Female Anopheles Research Articles

A Robust Malaria Cell Detection Framework Using Adaptive and Atrous Convolution-Based Recurrent Mobilenetv2 with Trans-MobileUNet + + -Based Abnormality Segmentation.

The highly contagious malaria disease is spread by the female Anopheles mosquito. This disease results in a patient's death or incapacity to move their muscles, if it is not appropriately identified in the early stages. A Rapid Diagnostic Test (RDT) is a frequently used approach to find malaria cells in red blood cells. However, it might not be able to identify infections with small amounts of samples. In the microscopic detection model, blood stains are placed under a microscope for diagnosing malaria. But accurate diagnosis is hard in this method, particularly in developing nations where the disease is most common. The microscopic detection processes are expensive and time-consuming due to the usage of microscopes. The quality of the blood smears and the availability of a qualified specialist, who is skilled in recognizing the disease, impact the accuracy of malaria detection results. The traditional deep learning-based malaria identification models need more processing power. Therefore, a deep learning-based adaptive method is designed to detect malaria cells through the medical image. Hence, the images are gathered from the standard sites and then fed to the segmentation process. Here, the abnormality segmentation is carried out with the help of a developed Trans-MobileUNet + + (T-MUnet + +) network. Trans-MobileUNet + + captures global context, so it is well-suited for segmentation tasks. The segmented image is applied to the adaptive detection phase where the Adaptive and Atrous Convolution-based Recurrent MobilenetV2 (AA-CRMV2) model is designed for the effective recognition of malaria cells. The efficiency of the designed approach is elevated by optimizing the parameters from the AA-CRMV2 network with the help of the Updated Random Parameter-based Fennec Fox Optimization (URP-FFO) algorithm. Several experimental analyses are evaluated in the implemented model over classical techniques to display their effectualness rate.

Efektifitas Kelambu Berinsektisida Long Lasting Insecticidal Nets (LLINS) terhadap Anopheles maculatus

Malaria is a vector-borne disease problem in several parts of Indonesia, including the Rejang Lebong Regency, Bengkulu Province. One way to break the chain of malaria transmission is by using insecticide-treated mosquito nets. The effectiveness of using insecticide-treated mosquito nets in the community needs to be studied. This study was conducted to evaluate the effectiveness of insecticide-treated mosquito nets against Anopheles maculatus based on the duration of use by the community. A fully randomized design study was used to compare the effectiveness of mosquito nets used for six months, six months to two years, and more than two years from 3 different sub-districts. The method used was the WHO bioassay cone test with an untreated polyester mosquito net as a control. Female Anopheles maculatus was tested in a cone bioassay and transferred to paper cups to observe for knockdown or death after 10, 30, and 60 minutes to 24 hours. The results showed that the mosquito nets used for <1 year resulted in 92% knockdown and 80% death. Meanwhile, the use of mosquito nets for 1-2 and >2 years resulted in 92.6% and 75.2% knockdown mosquitoes and 78% and 67.8% dead mosquitos. We concluded that insecticide-treated mosquito nets used for less than one year were still effective for use in controlling malaria.Routine monitoring and evaluation should be carried out to assess the effectiveness of the mosquito nets used.

Relationship between malaria vector survival, infectivity, and insecticide-treated net use in western Kenya

BackgroundSignificant effort and resources have been invested to control malaria transmission in sub-Saharan Africa, but it remains a major public health problem. For the parasite to be transmitted, the female Anopheles vector must survive 10–14 days following an infective bite to allow Plasmodium gametocytes to develop into infectious sporozoites. The goal of this study was to assess factors associated with wild-caught Anopheles survival and infection following host-seeking and indoor resting.MethodsThe study was conducted between January 2020 to March 2022 in a longitudinal cohort of 75 households in 5 villages including a total of 755 household members in Bungoma County, Kenya. Monthly adult mosquito collection was conducted by attenuated aspiration in all enrolled households, and mosquitoes were reared for 7 days. The daily mortality rate was determined through day 7. All mosquitoes were morphologically identified. Female Anopheles were dissected, and species-level members of the Anopheles gambiae complex were resolved by molecular methods. The abdomens of all samples were processed for Plasmodium falciparum oocyst detection by PCR.ResultsWithin a 25-month period, the total numbers of non-Anopheles and Anopheles mosquitoes collected indoors were 12,843 and 712, respectively. Anopheles gambiae and An. funestus were the major vectors, though their distributions varied between different villages; 61.2% (n = 436/712) of the Anopheles mosquitoes survived up to day 7, with the lowest mortality rate recorded on day 5 of captivity. The survival rate also varied between the different Anopheles species. Six hundred eighty-three of 712 mosquito abdomens were tested for P. falciparum; 7.8% (53/683) tested positive for P. falciparum, with An. funestus having a higher (10%) prevalence than An. gambiae s.s. (6.0%, p = 0.095, Pearson Chi-square test). The proportion of household members sleeping under a bednet the night before mosquito collection varied across time and village. Anopheles funestus survival times were refractory to household ITN usage, and An. gambaie s.s. survival was reduced only under very high (100%) ITN usage.ConclusionsDespite ITN usage, mosquitoes still acquired blood meals and P. falciparum infections. Survival differed across species and was inversely correlated with high ITN usage in the household but not oocyst development.Graphical

Environmental Factors to Malaria Incidence : A Literature Review

Malaria remains a major public health concern in Indonesia, particularly due to its high mortality rate among children under five, accounting for approximately two-thirds of all cases. The disease is transmitted by female Anopheles mosquitoes, which carry the Plasmodium parasite. In 2019, malaria caused 409,000 deaths globally, with 229 million cases reported, particularly in remote areas with poor access to healthcare, commonly in low-income countries. This literature review highlighted the environmental risk factors contributing to malaria incidence, based on studies from 24 scientific journals using data from the Sinta and Scopus databases. The study identified key environmental factors, including physical, chemical, biological, and socio-cultural elements, with the most significant risk linked to vector breeding sites. Among the reviewed articles, 62.5% (15 out of 24) found a statistically significant association between the presence of mosquito breeding sites and malaria incidence. Additional risk factors included the use of mosquito nets, housing conditions (specifically wall density), and nighttime outdoor activities. Effective malaria control measures require addressing these environmental factors, as they play a crucial role in the disease’s transmission. Strategies to disrupt the transmission cycle include eliminating mosquito breeding sites, applying larvicides to stagnant water, cleaning vector resting areas, promoting the use of insecticide-treated nets, and implementing Indoor Residual Spraying (IRS). A community-based, integrated approach to environmental management is essential to reducing malaria transmission and controlling its spread in affected regions.

Effectiveness of Essential Oils from Leaves of Two Plant Species in the Control of Anopheles gambiae

Background: The current method of controlling malaria vectors using synthetic chemicals has caused serious problems for human health and the environment. Hence, a need for alternative, cheap, readily available, and acceptable mosquito control methods. Objective: To evaluate the bioinsecticidal efficacy of Ocimum gratissimum and Mesosphaerum suaveolens against Anopheles gambiae using the bioassay method. Methods: Oil extracts in 5 ml, 25 ml, and 75 ml serially diluted twice in 100 ml of olive oil formed 0.05%, 0.25%, and 0.75%, while 1 m in 100 ml formed 1%. Olive oil only served as a control. Twenty-five female Anopheles mosquitoes, aged 2-4 days, were blown into tubes containing filter paper-coated essential oils of various concentrations in quadruplicates. Results: Over 50% mortality was recorded in mosquitoes exposed to 0.75% and 1% O. gratissimum compared to others (p <0.05). Knockdown time (KDT) was higher in mosquitoes exposed to 1% O. gratissimum compared to others (p <0.05). Generalized linear regressions showed that the essential oils of O. gratissimum and M. suaveolens contributed 4% (f2 = 0.042) and 14% (f2 = 0.167) to the variability of mortality with time. KDT50 (9.34 - 131.5 minutes) and KDT95 (77.6 - 275 minutes) of O. gratissimum as well as KDT50 (162.8 - 233.6 minutes) and KDT95 (302.8 - 415 minutes) of M. suaveolens were recorded. Stigmastane; 4,22-Stigmastadiene-3-one (Area: 45.88%) in O. gratissimum and gamma-Sitosterol (16.02%) in M. suaveolens were identified by Gas Chromatogram as the highest dose of chemical compounds. Conclusion: The low bioinsecticidal activities of these plant extracts could be attributed to the low occurrence of terpenoids and alkaloids.

Embedded System‐Based Malaria Detection From Blood Smear Images Using Lightweight Deep Learning Model

ABSTRACTThe disease of malaria, transmitted by female Anopheles mosquitoes, is highly contagious, resulting in numerous deaths across various regions. Microscopic examination of blood cells remains one of the most accurate methods for malaria diagnosis, but it is time‐consuming and can produce inaccurate results occasionally. Due to machine learning and deep learning advances in medical diagnosis, improved diagnostic accuracy can now be achieved while costs can be reduced compared to conventional microscopy methods. This work utilizes an open‐source dataset with 26 161 blood smear images in RGB for malaria detection. Our preprocessing resized the original dimensions of the images into 64 × 64 due to the limitations in computational complexity in developing embedded systems‐based malaria detection. We present a novel embedded system approach using 119 154 trainable parameters in a lightweight 17‐layer SqueezeNet model for the automatic detection of malaria. Incredibly, the model is only 1.72 MB in size. An evaluation of the model's performance on the original NIH malaria dataset shows that it has exceptional accuracy, precision, recall, and F1 scores of 96.37%, 95.67%, 97.21%, and 96.44%, respectively. Based on a modified dataset, the results improved further to 99.71% across all metrics. Compared to current deep learning models, our model significantly outperforms them for malaria detection, making it ideal for embedded systems. This model has also been rigorously tested on the Jetson Nano B01 edge device, demonstrating a rapid single image prediction time of only 0.24 s. The fusion of deep learning with embedded systems makes this research a crucial step toward improving malaria diagnosis. In resource‐constrained settings, the model's lightweight architecture and accuracy enhancements hold great promise for addressing the critical challenge of malaria detection.

Nanoparticles based Strategies for Treating and Managing Battle against Malaria: An Overview

: Malaria is a life-threatening disease spread via female Anopheles mosquitoes. Assortments of factors are causing the trouble i.e., (i) fierce opposition posed by the plasmodium life cycle and intracellular localization for pathogens in hepatocytes and erythrocytes; (ii) The decisive physical and chemical properties among most antimalarial drugs, that exhibit an amphiphilic property allowing them to be widely circulated in and out of body tissues since administration and quickly fully exploited in the liver; (iii) The unflattering fluidic circumstances confronted in blood flow that affect the relationship of ionic parts to target tissue. So rather than concentrating the entire energy on establishing novel medications, it is preferable to effort into refining operative medicine conveyance transporters to overcome these downsides. Anti-paludism medications have been effectively distributed via nanomaterials on adjacent concentrations high sufficient on the way to slay the pests and evade the growth of treatment obstruction, although upholding a small general amount to foil uncomplimentary poisonous sideways things. As of now, a few nanostructured frameworks like liposomes or dendrimers have been demonstrated to be fit for working on the viability of anti-malarial treatments. These nanoparticles are an auspicious medication conveyance automobile and could be utilized as remedial techniques intended for battling pests. This audit is expected to scrutinize the utilization of nanoparticles to further develop medicine effectiveness at various phases for both human and vampire congregations of miasm vermin.

The efficacy of attractive targeted sugar baits in reducing malaria vector abundance in low-endemicity settings of northwest Mali

BackgroundAttractive targeted sugar baits (ATSBs) have the potential to significantly reduce infective female Anopheles mosquitoes in arid areas, such as in Northern Mali. Malaria is epidemic in the north due to the limited viability of Anopheles species in the desert climate.The goal of this study was to determine of the effect of ATSB on the number of older female An. gambiae and on the number of sporozoite-positive females in villages in northern Mali.MethodsVillages were located in the north of Mali. In this study, 5677 ATSB stations were deployed, two on each home, in ten villages during late July and early August 2019. Ten villages served as controls. After a pre-treatment monitoring period in July, An. gambiae populations were monitored again from August to December using CDC-UV light traps, pyrethrum spray catches (PSC), and human landing catches (HLC). Mosquitoes were dissected to estimate their age, while ELISA detected sporozoite positivity. The monthly entomological inoculation rates (EIRs) were calculated for HLC indoors and outdoors. Data from villages were compared using t-tests, while bait station weighted density versus amount of collected females was checked with a Pearson’s correlation.ResultsA total of 2703 female An. gambiae were caught from treated villages, 4582 from control villages, a 41.0% difference. Dissection of 1759 females showed that ATSB significantly reduced the number of older females. The proportion of older females in treated villages was 0.93% compared to 9.4% in control villages. ELISA analysis of 7285 females showed that bait stations reduced the number of sporozoite-positive females. The infective females in treated villages was 0.30% compared to 2.73% in the controls. The greater the density of bait stations deployed, the fewer the older, infective females (P < 0.05).EIRs were low in control villages except in months when An. gambiae populations were high. EIRs in ATSB placement villages remained zero. Significant reductions (P < 0.0001) in An. gambiae males were observed.ConclusionsBait stations reduced all measures of vector populations in this study. In a low-transmission setting, ATSB has the potential to greatly reduce malaria.

Molecular Docking Assessment of Limonoids from Cameroonian Entandrophragma Species as Potential Inhibitors of Anopheles gambiae Acetylcholinesterase (AChE)

Malaria remains one of the great killers in tropical regions of the world due to the transmission of the Plasmodium parasite by the bites of the female mosquito Anopheles. The resistance of this species to synthetic insecticides contributes to an increase in the incidence of malaria and therefore necessitates the development of new potent and eco-friendly insecticides. In this study, twelve previously reported limonoids from four Entandrophragma species collected in Cameroon have been computationally evaluated for their Anopheles gambiae AChE inhibitory activity. The docking procedure was carried out through Molecular Operating Environment 2019.01 (MOE), while the UCSF Chimera program was used to model the docking results based on interactions between proteins and ligands, and molecular dynamics trajectories were analyzed using the GROMACS 2021.1 tool. Entandrophragmin and encandollens B and C with docking scores ranging from −6.45 to −7.28 kcal/mol were the most promising hits compared to the reference azadirachtin (−6.22 kcal/mol) and were further evaluated for their mechanism of action. Subsequent evaluation classified encandollen C as the best candidate for the development of new potent eco-friendly insecticides based on its lower average RMSD and RMSF and its compactness over a 150 ns duration with acetylcholinesterase.

Unraveling Cordia myxa’s anti-malarial potential: integrative insights from network pharmacology, molecular modeling, and machine learning

Malaria is a potentially fatal infective illness caused due to parasites that belong to the Plasmodium genus, which are transferred to humans with the help of the stings of affected female Anopheles mosquitoes, and it persists as a serious public wellness problem worldwide. Cordia myxa is a medicinal plant that possesses various medicinal characteristics like antimicrobial, anti-inflammation, antioxidant, and antidiabetic activities, which makes it an important natural resource for the therapy of different maladies in traditional medicine. In this investigation, a certain network pharmacology method has been utilized to identify the potent active components, possible targets as well as signaling pathways present in C. myxa in relation to malaria therapy. The active compounds were submitted to molecular docking approaches to validate their successful activity against the potential targets. The study concluded that three constituents named cosmosiin, stigmastanol, robinetin, and quercetin were highly active and could regulate the expression of Interleukin 6 (IL6) and Cysteine-aspartic acid protease 3 (CASP3), which may act as a potential therapeutic target for malaria treatment. These analyses are validated by molecular dynamics simulation which reflects on the overall structural stability of the intermolecular conformation and interactions. These results can also be witnessed in simulation-based trajectories binding free energies, which concluded the significant role of electrostatic and van der Waals energies in total intermolecular interactions. Finally, we utilized machine learning to predict the anti-malarial activity of C. myxa compounds, comparing them with approved drugs. Using the Chemprop model and MAIP predictions, we assessed ten compounds, revealing their potential as lead anti-malarial agents. This study establishes a groundwork for comprehending the function of the anti-malaria action of C. myxa.

A study on the effectiveness of (+)-usnic acid as oral toxic sugar bait against adult male and female Anopheles gambiae

BackgroundDespite the application of various tools for the control of vectors of Plasmodium falciparum, malaria remains the major killer disease in sub-Saharan Africa accounting for up to 90% of deaths due to the disease. Due to limitations of the useage of chemical insecticides such as resistance, negative impact on the environment and to nontarget organisms, the World Health Organization (WHO) requires that affected countries find alternative vector control tools. This study evaluated the effectiveness of ( +)-usnic acid (UA) as an insecticide through oral administration to male and female Anopheles gambiae as an alternative or additional active ingredient to be used in toxic sugar bait.Methods( +)-usnic acid was diluted using acetone at 5, 10, and 15 mg/ml concentrations in three replicates. A 5 ml mixture of 2% food dye and 10% sugar using chlorine-free water mixed with the dilutions of the ( +)-usnic acid and negative control was made containing 2% food dye and 10% sugar solution. The preparations were soaked on a ball of cotton wool and placed over the net of a cup. 5 male and 5 non-blood-fed female newly hatched starved An. gambiae Kisumu strain were introduced together into a cup and monitored for knockdown and mortalities after 4, 24 48, and 72 h. The data were analysed using a multiple linear regression model using the lm function, a base R function and a posthoc test were conducted on the significant main effects and interaction terms using the emmeans function from the emmeans R package. All analyses were performed in RStudio using base R (version 4.3.3).ResultsThere was high mortality of both male and female An. gambiae after ingestion of the toxic sugar bait. 15 mg/ml usnic acid caused the highest mortality (50%) within the first 4 h compared to 5 and 10 mg/ml ( +)-UA. There was a decline in the mortality rate with increased exposure time from 24 to 72 h, however, there was a significant difference in mortality at 5, 10 and 15 mg/ml. Acute toxicity was associated with ingestion of 15 mg/ml after 24 h. 72 h post-mortality was lower in all concentrations than in the control. High mortality was observed among females over the first 4 h (60%) compared to males (40%) due to higher feeding rate of the toxic agent. The proportion of dead males and females was equal after 24 h while after 48 h, the proportion of dead males was high.There was a significantly lower mortality rate after 72 h for both males and females (0 to 13.3%). Compared to all the treatments, high mortality of males was observed.ConclusionsThe results of this study indicate that ( +)-UA when administered as oral sugar bait to An. gambiae has insecticidal properties and is a suitable ingredient to be used as a toxic agent in the novel attractive toxic sugar bait for the control of malaria vectors. ( +)-UA may be an alternative active ingredient as toxic bait in the effort to reduce and eliminate the transmission of Plasmodium falciparum in Africa.

ERADICATING MALARIA AND SIMULATING THE CORRECT USE OF MOSQUITO NET FOR STUDENTS IN BIAK DORMITORY JAYAPURA CITY

Introduction: Malaria is a disease caused by the Plasmodium parasite. This disease is transmitted through the bite of a female Anopheles mosquito which is infected with this parasite and attacks all humans. How to prevent it by avoiding or reducing malaria mosquito bites is not doing activities outside the house at night, sleeping under a mosquito net, smearing the body with anti-mosquito bite material. , installing screens on ventilation, cleaning mosquito breeding areas, clearing bushes or shady trees around the house or by doing 3M (burying, draining and covering). The aim of this service is to increase Malaria knowledge among students and train students on how to use mosquito nets correctly at the Biak Dormitory, Jayapura City. Methods: Malaria eradication action methods, namely lectures conducted by providing information about the correct use of mosquito nets and simulations, namely practicing how to use and care for mosquito nets correctly, the activity was carried out at the Biak Dormitory located in Padang Bulan, Jayapura City on November 29 2023. There were 13 participants involved in this activity who had the status of active students at several universities. high in Jayapura City. Results: The results of the action to eradicate Malaria with the correct use of mosquito nets before giving students knowledge material were still lacking at 38.4% or there were still 5 students. After receiving the material, student knowledge increased 100% or all students already had correct knowledge about Malaria. Conclusion: The real action carried out by students at the Biak Dormitory is an effort to eradicate Malaria at the right target, because students can disseminate information about malaria prevention locally and can help with the Malaria Elimination program by 2030.

Human-to-Anopheles dirus mosquito transmission of the anthropozoonotic malaria parasite, Plasmodium knowlesi

BackgroundPlasmodium knowlesi, identified as the fifth human malaria parasite, has rapidly spread across various Southeast Asian countries, yet uncertainties persist regarding its human-mosquito-human transmission. Therefore, this study aims to explore the transmission potential of P. knowlesi from human blood to mosquitoes.MethodsA direct membrane-feeding assay was conducted by infecting laboratory-reared female Anopheles dirus mosquitoes with P. knowlesi-infected human blood from a single patient presenting with febrile malaria. Mosquitoes were dissected 7 days post-infection under a stereomicroscope to detect oocysts in the midgut, stained with mercurochrome. Salivary glands were examined 14 days post-infection for the presence of sporozoites. Malaria diagnosis employed microscopy by expert microscopists and nested PCR assays.ResultsUpon dissecting 745 out of 1439 blood-fed An. dirus mosquitoes on day 7 post-infection, two oocysts were identified in the midguts of two mosquitoes (0.27%). An additional 694 mosquitoes were dissected for salivary glands on day 14 post-infection, with three mosquitoes (0.43%) exhibiting sporozoites. Further confirmation by nested-PCR assay verified these sporozoites as belonging to the P. knowlesi species.ConclusionsThe findings underscore the potential transmission of P. knowlesi from human blood to mosquitoes. The significance of these findings necessitates further investigation, such as repeating similar experiments among natural vectors, to gain deeper insights into the transmission dynamics of P. knowlesi in Southeast Asia.Graphical

REVIEW ARTIKEL: PENINGKATAN KELARUTAN SENYAWA OBAT ANTIMALARIA MENGGUNAKAN METODE MODIFIKASI KO-KRISTAL

Malaria is an infectious disease caused by the Plasmodium parasite that infects humans through the bite of female Anopheles mosquitoes. Most antimalarial drugs have limitations in terms of solubility. Drug solubility is a very important parameter that determines the effectiveness of the drug, with good drug solubility, the drug can achieve optimal bioavailability and pharmacological effects, based on this, efforts are needed to overcome these problems in order to provide effective and efficient therapy to patients using existing antimalarial drugs that have been modified in their physicochemical properties so that their solubility increases. The purpose of this study was to review various studies that used the co-crystal modification method to increase the solubility of antimalarial drug compounds. This study was designed using the Narrative Review method, article searches were carried out using two databases, namely Google Scholar and PubMed, with the keywords "Co-crystal" OR "Antimalaria". In this study, 7 articles were found that met the inclusion and exclusion criteria. The selected articles are articles that discuss antimalarial drugs (artesunate, artemisinin, pyrimethamine) developed by the co-crystal method which experienced a multi-fold increase in solubility compared to its pure preparation. The co-crystal method can be a solubility enhancing solution for antimalarial drugs that have low solubility in water, increasing the solubility of antimalarial drugs causes the bioavailability of the drug to increase, so that the drug can provide good therapeutic effects.

A chromosomal reference genome sequence for the malaria mosquito, Anopheles marshallii, Theobald, 1903.

We present a genome assembly from an individual female Anopheles marshallii (the malaria mosquito; Arthropoda; Insecta; Diptera; Culicidae) from Lopé, Gabon. The genome sequence is 225.7 megabases in span. Most of the assembly is scaffolded into three chromosomal pseudomolecules with the X sex chromosome assembled. The complete mitochondrial genome was also assembled and is 15.4 kilobases in length.

Adulticidal activity of essential oils of Ageratum conyzoides L., Hyptis suaveolens L., Ocimum basilicum L. and their synergistic effects against anopheles mosquitoes

This study investigated the insecticidal efficacy of essential oils (EOs) extracted from Ageratum conyzoides, Hyptis suaveolens, and Ocimum basilicum against female Anopheles mosquitoes, aiming to explore their potential as alternatives to synthetic insecticides amidst rising resistance issues. EOs were obtained through steam distillation from freshly harvested plant aerial parts, and their chemical compositions were analyzed using gas chromatography-mass spectrometry. The results revealed significant variations in chemical profiles among the oils, with precocene I dominating in A. Conyzoides, eucalyptol in H. suaveolens, and estragole in O. basilicum. Thin layer chromatography analyses revealed various components with rf values ranging from 0.25 – 0.93. Mosquito bioassay demonstrated varying knockdown effects across the oils, with H. suavolens achieving 77.5% knockdown within six minutes of the observation period. None of the oils or their combinations reached susceptibility status (98–100% mortality), indicating prevalent resistance among the mosquito population in the study area. The combination of A. conyzoides and H. suavolens essential oil gave the highest percentage mortality (70%) at the least time (9 minutes), this is a suggestion of synergistic activity. Despite resistance challenges, this study highlights the promise of botanical insecticides in sustainable mosquito control and underscores the ongoing need for innovation and adaptation in vector management strategies.

Bionomics and distribution of malaria vectors in Kisumu city, Western Kenya: Implications for urban malaria transmission.

Increasing urbanization in tropical Africa may create new niches for malaria vectors, potentially leading to higher disease transmission rates. Vector control efforts remain largely targeted at ecologically rural bio-complexities with multiple hosts. Understanding mosquito species composition, ecology, host diversity and biting behavior in urban areas is crucial for planning effective control. This study assessed mosquito species diversity, abundance, behavioral patterns, and Plasmodium sporozoite infection rates of Anopheles vectors along an urban-rural transect in Kisumu city, western Kenya. Indoor and outdoor host-seeking and resting adult mosquitoes were collected using Centers for Disease Control and Prevention miniature light traps (CDC-LT) and mechanical aspirators (Prokopack) along an urban-rural transect. Females Anopheles mosquitoes collected were identified using morphological taxonomic keys to species level. Specimens belonging to the Anopheles gambiae complex and Anopheles funestus group were further processed using polymerase chain reaction (PCR) to identify members of each complex/group. Subsequently, sporozoite infection rates of the anopheline mosquitoes were determined using a multiplexed real-time quantitative PCR (qPCR) assay. A total of 3,394 female Anopheles mosquitoes were collected and identified. These comprised of An. gambiae s.l. (68%), An. funestus group (19.8%), An. coustani (7.8%), An. pharoensis (2.6%), An. maculipalipis (1.6%), and An. leesoni(0.2%). All six species were found in urban zone, but only three were found in peri-urban and rural sites. Overall, urban collections accounted for the majority of these collections (55.5%) of mosquitoes collected, followed by those from peri-urban (30%) and rural sites (14.5%). Species distribution across the three ecotypes showed Anopheles arabiensis was the dominant species in urban (84.3%) and peri-urban (89%) sites, while An. gambiae s.s. was predominantly found in the rural zone (60.2%) alongside An. arabiensis (39.7%). Anopheles funestus was the predominant species in peri-urban (98.4%) and rural (85.7%) areas, with An. leesoni accounted for 1.6% and 14.3%, respectively. In urban areas, all samples from the An. funestus group were identified as An. funestus s.s.. Majority (55.5%) of Anopheles mosquitoes were collected indoors, while secondary vectors were primarily caught outdoors. Overall, sporozoite rates were higher outdoors 3.5% compared to indoors 1.45% in rural areas. Specifically, sporozoite infectivity rates for An. funestus, An. gambiae s.s and An. arabiensis collected indoors in the rural zone was 2.5%, 1.4% and 1% respectively. Outdoors in rural areas, An. gambiae had a sporozoite rate of 5.3%, while An. arabiensis had a rate of 2.1%. In peri-urban areas An. gambiae had a sporozoite rate of 2.3%. No sporozoites were detected in samples from urban sites. The study highlights a shift of diversity of Anopheles species towards urban areas with increased outdoor activity, and significant outdoor malaria transmission in rural and peri-urban areas, emphasizing the need for tools targeting outdoor-biting mosquitoes. The presence of An. funestus in urban settings is of interest and highlights the critical importance of sustained entomological surveillance to inform integrated vector control and prevent future transmission risks.

Efficacy of Malaria Symptoms as an Indicator of Malaria Infection among Students of a Tertiary Institution in Ogun State Nigeria

Malaria is a life-threatening disease caused by the parasite Plasmodium, which is transmitted through the bite of an infected female Anopheles mosquito. Asymptomatic Plasmodium falciparum parasitemia refers to the presence of the parasite in the absence of fever or malaria-related symptoms. In Ijebu-Igbo, Ogun State, Nigeria, a study was conducted to ascertain the frequency of asymptomatic malaria among students attending higher education institutions and determine the efficacy of malaria symptoms as an indicator of malaria infection. A total of 115 students who consented to participate in the study were enrolled, and only a total of 93 of the respondents were recruited for the study, having met the inclusion criteria. A structured questionnaire was used to obtain data on socio-demographic characteristics, signs and symptoms of malaria, and malaria prevention strategy using Insecticide Treated Nets (ITN). Blood samples were collected from the respondents and diagnosed for malaria using Rapid Diagnostic Tests (RDT) kit. Of the 93 respondents, 32 (34%) were males while 61 (66%) were females. Analysis of the result showed that 77% of the respondents had malaria parasites, 38.7% of the respondents indicated that they do feel feverish sometimes while 47.3% responded that they rarely feel feverish, those who rarely show symptoms were observed to be asymptomatic as the result of the RDT was positive for malaria. On the use of Insecticide Treated Net (ITN) for both categories of students, those who are not using the net had a higher prevalence (64.5%) of malaria infection. The result of this study shows that malaria symptoms is not a good diagnostic tool for determining treatment. Asymptomatic malaria was a risk factor among the students therefore measures to reduce the prevalence are advocated.

Molecular characterization, expression and in-silico analysis of fibrinogen-related protein 1 (frep1) in malaria vector Anopheles stephensi.

Fibrinogen-related protein 1 (frep1) is a member of the pattern-recognizing receptor family (PRR) which generates an innate immune response after recognizing the pattern associated molecular pattern (PAMP) that occurs on the surface of microorganisms. The main objective of this study is to characterize frep1 and its in-silico analysis in Anopheles stephensi. The DNA was extracted from female Anopheles stephensi. PCR was performed for complete analysis of frep1 using specific primers. The gene sequence of frep1 was identified by Sanger sequencing. The bioinformatics structure analysis approach revealed the presence of 3 exons and 4 introns in the frep1. The sequence of frep1 was submitted to NCBI GeneBank with accession number ON817187.1. Quantitative real-time PCR was performed to analyze frep1 expression. At the developmental stage, frep1 is highly expressed in the L1 stage, egg, and adult female mosquito. In addition, frep1 is highly expressed in the tissue fat body, midgut, and salivary gland. After blood-fed, an upregulation of frep1 at 48h in the midgut, and downregulation in fat body were observed at different time intervals. The genomic data of frep1 is encoded by 12,443bp. The frep1 has a significant role in the early metamorphosis. Its expression in fat body and midgut suggests it could be important for fat metabolism and post-blood digestion. The conserved domain could be targeted for vector control. Further study is required to elucidate its function against malaria parasites to confirm its agonist role in malaria transmission.

Susceptibility status of female anopheles’ mosquito to organophosphate and carbamate insecticides in market environs in Itu LGA, Akwa Ibom State, Nigeria

Malaria remains a serious public health problem and is still responsible for death of individuals globally with the female Anopheles gambiae established to be one of the major vectors which aid the transmission of this disease. This study examined the susceptibility and resistance of An. gambiae to carbamate and organophosphate which has not been frequently used in vector control in Nigeria. The CDC (Centres for Disease Control and Prevention) bottle bioassay was employed to measure the susceptibility of An. gambiae to insecticides. The procedure involved 2–5-day old An. gambiae adult mosquito populations starved from blood. In this study, we employed a diagnostic time of 30 minutes to administer doses of 12.5µg/bottle of Bendiocarb and Propoxur (Carbamates) and 20µg Pirimiphos-methyl (Organophosphate) to Anopheles spp. populations. The knockdown effect of the three insecticides indicated that bendiocarb and propoxur (carbamates) had a mortality of 98% while pirimiphos-methyl (organophosphate) had 81% at 30 minutes, regarded as the HUH for measuring resistance/susceptibility of insecticides. Further exposure at 60 minutes yielded 100% mortality for both bendiocarb and propoxur while 98% mortality was applicable in pirimiphos-methyl insecticides. An. gambiae was susceptible to bendiocarb and propoxur insecticides and resistant to pirimiphos-methyl. Invariably, vector control decision-making in the area will be influenced by the result of the study being that it is a baseline data/information. It is paramount that before any vector control strategies are implemented, sufficient susceptibility/resistance data be taken into thought