In the last decades, the colonization of Mediterranean Europe and of other temperate regions by Aedes albopictus created an unprecedented nuisance problem in highly infested areas and new public health threats due to the vector competence of the species. The Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) are insecticide-free mosquito-control methods, relying on mass release of irradiated/manipulated males, able to complement existing and only partially effective control tools. The validation of these approaches in the field requires appropriate experimental settings, possibly isolated to avoid mosquito immigration from other infested areas, and preliminary ecological and entomological data. We carried out a 4-year study in the island of Procida (Gulf of Naples, Italy) in strict collaboration with local administrators and citizens to estimate the temporal dynamics, spatial distribution, and population size of Ae. albopictus and the dispersal and survival of irradiated males. We applied ovitrap monitoring, geo-spatial analyses, mark-release-recapture technique, and a citizen-science approach. Results allow to predict the seasonal (from April to October, with peaks of 928–9,757 males/ha) and spatial distribution of the species, highlighting the capacity of Ae. albopictus population of Procida to colonize and maintain high frequencies in urban as well as in sylvatic inhabited environments. Irradiated males shown limited ability to disperse (mean daily distance travelled <60m) and daily survival estimates ranging between 0.80 and 0.95. Overall, the ecological characteristics of the island, the acquired knowledge on Ae. albopictus spatial and temporal distribution, the high human and Ae. albopictus densities and the positive attitude of the resident population in being active parts in innovative mosquito control projects provide the ground for evidence-based planning of the interventions and for the assessment of their effectiveness. In addition, the results highlight the value of creating synergies between research groups, local administrators, and citizens for affordable monitoring (and, in the future, control) of mosquito populations.
In 2023, an unprecedentedly high number of locally acquired cases of dengue virus occurred in Europe, including the first large outbreak in Rome (Italy). Globally, 2023 was warmer than any previous year on record since 1850, with each month from June to December being warmer than the corresponding month in previous years. We conducted an extensive analysis of entomological data in Rome to investigate how the unprecedentedly high temperatures seen in 2023 affected the abundance and seasonal dynamics of the local vector Aedes albopictus population and the risk of autochthonous transmission of both dengue and chikungunya viruses. We applied a mathematical dynamic temperature-based model to analyse adult mosquito collections in 2023 compared to those available for 2012 and assess the consequent changes in the risk of arboviral transmission. Simulations of potential local transmission triggered by disease importation were used to evaluate the effectiveness of human and entomological surveillance for monitoring transmission risks, providing insights for future action plans RESULTS: Results highlight a higher abundance and longer active season of Ae. albopictus as well as a higher risk of local arbovirus transmission in 2023. Our findings raise concern in light of the predictions for more frequent extremely warm years in Europe in the near future.
Mosquitoes-borne diseases are major public health issues particularly in Africa. Vector control interventions and human-made environmental/climatic changes significantly affect the distribution and abundance of vector species. We carried out an entomological survey targeting host-seeking mosquitos in two different ecological contexts—coastal and inland—in Senegal, by CDC-light and BG-sentinel traps. Results show high predominance of Culex quinquefasciatus (90%) and of Anopheles arabiensis within malaria vectors (46%), with mean numbers of females/trap/nights =8 and <1, respectively, reinforcing previous evidence of changes in species composition and abundance, highlighting thus increasing risk of transmission of filariasis and emerging arboviruses in the Senegambia region. From the methodological perspective, results show a higher specificity of BG traps for Cx. quinquefasciatus and of CDC traps for An. gambiae s.l. and highlight that, despite both traps target the host-seeking fraction of the population, they provide different patterns of species abundance, temporal dynamics and host-seeking activity, leading to possible misinterpretation of the species bionomics. This draws attention to the need of taking into account trapping performance, in order to provide realistic quantification of the number of mosquitoes per units of space and time, the crucial parameter for evaluating vector–human contact, and estimating risk of pathogen transmission.
Malaria is still a leading cause mortality in Côte d’Ivoire despite extensive LLINs coverage. We present the results of an entomological survey conducted in a coastal and in an inland village with the aim to estimate Anopheles gambiae sensu lato (s.l.) female’s abundance indoor/outdoor and Plasmodium falciparum infection rate and analyze the occurrence of blood-feeding in relation to LLINs use. Pyrethrum spray (PSC) and window exit traps (WT) collections were carried out to target endophagic/endophilic and endophagic/exophilic females, respectively. Data on LLINs use in sampled houses were collected. (1) high levels of malaria transmission despite LLINs coverage >70% (~1 An. gambiae s.l. predicted mean/person/night and ~5% Plasmodium falciparum infection rate); (2) 46% of females in the PSC sample were blood-fed, suggesting that they fed on an unprotected host inside the house; (3) 81% of females in WT were unfed, suggesting that they were leaving the house to find an available host. Model estimates that if everyone sleeps under LLINs the probability for a mosquito to bite decreases of 48% and 95% in the coastal and inland village, respectively. The results show a high proportion of mosquito biting and resting indoors despite extensive LLINs. The biological/epidemiological determinants of accounting for these results merit deeper investigations.
The growing public health burden of Aedes mosquito-borne diseases requires a comprehensive understanding of Aedes species biology, ecology, and vector competence. Eco-epidemiological modelling of Aedes vector species has grown significantly in recent years, driven by the increasing reports of outbreaks in endemic and non-endemic temperate areas, as well as the latitudinal and altitudinal range expansion of these vectors. A prominent example is the Asian tiger mosquito, Aedes albopictus, a competent arbovirus vector that has spread across most continents through the movement of humans and goods. Species distribution models and mechanistic models have been used to predict the spatio-temporal distribution and dynamics of this vector. However, despite the potential of these models to capture the vector distribution and dynamics, integrating them into practical monitoring, surveillance, and vector control activities remains challenging, often due to a lack of communication and model co-development between scientists and public health stakeholders. This paper reports the results of a workshop on vector modelling held in Bologna (Italy) in September 2024, which brought together European experts in disease modelling, public health stakeholders, and medical entomologists. The workshop identified key priorities for advancing the operational use of Aedes-focused quantitative models, including sustained investment in surveillance, improved representation of environmental and biological drivers, standardisation of model outputs, and the establishment of long-term, co-produced modelling frameworks embedded within public health workflows.