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- REVIVE - Rede de Vigilância de Vetores: a chegada do invasor asiático, Aedes albopictusPublication . Alves, Maria João; Amaro, Fátima; Amaro F.; Osório, Hugo; Zé-Zé, Líbia; Silva, Manuel; Soares, PatriciaO programa REVIVE (Rede de Vigilância de Vectores resulta de protocolo entre a Direção-Geral da Saúde, as Administrações Regionais de Saúde do Algarve, Alentejo, Centro, Lisboa e Vale do Tejo e do Norte, o Instituto dos Assuntos Sociais e da Saúde da Madeira, a Direção Regional de Saúde dos Açores e o Instituto Nacional de Saúde Doutor Ricardo Jorge Este programa de vigilância entomológica visa - monitorizar a atividade de artrópodes hematófagos, nomeadamente mosquitos Culicidae carraças Ixodidae e flebótomos Psychodidae - caracterizar as espécies e sua ocorrência sazonal, - e identificar agentes patogénicos importantes em saúde pública.
- Mark-Release-Recapture of Aedes albopictus in Portugal: the influence of climatic factorsPublication . Soares, Patricia; Carvalho, Danilo O.; Silva, Susana Pereira; Gomez Pacheco, Maylen; Amaro, Fátima; Amaro F.; Osório, HugoAedes albopictus mosquitoes spread diseases like dengue, Zika, yellow fever, and chikungunya. The Sterile Insect Technique (SIT), which is based on production of male sterile mosquitoes through radiation and in the release in target areas, can be used as a prevention and control tool against Ae. albopictus native populations. Mark-Release-Recapture trials (MRR) estimate the number of mosquitoes to release during the SIT, but weather conditions can affect results. Thus, we aimed to understand the influence of climatic factors on mosquito collection. MRRs were conducted in October 2022 in Faro, Southern Portugal. Mosquito sterilisation, marking and transport followed protocols from the International Atomic Energy Agency. Releases occurred weekly for three consecutive weeks at two different sites, and mosquitoes were collected using Human Landing Collections (HLC) one, two, four and six days after release. Climatic data, such as temperature, humidity, wind intensity (moderate 15-35 km/h vs weak <15 km/h) and precipitation, were obtained from the Portuguese Institute of the Sea and the Atmosphere. We used generalised linear models with a negative binomial family and log function to estimate factors associated with the number of captured mosquitoes, estimated prevalence ratios (PRs), and the 95% confidence intervals (CI). We released 84 000 marked sterile male mosquitoes and recaptured 528 marked males (0.7%) by HLC. The prevalence of captured mosquitoes was 23% lower when the wind intensity was moderate compared with a weak wind intensity (PR: 0.77, 95% CI: 0.61−0.98). We did not find a statistically significant association between the number of captured mosquitoes and humidity (PR: 0.98, 95% CI: 0.96−1.00), temperature (PR: 1.03, 95% CI: 0.83−1.28) and precipitation (PR: 1.07, 95% CI: 0.60−2.03). Conclusion: It is crucial to plan MRRs carefully and consider weather conditions during their execution to avoid underestimating the population needed for the SIT and compromising the effectiveness of this control method.
- Remote monitoring of disease vector mosquitoes with a new optical sensor system for automatic classificationPublication . Silva, Manuel; Alves, Maria João; Amaro, Fátima; Zé-Zé, Líbia; Osório, HugoIntroduction: - Mosquitoes represent a major threat to public health given their ability to transmit several pathogens. Some species of Aedes can transmit viruses such as dengue, Zika, or chikungunya. - Prevention of vector-borne diseases largely depends on effective and sustainable vector surveillance. Objectives: - Help to develop a novel bioacustic sensor that is able to identify the mosquitoes' species in real time - Deploy the sensor in the field in Madeira and Algarve.
- Avaliação de conhecimentos, atitudes e práticas em relação a mosquitos enquanto vetores de doença numa comunidade estudantil em LisboaPublication . Simplício, Leonor; Soares, Patricia; Anjos, João; Almeida-Silva, Marina; Osório, HugoIntrodução: Os agentes infeciosos transmitidos por mosquitos vetores que provocam doenças como o dengue, Zika ou chikungunya são uma ameaça à saúde pública. Os mosquitos das espécies Aedes aegypti e Ae. albopictus são atualmente os principais vetores e responsáveis por surtos na região europeia (WHO, 2020). Torna-se crucial avaliar o conhecimento, atitudes e práticas em relação aos mosquitos e às doenças associadas, de modo a aumentar a adesão da população às medidas de controlo. Alguns exemplos destas medidas são a eliminação de criadouros domésticos, o uso de inseticidas e a aplicação da Técnica do Inseto Estéril (SIT), que consiste num método de controlo biológico com a aplicação de insetos machos estéreis em áreas alvo de intervenção, com o objetivo de suprimir a população (IAEA, 2023). Objetivos: Avaliar os conhecimentos, atitudes e práticas em relação aos mosquitos vetores, doenças associadas e medidas de controlo numa comunidade estudantil em Lisboa. Metodologia: Foi desenvolvido um questionário com recurso à ferramenta Google Forms e dividido em quatro secções: 1. Perceção sobre mosquitos na zona de residência, 2. Avaliação do conhecimento sobre mosquitos, 3. Prevenção individual e controlo vetorial e 4. Dados do participante. Este questionário foi aplicado à população alvo de uma escola de ensino superior localizada em Lisboa e divulgado em 2021 internamente via email, tendo ficado disponível à participação durante todo o mês de março. Posteriormente, foi feita uma análise descritiva dos resultados através da determinação da frequência absoluta e relativa. Resultados: Obteve-se um total de 140 questionários completos, dos quais 81% dos participantes correspondiam ao género feminino e 73% tinha uma idade inferior a 25 anos. Verificou-se que apenas duas pessoas acertaram todas as questões de conhecimento. Em relação à questão da técnica SIT, 86% dos participantes desconheciam esta técnica, contudo, 73% concorda totalmente com a sua aplicação. Apenas 13 participantes identificam que são os mosquitos do género feminino que picam e conhecem a técnica SIT e apenas um destes 13 participantes não concorda com a aplicação desta técnica. Em relação às práticas verificou-se que 16% dos participantes adotam medidas de proteção individual contra mosquitos e medidas de controlo nas suas residências e que cinco destes não considera estas medidas suficientes e eficazes. Outro resultado foi o facto de 7,1% dos participantes afirmarem extrema preocupação pelos mosquitos transmitirem doenças, contudo apenas cinco adotam medidas de proteção tanto individual como de controlo. Em relação ao nível de incomodidade, 89% dos participantes não sente qualquer incómodo em relação aos mosquitos e 25% dos participantes que sentem desconforto alteram as suas atividades ao ar livre. Conclusão: Os resultados evidenciam a importância de manter a população informada e de a integrar em atividades que visem o aumento do conhecimento em relação aos vetores e às doenças associadas, uma vez que um elevado número das doenças transmitidas por vetores pode ser evitável através de medidas de proteção e mobilização da comunidade (WHO, 2020).
- The potential role of scavenging flies as mechanical vectors of Lagovirus europaeus/GI.2Publication . Lopes, Ana M.; Almeida, Tereza; Osório, HugoThe European rabbit (Oryctolagus cuniculus) populations of the Iberian Peninsula have been severely affected by the emergence of the rabbit haemorrhagic disease virus (RHDV) Lagovirus europaeus/GI.2 (RHDV2/b). Bushflies and blowflies (Muscidae and Calliphoridae families, respectively) are important RHDV vectors in Oceania, but their epidemiological role is unknown in the native range of the European rabbit. In this study, scavenging flies were collected between June 2018 and February 2019 in baited traps at one site in southern Portugal, alongside a longitudinal capture-mark-recapture study of a wild European rabbit population, aiming to provide evidence of mechanical transmission of GI.2 by flies. Fly abundance, particularly from Calliphoridae and Muscidae families, peaked in October 2018 and in February 2019. By employing molecular tools, we were able to detect the presence of GI.2 in flies belonging to the families Calliphoridae, Muscidae, Fanniidae and Drosophilidae. The positive samples were detected during an RHD outbreak and absent in samples collected when no evidence of viral circulation in the local rabbit population was found. We were able to sequence a short viral genomic fragment, confirming its identity as RHDV GI.2. The results suggest that scavenging flies may act as mechanical vectors of GI.2 in the native range of the southwestern Iberian subspecies O. cuniculus algirus. Future studies should better assess their potential in the epidemiology of RHD and as a tool for monitoring viral circulation in the field.
- Mark–Release–Recapture Trial with Aedes albopictus (Diptera, Culicidae) Irradiated Males: Population Parameters and Climatic FactorsPublication . Amaro, Fátima; Amaro F.; Soares, Patricia; Velo, Enkelejda; Oliveira Carvalho, Danilo; Gomez, Maylen; Balestrino, Fabrizio; Puggioli, Arianna; Bellini, Romeo; Osório, HugoAedes albopictus is considered one of the major invasive species in the world and can transmit viruses such as dengue, Zika, or chikungunya. The Sterile Insect Technique (SIT) can be used to suppress the native populations of Ae. albopictus. Mark–release–recapture (MRR) studies are crucial to support the development of the release strategy during the SIT application. Meanwhile, weather conditions can affect the MRR trial’s results and it is critical to understand the influence of climatic factors on the results. In October 2022, 84,000 irradiated sterile males were released for three consecutive weeks in Faro, Southern Portugal. Mosquitoes were recaptured by human landing collection (HLC) one, two, four, and six days after release. Generalized linear models with a negative binomial family and log function were used to estimate the factors associated with the number of recaptured mosquitoes, prevalence ratios, and the 95% confidence intervals (CIs). A total of 84,000 sterile male mosquitoes were released, with 528 recaptured (0.8%) by HLC. The prevalence of recaptured mosquitoes was 23% lower when the wind intensity was moderate. Marked sterile males had an average median distance travelled of 88.7 m. The median probability of daily survival and the average life expectancy were 61.6% and 2.1 days, respectively. The wild male population estimate was 443.33 males/ha. Despite no statistically significant association being found with humidity, temperature, and precipitation, it is important to consider weather conditions during MRR trial analyses to obtain the best determinant estimation and a more efficient application of the SIT in an integrated vector management program.
- The spread of the invasive mosquito Aedes albopictus (Diptera: Culicidae) in Portugal: a first genetic analysisPublication . Zé-Zé, Líbia; Campos Freitas, Inês; Silva, Manuel; Soares, Patricia; Alves, Maria João; Osório, HugoBackground: Aedes albopictus, commonly known as the Asian tiger mosquito, has become one of the most invasive mosquito species. Over the last 5 decades, it has been introduced and established in various tropical and temperate regions worldwide. First reported in Europe in 1979 in Albania and later in Italy in 1990, the species is now established in 13 European Union (EU)/European Economic Area (EEA) countries and 337 regions (2023). In Portugal, Ae. albopictus was first detected in the Algarve and Penafiel regions in 2017, followed by Alentejo in 2022 and Lisbon in 2023. This mosquito species poses a significant public health risk as a vector for numerous pathogenic viruses, including dengue, Zika, and chikungunya. Methods: Aedes albopictus collected in Lisbon in 2023 were analyzed using cytochrome c oxidase I (COX) gene sequencing to understand their genetic relationships. Results: Our data indicate that the Ae. albopictus mosquito populations detected in three locations in Lisbon in 2023 correspond to recent but distinct introduction events. Conclusions: Although there has been no local transmission of Aedes-transmitted viruses in mainland Portugal to date, the spread of the mosquito and increased international travel increase the risk of Aedes-borne disease outbreaks. The ongoing spread of Ae. albopictus in the country and the confirmed multiple introductions in new locations raise awareness of the need to monitor mosquito vectors to control and prevent autochthonous Aedes-borne disease outbreaks.
- Wolbachia Screening in Aedes aegypti and Culex pipiens Mosquitoes from Madeira Island, PortugalPublication . Fernandes, Rita; Melo, Tiago; Marques Zé-Zé, Líbia Maria; Campos Freitas, Inês; Silva, Manuel; Dias, Eva; Santos, Nuno C.; Gouveia, Bruna R.; Seixas, Gonçalo; Costa Osório, HugoSimple Summary: Mosquitoes can spread serious diseases like dengue and West Nile virus. On Madeira Island, two mosquito species—Aedes aegypti and Culex pipiens—are present and may pose a risk to public health. Scientists are exploring new ways to control these mosquitoes using a natural bacterium called Wolbachia, which can reduce a mosquito’s ability to transmit viruses and even lower mosquito populations. However, for these methods to work, it is important to know first if the mosquitoes in the area already carry this bacterium. In this study, we tested Ae. aegypti and Cx. pipiens from Madeira for Wolbachia. Wolbachia was absent in all 100 Ae. aegypti tested but present in all 40 Cx. pipiens. We also found that the Wolbachia in Cx. pipiens belonged to a group commonly seen in other parts of the world. These results are important because they help us understand which mosquito control strategies might work in Madeira. Specifically, if scientists want to use Wolbachia to control Ae. aegypti on the island, they would need to introduce it artificially. This information can help improve public health efforts and reduce the risk of mosquito-borne diseases in the region.
- Distribution of the West Nile Virus vector, Culex pipiens, in mainland Portugal: A geospatial modelling studyPublication . Martinho, Júlia; Costa Osório, Hugo; Amaro, Fátima; Silva, Manuel; Marques Zé-Zé, Líbia Maria; Pereira Figueira Alves, Maria João; Nunes, Baltazar; Soares, PatriciaBackground: Culex pipiens, Portugal’s most abundant mosquito, is a vector for several pathogens including the West Nile virus. Understanding its spatial distribution can contribute to vector-borne diseases control and public health planning, given Portugal’s favourable climate. National-level data on its spatial distribution, especially in relation to climatic variables is limited. We aimed to predict the suitability of Culex pipiens distribution in mainland Portugal, considering climatic factors. Methods: A maximum entropy (Maxent) model was applied, using presence records for adult and larvae of Culex pipiens mosquitoes sampled across mainland Portugal between January 2017 and October 2023, as part of the REVIVE – Vector Surveillance Network program. Adults were sampled using CDC light traps and BG-Sentinel traps between May and October at random sites and year-round at point-of-entry sites. Larvae were sampled using dippers at breeding sites. Sampling bias was corrected by filtering presence records to one per 1 km2 cell grid. Climatic data, including temperature, precipitation and elevation, were used as predictors. Results: Out of 6,859 records, 354 unique sites were obtained after filtering and cell-duplicate removal. Suitable habitats seem to be primarily in the northern and central coastal regions. Temperature was the most important predictor. Convenience sampling bias may be present. Conclusions: Most West Nile virus case reports have come from southern Portugal, but Culex pipiens’s potential distribution covers the entire mainland territory, with seemingly higher distribution in the north. West Nile vector surveillance should be a priority in all regions to accurately assess transmission risk and implement effective control measures.