Anopheles Species Research Articles

Biology and Transmission Dynamics of Aedes flavivirus.

Aedes albopictus (Skuse) and Aedes aegypti (Linnaeus) (Diptera: Culicidae) mosquitoes transmit pathogenic arthropod-borne viruses, including dengue, chikungunya, and Zika viruses, with significant global health consequences. Both Ae. albopictus and Ae. aegypti also are susceptible to Aedes flavivirus (AEFV), an insect-specific flavivirus (ISF) first isolated in Japan from Ae. albopictus and Ae. flavopictus. ISFs infect only insect hosts and evidence suggests that they are maintained by vertical transmission. In some cases, ISFs interfere with pathogenic flavivirus infection, and may have potential use in disease control. We explored the host range of AEFV in 4 genera of mosquitoes after intrathoracic injection and observed greater than 95% prevalence in the species of Aedes and Toxorhynchites tested. Anopheles and Culex species were less permissive to infection. Vertical transmission studies revealed 100% transovarial transmission and a filial infection rate of 100% for AEFV in a persistently-infected colony of Ae. albopictus. Horizontal transmission potential was assessed for adult and larval mosquitoes following per os exposures and in venereal transmission experiments. No mosquitoes tested positive for AEFV infection after blood feeding, and infection with AEFV after sucrose feeding was rare. Similarly, 2% of adult mosquitoes tested positive for AEFV after feeding on infected cells in culture as larvae. Venereal transmission of AEFV was most frequently observed from infected males to uninfected females as compared with transmission from infected females to uninfected males. These results reveal new information on the infection potential of AEFV in mosquitoes and expand our understanding of both vertical and horizontal transmission of ISFs.

Situation of insecticide resistance in malaria vectors in the World Health Organization of Eastern Mediterranean region 1990-2020.

Malaria is the most important mosquito-borne disease, which is transmitted by Anopheles species. According to the recent report of World Health Organization, there were an estimated 229 million malaria cases in 2019 in 87 malaria endemic countries. There are several vector control method specially using pesticides. The aim of this study was to collect all the data about insecticide resistant of malaria vectors in the Eastern Mediterranean region countries. In this study, all the published papers related to insecticide resistance of malaria vectors in the region were collected and resistant status of vectors in the countries was mapped. Resistance to different insecticide classes such as pyrethroids, organophosphate, organochlorine and carbamates were evaluated using World Health Organization guidelines. Results showed a wide variety of susceptibility/resistance status to these chemicals according to the location, historical context of pesticide used, genetic background of vectors, age and abdominal conditions of adults may play a role in the susceptibility status of these species to different insecticides. The results of this study is providing a guideline for countries to manage their vector control activities against insecticide resistance of malaria vectors and provide novel approaches such as male sterility, using Wolbachia, using new insecticide with new mode of action.

Larval habitats, species composition and distribution of malaria vectors in regions with autochthonous and imported malaria in Roraima state, Brazil

BackgroundMalaria control requires local action. Assessing the vector diversity and abundance provides information on the local malariogenic potential or risk of transmission. This study aimed to determine the Anopheles species composition, habitats, seasonal occurrence, and distribution in areas with autochthonous and imported malaria cases in Roraima State.MethodsA longitudinal study was conducted from January 2017 to October 2018, sampling larvae and adult mosquitoes in three municipalities of Roraima State: Boa Vista, Pacaraima and São João da Baliza. These areas have different risks of malaria importation. Four to six mosquito larval habitats were selected for larval sampling at each municipality, along with two additional sites for adult mosquito collection. All larval habitats were surveyed every two months using a standardized larval sampling methodology and MosqTent for adult mosquitoes.ResultsA total of 544 Anopheles larvae and 1488 adult mosquitoes were collected from the three municipalities studied. Although the species abundance differed between municipalities, the larvae of Anopheles albitarsis s.l., Anopheles nuneztovari s.l. and Anopheles triannulatus s.l. were collected from all larval habitats studied while Anopheles darlingi were collected only from Boa Vista and São João da Baliza. Adults of 11 species of the genus Anopheles were collected, and the predominant species in Boa Vista was An. albitarsis (88.2%) followed by An. darlingi (6.9%), while in São João da Baliza, An. darlingi (85.6%) was the most predominant species followed by An. albitarsis s.l. (9.2%). In contrast, the most abundant species in Pacaraima was Anopheles braziliensis (62%), followed by Anopheles peryassui (18%). Overall, the majority of anophelines exhibited greater extradomicile than peridomicile-biting preference. Anopheles darlingi was the only species found indoors. Variability in biting times was observed among species and municipalities.ConclusionThis study revealed the composition of anopheline species and habitats in Boa Vista, Pacaraima and São João da Baliza. The species sampled differed in their behaviour with only An. darlingi being found indoors. Anopheles darlingi appeared to be the most important vector in São João da Baliza, an area of autochthonous malaria, and An. albitarsis s.l. and An. braziliensis in areas of low transmission, although there were increasing reports of imported malaria. Understanding the diversity of vector species and their ecology is essential for designing effective vector control strategies for these municipalities.

Blood meal analysis of Anopheles vectors of simian malaria based on laboratory and field studies

Blood feeding and host-seeking behaviors of a mosquito play an imperative role in determining its vectorial capacity in transmitting pathogens. Unfortunately, limited information is available regarding blood feeding behavior of Anopheles species in Malaysia. Collection of resting Anopheles mosquitoes for blood meal analysis poses a great challenge especially for forest dwelling mosquitoes. Therefore, a laboratory-based study was conducted to evaluate the potential use of mosquitoes caught using human landing catch (HLC) for blood meal analysis, and subsequently to document blood feeding behavior of local Anopheles mosquitoes in Peninsular Malaysia. The laboratory-based experiment from this study revealed that mosquitoes caught using HLC had the potential to be used for blood meal analysis. Besides HLC, mosquitoes were also collected using manual aspirator and Mosquito Magnet. Overall, 47.4% of 321 field-caught Anopheles mosquitoes belonging to six species were positive for vertebrate host DNA in their blood meal. The most frequent blood meal source was human (45.9%) followed by wild boar (27.4%), dog (15.3%) and monkey (7.5%). Interestingly, only Anopheles cracens and Anopheles introlatus (Leucosphyrus Group) fed on monkey. This study further confirmed that members of the Leucosphyrus Group are the predominant vectors for knowlesi malaria transmission in Peninsular Malaysia mainly due to their simio-anthropophagic feeding behavior.

Vector composition, abundance, biting patterns and malaria transmission intensity in Madang, Papua New Guinea: assessment after 7\xa0years of an LLIN-based malaria control programme

BackgroundA malaria control programme based on distribution of long-lasting insecticidal bed nets (LLINs) and artemisinin combination therapy began in Papua New Guinea in 2009. After implementation of the programme, substantial reductions in vector abundance and malaria transmission intensity occurred. The research reported here investigated whether these reductions remained after seven years of sustained effort.MethodsAll-night (18:00 to 06:00) mosquito collections were conducted using human landing catches and barrier screen methods in four villages of Madang Province between September 2016 and March 2017. Anopheles species identification and sporozoite infection with Plasmodium vivax and Plasmodium falciparum were determined with molecular methods. Vector composition was expressed as the relative proportion of different species in villages, and vector abundance was quantified as the number of mosquitoes per barrier screen-night and per person-night. Transmission intensity was quantified as the number of sporozoite-infective vector bites per person-night.ResultsFive Anopheles species were present, but vector composition varied greatly among villages. Anopheles koliensis, a strongly anthropophilic species was the most prevalent in Bulal, Matukar and Wasab villages, constituting 63.7–73.8% of all Anopheles, but in Megiar Anopheles farauti was the most prevalent species (97.6%). Vector abundance varied among villages (ranging from 2.8 to 72.3 Anopheles per screen-night and 2.2–31.1 Anopheles per person-night), and spatially within villages. Malaria transmission intensity varied among the villages, with values ranging from 0.03 to 0.5 infective Anopheles bites per person-night. Most (54.1–75.1%) of the Anopheles bites occurred outdoors, with a substantial proportion (25.5–50.8%) occurring before 22:00.ConclusionThe estimates of vector abundance and transmission intensity in the current study were comparable to or higher than estimates in the same villages in 2010–2012, indicating impeded programme effectiveness. Outdoor and early biting behaviours of vectors are some of the likely explanatory factors. Heterogeneity in vector composition, abundance and distribution among and within villages challenge malaria control programmes and must be considered when planning them.

Current status of insecticide resistance in malaria vectors in the Asian countries: a systematic review

Background: The application of insecticides for malaria vector control has led to a global problem, which is the current trend of increased resistance against these chemicals. This study aimed to review the insecticide resistance status was previously determined in Asia and how to implement the necessary interventions. Moreover, the implications of resistance in malaria vector control in this region were studied. Methods: This systematic review was conducted using a predefined protocol based on PRISMA-retrieved articles from four science databases, namely ProQuest, Science Direct, EBSCO, and PubMed in the last ten years (2009 to 2019). The searching process utilized four main combinations of the following keywords: malaria, vector control, insecticide, and Asia. In ProQuest, malaria control, as well as an insecticide, were used as keywords. The following criteria were included in the filter, namely full text, the source of each article, scholarly journal, Asia, and publication date as in the last ten years. Results: There were 1408 articles retrieved during the initial search (ProQuest=722, Science Direct=267, EBSCO=50, PubMed=285, and Scopus=84). During the screening, 27 articles were excluded because of duplication, 1361 based on title and abstract incompatibility with the inclusion criteria, and 20 due to content differences. In the final screening process, 15 articles were chosen to be analyzed. From the 15 articles, it is known that there wasorganochlorine (DDT), organophosphate (malathion), and pyrethroids resistance in several Anopheles species with a less than 80% mortality rate. Conclusion:This review found multiple resistance in several Anopheles includes resistance to pyrethroid.The reports of pyrethroid resistance were quite challenging because it is considered effective in the malaria vector control. Several countries in Asia are implementing an insecticide resistance management (IRM) strategy against malaria vectors following the Global Plan for IRM.

Dispersion routes of the main vectors of human malaria in the Americas: Genetic evidence from the mitochondrial COI gene.

In America, of the 44 species of Anopheles, nine are main vectors of malaria and, of these, genetic information exists for seven. Hence, this study sought to know the gene flow and diversity of the seven principal vectors of malaria at the Americas level. For the seven species and the sequences of the mitochondrial cytochrome c oxidase I (COI) gene obtained from the GenBank and Bold System, genetic analyzes of populations and genetic structure were performed and haplotype networks and phylogenetic trees were obtained. For the seven species, 1440 sequences were analyzed and 519 haplotypes were detected. The Hd and π values were higher within a continental context than by countries. Neutrality tests indicated positive and negative values with most of these being significant (p < 0.05). Phylogenetic analyses for all the species recovered three clades with no geographic pattern among them. Studies suggest that native species of Anopheles from the Americas have greater haplotype diversity and low genetic differentiation due to the lack of physical barriers to impede gene flow among these populations. Moreover, all the species are interconnected by roadways. This scenario complicates the epidemiological picture of malaria in the Americas.

Phylogenetic relationships of the supercontig of sodium channel subunit I (NaV) in 17 species of Anopheles (Diptera: Culicidae).

Malaria is a global health problem and is transmitted by the Anopheles species. Due to the epidemiological importance of the genus, studies on biological, phylogenetic, and evolutionary aspects have contributed to the understanding of adaptation, vector capacity, and resistance to insecticides. The latter may result from different causes such as mutations in the gene that encodes the sodium channel (NaV). In this study, the NaV subunit I scaffold of 17 anopheline species was used to infer phylogenetic relationships of the genus Anopheles using Bayesian inference. The evolutionary phylogenetic tree of the NaV gene was aligned in the AliView program and analyzed utilizing Bayesian inference, using the software MrBayes. The anophelines were grouped into five well-supported clusters: 1 - Anopheles darlingi and Anopheles albimanus; 2 - Anopheles sinensis and Anopheles atroparvus; 3 - Anopheles dirus; 4 - Anopheles minimus, Anopheles culicifacies, Anopheles funestus, Anopheles maculatus, and Anopheles stephensi; and 5 - Anopheles christyi, Anopheles epiroticus, Anopheles merus, Anopheles melas, Anopheles gambiae, Anopheles coluzzii, and Anopheles arabiensis. The topology confirms the phylogenetic relationships proposed in studies based on the genome of some anophelines and reflects the current taxonomy of the genus, which suggests that NaV undergoes selection pressure during the evolution of the species. These data are useful tools for inferring their ability to resist insecticides and also help in better understanding the evolutionary processes of the genus Anopheles.

The noble mission of Nobel Laureate Sir Ronald Ross

The noble mission of Nobel Laureate Sir Ronald Ross

BIO-EFFICACY OF GROUNDED SESAMUM RADIATUM AND PSORALEA CORYLITOLIA ON EMERGENCE OF ANOPHELES GAMBIAE AND CULEX QUINQUEFASCIATUS

Mosquito larvae are highly distributed species in tropical regions where breeding sites are diverse and causing a number of public health diseases, when they emerge. This study tested the efficacy of two grounded insecticidal plant powders against the emergence of Anopheles and Culex species. Larvae of mosquitoes were collected using 350mL deep ladles and scooping spoon from Ethiope East LGA, Delta State, Nigeria. The mosquito larvae were exposed to 0.5, 1.0, and 1.5g of Psoralea corylitolia and Sesamum radiatum in 100mL of water. This corresponded to 0.005, 0.01, and 0.015g/mL concentration of experimental set up respectively. Mosquitoes were exposed to these treatments in 20 larvae per concentration in quadruplicates. Mean mortality and time of mortality were recorded. Probit model was used to determine LT50 and LT95. Mortality of larvae increased as concentration and time increased. Highest mortality was recorded in Culex mosquitoes exposed to 1.5g of Psoralea corylitolia and was closely followed by Anopheles mosquitoes exposed to same concentration of Sesamum radiatum. The differences between the mortalities were highly significant (P&lt;0.00001). Emergence depreciated as the concentration increased with high mortality especially with 0.5g of Psoralea corylitolia exposed to Anopheles mosquito larvae. The insecticidal test plants did not determine the sex of mosquitoes and it was not significant (F sex ratio=1.127; P=0.357). Physicochemical parameters supported the mortality of both larvae exposed to Sesamum radiatum from 30 minutes till end of the post experimental exposure. Lethal time for 50% of mosquitoes ranged from 31 to 5858min whereas LT95 ranged from 1435 to 10218min for the two insecticidal test plants respectively. There is need for more study with the trial of oil of Sesamum radiatum and the determination of the gas chromatograph of this novel plant to ascertain the active components.

Susceptibility status of major malaria vectors to novaluron, an insect growth regulator South-Eastern Tanzania.

Introductionapplication of Insect Growth Regulator (IGR) such as pyriproxyfen has shown a promising result in controlling malaria transmitting mosquitoes through autodissemination technique. Novaluron that inhibits the chitin development at mosquito larval stage present a promising candidate IGR for rotation with pyriproxyfen to prevent a chance of resistance development. This study assessed the susceptibility of immature stages of Anopheles arabiensis, Anopheles gambiae and Anopheles funestus to novaluron.Methodssusceptibility bioassays using technical grade novaluron (98% active ingredient) were performed inside the semi-field system using first instar larvae of Anopheles species. For each tested species, a total of 1500 larvae were used in the bioassay. Concentration range of 0.01 mg/l to 2 mg/l of novaluron were tested to establish Lethal Concentration (LC) sufficient to kills 50%, 90% and 99% of the exposed larvae by using log-dose response analysis.Resultsof the tested mosquitoes, Anopheles gambiae were highly susceptible to novaluron followed by An. Arabiensis and then An. funestus. Lethal concentrations, LC50, LC90 and LC99 (95%CI) in mg/l for An. gambiae were 0.018, 0.332 and 2.001 respectively. For An. arabiensis were 0.026, 0.546 and 2.013; and for An. funestus were 0.032, 1.00 and 5.580. High larval mortality was recorded at high concentration (2mg/L), with 80% mortality within 3 days post exposure.Conclusionthe study demonstrates the efficacy of novaluron in controlling Anopheles mosquito species at immature stages via larval mortality. These findings warrant further testing of novaluron for autodissemination by different vector species for its inclusion in rotation to prevent development of resistance.

ETUDE DE LA NUISANCE DES MOUSTIQUES EN MILIEU UNIVERSITAIRE DE LA FACULTE DES SCIENCES ET TECHNIQUES, BAMAKO, MALI

Mosquitoes are potentially harmful and vectors of pathogens. They compromise the rest and well-being of humans and animals. The main goal of this study is to determine the composition of mosquitoes responsible of human biting at the Faculty of Sciences and Technics of Bamako-Mali. Longitudinal monitoring with monthly cross-sectional visit was carried out from September to December 2019, in order to collect the endophilic and endophagic mosquitoes. The spray-catch was used as a collection methodin 21 rooms selected randomly at the FST. Mosquitoes were identified morphologically andthen by PCR. ELISA-CSP test was used for Plasmodium infection index and the ELISA blood-meal test was to determine mosquitoes blood origin. In total, 802 mosquitoes were collected: 794Culex and 8Anopheles. There were 200 males and 602 females. Female mosquitoes were separated by gonotrophic stages: 231 unfed, 223 fed, 80 semi-gravid and 68 gravid. Up to 34% of Culex and 67% of Anopheles had a preference for human blood, but no female tested positive for Plasmodium infection. This result would be due to the small number of Anopheles captured. An. coluzzii is the only Anopheles species collected.This study shows that mosquitoes are linked to serious problems of nuisance and risk of pathogens transmission in the university. They highly prefer to feed on human host.

Larvicidal Activity of Solvent Extracts of Nicotiana tabacum L, and Datura metel L, (Solanales: Solanaceae) Against Larvae of Three Mosquito Species

Mosquitoes are insects that vector many of the life threatening diseases. Control of these insects is one of the major problems of the world today. Leaves and seed kernel extracts of Tobacco; Nicotiana tabacum (L.) and Thorn-Apple; Datura metel (L.) were assayed for larvicidal activity against three mosquito species of Aedes, Anopheles and Culex respectively. Samples of the three species were collected from mosquito breeding sites and reared in the laboratory for continued source of larvae following standard procedures. The plants parts used were extracted with hexane, chloroform and methanol in increasing order of polarity. Each extract was formulated into 0.9, 1.6, 2.4, 3.5 and 4.0mg/mL concentrations, and tested for larvicidal activity against 25 larvae of each genus in three replicates, alongside the controls over 12 to 72 hrs periods. The extracts that exhibited highest larvicidal activity were subjected to phytochemical screenings for searching active ingredients. Data were analyzed using Analysis of Variance, treatment means separated through DNMRT and lethal concentrations of the extracts were determined. Among the extracts tested, hexane extract of D. metel and methanol extract of N. tabacum caused highest larvicidal activity with more than 70% mortality on Aedes and Anopheles larvae when 4.0mg/mL was applied after 72 hrs (LC50 2.94±0.1 and LC502.58±0.1 mg/mL respectively). Culex larvae were less susceptible to all concentrations of the extracts. Though, larvicidal activity was observed to be directly proportional to concentrations and larval exposure periods, significant differences (p&lt; 0.05) in the means of larval death were observed. The active extracts were found to contain alkaloids, saponins steroids, flavonoids and glycosides from moderate to high quantity which could be responsible for larvicidal activity. Future formulation studies, toxicity profile and possible mechanism of action may lead to the development of potential insecticidal products.

Characteristics Environmental and Anopheles Larva Species In High And Low Clinical Malaria Cases In The Landak District of West Kalimantan Province

Malaria remains a health problem in Indonesia. West Kalimantan is a malaria endemic area with high and lowincidence. Landak District is one of the malaria endemic area. Malaria cases were found in the areas around illegalgold mining and oil palm plantations. The aims of this study were to describe the characteristics of the breeding sitesand species of Anopheles larvae found in high malaria cases area, namely Amboyo Utara Village and low clinicalmalaria cases, area namely Mandor Village. This research is a descriptive research with cross sectional design. Thesamples were Anopheles larvae collected with Accidental sampling technique in the breeding sites. Environmentalcharacterization of breeding sites were physical characteristic including water temperature and sun exposure,chemical characteristic including water pH and salinity, and biological characteristics including water biota. Theresults of this study ware environmental characteristics that have the potential to breed Anopheles mosquitoes inAmboyo Utara Village, including water temperature 26-30C, shandy, water pH 5.0-7.6, salinity 0.2-1.0 ppt, biotaswater hyacinth, grass and tadpole. The Mandor village, water temperature 29-30 ºC, shandy, pH of 6.9-8.0, salinity of0.5 ppt, water biota grass. Anopheles species found in Amboyo Utara village were larvae of An. vagus (94.30%), An.tessellatus (3.42%), An. subpictus (1.62%), An. indefinitus (0.81%) and An. maculatus (0.81%). Characteristics ofbreeding sites in Mandor village were larvae of An. maculatus (11.11%), An. subpictus (3.70%), and An. vagus(85.18%). The conclusion of this study was that di erent species found at breeding sites with di erent environmentalcharacteristics in both high and low malaria areas in Landak District, West Kalimantan Province.

Larval Habitat Characterization and Molecular Identification of Anopheles gambiae Complex in three Local Government Areas (LGAs) of Ekiti State, Nigeria

Background: Mosquito-borne diseases have remained a serious problem in many parts of the world despite several control efforts to manage the vector abundance. Mosquitoes transmit such diseases like malaria, dengue, lymphatic filariasis and yellow fever. Malaria parasites, transmitted through the bite of an infected female Anopheles mosquitoes still result in many morbidity and mortality in Nigeria. In this study, larval breeding site characterization and molecular identification of Anopheles mosquitoes were carried out in Ado, Oye and Ikole LGAs of Ekiti State, Nigeria . Methods: Mosquito larvae were collected from the study sites at different times during the mosquito breeding season from April to July 2019. Habitat characteristics were observed after which larvae collection was carried out. Identification of Anopheles adult mosquitoes was done using taxonomic keys and multiplex Polymerase Chain Reaction (PCR) and the results were analysed using the chi-squared test Results: A total of 2,011 Anopheles mosquitoes larvae were collected from the various habitats in the three LGAs. Larvae breeding sites characteristics and the respective abundance of larvae caught include: Sunlight 1,509(75.04), Shade 502(24.96); Presence of algae 1,152(57.28), Absence of algae 859(42.72); Presence of vegetation 1,426(70.91), Absence of vegetation 585(29.09); Turbid 617(30.68), Clear 1,394(69.32); Temporary 1,909(94.93), Permanent 102(5.07); Stagnant 2,011(100), Flowing 0(0.00); Natural 1,851(92.04), Manmade 160(7.96); Presence of settlement 1,978(98.36) and Absence of settlement 33(1.64). The difference between each compared group was significant (p&lt;0.05). Significant difference (p&lt;0.05) also exist for the Anopheles mosquitoes collected; An. gambiae s.l (91.5%), An. funestus (7.96%) and An. maculipalpis (0.6%). Molecular identification of An. gambiae s.l. showed that products were formed in 83.61%, 76.61% and 84.47% of the samples from Ado, Oye and Ikole LGAs respectively and only two members of the An gambiae complex were identified in the entire LGAs; An. gambiae s.s. (59.22%) and An. arabiensis (21.89%). Conclusion: This study identified the An. gambiae as the main Anopheles species in the study sites. This finding is similar to results from other parts of South-western Nigeria where An. gambiae was the predominant vector. There is therefore a need to intensify control efforts in the three LGAs .

Anopheles salivary antigens as serological biomarkers of vector exposure and malaria transmission: A systematic review with multilevel modelling.

Entomological surveillance for malaria is inherently resource-intensive and produces crude population-level measures of vector exposure which are insensitive in low-transmission settings. Antibodies against Anopheles salivary proteins measured at the individual level may serve as proxy biomarkers for vector exposure and malaria transmission, but their relationship is yet to be quantified. A systematic review of studies measuring antibodies against Anopheles salivary antigens (PROSPERO: CRD42020185449). Multilevel modelling (to account for multiple study-specific observations [level 1], nested within study [level 2], and study nested within country [level 3]) estimated associations between seroprevalence with Anopheles human biting rate (HBR) and malaria transmission measures. From 3981 studies identified in literature searches, 42 studies across 16 countries were included contributing 393 study-specific observations of anti-Anopheles salivary antibodies determined in 42,764 samples. A positive association between HBR (log transformed) and seroprevalence was found; overall a twofold (100% relative) increase in HBR was associated with a 23% increase in odds of seropositivity (OR: 1.23, 95% CI: 1.10-1.37; p<0.001). The association between HBR and Anopheles salivary antibodies was strongest with concordant, rather than discordant, Anopheles species. Seroprevalence was also significantly positively associated with established epidemiological measures of malaria transmission: entomological inoculation rate, Plasmodium spp. prevalence, and malarial endemicity class. Anopheles salivary antibody biomarkers can serve as a proxy measure for HBR and malaria transmission, and could monitor malaria receptivity of a population to sustain malaria transmission. Validation of Anopheles species-specific biomarkers is important given the global heterogeneity in the distribution of Anopheles species. Salivary biomarkers have the potential to transform surveillance by replacing impractical, inaccurate entomological investigations, especially in areas progressing towards malaria elimination. Australian National Health and Medical Research Council, Wellcome Trust.

Mapping of Malaria Receptivity Areas in Buton Regency, Southeast Sulawesi Province

Malaria is an acute and chronic infectious disease caused by Plasmodium infection that attacks erythrocytes and is characterized by the discovery of asexual forms in the blood with symptoms of fever, chills, anemia and enlarged spleen. Buton Regency is a district with an Annual Parasite Incidence (API) that is less than 1 per 1000 population for 4 consecutive years and is a low endemic area. This study aims to determine the level of receptivity of malaria transmission areas in Buton Regency, Southeast Sulawesi Province. This type of research is descriptive observational with a cross sectional study approach. The results showed that there were 3 species of Anopheles identified in adult mosquitoes, namely An.Minimus, An.Indifinitus and An.Kochi. Habitat Index (HI) of Anopheles vector, sp &gt; 1, breeding places for Anopheles vector wallows, rivers, ditches, ponds, rivers, swamps and rice fields with the characteristics of the presence of temporary and clear water, moss and mud, with a pH of 6 on a scale 6-6.5 and zero salinity. Vector confirmation by PCR is negative for all species. It was concluded that the level of malaria receptivity in Buton Regency, especially in the Village of Face Jaya, was at a moderate receptivity level.

Drug targeting of aminoacyl-tRNA synthetases in Anopheles species and Aedes aegypti that cause malaria and dengue

BackgroundMosquito-borne diseases have a devastating impact on human civilization. A few species of Anopheles mosquitoes are responsible for malaria transmission, and while there has been a reduction in malaria-related deaths worldwide, growing insecticide resistance is a cause for concern. Aedes mosquitoes are known vectors of viral infections, including dengue, yellow fever, chikungunya, and Zika. Aminoacyl-tRNA synthetases (aaRSs) are key players in protein synthesis and are potent anti-infective drug targets. The structure–function activity relationship of aaRSs in mosquitoes (in particular, Anopheles and Aedes spp.) remains unexplored.MethodsWe employed computational techniques to identify aaRSs from five different mosquito species (Anopheles culicifacies, Anopheles stephensi, Anopheles gambiae, Anopheles minimus, and Aedes aegypti). The VectorBase database (https://vectorbase.org/vectorbase/app) and web-based tools were utilized to predict the subcellular localizations (TargetP-2.0, UniProt, DeepLoc-1.0), physicochemical characteristics (ProtParam), and domain arrangements (PfAM, InterPro) of the aaRSs. Structural models for prolyl (PRS)-, and phenylalanyl (FRS)-tRNA synthetases—were generated using the I-TASSER and Phyre protein modeling servers.ResultsAmong the vector species, a total of 37 (An. gambiae), 37 (An. culicifacies), 37 (An. stephensi), 37 (An. minimus), and 35 (Ae. aegypti) different aaRSs were characterized within their respective mosquito genomes. Sequence identity amongst the aaRSs from the four Anopheles spp. was > 80% and in Ae. aegypti was > 50%.ConclusionsStructural analysis of two important aminoacyl-tRNA synthetases [prolyl (PRS) and phenylanalyl (FRS)] of Anopheles spp. suggests structural and sequence similarity with potential antimalarial inhibitor [halofuginone (HF) and bicyclic azetidine (BRD1369)] binding sites. This suggests the potential for repurposing of these inhibitors against the studied Anopheles spp. and Ae. aegypti.

Wing Morphometric and DNA Barcoding Analysis of Two Different Public Health Important Anopheles Mosquito Species

Accurate identification and bio-ecology of mosquito vectors is paramount importance in several respects including the development of species-specific vector control strategies. In the current study, we explored two different advance tools such as Geometric morphometric (GM) and DNA barcoding analysis, to supplement morpho-taxonomy based identification of malaria vectors. In landmark-based GM analysis, the pattern of wing shape was examined and we noticed a clear variation in their shape among different Anopheles species. Similarly, in the DNA barcoding studies, the phylogenetic analysis based upon the marker genes such as COI, Cytb and D3 region of 28s rDNA gene sequences were carried out. The neighbour joining tree was formed by distinctive conspecific clusters illustrating genetic variation among different group of Anopheles species. Further, genetic exchange among different Anopheline populations was analysed by considering the COI gene sequences. In the gene flow study, the frequent genetic divergence as well as gene exchange among Anopheles stephensi mosquito populations was observed. Our findings suggested that GM analysis of the wing shape along with DNA barcoding approach can effectively be used together for accurate identification of mosquito vectors including Anopheles stephensi and Anopheles barbirostris.

Phylogenetic analysis of the Neotropical Albitarsis Complex based on mitogenome data

BackgroundSome of the most important malaria vectors in South America belong to the Albitarsis Complex (Culicidae; Anophelinae; Anopheles). Understanding the origin, nature, and geographical distribution of species diversity in this important complex has important implications for vector incrimination, control, and management, and for modelling future responses to climate change, deforestation, and human population expansion. This study attempts to further explore species diversity and evolutionary history in the Albitarsis Complex by undertaking a characterization and phylogenetic analysis of the mitogenome of all 10 putative taxa in the Albitarsis Complex.MethodsMitogenome assembly and annotation allowed for feature comparison among Albitarsis Complex and Anopheles species. Selection analysis was conducted across all 13 protein-coding genes. Maximum likelihood and Bayesian inference methods were used to construct gene and species trees, respectively. Bayesian methods were also used to jointly estimate species delimitation and species trees.ResultsGene composition and order were conserved across species within the complex. Unique signatures of positive selection were detected in two species—Anopheles janconnae and An. albitarsis G—which may have played a role in the recent and rapid diversification of the complex. The COI gene phylogeny does not fully recover the mitogenome phylogeny, and a multispecies coalescent-based phylogeny shows that considerable uncertainty exists through much of the mitogenome species tree. The origin of divergence in the complex dates to the Pliocene/Pleistocene boundary, and divergence within the distinct northern South American clade is estimated at approximately 1 million years ago. Neither the phylogenetic trees nor the delimitation approach rejected the 10-species hypothesis, although the analyses could not exclude the possibility that four putative species with scant a priori support (An. albitarsis G, An. albitarsis H, An. albitarsis I, and An. albitarsis J), represent population-level, rather than species-level, splits.ConclusionThe lack of resolution in much of the species tree and the limitations of the delimitation analysis warrant future studies on the complex using genome-wide data and the inclusion of additional specimens, particularly from two putative species, An. albitarsis I and An. albitarsis J.Graphical