Microplastic dynamics and risk projections in West African coastal areas: Developing a vulnerability index, adverse ecological pathways, and mitigation framework using remote-sensed oceanographic profiles.

Microplastic pollution presents a serious risk to marine ecosystems worldwide, with West Africa being especially susceptible. This study sought to identify the key factors driving microplastic dynamics in the region. Using NASA's Giovanni system, we analyzed environmental data from 2019 to 2024. Results showed uniform offshore air temperatures due to turbulence (25.22-45.62 K) with significant variations nearshore. Salinity levels remained largely stable (4 PSU) but slightly decreased in southern Nigeria. Surface wind speeds rose from 4.206-5.026 m/s in Nigeria to over 5.848 m/s off Mauritania, while eastward stress hotspots were prominent in Nigeria and from Sierra Leone to Senegal. Photosynthetically available radiation (PAR) beam values peaked off Mauritania and dipped from Nigeria to Sierra Leone, with the inverse pattern observed for diffuse PAR. Hotspots of high absorption, particulate backscattering, elevated aerosol optical depth, and remote sensing reflectance all pointed to substantial particulate matter concentrations. The Microplastic Vulnerability Index (MVI) identifies the coastal stretch from Nigeria to Guinea-Bissau as highly vulnerable to microplastic accumulation due to conditions that favor buildup. In contrast, moderate vulnerability was observed from Guinea-Bissau to Senegal and in Mauritania, where conditions were less extreme, such as higher offshore temperatures that could promote widespread microplastic suspension and cooler nearshore temperatures that favor sedimentation. Increased turbulence and temperatures in coastal areas of Senegal and Mauritania may enhance microplastic transport and impact marine life. In Nigeria, stable coastal conditions-characterized by consistent temperatures, low turbulence, and uniform salinity-may lead to increased persistence and accumulation of microplastics in sensitive habitats like mangroves and coral reefs. These findings highlight the need for region-specific management strategies to address microplastic pollution and effectively protect marine ecosystems.

Urbanization effects on growth and otolith asymmetry in Chrysichthys nigrodigitatus and Oreochromis niloticus within tropical coastal lagoon watersheds.

In this study, we investigated the growth dynamics and otolith shape asymmetry of two fish species, Chrysichthys nigrodigitatus (CN) and Oreochromis niloticus (ON), within urbanized watersheds of the southern lagoon system, Nigeria. Using the von Bertalanffy growth model (VBGM), in addition to sediment metal concentration indices such as the average shale content, index of geoaccumulation (Igeo), contamination factor (CF), pollution load index (PLI), and potential ecological risk (PER) index, contamination levels were classified, and ecological risks were assessed. Notably, a lower growth potential (t0) was observed in CN at Ikorodu than at Epe, with similar trends for ON in the Epe during the dry season. Otolith asymmetry patterns, particularly in the CN at Ikorodu and ON in the Epe during the dry season, exhibited distinct ecological variations, indicating heightened stress levels at Ikorodu. Sediment analyses revealed moderate to strong contamination (Cd, Pb, Ni, and Cr) in both Lagos Lagoon (Ikorodu) and Epe Lagoon, with Ikorodu exhibiting notably high to moderate contamination levels according to the CF index. Elevated PLI values for Cd and Pb in Ikorodu, in addition to greater PER, indicated increased risk, with Cd posing a high risk (61.42%) and Pb posing a moderate risk (49.50%). Additionally, the reduced asymptotic length in the Epe during the dry season suggests that Chrysichthys nigrodigitatus is adaptable to seasonal variations, while divergent growth patterns in both areas indicate the existence of trade-off mechanisms in response to changing conditions. Habitat-specific otolith asymmetry and metal contamination underscore species adaptability, with wider stressor variability in Lagos than in Epe. Furthermore, multidimensional scaling analysis highlights the intricate relationship between otolith shape variables and environmental factors, emphasizing the need for tailored conservation efforts in urbanized watersheds.

Role of niche and micro-habitat preferences in per- and polyfluoroalkyl substances occurrence in the gills of tropical lake fish species.

The present study has investigated per- and poly-fluoroalkyl substances (PFAS) in the gill tissues of various fish species inhabiting different trophic levels within Eleyele Lake, a tropical freshwater lake in Nigeria. The mean concentrations of PFAS congeners were determined, and their trends and patterns were analyzed across different trophic species. The results revealed variations in congener abundance and species-specific patterns that was influenced by habitat and niche preferences. Multivariate associations using canonical-correlation analysis (CCA) revealed distinct trends in the relationships between gill concentrations of specific PFAS congeners and different trophic groups. The strongest congener relationships were observed in the pelagic omnivore (Oreochromic niloticus: ON) with positive associations for 4:2 FTS, 9CL-PF3ONS, PFTDA, MeFOSA and PFHxS. The differences in congener profiles for the two herbivorous fish (Sarotherodon melanotheron (SM) and Coptodon galilaeus (CG)) reflect possible divergence in microhabitat and niche preferences. Furthermore, the congener overlaps between the herbivore (CG), and benthic omnivore (Clarias gariepinus: ClG) indicate a possible niche and microhabitat overlap. Our study provides valuable insights into the congener dynamics of PFAS at Eleyele Lake. However, the dissimilarity and overlapping PFAS congener profile in fish gills reflects the interplay of species niche preference and microhabitat associations. The present study highlights the need for further research to assess ecological risks and develop effective PFAS management strategies.

Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer.

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10-4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

Predicting the dynamics of per- and polyfluoroalkyl substances in coastal regions of Africa: vulnerability index and adverse ecological pathways from remote-sensed variables.

This study aimed to predict the dynamics of per- and polyfluoroalkyl substance (PFAS) contamination and ecological vulnerability within coastal regions of Africa utilizing time-averaged remote-sensed data patterns from 2020 to 2023. The analysis identified PFAS contamination hotspots along the coast of Africa, particularly in western Africa around Nigeria and in areas spanning Equatorial Guinea and Guinea-Bissau, with risk influenced by eastward wind patterns, overland runoff, and elevated aerosol optical depth (AOD) values. Regional trends indicated that variations in solar energy absorption and surface air temperature could influence PFAS dynamics in North Africa, South Africa, East Africa, and West Africa. In North Africa, intermediate overland runoff and lower sea-surface temperatures were observed. In South Africa, there were intermediate runoff levels and warmer sea-surface temperatures. East Africa experienced intermediate runoff as well. In West Africa, there was increased susceptibility to high overland runoff and aerosol-related PFAS contamination. From the weighted vulnerability index, significant disparities in environmental conditions across African coastal regions revealed that North Africa had relatively lower vulnerability, while West Africa had the highest susceptibility to per- and polyfluoroalkyl substance (PFAS) contamination. This study emphasizes the necessity for region-specific vulnerability index models and targeted mitigation strategies to address diverse ecological and health risks from PFAS contamination along the African coast. Regional and international collaboration, spearheaded by organizations such as the AU and ECOWAS, is essential, with tailored policies aligned with the SDGs, Agenda 2063, and NEPAD crucial for effective environmental management, urging policymakers to prioritize cooperation and resource sharing for comprehensive sustainability goals.

Occurrence, bioaccumulation and trophic dynamics of per- and polyfluoroalkyl substances in two tropical freshwater lakes.

We have investigated the occurrence, distribution, and biomagnification of per- and polyfluoroalkyl substances (PFAS) in two tropical lakes (Asejire and Eleyele) of Southwestern Nigeria, with contrasting urban intensities. Over an 8-month period, we sampled sediment and fish species (Clarias gariepinus: CIG; Oreochromis niloticus: ON; Coptodon guineensis: CG; Sarotherodon melanotheron: SM) across trophic levels, and analyzed various PFAS congeners, in addition to a select group of toxicological responses. While herbivores (SM) and benthic omnivores (CIG) at Asejire exhibited elevated levels of PFBS and PFOS, the pelagic omnivores (ON) showed a dominance of PFOS, PFDA, PFHxDA and EtFOSE in the muscle. At the Eleyele urban lake, PFAS patterns was dominated by PFBS, EtFOSE, PFPeS, PFOcDA and PFOS in the herbivores (SM, CG), EtFOSE, PFOS and PFBS in the pelagic omnivore (ON) and benthic omnivore (ClG). The estimated biomagnification factor (BMF) analysis for both lakes indicated trophic level increase of PFOS, PFUnA and PFDA at the suburban lake, while PFOS and EtFOSE biomagnified at the urban lake. We detected the occurrence of diSAMPAP and 9CL-PF3ONS, novel compounds not commonly reported, in PFAS studies at both lakes. The studied toxicological responses varied across trophic groups in both lakes with probable modulations by environmental conditions, trophic structure, and relative PFAS exposures in the lakes. The present study documents, for the first time in Nigeria, or any other African country, the role of urbanization on contaminant load into the environment and their implications for contaminant dynamics within the ecosystem and for aquatic food safety.

Gonad pathology, sex hormone modulation and vitellogenin expression in Chrysichthys nigrodigitatus from Lagos and Epe lagoons within the southern-lagoon system, Nigeria.

Introduction: Estrogenic chemicals in aquatic environments impact fish reproductive health, with vitellogenin protein levels serving as a crucial biomarker for xenoestrogen exposure. Limited knowledge exists on estrogenic effects in tropical environments, prompting an investigation into the influence of environmental estrogens on Chrysichthys nigrodigitatus in Lagos and Epe lagoons. Methods: A total of 195 fish samples underwent analysis for vitellogenin protein, sex hormones (testosterone and 17 ß-estradiol), and gonad pathology in effluent-receiving areas of the specified lagoons. Results: Gonadal alterations were observed in male and female fish, including empty seminiferous tubules and distorted ovaries. Intersex occurred in 3.81% of Lagos and 3.33% of Epe. Testosterone levels were generally higher in females and males from both lagoons, while E2 levels were higher in females from both lagoons, with Lagos showing higher levels than Epe. Vtg levels were higher in males than females in Lagos samples but showed no significant difference in Epe samples. Discussion: Contaminant analysis revealed similar trends in metals (Hg, As, Cr) and phthalates (DEHP, DBP, DEP) in both sexes in the Epe population. Multivariate depictions from the PCA showed sex-specific patterns of metal uptake (Cd) in male fishes at the Lagos Lagoon. The positive association between higher pH loadings and metal and DBP levels in sediment at the Lagos lagoon suggests the influence of higher alkalinity in lower bioavailability of contaminants. Conclusion: Endocrine disrupting effects were observed in male and female Chrysichthys nigrodigitatus in Lagos and Epe lagoons populations, with notable differences in hormone and contaminant concentrations between the two lagoon systems. Identification of specific contaminants and their spatial and temporal trends can inform targeted management and remediation efforts to protect and restore these valuable aquatic ecosystems.

Habitat sensitivity in the West African coastal area: inferences and implications for regional adaptations to climate change and ocean acidification.

This study focuses on assessing coastal vulnerability and habitat sensitivity along the West African coast by delineating hotspots based on surface temperature, pH, chlorophyll-a, particulate organic carbon, and carbonate concentrations between 2018 and 2023 depending on data availability. Initial exploration of these variables revealed two distinct focal points i.e., the Togo-Nigerian coastal stretch and the stretch from Sierra Leone to Mauritania. Lower pH trends (acidification) in surface waters were observed off the West African coast, particularly in areas around the south-south Niger Delta in Nigeria and the coastal regions of Guinea and Guinea Bissau. Sea surface temperature analysis revealed highest temperatures (27-30°C) within Nigeria to Guinea coastal stretch, intermediate temperatures (24-27°C) within the Guinea Bissau and Senegal coastal stretch, and the lowest temperatures off the coast of Mauritania. Furthermore, correlation analysis between sea surface temperature and calcite concentration in the Mauritania-Senegal hotspot, as well as between overland runoff and particulate organic carbon in the Togo-Nigeria hotspot, revealed strong positive associations (r>0.60) and considerable predictive variability (R2 ≈ 0.40). From the habitat sensitivity analysis, certain regions, including Cape Verde, Côte d'Ivoire, Nigeria, Senegal, and Sierra Leone, exhibited high sensitivity due to environmental challenges and strong human dependence on coastal resources. Conversely, Gambia, Guinea, Guinea-Bissau, Liberia, and Togo displayed lower sensitivity, influenced by geographical-related factors (e.g. coastal layout, topography, etc.) and current levels of economic development (relatively lower industrialization levels). Regional pH variations in West African coastal waters have profound implications for ecosystems, fisheries, and communities. Addressing these challenges requires collaborative regional policies to safeguard shared marine resources. These findings underscore the link between ecosystem health, socioeconomics, and the need for integrated coastal management and ongoing research to support effective conservation.

Preliminary Study on Open Labelled Randomized Controlled Trial of the Safety and Efficacy of Hydroxychloroquine and Chloroquine Phosphate for the Treatment of Persons Infected with 2019 Coronavirus Disease in Nigeria.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a causative agent of COVID-19 is a leading cause of ill-health and deaths worldwide. Currently, COVID-19 has no known widely approved therapeutics. Thus, the need for effective treatment. OBJECTIVES: We investigated the safety and efficacy of two (2) therapeutic agents; chloroquine phosphate (CQ), 2- hydroxychloroquine (HCQ) and a control (standard supportive therapy) among hospitalized adults with COVID-19. METHODS: The clinical trial was done in accordance to the World Health Organization master protocol for investigational therapeutics for COVID-19. Atotal of 40 participants with laboratory-confirmed positive COVID-19 were enrolled. Blood samples and oropharyngeal (OP) swabs were obtained on days 1,3,15 and 29 for safety and efficacy assessments. RESULTS: The baseline demographics showed that the median ages in years (range) were 45 (31-57) in CQ, 45 (36.5-60.5) in HCQ, 43 (39.5-67.0) and 44.5 (25.3-51.3) in the control (P<0.042).At randomization, seven (7) participants were asymptomatic, thirty-three (33) had mild symptoms, eight (8) had moderate symptoms while three (3) had severe symptoms. The average day of conversion to negative COVID-19 was 15.5 days for CQ, 16 days for HCQ and 18 days for the control(P=0.036). CONCLUSION: The safety assessment revealed no adverse effect of the drugs in COVID-19 patients after treatment. These findings proved that chloroquine and hydroxychloroquine are effective for the treatment of COVID-19 among hospitalized adults. It also confirmed that they are safe.

CONTEXTE: Le coronavirus du syndrome respiratoire aigu sévère 2 (SARS-CoV-2),agentcausaldelaCOVID-19, est l'unedes principales causes demaladie et de décès dans le monde. À l'heure actuelle, il n'existe aucun traitement largement approuvé pour la COVID-19. Ainsi, ilya un besoin de traitement efficace. OBJECTIFS: Nous avons étudié l'innocuité et l'efficacité de deux (2) agents thérapeutiques, le phosphate de chloroquine (CQ) et l'hydroxychloroquine (HCQ), ainsi qu'un groupe témoin (traitement de soutien standard) chez des adultes hospitalisés atteints de la COVID-19.MÉTHODES: L'essai clinique a été mené conformément au protocole maître de l'Organisation mondiale de la santé pour les thérapeutiques à l'étude de la COVID-19. Au total, 40 participants atteints de la COVID-19, confirmée en laboratoire, ont été in scrits. Des échantillons de sang et des prélèvements oropharyngés (PO) ont été effectuésauxjours1,3,15et29pourévaluerl'innocuitéetl'efficacité. RÉSULTATS: Les données démographiques initiales ont révélé que l'âge médian en années (plage) était de 45 (31-57) pour le groupe CQ, de 45 (36,5-60,5) pour le groupe HCQ, de 43 (39,5-67,0) et de 44,5 (25,3-51,3) pour le groupe témoin (P<0,042). À la randomisation, sept (7) participants étaient asymptomatiques, trente-trois (33) présentaient des symptômes bénins, huit(8) avaient des symptômes modérés, tandis que trois(3) avaient des symptômes graves. Le jour moyende conversionentest COVID-19 négatif était de 15,5 jours pour le groupe CQ, de 16 jours pour le groupe HCQ et de 18 jours pourle groupe témoin (P=0,036). CONCLUSION: L'évaluation de la sécurité n'a révélé aucun effet indésirable des médicaments chez les patients atteints de la COVID-19 après le traitement. Ces conclusions ont prouvé que la chloroquine et l'hydroxychloroquine sont efficaces pour le traitement de la COVID-19 chez les adultes hospitalisés. Cela a également confirmé qu' ilssont sûrs. Mots-clés: COVID-19, SARS-CoV-2, essai clinique, innocuité, efficacité, thérapeutiques.

Development and Validation of Cannabis Use Disorder Scale among University Undergraduates in Nigeria.

BACKGROUND: Psychoactive substance use continues to be an important public health issue among the populace, most especially in adolescents and young adults. Cannabis is one of the commonly used substances with associated health complications, hence the necessity for its screening among at-risk people. Thus, our study set out to develop and validate a screening inventory, the Cannabis Use Disorder Scale (CUDS) for cannabis use detection among undergraduate students in Nigeria. METHODS: In a cross-sectional study of selected undergraduate students in a Nigerian University, the Cannabis Use Disorder Scale (CUDS) was developed by the authors and validated against a standard instrument, Cannabis Use Problem Identification Test (CUPIT). RESULTS: The mean age of the 306 participants was 21.9±2.69 years, made up of 70.6% males and 29.4% females. The mean score on CUDS was 41.00, and a score above this indicates a positive screen for cannabis use. In terms of validity, there was a strong correlation between CUDS and CUPIT scores, with Pearson Product Moment correlation coefficient, r=0.722** at p=0.01 on concurrent validity; and with construct validity, the Kaiser-Meyer Olkin (KMO) test yielded a KMO of 0.900, while the Barlett's tests of sphericity yielded an approximate Chi-Square of 2820.00,df=300, at p<0.01.Again, Cronbach's alpha for CUDS was found to be 0.906**, and Guttman split-half reliability to be 0.862** at p<0.05. CONCLUSION: In this study, the newly developed cannabis use screening inventory, CUDS was found to be a valid and reliable instrument for use in Nigeria.

CONTEXTE: L'utilisation de substances psychoactives continue d'être un problème de santé publique important parmi la population, en particulier chez les adolescents et les jeunes adultes. Le cannabis est l'une des substances couramment utilisées avec des complications de santé associées, d'où la nécessité de le dépister chez les personnes à risque. Ainsi, notre étude visait à développer et valider une échelle de dépistage, l'Échelle des Troubles Liés à la Consommation de Cannabis (CUDS) pour la détection de la consommation de cannabis chez les étudiants universitaires au Nigéria. MÉTHODES: Dans le cadre d'une étude transversale menée auprès d'étudiants universitaires sélectionnés dans une université nigériane, l'Échelle des Troubles Liés à la Consommation de Cannabis (CUDS) a été développée par les auteurs et validée par rapport à un instrument standard, le Test d'Identification des Problèmes Liés à la Consommation de Cannabis (CUPIT). RÉSULTATS: L'âge moyen des 306 participants était de 21,9±2,69 ans, avec une répartition de 70,6 % d'hommes et 29,4 % de femmes. Le score moyen au CUDS était de 41,00, et un score supérieur à cela indique un dépistage positif de la consommation de cannabis. En termes de validité, il y avait une forte corrélation entre les scores du CUDS et du CUPIT, avec un coefficient de corrélation de Pearson de 0,722** à p=0,01 pour la validité concurrente ; et en ce qui concerne la validité de construit, le test Kaiser-Meyer-Olkin (KMO) a donné un KMO de 0,900, tandis que le test de sphéricité de Barlett a donné un Chi-Carré approximatif de 2820,00, df=300, à p<0,01. De plus, l'alpha de Cronbach pour le CUDS s'est avéré être de 0,906**, et la fiabilité en demi-split de Guttman était de 0,862** à p<0,05. CONCLUSION: Dans cette étude, la nouvelle échelle de dépistage de la consommation de cannabis, le CUDS, s'est révélée être un instrument valide et fiable pour une utilisation au Nigéria. Mots-clés: Consommation de cannabis; CUDS; Validation Nigéria.

Redox-active metals and oxidative stress-mediated myopathies in Callinectes amnicola, blue crab populations from impacted sites of the Lagos Lagoon: inferences for adverse ecological outcomes.

While oxidative stress pathways are associated with a wide variety of tissue pathologies, its applications for evaluating and discerning ecological risks are limited. This study seeks to associate trends of lipid peroxidation and oxidative stress to risks of muscle pathologies in blue crabs inhabiting regions of the Lagos Lagoon. Crab samples (n = 520) were selected from pollution-impacted sites of the lagoon at Iddo, Ajah, Okobaba, Makoko, and the mid-lagoon area (control site). Antioxidant enzyme capacity, i.e., superoxide dismutase, catalase, glutathione peroxidase (GPx), and glutathione-S-transferase, and lipid peroxidation were evaluated in the muscle tissue of the blue crabs. The study findings showed distinct patterns of metal uptake in muscle, with redox-active metals (Cu and Zn) and redox-inactive metals (Pb and Cd) exhibiting site-specific differences. Additionally, there were changes in antioxidant modulation, lipid peroxidation, and the presence of associated myopathies. Blue crabs from sites (Makoko and Ajah) with greater uptake of redox-active metals (Cu and Zn) in muscle tissue showed higher trends of lipid peroxidation and the most prevalence of severe regression-type myopathies. Sites with lower uptake of redox-active metals showed the predominance of circulatory-type myopathies. This study also provides evidence of severe necrosis and myositis associated with digenean parasite cysts in crab muscle. Pathological evidence of severe skeletal muscle deterioration in the presence of greater lipid peroxidation could have implications for motor-neuron activity and reduced force-generating capacity necessary for adaptive responses in the wild. We conclude that elevated uptake of redox metals could aggravate the onset of myopathies in wild populations.

Baseline prevalence of molecular marker of sulfadoxine/pyrimethamine resistance in Ebonyi and Osun states, Nigeria: amplicon deep sequencing of dhps-540.

BACKGROUND: Chemoprevention plays an important role in malaria control strategy. Perennial malaria chemoprevention (PMC) using sulfadoxine/pyrimethamine (SP) is a WHO-approved strategy to combat malaria in young children and may lead to drug pressure. Introducing SP-PMC may therefore be compromised due to the emergence of Plasmodium falciparum resistant to SP, particularly mutation at K540E of the dihydropteroate synthase (dhps) gene. Molecular surveillance of resistance markers can support assessment of antimalarial efficacy and effectiveness. High prevalence of 540E is associated with reduced effectiveness of SP, and areas with more than 50% prevalence are considered unsuitable for intermittent preventative treatment in pregnancy (IPTp) implementation. Assessing 540E prevalence is an important undertaking before implementation of SP-PMC. METHODS: We conducted a rapid surveillance of dhps-540E to assess the suitability of SP as PMC in field studies from Ebonyi and Osun states in Nigeria. We used an in-house developed amplicon deep-sequencing method targeting part of the dhps gene. RESULTS: Our data reveal that 18.56% of individuals evaluated carried the 540E mutation mixed with the WT K540. Mutant variant 540E alone was not found, and 80% of isolates harboured only WT (K540). Clonal analysis of the sequencing data shows a very low proportion of 540E circulating in both states. CONCLUSIONS: Our data show that both states are suitable for SP-PMC implementation and, based on this finding, SP-PMC was implemented in Osun in 2022. Continuous monitoring of 540E will be required to ensure the chemoprevention effectiveness of SP in Nigeria.

Public health implications of endocrine disrupting chemicals in drinking water and aquatic food resources in Nigeria: A state-of-the-science review.

This state-of-the-science review is aimed at identifying the sources, occurrence, and concentrations of EDCs, including potential public health risks associated with drinking water and aquatic food resources from Nigerian inland waters. A total of 6024 articles from scientific databases (PubMed, Scopus, Web of science, ScienceDirect, Google Scholar, and African Journals Online) were identified, out of which, 103 eligible articles were selected for this study. Eleven (11) classes of EDCs (OCPs, PCBs, PBDEs, PAHs, BPA, OTs, PEs, PCs, PPCPs, sterols and n-alkanes) were identified from drinking waters, river sediments and aquatic food species from Nigerian rivers, showing that OCPs were the most studied and reported EDCs. Analytical methods used were HPLC, LC-MS/MS, GC-FID, GC-ECD and GC-MS with all EDCs identified to originate from anthropogenic sources. Carcinogenic, mutagenic, and teratogenic effects were the highest (54.4 %) toxicological effects identified, while reproductive/endocrine disruptive effects (15.2 %) and obesogenic effects (4.3 %) were the least identified toxicological effects. The targeted hazard quotient (THQ) and cancer risk (CR) were generally highest in children, compared to the adult populations, indicating age-specific toxicity. PEs produced the highest THQ (330.3) and CR (1.2) for all the EDCs in drinking water for the children population, suggesting enhanced vulnerability of this population group, compared to the adult population. Due to associated public health, wildlife and environmental risk of EDCs and their increasing concentrations in drinking water and food fish species from Nigerian inland waters, there is an urgent need for focused and strategic interventions, sensitization and policy formulation/implementation towards public health and aquatic food safety in Nigeria.

Efficacy of Hexetidine, Thymol and Hydrogen Peroxide-Containing Oral Antiseptics in Reducing Sars-Cov-2 Virus in the Oral Cavity: A Pilot Study.

BACKGROUND: Studies have demonstrated the role of sputum as a site of severe acute respiratory syndrome-coronavirus-2 (SARSCoV-2) transmission. However, there is limited literature on the virucidal efficacy of oral antiseptics against SARS-CoV-2 virus. This study investigated the virucidal efficacy of three oral-antiseptics compared to a placebo-control in the sputum of SARS-CoV-2 infected individuals. METHODOLOGY: A pilot study of adults with SARS-CoV-2 positive results, as determined by reverse transcription-polymerase chain reaction (RT-PCR) of <7 days. The oral antiseptics investigated were: Hexetidine (0.1% w/v); Thymol (0.063% w/v) and H2O2(1.5%) compared to de-mineralized sterile water (Placebo-control). The primary outcome measure was the proportion of negative RT-PCR results at 15-mins, 30-mins, 1-hour, 2-hours and 4-hours After Oral antiseptics Interventions (AOI) compared to the placebo-control. Statistical analysis was done using STATA 15.0 software with p-values of <0.05 considered statistically significant. RESULTS: Data from a total of 66 participants that were RT-PCR SARS-CoV-2 positive at baseline (0-min) was analysed. At 15-mins AOI, the highest proportion of negativation from sputum samples was observed in the Hexedine group, with 69.2% of the baseline PCR positive cases converting to negative compared to 46.7% in the placebo-control group. In addition, H2O2 demonstrated efficacy at 2-hours AOI compared to placebo-control (62.5% vs 37.5% respectively) and other oral-antiseptics. Across all time-points, the oral-antiseptic groups compared to the placebo-control group, there was no statistically significant difference in the proportion of sputum samples which converted to a negative status (p>0.05). CONCLUSION: The findings in this study suggest there was no significant difference in the proportion of participants who converted to a negative sputum status across the treatment groups at various time points. Future studies could compare the cycle threshold (ct) viral titre values of sputum samples to determine quantitative differences.

CONTEXTE: Des études ont démontré le rôle des expectorations comme un site de transmission du syndrome respiratoire aigu sévère-coronavirus- 2 (SRAS-CoV-2). Cependant, il existe peu de documentation sur l'efficacité virucide des antiseptiques oraux contre le virus du SRASCoV-2. Cette étude a examiné l'efficacité virucide de trois antiseptiques oraux par rapport à un contrôle placebo dans les expectorations de personnes infectées par le SRAS-CoV-2. MÉTHODOLOGIE: Une étude pilote menée auprès d'adultes dont les résultats sont positifs pour le SRAS-CoV-2, tels que déterminés par la réaction en chaîne de la polymérase par transcription inverse (RT-PCR) pendant 7 jours. Les antiseptiques oraux étudiés étaient : Hexetidine (0,1% p/v) ; Thymol (0,063% p/v) et H2O2 (1,5%) par rapport à l'eau stérile déminéralisée (Placebo-contrôle). Le principal critère d'évaluation était la proportion de résultats RT-PCR négatifs 15 minutes, 30 minutes, 1 heure, 2 heures et 4 heures après les interventions antiseptiques orales (AOI) par rapport au contrôle placebo. L'analyse statistique a été réalisée à l'aide du logiciel STATA 15.0, les valeurs p de <0,05 étant considérées comme statistiquement significatives. RÉSULTATS: Les données d'un total de 66 participants qui étaient positifs à la RT-PCR SARS-CoV-2 au départ (0 minute) ont été analysées. Au bout de 15 minutes, la plus forte proportion de négativation des échantillons d'expectoration a été observée dans le groupe Hexedine, 69,2 % des cas positifs au départ par PCR devenant négatifs, contre 46,7 % dans le groupe témoin placebo. En outre, l'H2O2 a démontré son efficacité à 2 heures après l'apparition de la maladie par rapport au groupe placebo (62,5 % contre 37,5 % respectivement) et aux autres antiseptiques oraux. Pour tous les points temporels, les groupes d'antiseptiques oraux comparés au groupe placebo n'ont pas présenté de différence statistiquement significative dans la proportion d'échantillons d'expectoration qui sont devenus négatifs (p>0,05). CONCLUSION: Les résultats de cette étude suggèrent qu'il n'y a pas de différence significative dans la proportion de participants qui sont passés à un statut négatif d'expectoration dans les groupes de traitement à différents moments. Les études futures pourraient comparer les valeurs du titre viral au seuil de cycle (ct) des échantillons d'expectoration afin de déterminer les différences quantitatives. MOTS CLÉS: SRAS-CoV-2, antiseptiques oraux, hexétidine, peroxyde d'hydrogène.

Determinants of Antimicrobial Use for Covid-19 Related Symptoms among Nigerians.

BACKGROUND: Antimicrobial use plays a key role in development and spread of antimicrobial resistance. Following the global coronavirus disease 2019 (COVID-19) pandemic and the report of the first confirmed case in Nigeria, several states embarked on either a full or partial lockdown as a measure to prevent or curtail the spread of the virus with its attendant challenges. This survey was designed to provide a snapshot of public antimicrobial use and common perception related to antimicrobial use for COVID-19 related symptoms among Nigerian populace. METHODS: We developed and tested a 29-question electronic questionnaire with Google forms asking respondents about their antimicrobial use and perceptions regarding appropriate antimicrobial use for real or perceived symptoms during the outbreak period. Respondents aged 18 years and above were recruited through crowd sourcing and they received the link to the survey tool through emails and social media including WhatsApp, Twitter, Facebook, LinkedIn, and Instagram. All data analysis was performed using SPSS version 26.0. RESULTS: A total of 410 responses were received from the six geopolitical zones in Nigeria comprising 200 (48.8%) females and 210 (51.2%) males. Majority (62.9%) of the respondents had taken antimicrobials in the 3 months period preceding the survey, while less than half (46.8%) received prescription for it. Previous intake of antimicrobial for similar illness was a predictor of antimicrobial intake (OR: 0.55, 95%CI: 0.30-1.01). The most consumed antimicrobial was antimalarial drugs, specifically Artemisinin-based combination therapy (43.4%), followed by antibiotics [Ciprofloxacin (20.2%)]. CONCLUSION: There was high levels of antimicrobial use for COVID-19 related symptoms by the Nigerian public. This is likely to escalate the already high prevalence of antimicrobial use previously reported and may further fuel the emergence of antimicrobial resistance.

CONTEXTE: L'utilisation d'antimicrobiens joue un rôle clé dans le développement et la propagation de la résistance aux antimicrobiens. À la suite de la pandémie mondiale de coronavirus 2019 (COVID-19) et du rapport du premier cas confirmé au Nigéria, plusieurs États se sont engagés dans un verrouillage complet ou partiel en tant que mesure pour prévenir ou freiner la propagation du virus avec ses défis associés. Cette enquête a été conçue pour fournir un aperçu de l'utilisation publique des antimicrobiens et de la perception commune liée à l'utilisation des antimicrobiens pour les symptômes liés au COVID-19 parmi la population nigériane. MÉTHODES: Nous avons développé et testé un questionnaire électronique de 29 questions avec des formulaires Google interrogeant les répondants sur leur utilisation d'antimicrobiens et leurs perceptions concernant l'utilisation appropriée d'antimicrobiens pour les symptômes réels ou perçus pendant la période d'épidémie. Les répondants âgés de 18 ans et plus ont été recrutés via le crowdsourcing et ils ont reçu le lien vers l'outil d'enquête via des e-mails et des médias sociaux, notamment WhatsApp, Twitter, Facebook, LinkedIn et Instagram. Toutes les analyses de données ont été effectuées à l'aide de la version 26.0 de SPSS. RÉSULTATS: Un total de 410 réponses ont été reçues des six zones géopolitiques du Nigéria comprenant 200 (48,8%) femmes et 210 (51,2%) hommes. La majorité (62,9%) des répondants avaient pris des antimicrobiens au cours des 3 mois précédant l'enquête, tandis que moins de la moitié (46,8%) en avaient reçu une prescription. La prise antérieure d'antimicrobiens pour une maladie similaire était un prédicteur de l'ingestion d'antimicrobiens (OR: 0,55, IC à 95%: 0,30-1,01). L'antimicrobien le plus consommé était les antipaludiques, en particulier les associations thérapeutiques à base d'artémisinine (43,4%), suivis des antibiotiques [Ciprofloxacine (20,2%)]. CONCLUSION: Il y avait des niveaux élevés d'utilisation d'antimicrobiens pour les symptômes liés au COVID-19 par le public nigérian. Cela est susceptible d'augmenter la prévalence déjà élevée de l'utilisation d'antimicrobiens rapportée précédemment et peut encore alimenter l'émergence de la résistance aux antimicrobiens.

Anti-hyperlipidemic and antioxidant potentials of aqueous leaf extract of Telfairia occidentalis (fluted pumpkin) in male Sprague-Dawley rats.

In Africa traditional medicine, certain plant leaves are employed in the treatment of metabolic disorders such as dyslipidaemia. Telfairia occidentalis is named among Nigerian plants that are under investigation for anti-hyperlipidemic activity. The antihperlipidemic and antioxidant potentials of Telfairia Occidentalis (TO) aqueous leaf extract were studied in male Sprague- Dawley rats. Twenty-four healthy male Sprague-Dawley rats were grouped into four of six rats thus: Group A (control) received normal saline (10mg/Kg); treated groups B, C and D, received, 50mg/kg; 100mg/kg; and 150mg/kg of Telfairia occidentalis aqueous leaf extract for 14 days respectively. At the end of the experiment serum cholesterol (CHOL), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) were determined. Liver enzymes' aspartate amino transferase (AST), alanine amino transferase (ALT), Alkaline phosphatase (ALP) were also assessed. Serum level creatinine was determined and antioxidant enzymes' reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were investigated. Lipid peroxidation's malonaldehyde (MDA) level was also assessed. Results from the current study showed a significant decrease in CHOL and LDL levels at all the doses tested (p<0.05) compared with control. Telfairia occidentalis produced a significant increase (p<0.05) in HDL level in all the tested doses compared with control However, TG was significantly decreased at 100mg and 150mg/kg compared with control (p<0.05). TO aqueous leaf extract produced a significant decrease (p<0.05) in AST level in all the tested doses compared with control. ALT level was significantly decreased (p<0.05) at 100mg/kg and 150mg/kg doses compared with control while ALP level significantly elevated (p<0.05) in all the doses tested compared with control. Creatinine level was significantly reduced at 50mg/kg and 100mg/kg doses when compared with control (p<0.05). The results from the antioxidant analysis revealed a significant increase in SOD, GSH and CAT with concomitant reduction in MDA's lipid peroxidation when compared with control (p<0.05). The current findings revealed that Telfairia occidentalis aqueous leaf extract is anti-hyperlipidemic, possesses hepato-reno effect and antioxidant potentials. However, care has to be taken during its use as it has ability to elevate LDL and the activities of liver enzymes at higher doses which may be deleterious to the body system.

A possible case of renal oxalate deposit reported in an African fruit bat (Epomops franqueti).

We report a possible spontaneous case of oxalate nephrosis in an African fruit bat (Epomops franqueti), incidentally observed in Ibadan, South-West Nigeria, in an anatomical and serological survey of the species. Wild caught bats underwent sedation, intracardial perfusion, necropsy and histopathology. All 15 wild-caught African fruit bats were apparently healthy. However, light microscopy revealed mild oligofocal tubulonephrosis with intraluminal deposition of polarizing crystals interpreted as subclinical oxalate nephrosis in one case. In summary, we suggest a dietary aetiology, based on seasonal availability of high ascorbic acid or oxalate containing fruits. However, exposure to anthropogenic contaminants cannot be completely ruled out.

Detection and occurrence of microplastics in the stomach of commercial fish species from a municipal water supply lake in southwestern Nigeria.

Microplastics (MPs) are physical anthropogenic pollutants and their ability to act as contaminant vectors in biological matrices is of serious ecosystem and human health concern. In the present study, we have, for the first time, screened and detected MPs in the stomach of a select group of commonly consumed fish species from a municipal water supply lake (Eleyele) in Nigeria. A total of 109 fish samples consisting of eight (8) species: Coptodon zillii (CZ: n = 38), Oreochromis niloticus (ON: n = 43), Sarotheron melanotheron (SM: n = 19), Chrysicthys nigrodigitatus (CN: n = 3), Lates niloticus (LN: n = 3), Paranchanna obscura (PO: n = 1), Hemichromis fasiatus (HF: n = 1), and Hepsetus odoe (HO: n = 1) were collected between February-April, 2018. Fish stomach content was screened for the presence of MPs using the density gradient separation technique (NaCl hypersaline solution) and examined using a fluorescence microscope. MPs were present in all the species screened (except H. fasciatus) with a frequency of 69.7% positive individuals in the examined species. MP prevalence was highest in ON (34%) > CZ (32%) > SM (13%) > CN (6%) and 5% each, for PO HO, and LN. On average, 1-6 MPs with sizes ranging between 124 µm and 1.53 mm were detected per individual. However, the highest number (34) of MPs was detected in the stomach of SM. Principal coordinate analysis (PCA) identified ecological variables such as habitat, feeding mode, and trophic levels as critical factors that may determine and influence MP uptake in fish population. The PCA showed stronger association between fish habitat, feeding mode, and trophic level with MP size and number in the benthopelagic species (ON CZ and SM), compared to demersal species (PO CN HO and LN). Given that MPs can act as vectors for the transfer of pathogens and environmental contaminants (both legacy and emerging), in addition to direct health risks to aquatic organisms, our findings raise concerns on the potential human/wildlife health effects of MPs in these economically and ecologically important food fishes.

Contaminant levels and endocrine disruptive effects in Clarias gariepinus exposed to simulated leachate from a solid waste dumpsite in Calabar, Nigeria.

Solid waste dumpsites (SWDs) and landfills are significant sources of emerging contaminants to terrestrial and aquatic ecosystems. We have studied the endocrine disruptive effects of simulated leachate from a solid waste dumpsite in Calabar, Nigeria. Juvenile C. gariepinus were exposed to simulated leachate, diluted to 0:0 (control), 1:10, 1:50, 1:100 for 3, 7 and 14 days. In addition, 17ß-estradiol (E2: 100 µg/L)-exposed positive control group was included. Hepatic transcripts for the genes encoding vitellogenin (vtg), estrogen receptor-α (er-α), and aromatase (cyp19a1) were analyzed by real-time PCR. Protein expression for Vtg and Cyp19 were measured by immunoblotting and plasma steroid hormones (testosterone: T and E2) were measured using enzyme immunoassay (EIA). Soil samples from the dumpsite were analyzed for selected group of contaminants showing that DEHP was the only detected phthalate ester (PE) at 1300 ±â€¯400 ng/g. Further, perfluoroalkyl substances (PFASs) such as PFBS, PFOS, PFHxA, PFOA, PFNA, PFDA, PFUnDA and PFDoDA were detected in the soil samples from the dumpsite. We observed significant and apparent concentration-dependent increases in mRNA (vtg, er-α, and cyp19a1) and their corresponding functional protein products, after exposure to the simulated leachates. Further, the simulated leachate produced concentration-specific changes in plasma E2 and T levels. In general, the estrogenic endocrine and reproductive alterations in the exposed fish may directly be attributed to the PFASs and DEHP detected at the dumpsites. However, in addition to PFASs and DEHP, there could be other estrogenic contaminants in the leachate. Given the rapid utilization, for residential purposes, and increases in human settlement in areas around the Lemna SWDs, this study provides a direct cause-and-effect evidence of the potential contaminants at the dumpsite with significant environmental and human health consequences.