scholarly journals Spotlight on Plasmodium falciparum evolutionary system in the southeastern Atlantic forest

2017 ◽  
Vol 17 (3) ◽  
Author(s):  
Gabriel Zorello Laporta

Abstract Malaria elimination is now set to occur in Brazil until 2030. While this achievement is feasible, as it is for other endemic regions worldwide, it is important to recognize resistance of parasites and vectors against anti-malarial interventions. Resistance against drugs and insecticides can lead to discontinuities of malaria transmission, known as residual malaria transmission. Herein, we described a novel phenomenon that is occurring in a residual malaria transmission scenario in the southeastern Atlantic forest. This novel phenomenon does not belong to what is known and therefore we decided to explain it based on an evolutionary perspective. Although it shall not be viewed as a threat to public health, the phenomenon has important aspects that should be highlighted. Specifically, it represents an adaptation of P. falciparum among vectors and hosts in the southeastern Atlantic forest. Knowledge about this phenomenon could be of importance, including to the on-going malaria elimination programs.

2020 ◽  
Vol 47 (4) ◽  
Author(s):  
Riyani Setiyaningsih

Abstract The target of malaria elimination in Indonesia is expected to be achieved in 2030. One of the activities to support malaria elimination is vector surveillance. Several districts in Indonesia have certificates of malaria, including Jembrana, Bali Province, Bulukumba, South Sulawesi Province, and Bengkalis, Riau Province. Analysis of the presence of malaria vectors and Plasmodium needs to be done for the potential occurances of malaria transmission in eliminated malaria areas. Bioecology study of malaria vectors were conducted to determine receptivity status and others risk factors and the potential for malaria transmission based on ecosystems in Jembrana, Bulukumba and Bengkalis districts. As part of national research of disease vector and reservoir (Rikhus Vektora), mosquitoes and larval field-collection methods, molecular plasmodium detection and blood meal analyses were carried out according Rikhus vektora guidelines. The result showed that Anopheles kochi and An. tesselatus were positive confirmed with Plasmodium falciparum by using PCR in Jembrana, Bali province, which were found in non-forest ecosystems near settlements and beaches near settlements. In addition, Anopheles barbirostris, Anopheles vagus, and Anopheles peditaeniatus were also positive confirmed with P. falciparum by using similar methods in Bulukumba, South Sulawesi province. An. barbirostris was found in forest ecosystems near settlement, Anopheles vagus was found in remote forest ecosystems of settlements and beaches near settlements, and Anopheles peditaenistus was found in non-forest ecosystems near settlements. While Anopheles sinensis was confirmed positive with P. falciparum in Bengkalis, Riau province. Jembrana, Bulukumba and Bengkalis districts are recognized as receptive areas and have potential for re-transmission of malaria. Vector surveillance and the implementation of approriate vector control and migration surveillance are needed to ascertain wheter the positive Anopheles with positives Plasmodium falciparum getting the parasites from imported cases or there has been a local transmission (indigenous) in these areas. This information is needed to prevent malaria re-transmission in the eliminated areas. Keywords : elimination, malaria, vector Abstrak Target eliminasi malaria di Indonesia harapannya dapat dicapai tahun 2030. Salah satu kegiatan yang dilakukan untuk menunjang elimnasi malaria adalah surveilans vektor. Beberapa Kabupaten di Indonesia telah memperoleh serfikat eliminasi malaria diantaranya Kabupaten Jembrana Propinsi Bali, Bulukumba Propinsi Sulawesi Selatan, dan Bengkalis Propinsi Riau. Analisis keberadaan vektor dan patogen malaria perlu dilakukan untuk melihat potensi terjadinya penularan malaria kembali di daerah yang telah mendapatkan sertifikat eliminasi malaria. Studi bioekologi vektor malaria dilakukan untuk mengetahui status reseptivitas dan faktor risiko lainnya, serta potensi penularan malaria berbasis ekosistem di daerah tersebut. Sebagai bagian dari dari Riset khusus (rikhus) vektora, koleksi lapangan nyamuk dan jentik, prosedur deteksi melekuler plasmodium dan analisis pakan darah dilakukan dengan menggunakan pedoman Rikhus vektora. Hasil studi menunjukkan bahwa Anopheles kochi dan Anopheles tesselatus, yang masing-masing ditemukan di eksoistem non hutan dekat pemukiman dan pantai dekat pemukiman ditemukan positif mengandung Plasmodium falciparum di Kabupaten Jembrana, Bali. Sedangkan di Kabupaten Bulukumba, Sulawesi Selatan, Anopheles barbirostris, Anopheles vagus, dan Anopheles peditaeniatus merupakan spesies Anopheles yang terkonfirmasi positif mengandung P. falciparum. An. barbirostris ditemukan di ekosistem hutan dekat pemukiman, Anopheles vagus ditemukan di ekosistem hutan jauh pemukiman dan pantai dekat pemukiman, dan Anopheles peditaenistus ditemukan di ekosistem non hutan dekat pemukiman. Sedangkan Anopheles sinensis merupakan satu-satunya spesies Anopheles yang ditemukan positif mengandung P. falciparum di Kabupaten Bengkalis, Riau. Dari hasil studi menunjukkan, Kabupaten Jembrana, Bulukumba, dan Bengkalis merupakan daerah reseptif dan berpotensi terjadinya penularan kembali malaria. Surveilans vektor dan implementasi pengendalian vektor yang tepat serta surveilans migrasi secara ketat diperlukan untuk memastikan apakah Anopheles yang positif tersebut mendapatkan parasit P. falciparum dari kasus import ataukah memang sudah terjadi transmisi secara lokal (indigenous) di wilayah tersebut. Hal ini perlu dilakukan agar tidak terjadi penularan kembali malaria di daerah yang sudah tereliminasi tersebut. Kata kunci: eliminasi, malaria, vektor


2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Gabriel Zorello Laporta ◽  
Marcelo Nascimento Burattini ◽  
Debora Levy ◽  
Linah Akemi Fukuya ◽  
Tatiane Marques Porangaba de Oliveira ◽  
...  

2020 ◽  
Author(s):  
Kiswendsida Thierry Guiguemde ◽  
Yakou Dieye ◽  
Aminata Collé Lô ◽  
Magatte Ndiaye ◽  
Aminata Lam ◽  
...  

Abstract Background: Malaria surveillance requires powerful tools and strategies to achieve malaria elimination. Rapid diagnostic tests for malaria (RDTs) are easily deployed on a large scale and are helpful sources for the parasite's DNA. The application of sensitive molecular techniques to these RDTs is a modern tool for improving malaria case detection and drug resistance surveillance. Several studies have made it possible to extract the DNA of P. falciparum on these RDTs. The knowledge of gametocyte carriage in the population is important to better assess the level of parasite transmission in elimination settings. The aim of this study was to detect P. falciparum gametocytes from used RDTs by quantitative PCR technique in order to use this new tool for molecular monitoring of malaria transmission. Methods: DNA was extracted from 303 RDT devices (SD Bioline Malaria Pf) using the Chelex-100 protocol. qPCR was performed in a 20 μL reaction to detect and quantify transcripts of the pfs25 gene. The cycle threshold (Ct) was determined by the emission fluorescence corresponding to the initial amount of amplified DNA. Results: We found an overall prevalence of 53.47% with an average Ct of 32.12 ± 4.28 cycles. In 2018, the prevalence of gametocytes was higher in the Ranérou district (76.24%) than in the Saint-Louis district (67.33%) where an increase in the number of gametocyte carriers in 2018 was noted, in comparison with 2017. Conclusions: RDTs are a good source of DNA for molecular monitoring of gametocyte carriage. This method, described for the first time, is a simple and effective tool to better understand the level of malaria transmission and reach elimination. Keywords: Malaria, RDT, Gametocytes, DNA extraction, Quantification, Plasmodium falciparum , qPCR.


Author(s):  
Renata Bortolasse Miguel ◽  
Hermano Gomes Albuquerque ◽  
Maria Carmen Arroyo Sanchez ◽  
José Rodrigues Coura ◽  
Simone da Silva Santos ◽  
...  

2020 ◽  
Author(s):  
Kiswendsida Thierry Guiguemde ◽  
Yakou Dieye ◽  
Aminata Collé Lô ◽  
Magatte Ndiaye ◽  
Aminata Lam ◽  
...  

Abstract Background: Malaria surveillance requires powerful tools and strategies to achieve malaria elimination. Rapid diagnostic tests for malaria (RDTs) are easily deployed on a large scale and are helpful sources for the parasite's DNA. The application of sensitive molecular techniques to these RDTs is a modern tool for improving malaria case detection and drug resistance surveillance. Several studies have made it possible to extract the DNA of P. falciparum on these RDTs. The knowledge of gametocyte carriage in the population is important to better assess the level of parasite transmission in elimination settings. The aim of this study was to detect P. falciparum gametocytes from used RDTs by quantitative PCR technique in order to use this new tool for molecular monitoring of malaria transmission. Methods: DNA was extracted from 303 RDT devices (SD Bioline Malaria Pf) using the Chelex-100 protocol. qPCR was performed in a 20 μL reaction to detect and quantify transcripts of the pfs25 gene. The cycle threshold (Ct) was determined by the emission fluorescence corresponding to the initial amount of amplified DNA. Results: We found an overall prevalence of 53.47% with an average Ct of 32.12 ± 4.28 cycles. In 2018, the prevalence of gametocytes was higher in the Ranérou district (76.24%) than in the Saint-Louis district (67.33%) where an increase in the number of gametocyte carriers in 2018 was noted, in comparison with 2017. Conclusions: RDTs are a good source of DNA for molecular monitoring of gametocyte carriage. This method, described for the first time, is a simple and effective tool to better understand the level of malaria transmission and reach elimination. Keywords: Malaria, RDT, Gametocytes, DNA extraction, Quantification, Plasmodium falciparum , qPCR.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Koudraogo Bienvenue Yaméogo ◽  
Rakiswendé Serge Yerbanga ◽  
Seydou Bienvenu Ouattara ◽  
Franck A. Yao ◽  
Thierry Lefèvre ◽  
...  

Abstract Background Seasonal malaria chemoprevention (SMC) consists of administration of sulfadoxine-pyrimethamine (SP) + amodiaquine (AQ) at monthly intervals to children during the malaria transmission period. Whether the addition of azithromycin (AZ) to SMC could potentiate the benefit of the intervention was tested through a double-blind, randomized, placebo-controlled trial. The effect of SMC and the addition of AZ, on malaria transmission and on the life history traits of Anopheles gambiae mosquitoes have been investigated. Methods The study included 438 children randomly selected from among participants in the SMC + AZ trial and 198 children from the same area who did not receive chemoprevention. For each participant in the SMC + AZ trial, blood was collected 14 to 21 days post treatment, examined for the presence of malaria sexual and asexual stages and provided as a blood meal to An. gambiae females using a direct membrane-feeding assay. Results The SMC treatment, with or without AZ, significantly reduced the prevalence of asexual Plasmodium falciparum (LRT X22 = 69, P < 0.0001) and the gametocyte prevalence (LRT X22 = 54, P < 0.0001). In addition, the proportion of infectious feeds (LRT X22 = 61, P < 0.0001) and the prevalence of oocysts among exposed mosquitoes (LRT X22 = 22.8, P < 0.001) was reduced when mosquitoes were fed on blood from treated children compared to untreated controls. The addition of AZ to SPAQ was associated with an increased proportion of infectious feeds (LRT X21 = 5.2, P = 0.02), suggesting a significant effect of AZ on gametocyte infectivity. There was a slight negative effect of SPAQ and SPAQ + AZ on mosquito survival compared to mosquitoes fed with blood from control children (LRTX22 = 330, P < 0.0001). Conclusion This study demonstrates that SMC may contribute to a reduction in human to mosquito transmission of P. falciparum, and the reduced mosquito longevity observed for females fed on treated blood may increase the benefit of this intervention in control of malaria. The addition of AZ to SPAQ in SMC appeared to enhance the infectivity of gametocytes providing further evidence that this combination is not an appropriate intervention.


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