Percorrer por autor "Silva, Manuel"
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- 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.
- Enhancing Entomological Surveillance: Real-Time Monitoring of Mosquito Activity with the VECTRACK System in Rural and Urban AreasPublication . Silva, Manuel; Gouveia, Bruna R.; Santos, José Maurício; Guerreiro, Nélia; Monteiro, Alexandra; Almeida, Soraia; Osório, Hugo CostaBackground: Mosquitoes from the Aedes (Ae.) genus are vectors of dengue, Zika, chikungunya, and other arboviruses, posing a significant public health threat. In 2005, Aedes aegypti was detected for the first time in Madeira Island, Portugal, in the city of Funchal, and has since become established in the region. In 2017, Aedes albopictus was detected for the first time in mainland Portugal. These invasion events require targeted entomological surveillance, which demands substantial human resources and a high management capacity for traditional vector monitoring. Following promising results obtained in laboratory conditions, a field-deployable model of a bioacoustic sensor for the automatic classification of mosquitoes integrated with a Biogents Sentinel trap as part of the VECTRACK system was tested in three regions in Portugal. Methods: The VECTRACK system was deployed in three locations: Funchal on Madeira Island, and Palmela and Algarve on mainland Portugal. Catch bags were manually inspected at intervals ranging from daily to weekly, resulting in a total of 38 captures in Madeira, 10 in Palmela, and 7 in the Algarve. Manual identifications were compared with those generated by the VECTRACK system, and the degree of correlation between the two datasets was assessed using Spearman's rank correlation coefficient. Results: A total of 176 mosquitoes were captured in Madeira, 732 in Palmela, and 143 in the Algarve. Both manual and sensor-based identifications demonstrated similar performance, with high correlation observed between the two methods. Spearman's rank correlation coefficients indicated high agreement for both female and male mosquitoes across all sites: Madeira: females = 0.84, males = 0.92, Palmela: females = 0.99, males = 0.84, Algarve: females = 0.98, and males = 0.99, all with p-values < 0.001. Conclusions: The VECTRACK system demonstrated strong performance in accurately distinguishing mosquitoes from non-mosquitoes, differentiating between Aedes and Culex genera, and identifying the sex of individual specimens. These promising results provide a solid foundation for the development of automated early warning systems and enhance mosquito surveillance strategies, which are critical for timely responses to potential vector-borne disease outbreaks.
- Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sexPublication . González-Pérez, María I.; Faulhaber, Bastian; Aranda, Carles; Williams, Mark; Villalonga, Pancraç; Silva, Manuel; Costa Osório, Hugo; Encarnaçao, Joao; Talavera, Sandra; Busquets, NúriaBackground: Mosquito-borne diseases are a major concern for public and veterinary health authorities, highlighting the importance of effective vector surveillance and control programs. Traditional surveillance methods are labor-intensive and do not provide high temporal resolution, which may hinder a full assessment of the risk of mosquito-borne pathogen transmission. Emerging technologies for automated remote mosquito monitoring have the potential to address these limitations; however, few studies have tested the performance of such systems in the field. Methods: In the present work, an optical sensor coupled to the entrance of a standard mosquito suction trap was used to record 14,067 mosquito flights of Aedes and Culex genera at four temperature regimes in the laboratory, and the resulting dataset was used to train a machine learning (ML) model. The trap, sensor, and ML model, which form the core of an automated mosquito surveillance system, were tested in the field for two classification purposes: to discriminate Aedes and Culex mosquitoes from other insects that enter the trap and to classify the target mosquitoes by genus and sex. The field performance of the system was assessed using balanced accuracy and regression metrics by comparing the classifications made by the system with those made by the manual inspection of the trap. Results: The field system discriminated the target mosquitoes (Aedes and Culex genera) with a balanced accuracy of 95.5% and classified the genus and sex of those mosquitoes with a balanced accuracy of 88.8%. An analysis of the daily and seasonal temporal dynamics of Aedes and Culex mosquito populations was also performed using the time-stamped classifications from the system. Conclusions: This study reports results for automated mosquito genus and sex classification using an optical sensor coupled to a mosquito trap in the field with highly balanced accuracy. The compatibility of the sensor with commercial mosquito traps enables the sensor to be integrated into conventional mosquito surveillance methods to provide accurate automatic monitoring with high temporal resolution of Aedes and Culex mosquitoes, two of the most concerning genera in terms of arbovirus transmission.
- A importância da monitorização da Rede de Vigilância de Vetores REVIVE: de novos mosquitos e velhas carraças a novas ameaças em saúde pública (2011-2020)Publication . Alves, Maria João; Santos, Ana Sofia; Osório, Hugo; Sousa, Rita de; Zé-Zé, Líbia; Lopes de Carvalho, Isabel; Amaro, Fátima; Silva, Manuel; Núncio, Maria Sofia; Equipa REVIVEO programa REVIVE (Rede de Vigilância de Vetores) resulta de colaboração entre a Direção-Geral da Saúde, as Administrações Regionais de Saúde do Algarve, Alentejo, Centro, Lisboa e Vale do Tejo e Norte, a Direção Regional da Saúde da Madeira, a Direção Regional da Saúde dos Açores e o Instituto Nacional de Saúde Doutor Ricardo Jorge. No âmbito do REVIVE é realizada a vigilância entomológica de mosquitos (Culicidae), carraças (Ixodidae) e flebótomos (Psychodidae) a nível nacional. O ano de 2020 representou o 13.º ano do programa REVIVE (2008-2020). Nesta publicação apresentam-se, de uma forma resumida, os resultados da vigilância de mosquitos e carraças realizada em 2020, e no período 2011- -2019, em todas as regiões do país, dando ênfase aos principais riscos em saúde pública em Portugal. Relativamente aos mosquitos destaca-se a presença dos mosquitos exóticos/invasores Aedes aegypti na Madeira e Aedes albopictus no norte e sul do continente e o risco da ocorrência de casos autóctones de dengue, Zika e chikungunya transmitidos por estes vetores. Na vigilância de ixodídeos, salienta-se o risco de casos de febre escaro-nodular e borreliose de Lyme e, a cada vez mais provável, ocorrência de casos de febre hemorrágica Crimeia Congo transmitida por carraças e descrita nos últimos anos em Espanha junto da fronteira com Portugal.
- Monitorização do mosquito invasor Aedes albopictus em Portugal pela Rede de Vigilância de Vetores (REVIVE), 2017-2019Publication . Osório, Hugo Costa; Amaro, Fátima; Zé-Zé, Líbia; Silva, Manuel; Alves, Maria João; Equipa REVIVEO mosquito Aedes albopictus, conhecido vulgarmente como Mos2017-2019quito Tigre Asiático, é um mosquito invasor procedente da região Ásia-Pacífico. Esta espécie é importante em saúde pública e veterinária devido ao seu papel na transmissão de diversos agentes patogénicos, nomeadamente os arbovírus chikungunya, dengue e Zika. Introduzido e estabelecido ao longo da costa mediterrânica europeia, incluindo Espanha desde 2004, este mosquito vetor tem sido responsável pelos surtos autóctones de arbovírus que têm ocorrido na Europa desde 2007. Em Portugal, o Ae. albopictus foi detetado pela primeira vez no âmbito da Rede de Vigilância de Vetores (REVIVE) em dois eventos de introdução independentes, na região norte em 2017 e no Algarve em 2018. O presente estudo teve como objetivo caracterizar a distribuição geográfica e atividade sazonal da espécie invasora Ae. albopictus em Portugal. A vigilância ativa foi significativamente incrementada pela REVIVE após estas deteções. Foram utilizadas armadilhas específicas para mosquitos adultos (Biogents Sentinel traps) e para as fases imaturas (Ovitraps) para determinar a sua distribuição geográfica e sazonal, abundância e avaliar o processo de estabelecimento e dispersão da espécie a nível regional e nacional. Estes dados são indispensáveis no planeamento estratégico de medidas de controlo vetorial para evitar a dispersão das populações de mosquitos vetores e prevenir surtos de doenças associadas a Ae. albopictus.
- Rede de Vigilância de Vetores - Flebótomos: a importância da vigilância de um vetor menos conhecidoPublication . Amaro, Fátima; Osório, Hugo; Silva, Manuel; Freitas, Inês Campos; Soares, Patrícia; Vilares, Anabela; Martins, Susana; Reis, Tânia; Gargaté, Maria João; Alves, Maria João; Equipa REVIVEO programa REVIVE (Rede de Vigilância de Vetores) resulta de colaboração entre a Direção-Geral da Saúde, as Administrações Regionais de Saúde do Algarve, Alentejo, Centro, Lisboa e Vale do Tejo e Norte, a Direção Regional da Saúde da Madeira, a Direção Regional da Saúde dos Açores e o Instituto Nacional de Saúde Doutor Ricardo Jorge. No âmbito do REVIVE é realizada a vigilância entomológica, a nível nacional, de mosquitos (Culicidae) desde 2008, carraças (Ixodidae) desde 2011 e flebótomos (Psychodidae) desde 2016. Para se determinar o risco de emergência de doenças transmitidas por flebótomos é indispensável desenvolver procedimentos para uma vigilância entomológica sistematizada. Desta forma, anualmente, de maio a outubro, técnicos colhem, com armadilhas luminosas CDC, flebótomos em todo o território de Portugal continental. Os insetos provenientes das colheitas são enviados para o Centro de Estudos de Vetores e Doenças Infeciosas do Instituto Nacional de Saúde Doutor Ricardo Jorge, para identificação de espécies e deteção de agentes patogénicos, nomeadamente flebovírus e Leishmania spp. Contrariamente ao que aconteceu com os culicídeos a partir de 2008 ou com os ixodídeos, a partir de 2011, a vigilância dos flebótomos tem vindo a ser implementada de uma forma gradual desde 2016. Verifica-se que a monitorização destes vetores, apesar de ter sofrido constrangimentos devido à pandemia, tem vindo a aumentar substancialmente nos últimos anos. O objetivo deste trabalho é apresentar, de uma forma sucinta, os resultados obtidos na vigilância de flebótomos em 2023, e no período que decorreu 2016 a 2022, em Portugal continental, realçando os principais riscos em saúde pública relacionados com este vector em Portugal.
- 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.
- 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.
- 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.
- Toscana Virus in Wild-Caught Sand Flies in Portugal, Findings from the National Vector Surveillance Network, 2023Publication . Amaro, Fátima; Zé-Zé, Líbia; Osório, Hugo Costa; Soares, Patrícia; Silva, Manuel; Freitas, Inês Campos; Alves, Maria JoãoPhlebotomine sand flies play a crucial role in both human and veterinary medicine, acting as vectors for Leishmania parasites and most known phleboviruses. In Portugal, the REVIVE program, a comprehensive national surveillance network under the Ministry of Health, has included sand fly surveys since 2016. REVIVE aims to identify existing sand fly species in the country, determine which pathogens are circulating among them, and provide actionable insights for prevention and control measures when necessary. In this way, annually, from May to October, health technicians collect sand flies across mainland Portugal with CDC light traps. The collected sand flies are sent to the Centre for Vectors and Infectious Diseases Research for species identification and molecular screening of pathogens. On 21 September 2023, Toscana virus (TOSV), a well-known phlebovirus in the Mediterranean region due to its capacity to cause neurological disease, was detected in a pool of 30 sand flies collected in Algarve, the southernmost region of Portugal. A 668 bp partial sequence of the nucleoprotein gene shows similarity with TOSV strains from Spain. To our knowledge, this is the first detection of TOSV in its vector in this country, having previously only been reported in vertebrate hosts. These findings highlight the important role of ongoing surveillance efforts in monitoring and understanding the dynamics of sand fly-borne diseases in Portugal.