Loading...
7 results
Search Results
Now showing 1 - 7 of 7
- 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.
- 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.
- Fatal Case of Crimean-Congo Hemorrhagic Fever, Portugal, 2024Publication . Zé-Zé, Líbia; Nunes, Cristina; Sousa, Micaela; De Sousa, Rita; Gomes, Carla; Santos, Ana Sofia; Alexandre, Rui T.; Amaro, Fátima; Loza, Tiago; Blanco, Miriam; Alves, MJ; Tiago Loza, Miriam Blanco, Maria J AlvesWe report a fatal case of Crimean-Congo hemorrhagic fever in Portugal. An 83-year-old man, initially suspected of having Mediterranean spotted fever, was later confirmed to have Crimean-Congo hemorrhagic fever by the detection of viral genome in the patient's serum and the presence of specific IgM antibodies.
- 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.
- Detection of Rickettsia in ticks using loop-mediated isothermal amplification (LAMP)Publication . Lansdell, Samantha; Hassan, Marwa M.; La Ragione, Roberto; Betson, Martha; Nuncio, MS; Lopes de Carvalho, Isabel; Zé-Zé, Líbia; de Sousa, Rita; Cutler, Sally; Davis, Joshua S.Objectives: The objective of the study was to develop a Loop-mediated Isothermal Amplification (LAMP) assay for screening of Rickettsia species circulating in ticks using the citrate synthase gene (gltA). The LAMP assay employed portable visualisation methods, making the assay more field-suitable. Furthermore, prior methods have not used gltA as the target, despite proven success in Polymerase Chain Reaction (PCR) methods. Methods: Using an alignment of 72 DNA sequences (comprised of 21 Rickettsia species) from GenBank we designed a novel set of gltA LAMP primers. Evaluation used DNA from 12 Rickettsia species as positive controls (extracted from cultures or naturally infected ticks) alongside a panel of negative controls representing different bacterial species. Subsequently this assay was used to screen 295 Ixodes ricinus and 24 I. hexagonus ticks collected from the UK (including northern and southern England and northern Scotland). Results: LAMP successfully detected 11 out of 12 (91.7%) Rickettsia species, excluding Rickettsia akari. Among 319 ticks collected in the UK, three were positive for Rickettsia (0.9%). All three positives were I. ricinus ticks, while none of the 24 I. hexagonus ticks were positive. Results were confirmed using a published PCR method. Sanger sequencing of PCR amplicons generated for each positive tick showed that they were all R. helvetica. Conclusions: This study introduces a novel field-applicable LAMP protocol for efficient Rickettsia screening in ticks to better assess its prevalence and consequent health risks. Furthermore, this assay has proven suitability for rickettsial detection in I. ricinus ticks, which has been reported as unsuccessful in previous European studies.
- 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.