispersal capacity of the released A. albopictus males in low- (NDVI index &lt;0.4) and high (NDVI index &gt;0.4)-vegetated areas. Consistent with previous studies, A. albopictus males have their maximal dispersion in the first days after release, while in the following days the males become more stationary. The similar field performances obtained with marked and unmarked radio-sterilized and untreated A. albopictus males on similar environments confirm the negligible effects of irradiation and marking procedures on the quality of the males released. The similar sterile to wild (S/W) male ratio measured in high- and low-vegetation areas in the release sites indicates a similar distribution pattern for the wild and the released sterile males. According to the MRR data collected, the Lincoln index estimated different A. albopictus mean population densities in the study areas equal to 7,000 and 3,000 male/ha, respectively