As arbovirus outbreaks continue to surge globally, a new study sheds light on the overlapping environmental risks for dengue, Zika, chikungunya, and yellow fever—all transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes. Among the contributing authors is Moritz Kramer, a researcher at the University of Oxford and a key member of the E4Warning project. The study is a result of international collaboration between leading institutions, including Oxford, the London School of Hygiene & Tropical Medicine, the University of Melbourne, the Boston Children’s Hospital, University of Washington University of Cambridge, Nagasaki University, niversity of Florida, the World Health Organization, and the Harvard Medical School.

 In this large-scale study, researchers compiled over 21,000 occurrence records and developed the most comprehensive global environmental suitability maps to date, using a joint ecological niche modelling approach. What makes this work stand out is its integration of multiple diseases, correcting for long-standing biases in surveillance data, and providing a common suitability framework for all four diseases.

 Key findings include:

• An estimated 5.66 billion people live in areas suitable for dengue, Zika, and chikungunya—around 73% of the global population.

• 1.54 billion people live in areas suitable for yellow fever transmission.

• The study reveals high overlap in suitable areas for dengue, Zika, and chikungunya, indicating that any region reporting one of these diseases could be at risk of the others.

• Risk maps show new potential hotspots in areas like West and Central Africa, southern Europe, and parts of Asia, where surveillance is low or diseases are underreported.

• Models highlight that underreporting and limited diagnostic capacity in low-income countries may skew perceived disease distribution, underlining the importance of adjusting for surveillance capability in global risk mapping.

By using a two-stage modelling strategy—one for disease risk and one for surveillance capacity—the researchers produce more accurate and actionable risk assessments, offering a better foundation for targeted disease surveillance, early warning, and response systems.  The results emphasize the need for integrated arbovirus monitoring and the value of cross-disease models in a world of expanding ecological and climate pressures.

Read the full open access here: https://doi.org/10.1038/s41467-025-58609-5

Lim, A., Shearer, F. M., Sewalk, K., Pigott, D. M., Clarke, J., Ghouse, A., Judge, C., Kang, H., Messina, J. P., Kraemer, M. U. G., Gaythorpe, K. A. M., de Souza, W. M., Nsoesie, E. O., Celone, M., Faria, N., Ryan, S. J., Rabe, I. B., Rojas, D. P., Hay, S. I., Brownstein, J. S., Golding, N., & Brady, O. J. 2025. The overlapping global distribution of dengue, chikungunya, Zika and yellow fever. Nature Communications, 16, 3418. https://doi.org/10.1038/s41467-025-58609-5

And in the E4Warning Zenodo repository: https://zenodo.org/records/15223772

A new study, part of the E4Warning and IDAlert projects, has provided a comprehensive snapshot of mosquito biodiversity across the Attica region in Greece—home to half the country’s population. Conducted by the Benaki Phytopathological Institute (BPI) and the University of West Attica in Athens, the survey spans two years (2021–2022) and highlights the presence, spread, and diversity of medically important mosquito species, including invasive ones like Aedes albopictus.

Key Findings:

• The three most widespread species were Aedes albopictus, Culex pipiens s.l., and Culiseta longiareolata, found in 100% of traps.

• A total of 23 mosquito species were detected, with some reappearing after years of absence.

• East Attica had the highest species diversity; South Athens and the islands the lowest.

• Molecular tools complemented traditional identification, confirming difficult or damaged specimens.

The study highlights the dynamic nature of mosquito populations in urbanized regions like Attica, where invasive species such as Aedes albopictus now coexist with native vectors like Culex pipiens s.l. The detection of medically important species, including Culex perexiguus and Aedes caspius, not commonly reported in past surveys, underscores changing vector dynamics and potential public health risks.

Molecular tools proved essential for identifying species when morphological traits were insufficient, reinforcing the value of combining traditional and modern surveillance methods. Continuous, localized monitoring is key for early detection of new threats—especially in the face of climate change and urban expansion—and provides critical data to support proactive, targeted mosquito control strategies.

Trap Positivity Rate (%) by Mosquito Species (2021–2022)

Read the full-open access here: https://doi.org/10.3390/insects16040406

Bisia, M., Balatsos, G., Sakellariou Sofianou, M., Beleri, S., Tegos, N., Zavitsanou, E., Karras, V., Kollia, D., Michaelakis, A., & Patsoula, E. (2025). Two-Year Entomological Survey of Mosquito Fauna in the Attica Region, Greece: Species Composition. Insects, 16 (4), 406. https://doi.org/10.3390/insects16040406

In December 2024, Elisa Mora and Alex Richter-Boix (CEAB-CSIC), members of the E4Warning consortium, participated as invited speakers at the EMCA workshop “Dialogue with Wings: Communicating Mosquito Science Effectively”, held at the SUPSI Campus in Mendrisio, Switzerland. The event brought together experts and practitioners from 14 countries to explore innovative ways to communicate mosquito science and mosquito-borne diseases.

Elisa and Alex shared their experiences with the citizen science initiative Mosquito Alert, emphasizing how it has effectively communicated complex topics like mosquito ecology and vector-borne diseases to the public and stakeholders. Elisa Mora also participated in a plenary roundtable moderated by David T. Dyjack (National Environmental Health Association) and joined by Ljubica Latinovic (World Health Organization), Andrea Delucchi (Institute of Design SUPSI), and journalist Julian Michaels (Radiotelevisione Svizzera).

During the second day, they led one of the hands-on workshops focused on communication strategies. The session was part of a broader program attended by 77 participants, which explored six key themes over three days:

• Risk Communication
• Visual Communication
• Community Engagement
• Stakeholder Communication
• Media Relations
• Funding for Communication

Through interactive activities and real-world scenarios, participants gained practical tools to adapt their messaging to diverse audiences, foster partnerships, and counter misinformation.

Exploring Sterile Insect Technology (SIT) Communication

The workshop concluded with an EMCA side-event dedicated to communication strategies for the Sterile Insect Technique (SIT), a groundbreaking method to control Aedes mosquito populations by releasing sterilized insects. Case studies highlighted SIT initiatives in regions such as Indonesia, Sri Lanka, French Polynesia, La Réunion, Tunisia, Florida (USA), and parts of Africa. Charles m’Bogo (PAMCA) shared insights from the African context.

Discussions focused on the challenges of engaging stakeholders and citizens in SIT programs and the difficulties encountered in communicating these innovative technologies. The participants explored the possibility of collaborating on a unified document of best practices for SIT communication, paving the way for more effective and globally consistent outreach efforts.

The workshop not only strengthened the knowledge and tools available for mosquito-related communication but also reinforced the importance of collaboration across sectors and countries in the fight against mosquito-borne diseases.

Find all the details of the agenda here: https://www.emca-online.eu/assets/PDFs/2024_Switzerland/2024_TDR_SIT_FINAL_AGENDA.pdf

A recent study, published in Insects with E4Warning participation, explores the residual longevity of sterile male mosquitoes and its significance for understanding their field performance in Sterile Insect Technique (SIT) programs: an eco-friendly vector control method where sterile male mosquitoes are released to mate with wild females, reducing mosquito populations over time.

The study aimed to assess the longevity and quality of sterile and non-sterile male Aedes albopictus mosquitoes by using the “mark-release-recapture” (MRR) method. The findings revealed several important insights:

1. Sterile Males’ Longevity: Contrary to expectations, the study found that sterile male mosquitoes had a longer lifespan than their non-sterile counterparts when released into the wild. This extended longevity is a significant advantage for SIT programs, as it increases the likelihood of sterile males mating with wild females, thereby enhancing the effectiveness of population suppression efforts.

2. Effect of Wild Exposure: Sterile males that had been released into the wild lived longer when recaptured and monitored in a laboratory setting. This suggests that exposure to the wild, including factors like fluctuating environmental conditions and access to richer food sources, may improve the performance of sterile males.

3. No Negative Effect of Marking or Sterilization: The process of marking the mosquitoes with fluorescent dyes (following IAEA protocols) and sterilization via gamma radiation did not negatively affect their longevity. This supports the continued use of these practices in SIT programs.

4. Transport and Mass Rearing: Males reared and transported from large-scale production facilities exhibited slightly shorter lifespans compared to those reared locally under small-scale conditions. This suggests that optimizing transportation and rearing conditions can further improve the performance of sterile mosquitoes in the field.

Understanding the longevity and quality of sterile mosquitoes is crucial for optimizing SIT programs, particularly in areas where mosquito populations pose a significant public health threat. The study underscores the importance of refining rearing, sterilization, and transportation techniques to maximize the success of SIT in controlling vector populations and reducing the risk of mosquito-borne diseases.

This research advances our understanding of how sterile males perform in the field, providing valuable insights that can be applied to ongoing and future SIT initiatives and vector dispersal capacity estimation within the E4Warning project.

The study was a collaborative effort involving several institutions and experts across Europe. Key contributors included researchers from the following institutions: Benaki Phytopathological Institute (BPI) in Greece, Centre d’Estudis Avançats de Blanes (CEAB-CSIC), CREAF, and ICREA in Spain, Centro Agricoltura Ambiente “G. Nicoli” in Crevalcore, Italy, Centre for Vectors and Infectious Diseases Research Doutor Francisco Cambournac (CEVDI) at the National Institute of Health Doutor Ricardo Jorge (INSA) in Palmela, Portugal, and the Faculty of Medicine, Environmental Health Institute (ISAMB) at the University of Lisbon, and ASTRE, CIRAD, INRAE, based in La Réunion, France.

Link to the paper: Balatsos, G., Blanco-Sierra, L., Karras, V., Puggioli, A., Costa Osório, H., Bellini, R., Papachristos, D.P., Bouyer, J., Bartumeus, F., Papadopoulos, N.T., & Michaelakis, A. 2024. Residual Longevity of Recaptured Sterile Mosquitoes as a Tool to Understand Field Performance and Reveal Quality. Insects 15, no. 11: 826. https://doi.org/10.3390/insects15110826

You can find other scientific papers produced by E4Warning in our “Publication website”: https://www.e4warning.eu/outputs/publications/

In our ongoing efforts to enhance mosquito surveillance and early warning systems, the E4Warning consortium is leveraging innovative technologies, including the improvement of the IRIDEON SL smart-traps. These smart-traps are designed to automate and improve the efficiency of mosquito monitoring, addressing the challenges faced by traditional methods.

Overcoming Traditional Surveillance Challenges

Traditional mosquito surveillance methods are costly and time-consuming, requiring significant professional resources for trap placement, sample collection, and laboratory analysis. Additionally, there is an inevitable time lag between placing traps and collecting samples, which can lead to inaccurate and untimely monitoring of mosquito populations.

The IRIDEON smart traps are off-the-shelf commercial suction traps equipped with the VECTRACK optoelectronic sensor prototype developed by IRIDEON SL in Barcelona. These sensors are capable of distinguishing between mosquito species, sex, and age under both laboratory and field conditions. The VECTRACK sensor includes an emitter, an array of LEDs, and photo-transistors acting as photoreceptors, all working together to create a light field. When a mosquito is drawn into the trap, its wing flapping modulates the light field, generating a species-specific signature. This signature is processed using AI methods, including rule-based systems, genetic algorithms, artificial neural networks, and fuzzy models, to classify the mosquito by genus, species, sex, and age.

Each VECTRACK recording includes GPS coordinates, date and time of capture, ambient temperature, and relative humidity. Every 30 minutes, the field sensor transmits data batches to the server via the mobile phone network. The server then classifies each mosquito event, providing detailed and accurate data on mosquito populations in real-time. This automation reduces the need for manual intervention and enables continuous monitoring.

Field Performance and Global Testing

The VECTRACK sensor has demonstrated its effectiveness in real-world scenarios, achieving high accuracy in field trials conducted in Spain. In El Prat de Llobregat (2021) and Rubí (2022), the sensor achieved 95.5% accuracy in species detection and 88.8% accuracy in classifying the genus and sex of mosquitoes. Check the work performed by Gozález-Pérez et al.: Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sex. Parasites Vectors 17, 97 (2024). https://doi.org/10.1186/s13071-024-06177-w

Ongoing Field Tests Under E4Warning

The E4Warning project is testing the efficacy of the IRIDEON smart-traps under various conditions:

• Spain (Barcelona): VECTRACK sensors are deployed at five strategic monitoring sites across the city, focusing on Culex pipiens and Aedes albopictus. Agència de Salut Pública de Barcelona – ASPB
• Brazil (Rio de Janeiro and Brasilia): Field trials with local populations of Aedes aegypti and Culex quinquefasciatus in collaboration with Instituto Oswaldo Cruz, Fiocruz. Fundação Oswaldo Cruz (Fiocruz)
• Spain (Girona): Testing in non-urban environments like the Botanical Garden of Blanes and Aiguamolls de l’Empordà Natural Park, where diverse mosquito species are present. CSIC
• Greece (Athens): Planned deployment in the Attica region, focusing on critical points of entry for Aedes aegypti and areas of significant vector importance. Benaki Phytopathological Institute

To learn more about IRIDEON smart-traps refer to:

• González-Pérez, M.I., Faulhaber, B., Aranda, C. et al. Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sex. Parasites Vectors 17, 97 (2024). https://doi.org/10.1186/s13071-024-06177-w
• González-Pérez MI, Faulhaber B, Williams M, Brosa J, Aranda C, Pujol N, et al. A novel optical sensor system for the automatic classification of mosquitoes by genus and sex with high levels of accuracy. Parasit Vectors. 2022;15:190. https://doi.org/10.1186/s13071-022-05324-5.

During the E4Warning project, we are employing various methods to collect blood-engorged female mosquitoes to study their feeding patterns. The techniques include carbon-dioxide-baited BG-traps, mechanical aspiration with a powered vacuum aspirator, and artificial resting sites. Sampling began in April 2024 and will continue monthly until November 2024 for this year.

From June 10-15, we hosted Dr. Nathan Burkett-Cadena and Tanise Steen from the Florida Medical Entomology Laboratory, University of Florida, at our study area in Aiguamolls de l’Empordà (Girona, Spain). Their visit aimed to test these collection techniques and share their expertise. They brought vacuum aspirators and resting traps developed by their lab to evaluate their combined efficacy in capturing blood-fed female mosquitoes across different habitats.

The Florida researchers developed human-powered resting traps designed for cavity-resting mosquitoes like Culex. These traps, set among vegetation in dark areas, attract mosquitoes seeking refuge during the day. Traps are placed horizontally to attract Culex and vertically to attract Anopheles mosquitoes and are collected the following day.

To maximize mosquito collection, we combined resting shelter traps and BG-traps with a large-diameter aspirator. These aspirators, designed by Dr. Burkett-Cadena’s team, use an automotive radiator fan to create directional airflow, capturing mosquitoes in a mesh-bottom plastic collection cup.

The insights gained during this visit and throughout the 2024 mosquito season will help finalize protocols for capturing blood-fed females, aiding in our study of mosquito feeding patterns.

• Burkett-Cadena. 2011. A wire-frame shelter for collecting resting mosquitoes. Journal of the American Mosquito Control Association 27: 153–155
• Burkett-Cadena et al. 2019. Human-powered pop-up resting shelter for sampling cavity-resting mosquitoes. Acta Tropica 190: 288-292
• Sloyer et al. 2022. Evaluating sampling strategies for enzootic Venezuelan equine encephalitis virus vectors in Florida and Panama. PLoS Negl Trop Dis.16:e0010329
•  Jaworski et al. 2022. Artificial resting sites: An alternative sampling method for adult mosquitoes. Medical and Veterinary Entomology 36: 139–148

Eva Veronesi (SUPSI) attended the 6th International Workshop on Aedes albopictus in Phnom Penh, Cambodia, from March 28-29, 2024. Organized by the Institute Pasteur of Cambodia, the workshop was led by Dr. Sébastien Boyer (head of the Medical and Veterinary Entomology Unit at the Institute). The opening session was presided over by Prof. André Spiegel, Director of the Institute Pasteur of Cambodia, with the presence of Professor Chheang Ra, Minister of Health of Cambodia, Mr. Jacques Pellet, Ambassador of France to Cambodia, and Dr. Boyer, who delivered the introductory talk.

The Aedes albopictus, commonly known as the tiger mosquito, is a principal carrier of Dengue fever, Chikungunya, Zika, and at least 20 other significant pathogens impacting public health. Originating from the tropical and subtropical zones of Southeast Asia, the tiger mosquito has expanded its reach globally over the last century, facilitated by international trade and travel. Distinguished by distinctive white stripes on its legs and body, the species has adapted well to human environments. As a considerable nuisance, the tiger mosquito typically resides close to human habitats and is known for its daytime biting behavior, especially during early morning and late afternoon periods.

The event was focused on enhancing scientific collaboration and showing innovative vector control strategies. Key research topics covered included vector models of invasion and dispersal, and the role of the species as a bridge vector, including the influence of climate change on vector behavior. For that, the workshop unfolded five sessions:

• Aedes albopictus in Asia.
• Biology and Ecology of Aedes albopictus.
• Vector control: challenges and innovations.
• Vector control: insecticide resistance.
• New surveillance strategies.

It was during the session on innovative surveillance strategies that E4Warning was spotlighted. The presentation titled “The Role of E4Warning in Combating the Spread of Dengue in Asia and its Potential Incursion into Europe” by Eva Veronesi showcased to the audience the surveillance tools involved in the project, such as Mosquito Alert (CSIC, UPF), VECMAP (AVIA-GIS)  and the smart traps designed by IRIDEON. Additionally, it highlighted the dengue models developed by the Barcelona Supercomputing Center (BSC) and HR Wallingford.

Link to the agenda of the event: Agenda 6th International Workshop on Aedes albopictus