Browsing by Author "Rodrigues, A."
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- Monitoring and molecular profiling of contemporary insecticide resistance status of malaria vectors in Guinea-BissauPublication . Silva, R.; Mavridis, K.; Vontas, J.; Rodrigues, A.; Osório, H.Despite reduction in the prevalence of malaria, Guinea-Bissau (GB) is still widely affected by the disease that is primarily vectored by Anopheles gambiae s.l. mosquitoes. Monitoring mosquito susceptibility and investigating the insecticide resistance status is an integral part of malaria control actions. Here, mosquito populations from five regions of GB: Bafatá, Bissau, Buba, Cacheu and Gabu were monitored for species ID and insecticide resistance, using diagnostic and intensity WHO bioassays, as well as molecular assays. Phenotypic and molecular identification of species showed the presence of An. gambiae s.s. (S form), An. coluzzii (M form) and An. arabiensis, as well as rare An. arabiensis/ An. gambiae hybrids. Resistance to permethrin and deltamethrin was found in all Anopheles populations assayed, with the intensity of resistance for permethrin being moderate to high, as confirmed by bioassays performed at concentration intensities of 5X and 10X. Consistent to these findings, molecular analysis showed a higher frequency of knock-down resistance (kdr) mutations (L1014F, L1014S, reaching > 90% in some areas) compared to previous studies in the same region, as well as detected for the first time the presence of the super kdr mutation (N1575Y) in GB. The “iAche” (G119S) resistance mutation was also found in GB in low frequencies (up to 12.41%). Additionally, the synergistic PBO-permethrin bioassays suggested partial involvement of non target (metabolic and/or reduced penetration) resistance mechanism. Expression analysis of known pyrethroid metabolisers indicated the slight overexpression and possible association of the cytochrome P450s CYP6Z1, CYP4G16 with the pyrethroid resistance phenotype. The findings should guide future evidence-based resistance management strategies in GB.
- Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?Publication . Caini, S.; Andrade, W.; Badur, S.; Balmaseda, A.; Barakat, A.; Bella, A.; Bimohuen, A.; Brammer, L.; Bresee, J.; Bruno, A.; Castillo, L.; Ciblak, M.A.; Clara, A.W.; Cohen, C.; Daouda, C.; de Lozano, C.; De Mora, D.; Dorji, K.; Emukule, G.O.; Fasce, R.A.; Feng, L.; Ferreira de Almeida, W.A.; Guiomar, R.; Heraud, J.M.; Holubka, O.; Huang, Q.S.; Kadjo, H.A.; Kiyanbekova, L.; Kosasih, H.; Kusznierz, G.; Lee, V.; Lara, J.; Li, M.; Lopez, L.; Mai, H.P.; Pessanha, H.C.; Matute, M.L.; Mironenko, A.; Moreno, B.; Mott, J.A.; Njouom, R.; Nurhayati; Ospanova, A.; Owen, R.; Pebody, R.; Pennington, K.; Puzelli, S.; Quynh, Le M.T.; Razanajatovo, N.H.; Rodrigues, A.; Rudi, J.M.; Venter, M.; Vernet, M.A.; Wei, A.L.; Wangchuk, S.; Yang, J.; Yu, H.; Zambon, M.; Schellevis, F.; Paget, J.; Global Influenza B StudyIntroduction: Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes. Methods: This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with the most reported cases (overall, A, and B) in the season. The duration of seasonal activity was assessed using the maximum proportion of influenza cases during three consecutive months and the minimum number of months with 80% of cases in the season. We also assessed whether co-circulation of A and B virus types affected the duration of influenza epidemics. Results: 212 influenza seasons and 571,907 cases were included from 30 countries. In tropical countries, the seasonal influenza activity lasted longer and the peaks of influenza A and B coincided less frequently than in temperate countries. Temporal characteristics of influenza epidemics were heterogeneous in the tropics, with distinct seasonal epidemics observed only in some countries. Seasons with co-circulation of influenza A and B were longer than influenza A seasons, especially in the tropics. Discussion: Our findings show that influenza seasonality is less well defined in the tropics than in temperate regions. This has important implications for vaccination programmes in these countries. High-quality influenza surveillance systems are needed in the tropics to enable decisions about when to vaccinate.