Establishment of the HPLC fluorescence detection method for plasma trace ivermectin and its pharmacokinetics in Bactrian camel.

BACKGROUND AND OBJECTIVE: Ivermectin (IVM), a widely used veterinary anthelmintic, lacks recommended doses for Bactrian camels. This study aims to establish its pharmacokinetics in Bactrian camels, comparing with other livestock. METHODS: A method for high-performance liquid chromatography fluorescence detection of IVM in plasma was developed. RESULTS: IVM exhibited linear scaling (y = 0.6946x + 0.0088, R2 = 0.9988) within 0.025-5 ng/mL, with a lower limit of quantification of 25.00 pg/mL, high recovery (>70%) and low RSD (<7%). In Bactrian camels, IVM injection showed a low Cmax, extended Tmax and apparent secondary absorption compared to cattle and sheep. CONCLUSIONS: Slow absorption and widespread distribution were observed, with peak concentration and area under the curve correlating positively with the dose. This study provides insights into IVM pharmacokinetics in Bactrian camels, informing dose determination and highlighting potential metabolic differences compared to other livestock.

Characterization of a pleiotropic regulator MtrA in Streptomyces avermitilis controlling avermectin production and morphological differentiation.

BACKGROUND: The macrolide antibiotic avermectin, a natural product derived from Streptomyces avermitilis, finds extensive applications in agriculture, animal husbandry and medicine. The mtrA (sav_5063) gene functions as a transcriptional regulator belonging to the OmpR family. As a pleiotropic regulator, mtrA not only influences the growth, development, and morphological differentiation of strains but also modulates genes associated with primary metabolism. However, the regulatory role of MtrA in avermectin biosynthesis remains to be elucidated. RESULTS: In this study, we demonstrated that MtrA, a novel OmpR-family transcriptional regulator in S. avermitilis, exerts global regulator effects by negatively regulating avermectin biosynthesis and cell growth while positively controlling morphological differentiation. The deletion of the mtrA gene resulted in an increase in avermectin production, accompanied by a reduction in biomass and a delay in the formation of aerial hyphae and spores. The Electrophoretic Mobility Shift Assay (EMSA) revealed that MtrA exhibited binding affinity towards the upstream region of aveR, the intergenic region between aveA1 and aveA2 genes, as well as the upstream region of aveBVIII in vitro. These findings suggest that MtrA exerts a negative regulatory effect on avermectin biosynthesis by modulating the expression of avermectin biosynthesis cluster genes. Transcriptome sequencing and fluorescence quantitative PCR analysis showed that mtrA deletion increased the transcript levels of the cluster genes aveR, aveA1, aveA2, aveC, aveE, aveA4 and orf-1, which explains the observed increase in avermectin production in the knockout strain. Furthermore, our findings demonstrate that MtrA positively regulates the cell division and differentiation genes bldM and ssgC, while exerting a negative regulatory effect on bldD, thereby modulating the primary metabolic processes associated with cell division, differentiation and growth in S. avermitilis, consequently impacting avermectin biosynthesis. CONCLUSIONS: In this study, we investigated the negative regulatory effect of the global regulator MtrA on avermectin biosynthesis and its effects on morphological differentiation and cell growth, and elucidated its transcriptional regulatory mechanism. Our findings indicate that MtrA plays crucial roles not only in the biosynthesis of avermectin but also in coordinating intricate physiological processes in S. avermitilis. These findings provide insights into the synthesis of avermectin and shed light on the primary and secondary metabolism of S. avermitilis mediated by OmpR-family regulators.

Considering ivermectin for treatment of schistosomiasis.

Because of recent reports of praziquantel resistance in schistosome infections, there have been suggestions to employ ivermectin as a possible alternative, especially as its chemical composition is different from that of praziquantel, so cross-resistance is not expected. In order to ascertain possible damage and elimination of worms, we used ivermectin by oral gavage in infected mice, at a high dose (30.1 mg/kg, bordering toxicity). We also tested the efficacy of the drug at various times postinfection (PI), to check on possible effect on young and mature stages of the parasites. Thus, we treated mice on days 21 and 22 or on days 41 and 42 and even on days 21, 22, 41, and 42 PI. None of the treatment regimens resulted in cure rates or signs of lessened pathology in the mice. We also compared the effect of ivermectin to that of artemisone, an artemisinin derivative which had served us in the past as an effective anti-schistosome drug, and there was a stark difference in the artemisone's efficacy compared to that of ivermectin; while ivermectin was not effective, artemisone eliminated most of the worms, prevented egg production and granulomatous inflammatory response. We assume that the reported lack of activity of ivermectin, in comparison with praziquantel and artemisinins, originates from the difference in their mode of action. In wake of our results, we suggest that ivermectin is not a suitable drug for treatment of schistosomiasis.

A randomized trial to assess the acceleration of viral clearance by the combination Favipiravir/Ivermectin/Niclosamide in mild-to-moderate COVID-19 adult patients (FINCOV).

BACKGROUND: The efficacy of the viral clearance and clinical outcomes of favipiravir (FPV) in outpatients being treated for coronavirus disease 2019 (COVID-19) is unclear. Ivermectin (IVM), niclosamide (NCL), and FPV demonstrated synergistic effects in vitro for exceed 78% inhibiting severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) replication. METHODS: A phase 2, open-label, 1:1, randomized, controlled trial was conducted on Thai patients with mild-to-moderate COVID-19 who received either combination FPV/IVM/NCL therapy or FPV alone to assess the rate of viral clearance among individuals with mild-to-moderate COVID-19. RESULTS: Sixty non-high-risk comorbid patients with mild-to-moderate COVID-19 were randomized; 30 received FPV/IVM/NCL, and 30 received FPV alone. Mixed-effects multiple linear regression analysis of the cycle threshold value from SARS-CoV-2 PCR demonstrated no statistically significant differences in viral clearance rates between the combined FPV/IVM/NCL therapy group and the FPV-alone group. World Health Organization Clinical Progression scores and symptomatic improvement did not differ between arms on days 3, 6, and 10, and no adverse events were reported. No patients required hospitalization, intensive care unit admission, or supplemental oxygen or died within 28 days. C-reactive protein on day 3 was lower in the FPV/IVM/NCL group. CONCLUSION: Viral clearance rates did not differ significantly between the FPV/IVM/NCL combination therapy and FPV-alone groups of individuals with mild-to-moderate COVID-19, although the combined regimen demonstrated a synergistic effect in vitro. No discernible clinical benefit was observed. Further research is required to explore the potential benefits of FVP beyond its antiviral effects. TRIAL REGISTRATION: TCTR20230403007, Registered 3 April 2023 - Retrospectively registered,https://trialsearch.who.int/Trial2.aspx?TrialID=TCTR20230403007.

Biochemistry and transcriptomic analyses of Phthorimaea absoluta (Lepidoptera: Gelechiidae) response to insecticides.

Phthorimaea absoluta is an invasive solanaceous plant pest with highly devastating effects on tomato plant. Heavy reliance on insecticide use to tackle the pest has been linked to insecticide resistance selection in P. absoluta populations. To underline insights on P. absoluta insecticide resistance mechanisms to diamides and avermectins, we evaluated the transcriptomic profile of parental (field-collected) and F8 (lab-reared) populations. Furthermore, to screen for the presence of organophosphate and pyrethroid resistance, we assessed the gene expression levels of acetylcholinesterase (ace1) and para-type voltage-gated sodium channel (VGSG) genes in the F1 to F8 lab-reared progeny of diamide and avermectin exposed P. absoluta field-collected populations. The VGSG gene showed up-regulation in 12.5% and down-regulation in 87.5% of the screened populations, while ace1 gene showed up-regulation in 37.5% and down-regulation in 62.5% of the screened populations. Gene ontology of the differentially expressed genes from both parental and eighth generations of diamide-sprayed P. absoluta populations revealed three genes involved in the metabolic detoxification of diamides in P. absoluta. Therefore, our study showed that the detoxification enzymes found could be responsible for P. absoluta diamide-based resistance, while behavioural resistance, which is stimulus-dependent, could be attributed to P. absoluta avermectin resistance.

Mitochondrial coding genes mediate insecticide tolerance in the oriental fruit fly, Bactrocera dorsalis (Hendel).

The oriental fruit fly, Bactrocera dorsalis (Hendel), an invasive insect pest infesting fruits and vegetables, possesses a remarkable capacity for environmental adaptation. The investigation of behind mechanisms of the stress adaptability in B. dorsalis holds significantly practical relevance. Previous studies on the molecular mechanism underlying stress resistance in B. dorsalis have predominantly focused on nuclear-coding genes, with limited exploration on organelle-coding genes. In this study, we assessed alterations in the mitochondrial physiological parameters of B. dorsalis under exposure to malathion, avermectin, and beta-cypermethrin at LD50 dosages. The results showed that all three insecticides were capable of reducing mitochondrial complex IV activity and ATP content. Expression patterns of mitochondrial coding genes across different developmental stages, tissues and insecticide exposures were analyzed by RT-qPCR. The results revealed that these mitochondrial coding genes were expressed in various tissues and at different developmental stages. Particularly noteworthy, atp6, cox2, and cytb exhibited substantial up-regulation in response to malathion and avermectin treatment. Furthermore, RNAi-mediated knockdown of atp6 and cox2 resulted in the increased toxicity of malathion and avermectin against B. dorsalis, and cox2 silencing was also associated with the decreased complex IV activity. These findings suggest that atp6 and cox2 most likely play pivotal roles in mediating tolerance or resistance to malathion and avermectin in B. dorsalis. Our results provide novel insights into the role of mitochondrial coding genes in conferring tolerance to insecticides in B. dorsalis, with practical implications for controlling this pest in the field.

The combination of chemical fertilizer affected the control efficacy against root-knot nematode and environmental behavior of abamectin in soil.

Chemical fertilizer and pesticide are necessary in agriculture, which have been frequently used, sometimes even at the same time or in combination. To understand the interactions of them could be of significance for better use of these agrochemicals. In this study, the influence of chemical fertilizers (urea, potassium sulfate, ammonium sulfate and superphosphate) on the control efficacy and environmental behavior of abamectin was investigated, which could be applied in soil for controlling nematodes. In laboratory assays, ammonium sulfate at 1 and 2 g/L decreased the LC50 values of abamectin to Meloidogyne incognita from 0.17 mg/L to 0.081 and 0.043 mg/L, indicating it could increase the contact toxicity. In greenhouse trial, ammonium sulfate at 1000 mg/kg increased the control efficacy of abamectin by 1.37 times. Meanwhile, the combination of abamectin with ammonium sulfate could also promote the tomato seedling growth as well as the defense-related enzyme activity under M. incognita stress. The persistence and mobility of abamectin in soil were significantly elevated by ammonium sulfate, which could prolong and promote the control efficacy against nematodes. These results could provide reference for reasonable use of abamectin and fertilizers so as to increase the control efficacy and minimize the environmental risks.

CncC-Keap1-P450s pathway is involved in the detoxification of emamectin benzoate in the spongy moth Lymantria dispar.

The detoxification of insecticides in insects is dependent on the expression and activity of multiple detoxification enzymes. As an important modulator of detoxification enzymes, the CncC-Keap1 pathway was involved in the detoxification of various pesticides. However, whether the CncC-Keap1 pathway is involved in the detoxification of emamectin benzoate (EMB) is unclear. In this study, we cloned the LdCncC and LdKeap1 from spongy moths (Lymantria dispar). Our results showed that EMB exposure induced oxidative stress, and activated the CncC-Keap1 pathway at mRNA and protein levels. Removing ROS by N-acetylcysteine remarkably decreased H2O2 levels and restored the expression of LdCncC and LdKeap1. The silencing LdCncC, not LdKeap1, by dsRNA significantly decreased the cytochrome P450 activities, and increased the sensitivity of larvae to EMB. Besides, the expression of CYP6B7v1, CYP321A7 and CYP4S4v1 were significantly decreased after silencing LdCncC. Notably, the knockdown of CYP6B7v1, CYP321A7 or CYP4S4v1 significantly increased the mortality induced by EMB exposure. Therefore, we proposed that activation of CncC-Keap1 pathway induced by ROS increased the detoxification of EMB in spongy moths by regulating the expression of CYP6B7v1, CYP321A7 and CYP4S4v1. Our study strengthened the understanding of the detoxification of EMB from the perspective of CncC-Keap1-P450s pathway.

Impact of annual community-directed treatment with ivermectin on the incidence of epilepsy in Mvolo, a two-year prospective study.

OBJECTIVES: The potential impact of cumulative community-directed treatment with ivermectin (CDTI) on epilepsy epidemiology in Mvolo County, South Sudan, an onchocerciasis-endemic area with high epilepsy prevalence, was investigated. Annual CDTI was introduced in 2002 in Mvolo, with interruptions in 2016 and 2020. METHODS: Comprehensive house-to-house surveys in Mvolo (June 2020 and 2022) identified cases of epilepsy, including probable nodding syndrome (pNS). Community workers screened households in selected sites for suspected epilepsy, and medical doctors confirmed the diagnosis and determined the year of seizure onset. The incidence of epilepsy, including pNS, was analysed using 95% confidence intervals (CIs). Data on ivermectin intake and onchocerciasis-associated manifestations (itching and blindness) were collected. RESULTS: The surveys covered 15,755 (2020) and 15,092 (2022) individuals, identifying 809 (5.2%, 95% CI: 4.8-5.5%) and 672 (4.5%, 95% CI: 4.1-4.8%) epilepsy cases, respectively. Each survey reported that a third of the surveyed population experienced skin itching, and 3% were blind. Epilepsy incidence per 100,000 person-years gradually declined, from 326.5 (95% CI: 266.8-399.1) in 2013-2015 to 96.6 (95% CI: 65.5-141.7) in 2019-2021. Similarly, pNS incidence per 100,000 person-years decreased from 151.7 (95% CI: 112.7-203.4) to 27.0 (95% CI: 12.5-55.5). Coverage of CDTI was suboptimal, reaching only 64.0% of participants in 2019 and falling to 24.1% in 2021 following an interruption in 2020 due to COVID-19 restrictions. Additionally, while 99.4% of cases had active epilepsy in 2022, less than a quarter of these had access to antiseizure medication. CONCLUSIONS: The observed decrease in epilepsy incidence despite suboptimal CDTI coverage highlights the potential impact of onchocerciasis control efforts and underscores the need to strengthen these efforts in Mvolo County and across South Sudan. As a proactive measure, Mvolo and neighbouring counties are transitioning to biannual CDTI. Furthermore, the substantial epilepsy treatment gap in Mvolo should be addressed.

Deciphering the impact of greenhouse pesticides on hepatic metabolism profile: Toxicity experiments on HepG2 cells using chlorpyrifos and emamectin benzoate.

Epidemiological evidence on the health effects of pesticide exposure among greenhouse workers is limited, and the mechanisms are lacking. Building upon our team's previous population study, we selected two pesticides, CPF and EB, with high detection rates, based on the theoretical foundation that the liver serves as a detoxifying organ, we constructed a toxicity model using HepG2 cells to investigate the impact of individual or combined pesticide exposure on the hepatic metabolism profile, attempting to identify targeted biomarkers. Our results showed that CPF and EB could significantly affect the survival rate of HepG2 cells and disrupt their metabolic profile. There were 117 metabolites interfered by CPF exposure, which mainly affected ABC transporter, biosynthesis of amino acids, center carbon metabolism in cancer, fatty acid biosynthesis and other pathways, 95 metabolites interfered by EB exposure, which mainly affected center carbon metabolism in cancer, HIF-1 signaling pathway, valine, leucine and isoleucine biosynthesis, fatty acid biosynthesis and other pathways. The cross analysis and further biological experiments confirmed that CPF and EB pesticide exposure may affect the HIF-1 signaling pathway and valine, leucine and isoleucine biosynthesis in HepG2 cells, providing reliable experimental evidence for the prevention and treatment of liver damage in greenhouse workers.

68Ga-FAPI-04 PET/CT in Non-Small Cell Lung Cancer: Accurate Evaluation of Lymph Node Metastasis and Correlation with Fibroblast Activation Protein Expression.

Fibroblast activation protein (FAP) is a promising diagnostic and therapeutic target in various solid tumors. This study aimed to assess the diagnostic efficiency of 68Ga-labeled FAP inhibitor (FAPI)-04 PET/CT for detecting lymph node metastasis in non-small cell lung cancer (NSCLC) and to investigate the correlation between tumor 68Ga-FAPI-04 uptake and FAP expression. Methods: We retrospectively enrolled 136 participants with suspected or biopsy-confirmed NSCLC who underwent 68Ga-FAPI-04 PET/CT for initial staging. The diagnostic performance of 68Ga-FAPI-04 for the detection of NSCLC was evaluated. The final histopathology or typical imaging features were used as the reference standard. The SUVmax and SUVmean, 68Ga-FAPI-avid tumor volume (FTV), and total lesion FAP expression (TLF) were measured and calculated. FAP immunostaining of tissue specimens was performed. The correlation between 68Ga-FAPI-04 uptake and FAP expression was assessed using the Spearman correlation coefficient. Results: Ninety-one participants (median age, 65 y [interquartile range, 58-70 y]; 69 men) with NSCLC were finally analyzed. In lesion-based analysis, the diagnostic sensitivity and positive predictive value of 68Ga-FAPI-04 PET/CT for detection of the primary tumor were 96.70% (88/91) and 100% (88/88), respectively. In station-based analysis, the diagnostic sensitivity, specificity, and accuracy for the detection of lymph node metastasis were 72.00% (18/25), 93.10% (108/116), and 89.36% (126/141), respectively. Tumor 68Ga-FAPI-04 uptake (SUVmax, SUVmean, FTV, and TLF) correlated positively with FAP expression (r = 0.470, 0.477, 0.582, and 0.608, respectively; all P ≤ 0.001). The volume parameters FTV and TLF correlated strongly with FAP expression in 31 surgical specimens (r = 0.700 and 0.770, respectively; both P < 0.001). Conclusion: 68Ga-FAPI-04 PET/CT had excellent diagnostic efficiency for detecting lymph node metastasis, and 68Ga-FAPI-04 uptake showed a close association with FAP expression in participants with NSCLC.

Strongyloidiasis in Auckland: A ten-year retrospective study of diagnosis, treatment and outcomes of a predominantly Polynesian and Fijian migrant cohort.

BACKGROUND: Strongyloides stercoralis is not endemic in Aotearoa New Zealand (AoNZ). However, approximately one third of Auckland residents are born in endemic countries. This study aimed to describe the epidemiology and management of strongyloidiasis in Auckland, with a focus on migrants from Pacific Island Countries and Territories. METHODS: This study retrospectively reviewed clinical, laboratory and pharmacy records data for all people diagnosed with strongyloidiasis in the Auckland region between July 2012 and June 2022. People with negative Strongyloides serology were included to estimate seropositivity rate by country of birth. FINDINGS: Over ten years, 691 people were diagnosed with strongyloidiasis. Most diagnoses were made by serology alone (622, 90%). The median age was 63 years (range 15-92), 500 (72%) were male, and the majority were born in Polynesia (350, 51%), Fiji (130, 19%) or were of Pasifika ethnicity (an additional 7%). Twelve participants (1.7%) had severe strongyloidiasis at diagnosis. The total proportion treated with ivermectin was only 70% (484/691), with no differences between immunocompromised and immunocompetent participants, nor by ethnicity. The outcome of treatment (based on a combination of serology and/or eosinophilia and/or stool microscopy) could only be determined in 50% of the treated cohort. One participant failed treatment with ivermectin, experiencing recurrent strongyloidiasis, and another participant died in association with severe strongyloidiasis. The rate of 'positive' Strongyloides serology was highest among participants born in Samoa (48%), Fiji (39%), and Southeast Asian countries (34%). INTERPRETATION: Strongyloidiasis was common and under-treated in Auckland during the study period. Clinicians should have a low threshold for considering strongyloidiasis in migrants from endemic countries, including Polynesia and Fiji.

Elimination of transmission of onchocerciasis (river blindness) with long-term ivermectin mass drug administration with or without vector control in sub-Saharan Africa: a systematic review and meta-analysis.

BACKGROUND: WHO has proposed elimination of transmission of onchocerciasis (river blindness) by 2030. More than 99% of cases of onchocerciasis are in sub-Saharan Africa. Vector control and mass drug administration of ivermectin have been the main interventions for many years, with varying success. We aimed to identify factors associated with elimination of onchocerciasis transmission in sub-Saharan Africa. METHODS: For this systematic review and meta-analysis we searched for published articles reporting epidemiological or entomological assessments of onchocerciasis transmission status in sub-Saharan Africa, with or without vector control. We searched MEDLINE, PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, African Index Medicus, and Google Scholar databases for all articles published from database inception to Aug 19, 2023, without language restrictions. The search terms used were "onchocerciasis" AND "ivermectin" AND "mass drug administration". The three inclusion criteria were (1) focus or foci located in Africa, (2) reporting of elimination of transmission or at least 10 years of ivermectin mass drug administration in the focus or foci, and (3) inclusion of at least one of the following assessments: microfilarial prevalence, nodule prevalence, Ov16 antibody seroprevalence, and blackfly infectivity prevalence. Epidemiological modelling studies and reviews were excluded. Four reviewers (NM, AJ, AM, and TNK) extracted data in duplicate from the full-text articles using a data extraction tool developed in Excel with columns recording the data of interest to be extracted, and a column where important comments for each study could be highlighted. We did not request any individual-level data from authors. Foci were classified as achieving elimination of transmission, being close to elimination of transmission, or with ongoing transmission. We used mixed-effects meta-regression models to identify factors associated with transmission status. This study is registered in PROSPERO, CRD42022338986. FINDINGS: Of 1525 articles screened after the removal of duplicates, 75 provided 282 records from 238 distinct foci in 19 (70%) of the 27 onchocerciasis-endemic countries in sub-Saharan Africa. Elimination of transmission was reported in 24 (9%) records, being close to elimination of transmission in 86 (30%) records, and ongoing transmission in 172 (61%) records. I2 was 83·3% (95% CI 79·7 to 86·3). Records reporting 10 or more years of continuous mass drug administration with 80% or more therapeutic coverage of the eligible population yielded significantly higher odds of achieving elimination of transmission (log-odds 8·5 [95% CI 3·5 to 13·5]) or elimination and being close to elimination of transmission (42·4 [18·7 to 66·1]) than those with no years achieving 80% coverage or more. Reporting 15-19 years of ivermectin mass drug administration (22·7 [17·2 to 28·2]) and biannual treatment (43·3 [27·2 to 59·3]) were positively associated with elimination and being close to elimination of transmission compared with less than 15 years and no biannual mass drug administration, respectively. Having had vector control without vector elimination (-42·8 [-59·1 to -26·5]) and baseline holoendemicity (-41·97 [-60·6 to -23·2]) were associated with increased risk of ongoing transmission compared with no vector control and hypoendemicity, respectively. Blackfly disappearance due to vector control or environmental change contributed to elimination of transmission. INTERPRETATION: Mass drug administration duration, frequency, and coverage; baseline endemicity; and vector elimination or disappearance are important determinants of elimination of onchocerciasis transmission in sub-Saharan Africa. Our findings underscore the importance of improving and sustaining high therapeutic coverage and increasing treatment frequency if countries are to achieve elimination of onchocerciasis transmission. FUNDING: The Bill & Melinda Gates Foundation and Neglected Tropical Diseases Modelling Consortium, UK Medical Research Council, and Global Health EDCTP3 Joint Undertaking. TRANSLATIONS: For the Swahili, French, Spanish and Portuguese translations of the abstract see Supplementary Materials section.

Impact assessment of onchocerciasis through lymphatic filariasis transmission assessment surveys using Ov-16 rapid diagnostic tests in Sierra Leone.

BACKGROUND: Onchocerciasis is endemic in 14 of Sierra Leone's 16 districts with high prevalence (47-88.5%) according to skin snips at baseline. After 11 rounds of mass treatment with ivermectin with good coverage, an impact assessment was conducted in 2017 to assess the progress towards eliminating onchocerciasis in the country. METHODS: A cluster survey was conducted, either integrated with lymphatic filariasis (LF) transmission assessment survey (TAS) or standalone with the LF TAS sampling strategy in 12 (now 14) endemic districts. Finger prick blood samples of randomly selected children in Grades 1-4 were tested in the field using SD Bioline Onchocerciasis IgG4 rapid tests. RESULTS: In total, 17,402 children aged 4-19 years in 177 schools were tested, and data from 17,364 children aged 4-14 years (14,230 children aged 5-9 years) were analyzed. Three hundred forty-six children were confirmed positive for Ov-16 IgG4 antibodies, a prevalence of 2.0% (95% CI 1.8-2.2%) in children aged 4-14 years with prevalence increasing with age. Prevalence in boys (2.4%; 95% CI 2.1-2.7%) was higher than in girls (1.6%; 95% CI 1.4-1.9%). There was a trend of continued reduction from baseline to 2010. Using data from children aged 5-9 years, overall prevalence was 1.7% (95% CI 1.5-1.9%). The site prevalence ranged from 0 to 33.3% (median prevalence = 0.0%): < 2% in 127 schools, 2 to < 5% in 34 schools and ≥ 5% in 16 schools. There was a significant difference in average prevalence between districts. Using spatial analysis, the Ov-16 IgG4 antibody prevalence was predicted to be < 2% in coastal areas and in large parts of Koinadugu, Bombali and Tonkolili Districts, while high prevalence (> 5%) was predicted in some focal areas, centered in Karene, Kailahun and Moyamba/Tonkolili. CONCLUSIONS: Low Ov-16 IgG4 antibody prevalence was shown in most areas across Sierra Leone. In particular, low seroprevalence in children aged 5-9 years suggests that the infection was reduced to a low level after 11 rounds of treatment intervention. Sierra Leone has made major progress towards elimination of onchocerciasis. However, attention must be paid to those high prevalence focal areas.

Identification of inositol monophosphatase as a broad-spectrum antiviral target of ivermectin.

Ivermectin has broad-spectrum antiviral activities. Despite the failure in clinical application of COVID-19, it can serve as a lead compound for the development of more effective broad-spectrum antivirals, for which a better understanding of its antiviral mechanisms is essential. We thus searched for potential novel targets of ivermectin in host cells by label-free thermal proteomic profiling using Huh-7 cells. Inositol monophosphatase (IMPase) was found among the proteins with shifted thermal stability by ivermectin. Ivermectin could inhibit IMPase activity and reduce cellular myo-inositol and phosphatidylinositol-4-phosphate levels. On the other hand, inositol could impair the antiviral activity of ivermectin and lithium, an IMPase inhibitor with known antiviral activity. As phosphatidylinositol phosphate is crucial for the replication of many RNA viruses, inhibition of cellular myo-inositol biosynthesis may be an important antiviral mechanism of ivermectin. Hence, inhibition of IMPase could serve as a potential target for broad-spectrum antiviral development.

Epidemiology and field efficacy of anthelmintic drugs associated with gastrointestinal nematodes of sheep in Nejo district, Oromia, Ethiopia.

Gastrointestinal nematodes (GINs) are major constraints to health and productivity of small ruminants. Methods of their control relies mainly on anthelmintic drugs; however, the indiscriminate use of these drugs could lead to the development of anthelmintic resistance (AR). This study aimed to investigate the epidemiology of GINs infection, and field evaluation of anthelmintic efficacy in sheep. The epidemiological data were collected using a cross-sectional study design while a farm-based field study design was employed for the evaluation of anthelminthic efficacy. Furthermore, standard parasitological techniques were employed for qualitative and quantitative worm identification. The overall prevalence indicated 50.3%. Six genera of GINs (Haemonchus, Trichostrongylus, Oesophagostomum/Chabertia, Trichuris, Teladosargia/Ostertagia and Nematodirus) were identified. Among the identified genera, Haemonchus (25.4%) and Trichostrongylus (24.8%) were the dominant genera followed by mixed infection (21.8%), Oesophagostomum/Chabertia (10.4%), Trichuris (7.8%), Teladosargia (Ostertagia) (5.7%) and Nematodirus (4.1%). Mixed infections consisted either of double infections with Haemonchus and Trichostrongylus, or triple infections with Haemonchus, Trichostrongylus and Trichuris. The McMaster egg counting results showed that the mean EPG of infected sheep was 845.6. The results also showed 66 (34.2%), 101 (52.3%) and 26 (13.5%) sheep had low, moderate and heavy worm burden, respectively. Albendazole and Ivermectin showed low efficacy (percentage reductions = 90% and 92%; 95% lower confidence limit = 82.1% and 83.6% respectively) whereas Tetramisole was effective (FECR% = 96.8%; 95% LCL = 93.4%). Factors such as age, body condition, management system and past deworming history of sheep were found to have a statistically significant (p < 0.05) influence on the occurrence and burden of the worms. This is further explained as the highest prevalence and worm burden was detected in sheep of young age (p = 0.008; OR = 0.58; 95% CI = 0.39-0.87), poor body condition (p = 0.001; OR = 0.08; 95% CI = 0.04-0.16) and sheep kept under semi-intensive (p = 0.04; OR = 1.53; 95% CI = 1.02-2.29) with no deworming history for the last two months (p = 0.001; OR = 2.97; 95% CI = 1.94-4.56). The study results revealed that nematode infections were among sheep health constraints that could hurt their productivity while low efficacy of Albendazole and Ivermectin were detected. Therefore, the appropriate management techniques of GIN infections should be designed and implemented. Moreover, a further study involving more sensitive techniques (e.g. Mini-FLOTAC, molecular, and serological techniques) should be conducted by considering different host and environmental risk factors such as production level and seasons.

Co-Processed Crystalline Solids of Ivermectin with Span® 60 as Solubility Enhancers of Ivermectin in Natural Oils.

Despite being discovered over five decades ago, little is still known about ivermectin. Ivermectin has several physico-chemical properties that can result in it having poor bioavailability. In this study, polymorphic and co-crystal screening was used to see if such solid-state modifications can improve the oil solubility of ivermectin. Span® 60, a lipophilic non-ionic surfactant, was chosen as co-former. The rationale behind attempting to improve oil solubility was to use ivermectin in future topical and transdermal preparations to treat a range of skin conditions like scabies and head lice. Physical mixtures were also prepared in the same molar ratios as the co-crystal candidates, to serve as controls. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR spectra of the co-crystal candidates showed the presence of Span® 60's alkyl chain peaks, which were absent in the spectra of the physical mixtures. Due to the absence of single-crystal X-ray data, co-crystal formation could not be confirmed, and therefore these co-crystal candidates were referred to as co-processed crystalline solids. Following characterization, the solid-state forms, physical mixtures and ivermectin raw material were dissolved in natural penetration enhancers, i.e., avocado oil (AVO) and evening primrose oil (EPO). The co-processed solids showed increased oil solubility by up to 169% compared to ivermectin raw material. The results suggest that co-processing of ivermectin with Span® 60 can be used to increase its oil solubility and can be useful in the development of oil-based drug formulations.

PHARMACOKINETICS AND EFFICACY OF A SINGLE TOPICAL DOSE OF EPRINOMECTIN IN GIRAFFE (GIRAFFA SPP.).

Growing resistance to current antiparasitic medications, both in livestock and in zoological species under human care, makes it imperative to evaluate available drugs on the market, such as eprinomectin. In this prospective study, five males and one female of reticulated (Giraffa reticulata; n = 2), Masai (Giraffa tippelskirchii; n = 1), Nubian (Giraffa camelopardalis; n = 2), and hybrid subspecies (n = 1) of giraffe, received 1.5 mg/kg eprinomectin topically along the dorsum. Using high-performance liquid chromatography, concentrations of eprinomectin in plasma samples collected at 0, 4, 24, and 48 h, and 7, 14, 21, and 28 d were evaluated following drug administration. Complete blood cell counts and biochemistry panels were performed before (n = 6) and after (n = 3) eprinomectin administration. Samples for modified double centrifugal fecal flotation (n = 6) were evaluated prior to eprinomectin administration to evaluate for endoparasites and were repeated after the study (n = 5). Noncompartmental pharmacokinetic analysis was applied to the data. The observed maximum plasma concentration was 11.45 ng/ml and the time of observed maximum concentration was 2.67 d. The mean terminal half-life was 5.16 d. No adverse effects were observed related to eprinomectin administration and no blood work changes were observed. Parasite loads decreased (n = 3) or did not change (n = 2) after eprinomectin administration. The mean peak plasma concentration of eprinomectin in giraffe was similar to that achieved in cattle, despite using three times the dose.