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Scientific Reports Jul 2023Aedes aegypti and Anopheles stephensi have challenged human health by transmitting several infectious disease agents, such as malaria, dengue fever, and yellow fever....
Aedes aegypti and Anopheles stephensi have challenged human health by transmitting several infectious disease agents, such as malaria, dengue fever, and yellow fever. Larvicides, especially in endemic regions, is an effective approach to the control of mosquito-borne diseases. In this study, the composition of three essential oil from the Artemisia L. family was analyzed by Gas Chromatography-Mass Spectrometry. Afterward, nanoliposomes containing essential oils of A. annua, A. dracunculus, and A. sieberi with particle sizes of 137 ± 5, 151 ± 6, and 92 ± 5 nm were prepared. Besides, their zeta potential values were obtained at 32 ± 0.5, 32 ± 0.6, and 43 ± 1.7 mV. ATR-FTIR analysis (Attenuated Total Reflection-Fourier Transform InfraRed) confirmed the successful loading of the essential oils. Moreover, The LC values of nanoliposomes against Ae. aegypti larvae were 34, 151, and 197 µg/mL. These values for An.stephensi were obtained as 23 and 90, and 140 µg/mL, respectively. The results revealed that nanoliposomes containing A. dracunculus exerted the highest potential larvicidal effect against Ae. aegypti and An. stephensi, which can be considered against other mosquitoes.
Topics: Animals; Humans; Aedes; Anopheles; Artemisia; Oils, Volatile; Culex; Larva; Insecticides; Plant Leaves; Plant Extracts
PubMed: 37420038
DOI: 10.1038/s41598-023-38284-6 -
Journal of Medical Entomology Sep 2023Five sibling species of the Lindesayi Complex of the genus Anopheles have been discovered in Bhutan: An. druki Somboon, Namgay & Harbach, An. himalayensis Somboon,...
Five sibling species of the Lindesayi Complex of the genus Anopheles have been discovered in Bhutan: An. druki Somboon, Namgay & Harbach, An. himalayensis Somboon, Namgay & Harbach, An. lindesayi Giles, An. lindesayi species B, and An. thimphuensis Somboon, Namgay & Harbach. The species are morphologically similar in the adult and/or immature stages. This study aimed to develop a multiplex PCR assay to identify the 5 species. Allele-specific primers were designed for specific nucleotide segments of ITS2 sequences previously reported for each species. The assay provided products of 183 bp for An. druki, 338 bp for An. himalayensis, 126 bp for An. lindesayi, 290 bp for An. lindesayi species B, and 370 bp for An. thimphuensis. The use of the assay produced consistent results. The assay is relatively inexpensive, enables the rapid identification of a large number of specimens, and will foster further studies of the Lindesayi Complex.
Topics: Animals; Anopheles; Multiplex Polymerase Chain Reaction; Bhutan
PubMed: 37417304
DOI: 10.1093/jme/tjad089 -
GigaByte (Hong Kong, China) 2023Characterizing the entomological profile of malaria transmission at fine spatiotemporal scales is essential for developing and implementing effective vector control...
Characterizing the entomological profile of malaria transmission at fine spatiotemporal scales is essential for developing and implementing effective vector control strategies. Here, we present a fine-grained dataset of mosquitoes (Diptera: Culicidae) collected in 55 villages of the rural districts of Korhogo (Northern Côte d'Ivoire) and Diébougou (South-West Burkina Faso) between 2016 and 2018. In the framework of a randomized controlled trial, mosquitoes were periodically collected by Human Landing Catches experts inside and outside households, and analyzed individually to identify the genus and, for a subsample, species, insecticide resistance genetic mutations, infection, and parity status. More than 3,000 collection sessions were carried out, achieving about 45,000 h of sampling efforts. Over 60,000 were collected (mainly s.s., , and ). The dataset is published as a Darwin Core archive in the Global Biodiversity Information Facility, comprising four files: events, occurrences, mosquito characterizations, and environmental data.
PubMed: 37408730
DOI: 10.46471/gigabyte.83 -
Malaria Journal Jul 2023Entomological surveillance is traditionally conducted by supervised teams of trained technicians. However, it is expensive and limiting in the number of sites visited....
Evaluation of community-based vector surveillance system for routine entomological monitoring under low malaria vector densities and high bed net coverage in western Kenya.
BACKGROUND
Entomological surveillance is traditionally conducted by supervised teams of trained technicians. However, it is expensive and limiting in the number of sites visited. Surveillance through community-based collectors (CBC) may be more cost-effective and sustainable for longitudinal entomological monitoring. This study evaluated the efficiency of CBCs in monitoring mosquito densities compared to quality-assured sampling conducted by experienced entomology technicians.
METHODS
Entomological surveillance employing CBCs was conducted in eighteen clusters of villages in western Kenya using indoor and outdoor CDC light traps and indoor Prokopack aspiration. Sixty houses in each cluster were enrolled and sampled once every month. Collected mosquitoes were initially identified to the genus level by CBCs, preserved in 70% ethanol and transferred to the laboratory every 2 weeks. Parallel, collections by experienced entomology field technicians were conducted monthly by indoor and outdoor CDC light traps and indoor Prokopack aspiration and served as a quality assurance of the CBCs.
RESULTS
Per collection, the CBCs collected 80% fewer Anopheles gambiae sensu lato (s.l.) [RR = 0.2; (95% CI 0.14-0.27)] and Anopheles coustani [RR = 0.2; (95% CI 0.06-0.53)] and 90% fewer Anopheles funestus [RR = 0.1; (95% CI 0.08-0.19)] by CDC light traps compared to the quality assured (QA) entomology teams. Significant positive correlations were however observed between the monthly collections by CBCs and QA teams for both An. gambiae and An. funestus. In paired identifications of pooled mosquitoes, the CBCs identified 4.3 times more Anopheles compared to experienced technicians. The cost per person-night was lower in the community-based sampling at $9.1 compared to $89.3 by QA per collection effort.
CONCLUSION
Unsupervised community-based mosquito surveillance collected substantially fewer mosquitoes per trap-night compared to quality-assured collection by experienced field teams, while consistently overestimating the number of Anopheles mosquitoes during identification. However, the numbers collected were significantly correlated between the CBCs and the QA teams suggesting that trends observed by CBCs and QA teams were similar. Further studies are needed to evaluate whether adopting low-cost, devolved supervision with spot checks, coupled with remedial training of the CBCs, can improve community-based collections to be considered a cost-effective alternative to surveillance conducted by experienced entomological technicians.
Topics: Animals; Humans; Malaria; Anopheles; Kenya; Mosquito Vectors; Feeding Behavior; Mosquito Control
PubMed: 37400805
DOI: 10.1186/s12936-023-04629-9 -
Toxins Jun 2023Malaria is an infectious disease caused by spp. and it is mainly transmitted to humans by female mosquitoes of the genus . Malaria is an important global public health... (Review)
Review
Malaria is an infectious disease caused by spp. and it is mainly transmitted to humans by female mosquitoes of the genus . Malaria is an important global public health problem due to its high rates of morbidity and mortality. At present, drug therapies and vector control with insecticides are respectively the most commonly used methods for the treatment and control of malaria. However, several studies have shown the resistance of to drugs that are recommended for the treatment of malaria. In view of this, it is necessary to carry out studies to discover new antimalarial molecules as lead compounds for the development of new medicines. In this sense, in the last few decades, animal venoms have attracted attention as a potential source for new antimalarial molecules. Therefore, the aim of this review was to summarize animal venom toxins with antimalarial activity found in the literature. From this research, 50 isolated substances, 4 venom fractions and 7 venom extracts from animals such as anurans, spiders, scorpions, snakes, and bees were identified. These toxins act as inhibitors at different key points in the biological cycle of and may be important in the context of the resistance of to currently available antimalarial drugs.
Topics: Female; Humans; Animals; Antimalarials; Venoms; Mosquito Vectors; Plasmodium; Malaria; Toxins, Biological; Anopheles; Plasmodium falciparum
PubMed: 37368676
DOI: 10.3390/toxins15060375 -
PLoS Neglected Tropical Diseases Jun 2023Malaria is caused by parasite of the genus Plasmodium and is still one of the most important infectious diseases in the world. Several biological characteristics of...
Malaria is caused by parasite of the genus Plasmodium and is still one of the most important infectious diseases in the world. Several biological characteristics of Plasmodium vivax contribute to the resilience of this species, including early gametocyte production, both of which lead to efficient malaria transmission to mosquitoes. This study evaluated the impact of currently used drugs on the transmission of P. vivax. Participants received one of the following treatments for malaria: i) chloroquine [10 mg/kg on day 1 and 7.5 mg/kg on day 2 and 3] co-administered with Primaquine [0.5 mg/kg/day for 7 days]; ii) Chloroquine [10 mg/kg on day 1 and 7.5 mg/kg on day 2 and 3] co-administered with one-dose of Tafenoquine [300 mg on day 1]; and iii) Artesunate and Mefloquine [100 mg and 200 mg on day 1, 2 and 3] co-administered with Primaquine [0.5 mg/kg/day for 14 days]. Patient blood was collected before treatment and 4 h, 24 h, 48 h and 72 h after treatment. The blood was used to perform a direct membrane feeding assay (DMFA) using Anopheles darlingi mosquitoes. The results showed 100% inhibition of the mosquito infection after 4 h using ASMQ+PQ, after 24 h for the combination of CQ+PQ and 48 h using CQ+TQ. The density of gametocytes declined over time in all treatment groups, although the decline was more rapid in the ASMQ+PQ group. In conclusion, it was possible to demonstrate the transmission-blocking efficacy of the malaria vivax treatment and that ASMQ+PQ acts faster than the two other treatments.
Topics: Animals; Humans; Antimalarials; Primaquine; Malaria, Vivax; Anopheles; Chloroquine; Malaria; Plasmodium vivax
PubMed: 37327209
DOI: 10.1371/journal.pntd.0011425 -
PLoS Neglected Tropical Diseases Jun 2023West Nile virus (WNV) and Usutu virus (USUV) are two arthropod-borne viruses that circulate in mainland France. Assessing vector competence has only been conducted so...
West Nile virus (WNV) and Usutu virus (USUV) are two arthropod-borne viruses that circulate in mainland France. Assessing vector competence has only been conducted so far with mosquitoes from southern France while an increasingly active circulation of WNV and USUV has been reported in the last years. The main vectors are mosquitoes of the Culex genus and the common mosquito Culex pipiens. Here, we measure the vector competence of five mosquito species (Aedes rusticus, Aedes albopictus, Anopheles plumbeus, Culex pipiens and Culiseta longiareolata) present in northeastern France. Field-collected populations were exposed to artificial infectious blood meal containing WNV or USUV and examined at different days post-infection. We show that (i) Cx. pipiens transmitted WNV and USUV, (ii) Ae. rusticus only WNV, and (iii) unexpectedly, Ae. albopictus transmitted both WNV and USUV. Less surprising, An. plumbeus was not competent for both viruses. Combined with data on distribution and population dynamics, these assessments of vector competence will help in developing a risk map and implementing appropriate prevention and control measures.
Topics: Animals; West Nile virus; Flavivirus; Culex; Aedes; France; Mosquito Vectors; West Nile Fever
PubMed: 37276229
DOI: 10.1371/journal.pntd.0011144 -
Parasites & Vectors Jun 2023Historically, malaria due to Plasmodium vivax has been epidemic in Henan Province, China, with Anopheles sinensis as the main vector. The most effective measures to...
BACKGROUND
Historically, malaria due to Plasmodium vivax has been epidemic in Henan Province, China, with Anopheles sinensis as the main vector. The most effective measures to prevent malaria transmission are based on vector control through the use of insecticides. However, insecticides exert a strong selective pressure on mosquito populations for insecticide resistance. The aim of this study was to investigate the susceptibility profile and population genetic characteristics of An. sinensis to provide basic data and scientific guidance for the study of resistance mechanisms and the control of An. sinensis in Henan Province.
METHODS
Adult Anopheles mosquitoes were collected at sites near local farmers' sheepfolds, pigsties and/or cowsheds located in Pingqiao, Xiangfu, Xiangcheng and Tanghe counties/districts of Henan Province during July-September 2021 for insecticide susceptibility testing. Molecular identification of collected mosquitoes as belonging to genus Anopheles was by PCR, and the frequencies of mutations in the knockdown resistance gene (kdr) and acetylcholinesterase-1 gene (ace-1) were detected using gene amplification. The mitochondrial DNA cytochrome oxidase subunit I (COI) gene was amplified in deltamethrin-resistant and deltamethrin-sensitive mosquitoes to analyze the genetic evolutionary relationship.
RESULTS
A total of 1409 Anopheles mosquitoes were identified by molecular identification, of which 1334 (94.68%) were An. sinensis, 28 (1.99%) were An. yatsushiroensis, 43 (3.05%) were An. anthropophagus and four (0.28%) were An. belenrae. The 24-h mortality rates of An. sinensis in Pingqiao, Tanghe, Xiangcheng and Xiangfu counties/districts exposed to deltamethrin were 85.85%, 25.38%, 29.73% and 7.66%, respectively; to beta-cyfluthrin, 36.24%, 70.91%, 34.33% and 3.28%, respectively; to propoxur, 68.39%, 80.60%, 37.62% and 9.29%, respectively; and to malathion, 97.43%, 97.67%, 99.21% and 64.23%, respectively. One mutation, G119S, was detected in the ace-1 gene. The frequencies of the main genotypes were 84.21% of specimens collected in Xiangfu (G/S), 90.63% of speciments collected in Xiangcheng (G/G) and 2.44% of speciments collected in Tanghe (S/S). Significantly higher G119S allele frequencies were observed in both propoxur- and malathion-resistant mosquitoes than in their sensitive counterparts in the Tanghe population (P < 0.05). Three mutations, L1014F (41.38%), L1014C (9.15%) and L1014W (0.12%), were detected in the kdr gene. The genotypes with the highest frequency in the populations of An. sinensis in Xiangfu and Tanghe were the mutant TTT (F/F) and wild-type TTG (L/L), at 67.86% (57/84) and 74.29% (52/70), respectively. In Pingqiao and Xiangfu, higher frequencies of the L1014F allele and lower frequencies of the L1014C allele were observed in mosquitoes resistant for beta-cyfluthrin than in those which were sensitive for this insecticide (P < 0.05). The results of Tajima's D and of Fu and Li's D and F were not significantly negative (P > 0.10), and each haplotype was interlaced and did not form two distinct branches.
CONCLUSIONS
High resistance to pyrethroids and propoxur was observed at four sites, but the resistance to malathion varied according to the location. Anopheles belenrae and the L1014W (TGG) mutation in An. sinensis were first discovered in Henan Province. The deltamethrin-resistant and deltamethrin-sensitive mosquito populations showed no genetic differentiation. The generation of resistance might be the result of the combination of multiple factors.
Topics: Animals; Insecticides; Insecticide Resistance; Anopheles; Propoxur; Acetylcholinesterase; Malathion; Mosquito Vectors; Pyrethrins; Malaria; China
PubMed: 37268968
DOI: 10.1186/s13071-023-05796-z -
Cold Spring Harbor Protocols Mar 2024mosquitoes can transmit several human pathogens, including viruses such as o'nyong-nyong and parasites including spp. and spp., which cause malaria and filariasis,...
mosquitoes can transmit several human pathogens, including viruses such as o'nyong-nyong and parasites including spp. and spp., which cause malaria and filariasis, respectively. Rearing species of medical importance under laboratory conditions allows researchers to carry out experiments to better understand their genetics, physiology, and behavior. However, species vary in how easily they can be reared in the laboratory, and some species have been difficult to colonize. Once established, members of the important African complex thrive following a standard protocol and are predictable in growth and development rates. Here, we provide useful basic information and guidance to successfully maintain colonies of and other species of in a laboratory setting. We also provide an example of a 3-wk rearing schedule that produces sufficient numbers of mosquitoes while minimizing the work required during weekends. In the accompanying protocols, we detail efficient methods and techniques suitable for several species of this genus at the egg, larva, pupae, and adult stages; however, it will be necessary for researchers to adjust methods as needed based on site-specific rearing observations of their particular strains.
Topics: Animals; Anopheles
PubMed: 37160331
DOI: 10.1101/pdb.top107802 -
Methods and Protocols Apr 2023Malaria is a parasitic infection caused by a protozoon of the genus , transmitted to humans by female biting mosquitoes of the genus . Chloroquine and its derivates have...
Malaria is a parasitic infection caused by a protozoon of the genus , transmitted to humans by female biting mosquitoes of the genus . Chloroquine and its derivates have caused the parasite to develop drug resistance in endemic areas. For this reason, new anti-malarial drugs as treatments are crucial. This work aimed to evaluate the humoral response. with hyper-immune sera, of mice immunized with six derivatives of tetrahydro-(2H)-1,3,5-thiadiazine-2-thione (bis-THTT) by indirect ELISA test. The cross-reactivity between the compounds as antigens and their microbial activity on Gram-positive and Gram-negative bacteria was evaluated. The results of the humoral evaluation by indirect ELISA show that three bis-THTTs react with almost all of the above. Besides, three compounds used as antigens stimulate the BALB/c mice's immune system. The best combination of two antigens as a combined therapy displays similar absorbances between the antigens in the mixture, showing similar recognition by antibodies and their compounds. In addition, our results showed that different bis-THTT presented antimicrobial activity on Gram-positive bacteria, mainly on strains, and no inhibitory activity was observed on the Gram-negative bacteria tested.
PubMed: 37104019
DOI: 10.3390/mps6020037