Malaria Disease Research Articles

Splenic filtration of red blood cells in physiology, malaria and sickle cell disease.

The human spleen clears the blood from circulating microorganisms and red blood cells (RBCs) displaying alterations. This review analyzes how generic mechanisms by which the spleen senses RBC, such pitting, trapping and erythrophagocytosis, impact the pathogenesis of two major spleen-related diseases, malaria and sickle cell disease (SCD). Scintigraphy, functional histology, comparison of circulating and splenic RBC, ex-vivo perfusion of human spleens and in-silico modeling enable relevant exploration of how the spleen retains and processes RBC in health and disease. Iterative cross-validations between medical observations, in-vitro experiments and in-silico modeling point to mechanical sensing of RBC as a central event in both conditions. Spleen congestion is a common pathogenic process explaining anemia and splenomegaly, the latter carrying a risk of severe complications such as acute splenic sequestration crisis and hypersplenism in SCD. Sickling of hemoglobin S-containing RBC may contribute to these complications without necessarily being the trigger. Ongoing progress in the exploration and understanding of spleen-related complications in malaria and SCD open the way to optimized prognosis evaluation and therapeutic applications.

Systematic Review on Citizen Science and Artificial Intelligence for Vector-Borne Diseases

Abstract. Vector-borne diseases (VBDs) pose a significant threat to public health globally. VBDs are a significant public health concern worldwide, with infections such as Malaria, Dengue Fever, Zika Virus, and Lyme Disease posing a threat to global health security. There is a need for innovative and effective strategies to control these diseases. One potential solution lies in the integration of citizen science and artificial intelligence technologies. Citizen science, which involves the participation of volunteers in scientific research, can greatly contribute to data collection and monitoring efforts for vector-borne diseases. Artificial intelligence can enhance the analysis of this data, leading to improved disease surveillance, prediction, and control strategies. Citizen Science involves active public participation in scientific research, data collection, and analysis, while AI and Machine Learning (ML) techniques offer powerful tools for processing and interpreting large datasets. By leveraging the power of citizen science and artificial intelligence, we can harness the collective efforts of volunteers and advanced technology to better understand, track, and mitigate the spread of vector-borne diseases. Through the combination of citizen science and artificial intelligence, a more comprehensive and efficient approach can be taken to gather data on vector-borne diseases, analyze the data, and inform public health interventions. This systematic review aims to explore the role of citizen science and artificial intelligence in addressing the challenges associated with vector-borne diseases. It will examine the existing literature on the use of citizen science and artificial intelligence in vector-borne disease research, including their applications, benefits, and limitations, in order to provide insights and recommendations for future research and public health strategies.

Экология техносферы человеческого сообщества

In the 19th century, the sphere of interest of the science of “ecology” was formulated. Over the course of a century and a half, the semantics of its tasks has undergone significant changes. However, the original definition of ecology given by E.G. Haeckel, as a science about the interaction of living and inanimate nature, has again become relevant with the technological development of mankind. This development led to the emergence of an alternative habitat - the technosphere. The technosphere, within the framework of environmental ideas, is considered as a formation deeply hostile to nature in its essence. Nature is considered as a certain ideal that creates favorable conditions for the existence of living organisms in it. The experience of natural disasters and cataclysms, accompanied by the mass death of living organisms, indicates that this is an idealized idea. The existence of modern man outside the technosphere is practically impossible. The techno-sphere takes on the task of providing humanity with protection from pathogens. An example of such control is the use of DDT against vectors of malaria and other diseases. The technosphere solves problems in relation to humanity that are similar to providing the body with food, solving the problems of energy supply and movement over various distances – both people and cargo. The technosphere is evolving, using the achievements of developing sciences and technologies, reducing the specific impact on the natural environment while meeting the needs of the individual. For the further development of human ecology at the intersection of natural and artificial, the solution of traditional management problems is required: strict control of raw materials, technologies and products used, and their rational distribution. This is important since the human population is steadily growing and a significant part of the planet’s population finds itself in conditions of food and energy shortages, while the other part has an abundance of resources.

Empowering rural communities for effective larval source management: A small-scale field evaluation of a community-led larviciding approach to control malaria in south-eastern Tanzania

IntroductionLarval source management, particularly larviciding, is mainly implemented in urban settings to control malaria and other mosquito-borne diseases. In Tanzania, the government has recently expanded larviciding to rural settings across the country, but implementation faces multiple challenges, notably inadequate resources and limited know-how by technical staff. This study evaluated the potential of training community members to identify, characterize and target larval habitats of Anopheles funestus mosquitoes, the dominant vector of malaria transmission in south-eastern Tanzania. MethodsA mixed-methods study was used. First, interviewer-administered questionnaires were employed to assess knowledge, awareness, and perceptions of community members towards larviciding (N = 300). Secondly community-based volunteers were trained to identify and characterize aquatic habitats of dominant malaria vector species, after which they treated the most productive habitats with a locally-manufactured formulation of the biolarvicide, Bacillus thuringiensis var. israelensis. Longitudinal surveys of mosquito adults and larvae were used to assess impacts of the community-led larviciding programme in two villages in rural south-eastern Tanzania. ResultsAt the beginning of the program, the majority of village residents were unaware of larviciding as a potential malaria prevention method, and about 20 % thought that larvicides could be harmful to the environment and other insects. The trained community volunteers identified and characterized 360 aquatic habitats, of which 45.6 % had Anopheles funestus, the dominant malaria vector in the area. The preferred larval habitats for An. funestus were deep and had either slow- or fast-moving waters. Application of biolarvicides reduced the abundance of adult An. funestus and Culex spp. species inside human houses in the same villages, by 46.3 % and 35.4 % respectively. Abundance of late-stage instar larvae of the same taxa was also reduced by 74 % and 42 %, respectively. ConclusionThis study demonstrates that training community members to identify, characterize, and target larval habitats of the dominant malaria vectors can be effective for larval source management in rural Tanzania. Community-led larviciding reduced the densities of adult and late-stage instar larvae of An. funestus and Culex spp. inside houses, suggesting that this approach may have potential for malaria control in rural settings. However, efforts are still needed to increase awareness of larviciding in the relevant communities.

Climate Change and Vector-Borne Diseases: A Scoping Review on the Ecological and Public Health Impacts

Climate change is increasingly recognized as a significant driver of ecological and public health changes, particularly concerning vectorborne diseases. This scoping review aims to systematically map the current research on the impact of climate change on vector ecology and the subsequent effects on disease transmission dynamics. We conducted a comprehensive literature review across multiple databases to identify critical vectors, such as mosquitoes, ticks, and fleas. We examined how climate variables like temperature, precipitation, and humidity affect their populations, behaviors, and life cycles. Additionally, we explored the shifting geographic distributions of these vectors, investigating how climate change influences their spread and the emergence of diseases such as malaria, dengue, and Lyme disease in new regions. The review highlights the complex and multifaceted interactions between climate change and vector-borne diseases, emphasizing the necessity of understanding these relationships to inform effective public health strategies. Our findings indicate considerable variability in the impacts of climate change across different regions and vector species, underscoring the need for localized studies and tailored interventions. Moreover, significant research gaps were identified, particularly in predictive modeling, long-term surveillance, and the socio-economic impacts of vector-borne diseases exacerbated by climate change. We suggest directions for future research, including the development of integrated climate-health models and enhanced disease surveillance systems, to better anticipate and mitigate the effects of climate change on vector-borne disease transmission. This review underscores the urgency of addressing climate change as a critical component of global health initiatives and the importance of interdisciplinary approaches in tackling this complex issue. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 915-933

Relationship between red blood cell polymorphisms and effectiveness of seasonal malaria chemoprevention in 2020 in Dangassa, Mali.

Treatment failure with amodiaquine was reported in Dangassa, where red blood cell (RBC) polymorphisms are found and seasonal malaria chemoprevention (SMC) is underway. Here, we aimed at assessing the influence of RBC polymorphisms on SMC effectiveness. This was a secondary analysis of data from a study conducted in Dangassa. Children aged 5 to 14years enrolled in an open randomized study were assigned either to receive SMC (intervention arm) or not (control arm). SMC was implemented from July to November. For all children, hemoglobin type and blood group were determined at enrolment in July, and parasitemia and hemoglobin level were monthly monitored by finger-prick. Overall, 166 children were enrolled among which 82 (49.40%) in the control arm and 84 (50.60%) in the SMC arm. The prevalence of HbAS was 10.24% (17/166) with 12.20% in the control and 8.33% in the SMC arm. O group was the most common overall (45%) and in the SMC arm (54%), but the control arm had more B (39.02%) than O (36.59%). In the SMC arm, no case of Plasmodium infection and malaria disease was observed in the 7 HbAS children while in Non-HbAS children, peaks of infection and disease prevalence were respectively observed in October (24.66%) and November (7.14%). For the SMC arm, in group O and Non-group O, Plasmodium infection cases were observed from August to December. Plasmodium infection and malaria disease were more frequently observed in HbAS children in the control arm than in the SMC arm. Further studies are needed to assess factors associated with the asymptomatic carriage of parasites during SMC in Dangassa. NCT04149106.

Projected impact of climate change on human health in low- and middle-income countries: a systematic review

Low- and middle-income countries (LMICs) contribute relatively little to global carbon emissions but are recognised to be among the most vulnerable parts of the world to health-related consequences of climate...

MFSD7C protects hemolysis-induced lung impairments by inhibiting ferroptosis

Hemolysis drives susceptibility to lung injury and predicts poor outcomes in diseases, such as malaria and sickle cell disease (SCD). However, the underlying pathological mechanism remains elusive. Here, we report that major facilitator superfamily domain containing 7 C (MFSD7C) protects the lung from hemolytic-induced damage by preventing ferroptosis. Mechanistically, MFSD7C deficiency in HuLEC-5A cells leads to mitochondrial dysfunction, lipid remodeling and dysregulation of ACSL4 and GPX4, thereby enhancing lipid peroxidation and promoting ferroptosis. Furthermore, systemic administration of MFSD7C mRNA-loaded nanoparticles effectively prevents lung injury in hemolytic mice, such as HbSS-Townes mice and PHZ-challenged 7 C−/− mice. These findings present the detailed link between hemolytic complications and ferroptosis, providing potential therapeutic targets for patients with hemolytic disorders.

Epidemiology of Anaemia in Children under Five in Uganda: Current Trends, Challenges, and Strategic Approaches

Anaemia in children under five years old is a significant public health issue in Uganda, affecting over half of the vulnerable population and posing challenges to their health and development. The issue is influenced by nutritional deficiencies, infectious diseases, socioeconomic factors, and limited healthcare access. Clinical manifestations include pallor, fatigue, and developmental delays, and early detection is difficult due to non-specific symptoms, resource constraints, and cultural practices. The impact of anaemia on child health and development is profound, affecting physical growth, cognitive and motor skills, and overall well-being. Nutritional interventions, such as iron supplementation, fortified foods, and dietary education, are crucial for managing anaemia. Effective healthcare responses and policies, including routine screenings, treatment programs, and community outreach, are also necessary. Preventive measures and treatment programs are crucial for combating malaria and other infectious diseases. Community-based approaches, including training health workers and implementing grassroots education programs, are essential for improving anaemia management. Addressing gender dynamics and socioeconomic determinants is vital for reducing anaemia rates. Monitoring and evaluation frameworks are essential for assessing the effectiveness of anaemia control programs and guiding future efforts. In conclusion, a coordinated approach integrating nutritional, healthcare, environmental, and socioeconomic strategies is necessary to combat anaemia in Uganda. Through continued efforts and collaboration, the burden of anaemia can be mitigated, leading to improved health outcomes for children under five. Keywords: Anaemia, Children, Uganda, Current Trends, Challenges, Strategic Approaches

Prevalence and Socio-demographic Variations in Traditional Medicine Use: A Study from East Nile Locality, Sudan

Traditional medicine (TM) remains a cornerstone of healthcare in Sudan, across urban and rural settings. We explored TM use and its association with socio-demographic characteristics (age, sex, education, economic status, and residence) in East Nile locality (ShargAlneil), Khartoum State. A survey encompassing 609 households (44.7% rural, 55.3% urban) revealed a high prevalence of TM use: over 80% reported using at least one form. Notably, significant socio-demographic variations emerged. Individuals with higher education leaned towards herbalists (p<0.05), while those with lower education favored religious healers (p<0.05). Similarly, older adults preferred religious healers (p<0.05), while males tended to choose herbalists (p<0.05). The most common ailments preferred to be treated by TM practitioners were spiritual and psychological issues, bone injuries, stomachaches, and headaches. Conversely, conditions like malaria, diabetes, hypertension, and heart disease were primarily preferred to be managed by modern medicine. This study highlights the widespread use of TM across diverse demographics, with preferences for specific types of practitioners. It also underscores a selective trust in modern medicine for certain diseases. Integrating socio-demographic and cultural perspectives into healthcare delivery can enhance understanding of community needs and guide the development of appropriate interventions. Further research is warranted to delve deeper into the reasons behind these variations in treatment preferences.

Malaria tracker: The best bet for malaria elimination in Nigeria

Malaria is a significant public health burden in Nigeria, accounting for a substantial number of cases and deaths annually. Regrettably, the Malaria disease burden in line with the WHO (2023) report showed that there were 249 million cases of malaria in 2022 when compared to 244 million cases in 2021 and the number of malaria deaths stood at 608,000 in 2022 compared to 610 000 in 2021. It is highly appalling that among the list of four African countries that accounted for just over half of all malaria deaths worldwide, Nigeria is leading with the limited data provided at 26.8%, followed by the Democratic Republic of the Congo (12.3%), Uganda (5.1%) and Mozambique (4.2%) (WHO, 2023)

Hybrid Diffusion Model for Stable, Affinity-Driven, Receptor-Aware Peptide Generation.

The convergence of biotechnology and artificial intelligence has the potential to transform drug development, especially in the field of therapeutic peptide design. Peptides are short chains of amino acids with diverse therapeutic applications that offer several advantages over small molecular drugs, such as targeted therapy and minimal side effects. However, limited oral bioavailability and enzymatic degradation have limited their effectiveness. With advances in deep learning techniques, innovative approaches to peptide design have become possible. In this work, we demonstrate HYDRA, a hybrid deep learning approach that leverages the distribution modeling capabilities of a diffusion model and combines it with a binding affinity maximization algorithm that can be used for de novo design of peptide binders for various target receptors. As an application, we have used our approach to design therapeutic peptides targeting proteins expressed by Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) genes. The ability of HYDRA to generate peptides conditioned on the target receptor's binding sites makes it a promising approach for developing effective therapies for malaria and other diseases.

A Scientific Review of Pesticides: Classification, Toxicity, Health Effects, Sustainability, and Environmental Impact.

Over the years, the useof pesticides has risen significantly, primarily to combat undesirable organisms that threaten crucial crops. A variety of pesticides are available, each designed to protect crops from specific threats like fungi, bacteria, and other pests. Other than crop protection, pesticides are also used in controlling insect vector-borne diseases like malaria and Lyme disease in humans.However, the application of these pesticides must be carefully measured and managed to prevent adverse effects on humans, non-target animals, and the environment. This reviewdelves into the detailed classification of pesticides, exploring their mechanisms of action, applications, benefits, and potential side effects. Understanding the different categories of pesticides, such as herbicides, insecticides, fungicides, rodenticides, and biopesticides, helps us comprehend how each function to control pests. Additionally, we discuss the advantages of pesticide use, including increased crop yields and the prevention of crop diseases, which contribute to food security and agricultural productivity. This review also addresses the significant concerns related to pesticide usage, such as the development of pest resistance, health risks to humans through exposure and residues in food, as well as the impact on biodiversity and ecosystems. The review emphasizes the importance of using pesticides responsibly and implementing integrated pest management strategies to mitigate this risk of exposure. By providing a comprehensive overview of pesticide classification, mechanisms of action, and implications, this review aims to inform and guide us to the safe and effective use of pesticides for daily agricultural practices.

Patterns and outcomes of Emergency Pediatric Unit admissions in Usmanu Danfodiyo University Teaching Hospital in Sokoto State, Nigeria: a five-year review

Children are susceptible to illnesses that often require urgent medical attention, with attendant high mortality rates, especially in resource-constrained settings. Periodic audits in tertiary care facilities can guide preventive and therapeutic policies. The aim was to determine the admissions pattern and outcome over five years in the Emergency Paediatric Unit (EPU) of Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto, a major tertiary facility in North Western Nigeria. This was a retrospective study between January 2017 and December 2021. The admission records of children aged >1 month to 15 years were retrieved, relevant information extracted, and entered into a study proforma. Data was analyzed using SPSS version 23. There were 6088 admissions. Under-fives constituted 4448 (73.1%), and males were 3558 (58.4%). The median age was 24.0 months (Interquartile Range, IQR, 12, 60). Top admissions were severe malaria (1100; 18.1%), acute diarrhoeal disease (631; 10.4%), Sickle Cell Disease (SCD) (624; 10.2%), pneumonia (547;9.0%), Severe Acute Malnutrition (SAM) (438;7.2%), febrile convulsions (421;6.9%), pharyngotonsillitis (402;6.6%) and sepsis (398;6.5%). Total discharges were 2483 (40.8%), 2635 (43.3%) were transferred, and mortalities were 679 (11.2%). Case fatality rates of the top admissions were sepsis (19.6%), SAM (19.4%), severe malaria (13.7%), pneumonia (10.6%), febrile convulsions (5.0%), acute diarrhoeal disease (4.9%), pharyngotonsillitis (2.5%) and SCD (2.1%). SCD was the most common non-infectious morbidity and responsible for most re-admissions. Malaria was the top cause of mortality in all age groups except infancy, where sepsis and pneumonia predominated. In conclusion, malaria and other infectious diseases accounted for most admissions. Non-communicable diseases, like SCD, also constitute significant morbidity. Hence, policymakers need to scale up targeted preventive measures.

Advancing spatial repellents for malaria control: effectiveness and cost-effectiveness of a spatial repellent under operational use in Northern Uganda—study protocol for a cluster randomized controlled trial

BackgroundSpatial repellents (SRs) have been widely used for the prevention of mosquito bites, and preliminary findings suggest efficacy against both malaria (1) and Aedes-borne viruses (2) but their effectiveness in reducing mosquito-borne diseases under operational use has never been evaluated. SRs have the potential of being critical tools in the prevention of mosquito-borne diseases in contexts where typical vector control strategies, such as insecticide-treated nets (ITNs) and indoor residual spraying, are inaccessible or underutilized such as among displaced persons or in emergency relief settings.MethodsChildren will be enrolled in 3 separate cohorts to establish the effectiveness of SRs in reducing malaria infection in different distribution channels. One cohort will estimate the direct effect of the SR distributed through a reference channel (study personnel distribution). The two remaining cohorts will estimate the protection of the SR distributed through a voucher channel and the Village Health Team channel. Cohorts will be followed twice a month (approximately every 15 days): during the first scheduled household visit in the month, a blood sample will be taken for malaria rapid diagnostic test (Monthly Visit #1); and, during the second scheduled household visit, a blood sample will only be taken if the participant has a recent history of fever (Monthly Visit #2). The incidence of malaria in each cohort will be estimated and compared to the reference cohort to determine the benefit of using a SR in an area with high, year-round transmission of malaria.DiscussionThis study will address the knowledge gap of whether or not SRs are effective in reducing human malaria disease in humanitarian assistance and emergency response settings in sub-Saharan Africa where underlying transmission rates are historically high and ITNs may or may not be widely deployed. This research will inform policy makers on whether to recommend SRs as a means to further reduce malaria transmission for such operational programs.Trial registrationClinicalTrials.gov NCT06122142. Registered on November 8, 2023.

Expanded roles of community health workers to sustain malaria services in the Asia-Pacific: A landscaping survey.

Malaria Community Health Workers (CHWs) in the Greater Mekong Subregion (GMS) are an important component of malaria elimination efforts. As malaria declines with intensified efforts to eliminate by 2030, expanding their roles beyond malaria could help to sustain funding and provision of malaria services at the community level. Evidence of how programmes have implemented and managed CHWs performing both malaria and non-malaria roles across the Asia-Pacific region can provide insight into the viability of this strategy. A short survey was distributed to national malaria programmes and implementing organizations in the Asia-Pacific region in 2021-2022. The survey identified CHW programmes in the region, and collected information on malaria and non-malarial services provided by CHWs, characteristics of each identified programme, and the impact of COVID-19 on these programmes. 35 survey responses identified 28 programmes in 14 countries. The most frequently reported services provided by malaria CHWs were health promotion and education for malaria (13/14 countries) and other diseases (11/14); and COVID-19 related activities (10/14). Most programmes were financed wholly through donor funding (18/28 programmes), or donor plus government funding (6/28). Of 21 programmes which performed programme evaluation, only 2 evaluated their impacts on diseases beyond malaria. Declining donor funding, and COVID-19 related travel and activity restrictions were identified as implementation challenges. CHWs across the Asia Pacific provide a range of health services with malaria and are resilient under changing public health landscapes such as the COVID-19 pandemic. Further investigation into the impact of additional roles on malaria CHW performance and targeted health outcomes is needed to verify the benefits and feasibility of role expansion. As the GMS approaches elimination, and funding declines, verifying the cost effectiveness of malaria CHW programmes will be vital to persuade donors and countries to invest in malaria CHWs to sustain malaria services, and strengthen community-based health care.

Under-Five Mortality and Associated Risk Factors in Children Hospitalized at David Bernardino Pediatric Hospital (DBPH), Angola: A Hierarchical Approach.

Reducing under-five mortality is a crucial indicator of overall development in a country. However, in Angola, understanding the factors contributing to hospital deaths in this vulnerable demographic remains incomplete despite improvements in healthcare infrastructure and public health policies. With one of the highest under-five mortality rates in sub-Saharan Africa, Angola faces significant challenges such as malaria, malnutrition, pneumonia, neonatal conditions, and intestinal infectious diseases, which are the leading causes of death among children. This study aimed to identify factors associated with hospital deaths among children aged 28 days to five years admitted to DBPH in Luanda between May 2022 and June 2023. Using a hospital-based case-control design, the study included 1020 children, among whom 340 experienced hospital deaths. Distal and intermediate determinants emerged as primary predictors of hospital mortality, showing significant associations with: mother without schooling (OR [95%CI] 4.3 [1.2-15.7], p < 0.027); frequent alcohol consumption during pregnancy (OR [95%CI] 3.8 [2.5-5.9], p < 0.001); hospital stay ≤24 h (OR [95%CI] 13.8 [6.2-30.8], p < 0.001); poor nutritional status (OR [95%CI] 2.1 [1.4-3.2], p < 0.001); short interbirth interval (OR [95%CI] 1.7 [1.1-2.5], p < 0.014); maternal age ≤19 years (OR [95%CI] 5.6 [3.0-10.8], p < 0.001); and maternal age ≥35 years (OR [95%CI] 2.1 [1.2-3.7], p < 0.006). These findings highlight the preventable nature of most under-five hospital deaths and underscore the urgent need to address social inequities and improve the quality of primary healthcare services to effectively reduce child mortality in Angola.

A transfer learning approach to identify Plasmodium in microscopic images.

Plasmodium parasites cause Malaria disease, which remains a significant threat to global health, affecting 200 million people and causing 400,000 deaths yearly. Plasmodium falciparum and Plasmodium vivax remain the two main malaria species affecting humans. Identifying the malaria disease in blood smears requires years of expertise, even for highly trained specialists. Literature studies have been coping with the automatic identification and classification of malaria. However, several points must be addressed and investigated so these automatic methods can be used clinically in a Computer-aided Diagnosis (CAD) scenario. In this work, we assess the transfer learning approach by using well-known pre-trained deep learning architectures. We considered a database with 6222 Region of Interest (ROI), of which 6002 are from the Broad Bioimage Benchmark Collection (BBBC), and 220 were acquired locally by us at Fundação Oswaldo Cruz (FIOCRUZ) in Porto Velho Velho, Rondônia-Brazil, which is part of the legal Amazon. We exhaustively cross-validated the dataset using 100 distinct partitions with 80% train and 20% test for each considering circular ROIs (rough segmentation). Our experimental results show that DenseNet201 has a potential to identify Plasmodium parasites in ROIs (infected or uninfected) of microscopic images, achieving 99.41% AUC with a fast processing time. We further validated our results, showing that DenseNet201 was significantly better (99% confidence interval) than the other networks considered in the experiment. Our results support claiming that transfer learning with texture features potentially differentiates subjects with malaria, spotting those with Plasmodium even in Leukocytes images, which is a challenge. In Future work, we intend scale our approach by adding more data and developing a friendly user interface for CAD use. We aim at aiding the worldwide population and our local natives living nearby the legal Amazon's rivers.

Organophosphate and carbamate susceptibility profiling of Anopheles gambiae sl. across different ecosystems in southern Benin

Background To overcome the spread of high pyrethroid resistance in the main malaria vectors and malaria disease persistence, it is crucial to look for effective and better resistance management strategies. Understanding the phenotypic profile of Anopheles gambiae sl. against alternatives insecticides like organophosphates and carbamates is crucial. Methods Anopheles larvae and pupae were collected from the breeding sites in rice fields, pineapple crop areas, and peri-urban areas. WHO susceptibility tests were conducted on unfed female mosquitoes aged 3–5 days old. Mosquitoes were exposed to malathion 5%, pirimiphos-methyl 0.25%, and bendiocarb 0.1% using the standard WHO protocol. Polymerase chain reaction (PCR) techniques were used to detect species, kdr and Ace-1 mutations. Results Anopheles gambiae sl. from Sèdjè-Dénou rice field population was resistant to bendiocarb (0.1%) with a mortality rate of 72.2% whereas Anopheles gambiae sl. populations from Zinvié-Dokomey (rice field), Zè-Tozounmè (pineapple field), and Adjagbo (peri-urban area) were suspected to be resistant with mortality rates of 90%, 93.5%, 95.4% respectively. However, all of them were susceptible to organophosphates (malathion and pirimiphos-methyl) with a mortality rate of 100%. PCR assay revealed that 100% of the mosquitoes tested were Anopheles coluzzii. The frequencies of Ace-1R mutation in all Anopheles coluzzii populations tested were low (3–27%). Conclusions Organophosphates (malathion and pirimiphos-methyl) have maintained their efficacy against Anopheles coluzzii populations from Sèdjè-Dénou (rice field), Zè Tozounmè (pineapple field), Zinvié Dokomey (rice field), or Adjagbo (peri-urban area). The good efficacy of these organophosphates against Anopheles coluzzii populations from the southern part of Benin are observed in the current study. The use of pirimiphos-methyl for IRS in this part of the country would be a successful alternative for malaria control in this area.

Electronic and vibrational spectroscopic study complemented with the computational evaluation of hydroxychloroquine mixed with silver nanoparticles

Synthesized silver nanoparticles via laser liquid ablation were characterized using XRD, TEM, EDS, UV–Vis, and Raman spectroscopy. The AgNPs were then conjugated with HCQ at different concentrations. The study aimed to explore the effectiveness of HCQ against malaria and autoimmune diseases as well as how conjugating AgNPs with HCQ would broaden its activity against various infections and diseases, owing to the antimicrobial activity of AgNPs. The electronic and vibrational study of HCQ and its mixture showed a successful conjugation of the two, which would increase the potent of HCQ against SARS Coronavirus (SARS-COV-2) infection. Steady-state absorption measurements revealed a broadband peak at around 337.4 nm (3.68 eV), corresponding to a π to π* transition in the quinoline ring of the HCQ molecule. In addition, the AgNPs Localized Surface Plasmon Resonance (LSPR) band centred around 408 nm exhibited an intensity decrease with an increase in the concentration of HCQ. The experimental Raman spectra exhibited bands similar to the density function theory (DFT) calculated spectra centred at 392 cm−1, 768 cm−1, 1392 cm−1, 2928 cm−1, 3224 cm−1, 3656 cm−1, and 3808 cm−1. TEM, EDS, and XRD analysis confirmed the formation of 8.75 nm AgNPs. Understanding the electronic and vibrational spectroscopic properties of the interaction between HCQ and AgNPs, as deduced from the spectroscopic results supported by DFT, can significantly benefit researchers in the pharmaceutical industry. Researchers could apply this knowledge to overcome drug resistance, repurpose existing drugs, and reduce the side effects of conventional clinically approved drugs.