Predicting haemoglobin deferral using machine learning models: Can we use the same prediction model across countries?

BACKGROUND AND OBJECTIVES: Personalized donation strategies based on haemoglobin (Hb) prediction models may reduce Hb deferrals and hence costs of donation, meanwhile improving commitment of donors. We previously found that prediction models perform better in validation data with a high Hb deferral rate. We therefore investigate how Hb deferral prediction models perform when exchanged with other blood establishments. MATERIALS AND METHODS: Donation data from the past 5 years from random samples of 10,000 donors from Australia, Belgium, Finland, the Netherlands and South Africa were used to fit random forest models for Hb deferral prediction. Trained models were exchanged between blood establishments. Model performance was evaluated using the area under the precision-recall curve (AUPR). Variable importance was assessed using SHapley Additive exPlanations (SHAP) values. RESULTS: Across the validation datasets and exchanged models, the AUPR ranged from 0.05 to 0.43. Exchanged models performed similarly within validation datasets, irrespective of the origin of the training data. Apart from subtle differences, the importance of most predictor variables was similar in all trained models. CONCLUSION: Our results suggest that Hb deferral prediction models trained in different blood establishments perform similarly within different validation datasets, regardless of the deferral rate of their training data. Models learn similar associations in different blood establishments.

Electrocatalytic Properties of Oxygen-Deficient Perovskites Ca3Fe3-xMnxO8 (x = 1-2) for the Hydrogen Evolution Reaction.

We have demonstrated a systematic trend in the electrocatalytic activity for the hydrogen evolution reaction (HER) and its correlations with transition-metal type, structural order, and electrical conductivity. The materials studied in this work, Ca3FeMn2O8 (CaFe1/3Mn2/3O3-1/3), Ca3Fe1.5Mn1.5O8, and Ca3Fe2MnO8, belong to the family of oxygen-deficient perovskites and show a gradual increase in the ordering of oxygen vacancies. Ca3FeMn2O8 (CaFe1/3Mn2/3O3-1/3) contains randomly distributed oxygen vacancies, which begin to order in Ca3Fe1.5Mn1.5O8, and are fully ordered in Ca3Fe2MnO8. The gradual increase in the structural order is associated with a systematic enhancement of the electrocatalytic activity for HER in acidic conditions, Ca3FeMn2O8 < Ca3Fe1.5Mn1.5O8 < Ca3Fe2MnO8. While the improvement of the HER activity is also associated with an increase in the Fe content, we have shown that the type of structural order plays a more important role. We demonstrated this effect by control experiments on an analogous material where all Mn was substituted by Fe, leading to a different type of structural order and showing an inferior HER activity compared to the above three materials. Furthermore, electrical conductivity studies in a wide range of temperatures, 25-800 °C, indicate that the trend in the electrical conductivity is the same as that of the HER activity. These findings reveal several important structure-property relationships and highlight the importance of synergistic effects in enhancing the electrocatalytic properties.

Enhancement of Electrocatalytic and Pseudocapacitive Properties as a Function of Structural Order in A2Fe2O5 (A = Sr, Ba).

Significant enhancements of electrocatalytic activities for both half-reactions of water-electrolysis, i.e., oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), as well as pseudocapacitive charge-storage properties are demonstrated upon changing the structural order in a perovskite-type system. The structural change is prompted by the increase in the ionic radius of the A-site ion in A2Fe2O5. The structure of Sr2Fe2O5 consists of alternating layers of FeO6 octahedra and FeO4 tetrahedra, whereas Ba2Fe2O5 comprises seven different coordination geometries for Fe. We note that the catalytically active metal, i.e., iron, and the oxygen stoichiometry are the same for both materials. Nevertheless, the change in the structural order results in significantly greater electrocatalytic activity of Ba2Fe2O5, manifested in smaller overpotentials, smaller charge-transfer resistance, greater electrocatalytic current, and faster reaction kinetics. In addition, this material shows significantly enhanced pseudocapacitive properties, with greater specific capacitance and energy density compared to Sr2Fe2O5. These findings indicate the important role of structural order in directing the electrochemical properties.

Regular high-frequency whole blood donation and risk of cardiovascular disease in middle-aged and older blood donors in Australia.

BACKGROUND: Previous mixed findings on the associations between whole blood (WB) donation and risk of cardiovascular diseases (CVD) may in part reflect inadequate adjustment for the "healthy donor effect" (HDE). METHODS: We used the Sax Institute's 45 and Up Study linked with blood donation history and other health-related databases to examine the association between regular, high-frequency WB donation and the risk of CVD. To mitigate the impact of HDE, we used a "5-years qualification period," in which donors must donate at least 1 WB donation in the 1st and 5th year of "qualification period." We then compared the risk of CVD in the years following the "qualification period" between the regular high-frequency WB donors (≥2 WB donation in each qualification year) and others using Cox proportional-hazards models. Analyses were adjusted for potential confounders, such as sociodemographic, lifestyle, and health-related variables, and results are reported separately for male and female donors. RESULTS: A total of 2736 male and 2917 female donors were included in the analyses. The median years of follow-up per donor was 5.84 years (Q1-Q3, 5.47-6.23). The rate of CVD hospitalization was 11.20 and 4.50 per 1000 person-years for males and females, respectively. In fully adjusted models, the risk (hazard ratio) of CVD in regular high-frequency donors compared to other donors was 0.93 (95% Confidence Interval (CI), 0.68-1.29) for males and 0.79 (95% CI, 0.49-1.28) for females. CONCLUSIONS: We did not observe a statistically significant reduction of CVD risk in regular, high-frequency WB donors when adjusted for potential confounders.

Trend of Antimicrobial Use in Food-Producing Animals from 2018 to 2020 in Nepal.

Antimicrobial resistance is a global public health problem and is primarily driven by the widespread overuse of antibiotics. However, antimicrobial use data in animals are not readily available due to the absence of a national database in many developing countries, including Nepal. This study was conducted to estimate the quantities of antimicrobials available in Nepal as an indicator of their use in food-producing animals between 2018 and 2020. Data were collected through surveys targeting major stakeholders: (i) the Department of Drug Administration (DDA), the Government of Nepal (GoN) for the authorized antimicrobials for veterinary use in Nepal, (ii) veterinary pharmaceuticals for antimicrobials produced in Nepal, (iii) the DDA and Veterinary Importers Association for antimicrobials bought by veterinary drug importers, and (iv) the Department of Customs, GoN, for antibiotics sourced through customs. Data showed that in the 3 years, a total of 96 trade names, comprising 35 genera of antibiotics representing 10 classes, were either produced or imported in Nepal. In total, 91,088 kg, 47,694 kg, and 45,671 kg of active ingredients of antimicrobials were available in 2018, 2019, and 2020, respectively. None of the antibiotics were intended for growth promotion, but were primarily for therapeutic purposes. Oxytetracycline, tilmicosin, and sulfadimidine were among the most-used antibiotics in Nepal in 2020. Oxytetracycline was primarily intended for parenteral application, whereas tilmicosin was solely for oral use. Sulfadimidine was available for oral use, except for a small proportion for injection purposes. Aminoglycosides, fluroquinolones, nitrofurans, sulfonamides, and tetracyclines were mostly produced locally, whereas cephalosporins, macrolides and "other" classes of antimicrobials were imported. Amphenicols and penicillins were exclusively imported and nitrofurans were produced locally only. In general, except for tetracyclines, the volume of antimicrobials produced locally and/or imported in 2020 was lower than that in 2018, which corresponded to a decreasing trend in total antimicrobials available. Furthermore, the subsequent years have seen a decrease in the use of critically important antibiotics, particularly class I antibiotics. Finally, this study has firstly established a benchmark for future monitoring of antimicrobial usage in food-producing animals in Nepal. These data are useful for risk analysis, planning, interpreting resistance surveillance data, and evaluating the effectiveness of prudent use, efforts, and mitigation strategies.

An international comparison of haemoglobin deferral prediction models for blood banking.

BACKGROUND AND OBJECTIVES: Blood banks use a haemoglobin (Hb) threshold before blood donation to minimize donors' risk of anaemia. Hb prediction models may guide decisions on which donors to invite, and should ideally also be generally applicable, thus in different countries and settings. In this paper, we compare the outcome of various prediction models in different settings and highlight differences and similarities. MATERIALS AND METHODS: Donation data of repeat donors from the past 5 years of Australia, Belgium, Finland, the Netherlands and South Africa were used to fit five identical prediction models: logistic regression, random forest, support vector machine, linear mixed model and dynamic linear mixed model. Only donors with five or more donation attempts were included to ensure having informative data from all donors. Analyses were performed for men and women separately and outcomes compared. RESULTS: Within countries and overall, different models perform similarly well. However, there are substantial differences in model performance between countries, and there is a positive association between the deferral rate in a country and the ability to predict donor deferral. Nonetheless, the importance of predictor variables across countries is similar and is highest for the previous Hb level. CONCLUSION: The limited impact of model architecture and country indicates that all models show similar relationships between the predictor variables and donor deferral. Donor deferral is found to be better predictable in countries with high deferral rates. Therefore, such countries may benefit more from deferral prediction models than those with low deferral rates.

"Please help us with important research": A retrospective analysis examining the impact of research invitation and participation on subsequent blood donor behavior.

BACKGROUND: As over-communication can negatively impact consumer behavior, it is important to understand the impact of research communication on donors' future donation behavior. The aim of this study was to determine the effect of (i) being invited to participate in research, and (ii) participating in that research, on future donation behavior. STUDY DESIGN AND METHODS: A retrospective cohort analysis was conducted with 36,418 donors who were invited to participate in one of 17 research projects, and a matched control group of 36,252 non-invited donors. Poisson regression models were used to examine the associations between invitation or participation in the studies and the likelihood of creating an appointment to donate and attending an appointment at 1, 3, and 6 months. RESULTS: Donors were significantly more likely to create an appointment within 14 days of receiving an invitation compared to controls (RR: 1.91, 95% CI 1.81-2.02), and to return to donate at 1 (RR:1.18, 95% CI 1.13-1.24), 3 (RR:1.10, 95% CI 1.07-1.13) and 6 (RR:1.11, 95% CI 1.09-1.13) months compared to non-invited controls. Donors who participated in the research were more likely to return than control donors at all time points, while donors who were invited but did not participate were also likely to return more at 1 month (RR:1.06, 95% CI 1.00-1.11) and 6 months (RR:1.03, 95% CI 1.00-1.5) than non-invited controls. DISCUSSION: Our findings suggest that research participation is positively associated with future donor behavior and provides reassurance that contacting donors for research does not negatively impact blood collections.

Feeding, caregiving practices, and developmental delay among children under five in lowland Nepal: a community-based cross-sectional survey.

BACKGROUND: Nurturing care, including adequate nutrition, responsive caregiving and early learning, is critical to early childhood development. In Nepal, national surveys highlight inequity in feeding and caregiving practices for young children. Our objective was to describe infant and young child feeding (IYCF) and cognitive and socio-emotional caregiving practices among caregivers of children under five in Dhanusha district, Nepal, and to explore socio-demographic and economic factors associated with these practices. METHODS: We did a cross-sectional analysis of a subset of data from the MIRA Dhanusha cluster randomised controlled trial, including mother-child dyads (N = 1360), sampled when children were median age 46 days and a follow-up survey of the same mother-child dyads (N = 1352) when children were median age 38 months. We used World Health Organization IYCF indicators and questions from the Multiple Indicator Cluster Survey-4 tool to obtain information on IYCF and cognitive and socio-emotional caregiving practices. Using multivariable logistic regression models, potential explanatory household, parental and child-level variables were tested to determine their independent associations with IYCF and caregiving indicators. RESULTS: The prevalence of feeding indicators varied. IYCF indicators, including ever breastfed (99%), exclusive breastfeeding (24-hour recall) (89%), and vegetable/fruit consumption (69%) were common. Problem areas were early initiation of breastfeeding (16%), colostrum feeding (67%), no pre-lacteal feeding (53%), timely introduction of complementary feeding (56%), minimum dietary diversity (49%) and animal-source food consumption (23%). Amongst caregiving indicators, access to 3+ children's books (7%), early stimulation and responsive caregiving (11%), and participation in early childhood education (27%) were of particular concern, while 64% had access to 2+ toys and 71% received adequate care. According to the Early Child Development Index score, only 38% of children were developmentally on track. Younger children from poor households, whose mothers were young, had not received antenatal visits and delivered at home were at higher risk of poor IYCF and caregiving practices. CONCLUSIONS: Suboptimal caregiving practices, inappropriate early breastfeeding practices, delayed introduction of complementary foods, inadequate dietary diversity and low animal-source food consumption are challenges in lowland Nepal. We call for urgent integrated nutrition and caregiving interventions, especially as interventions for child development are lacking in Nepal.

Risk Factors Associated with Avian Influenza Subtype H9 Outbreaks in Poultry Farms of Central Lowland Nepal.

Low pathogenic avian influenza (LPAI) of subtype H9 outbreaks have been frequently occurring in major commercial hubs of Nepal including Chitwan, a central lowland area, causing substantial economic losses to the farmers. However, the risk factors associated with these outbreaks have been poorly understood, and hence, this case-control study was conducted in Chitwan, Nawalpur, and Makawanpur districts of Nepal from October 2019 to March 2020. A total of 102 farms were selected in which 51 were case farms, and 51 were controls. Case farms were avian influenza (AI)-subtype-H9-confirmed farms through polymerase chain reaction (PCR) assays on poultry samples. Control farms included farms that were AI-negative in the antigen test brought to the National Avian Disease Investigation Laboratory, Chitwan, for diagnosis during the study period. Each farm was visited to collect information using a semi-structured questionnaire. A total of 25 variables representing farm characteristics and biosecurity measures were considered as potential risk factors. The final multivariable model showed that distance of less than 0.5 km from the main road (OR = 4.04, 95% CI = 1.20-13.56, p = 0.023), distance of less than 1 km from a nearest infected farm (OR = 76.42, 95% CI = 7.17-814.06, p = 0.0003), and wild birds coming around the farm (OR = 6.12, 95% CI = 1.99-18.79, p = 0.0015) were risk factors for avian influenza type H9, whereas using apron or separate cloth inside the shed (OR = 0.109, 95% CI = 0.020-0.577, p = 0.0092) was shown to reduce the risk of farms being positive for AI subtype H9. These findings suggest that due consideration should be given to site selection while establishing the farms and the importance of implementing appropriate biosecurity measures, such as using separate cloth inside the shed and preventing the entry of wild birds inside the farm to reduce the potential risk of introduction of avian influenza type H9 to their poultry farms.

Improving donor retention following a temporary deferral: A cluster randomized controlled trial of deferral educational materials.

BACKGROUND: Providing educational materials to deferred donors has been shown to increase their understanding about their deferral and knowledge about their return. The aim of this study was to determine the effectiveness of educational materials in increasing the retention of deferred donors. STUDY DESIGN AND METHODS: A three-arm cluster randomized controlled trial was conducted, with the following conditions: (a) Incenter Brochure plus Email; (b) Email Only; (c) Control. The Incenter Brochure plus Email condition also included a guided conversation led by staff at the point of deferral. Donors were followed up for 3 months after their deferral had ended to determine if they had attempted to donate. RESULTS: Compared with the Control condition, donors in the Incenter Brochure plus Email condition had increased odds of return at 3 months after their deferral ended (OR: 1.16; 95% CI 1.00-1.33). Subgroup analysis highlighted that novice (OR: 1.38; 95% CI 1.04-1.83) and established donors (OR: 1.36; 95% CI 1.13-1.64) had increased odds of return if they received the incenter materials. Donors who were deferred to maintain their well-being (OR: 1.28; 95% CI 1.03-1.60) and donors with a prior deferral history (OR: 1.55; 95% CI 1.15-1.55) had increased odds of return if they received the incenter materials. No significant differences were found between the Email Only and Control conditions. DISCUSSION: This trial demonstrates the benefits of providing onsite educational materials to donors at the point of deferral. This is a simple, effective strategy to increase the return behavior of donors within 3 months of their deferral ending.

Exploring potentialities of avian genomic research in Nepalese Himalayas.

Nepal, a small landlocked country in South Asia, holds about 800 km of Himalayan Mountain range including the Earth's highest mountain. Within such a mountain range in the north and plain lowlands in the south, Nepal provides a habitat for about 9% of global avian fauna. However, this diversity is underrated because of the lack of enough studies, especially using molecular tools to quantify and understand the distribution patterns of diversity. In this study, we reviewed the studies in the last two decades (2000‒2019) that used molecular methods to study the biodiversity in Nepal to examine the ongoing research trend and focus. Although Nepalese Himalaya has many opportunities for cutting-edge molecular research, our results indicated that the rate of genetic/genomic studies is much slower compared to the regional trends. We found that genetic research in Nepal heavily relies on resources from international institutes and that too is mostly limited to research on species monitoring, distribution, and taxonomic validations. Local infrastructures to carry out cutting-edge genomic research in Nepal are still in their infancy and there is a strong need for support from national/international scientists, universities, and governmental agencies to expand such genomic infrastructures in Nepal. We particularly highlight avian fauna as a potential future study system in this region that can be an excellent resource to explore key biological questions such as understanding eco-physiology and molecular basis of organismal persistence to changing environment, evolutionary processes underlying divergence and speciation, or mechanisms of endemism and restrictive distribution of species. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40657-021-00290-5.

Visits to general practitioners after iron-related deferrals from blood donation in middle-aged and older Australian blood donors.

BACKGROUND: Australian Red Cross Lifeblood (Lifeblood) advises donors to visit their general practitioner (GP) for medical follow-up if they are deferred from donating due to having a lower than acceptable level of hemoglobin (Hb) and/or serum ferritin (iron-related deferrals). METHODS: We used the Sax Institute's 45 and Up Study data linked to Lifeblood's donor datasets and other health administrative datasets. We examined the rate of visits to a GP after iron-related deferral from donation, and investigated whether an early visit to a GP (within 30 days following the deferral) had an impact on return to make successful donation within 12, 18, and 24 months compared to a delayed or no GP visit. RESULTS: A total of 1928 donors underwent iron-related deferral. The rate of visits to a GP in the first month after deferral was double the rate observed a month prior. However, only 52.4% of those deferred visited a GP early with slightly more than half of those receiving an iron-monitoring test. Return to donate over the 24 months was lower in donors visiting their GP early (adjusted Hazard Ratio [aHR] 0.86, 95% CI 0.77-0.97). Early GP visitors were likely to have a relatively poorer health than the delayed or no GP visit group. CONCLUSIONS: Only half of the donors with an iron-related deferral followed advice from Lifeblood and visited their GP within 30 days of deferral, and these donors have a significantly reduced likelihood of future successful blood donation which may be due to their relatively poorer health status.

Willingness of blood donors in Australia to provide additional data and blood sample for health research.

BACKGROUND: Many blood collection agencies are generating important data on donor health outcomes using large-scale blood donor cohort studies. Such studies can be very effective when donors provide access to linkage of their data to external health databases, and storage and genomic testing of their blood sample. In this study, we aimed to assess the willingness of Australian blood donors to provide additional data and blood sample for donation-related and other health research. STUDY DESIGN AND METHODS: We invited 2017 donors to complete a survey using four methods (postal letter, postal letter and email, email only, and in-center recruitment). The survey asked for information on demographics, lifestyle behaviors, health, experience and attitude to blood donation, and willingness to give blood sample and additional data for research. RESULTS: Response rates ranged from 23.8% for email only to 77.2% for in-center recruitment. Of those who responded (n = 827), 95.5% indicated they would be willing to provide a blood sample for donation and transfusion-related research. Of these, >90.0% were willing for their sample to be used in research involving genetic testing and other health-related topics. Also, >90.0% were willing to consent for linkage of their information to external health databases. CONCLUSIONS: Donors surveyed reported a high willingness to participate in health research by completing surveys, allowing linkage to external datasets, and providing a blood sample. These findings provide strong support for future longitudinal research studies with Australian blood donors.

Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal.

BACKGROUND: The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. RESULTS: In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). CONCLUSIONS: This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

Characteristics and effects of integrated nutrition and stimulation interventions to improve the nutritional status and development of children under 5 years of age: a systematic review and meta-analysis.

INTRODUCTION: Around 250 million children in low-income and middle-income countries are at risk of not fulfilling their developmental potential. There is a need to update syntheses investigating the effects of combined nutrition and stimulation interventions on children's growth and development and identify intervention characteristics associated with positive effects. METHODS: We did a systematic review to: (1) understand the effects of integrated nutrition and stimulation interventions versus (i) usual care and (ii) standalone nutrition or stimulation interventions, on the growth and development of children under five; (2) explore intervention characteristics (delivery strategies, behaviour change techniques, intensity and personnel) associated with positive effects. We searched eight databases for studies published from inception to 16 November 2020. Eligible studies were randomised and non-randomised controlled trials of integrated nutrition and stimulation interventions examining growth and developmental outcomes. We performed meta-analyses for length-for-age/height-for-age, weight-for-age and weight-for-length/weight-for-height Z scores and cognitive, motor and language development scores, and subgroup analyses by intervention characteristics. We conducted random-effects metaregression to assess potential subgroup differences in outcomes by intervention characteristics. RESULTS: Twenty trials were included in the meta-analysis. Pooled effect sizes showed significant benefits of integrated interventions on developmental outcomes compared with usual care and standalone nutrition interventions (I2 >75%) but not on growth outcomes. Moreover, integrated interventions have non-significant effects on developmental outcomes compared with standalone stimulation interventions. Integrated interventions showed greater effects on cognitive (p=0.039) and language (p=0.040) outcomes for undernourished children compared with adequately nourished children. The effects of integrated interventions on developmental outcomes did not differ by intervention characteristics. CONCLUSION: Integrated interventions have greater benefits for children's development than usual care or standalone nutrition interventions, especially in settings with high levels of undernutrition. Future studies should use standardised reporting of implementation processes to identify intervention characteristics linked to positive effects.

Antibiotic Use in Broiler Poultry Farms in Kathmandu Valley of Nepal: Which Antibiotics and Why?

Inappropriate antibiotic use in food-producing animals is associated with the emergence and spread of antibiotic resistance. In industrial broiler poultry farms in three districts of Kathmandu valley, Nepal, we assessed antibiotic use prevalence, and their classes, types, and quantities. A cross-sectional questionnaire study involving field visits to large poultry farms (flock size ≥ 3000) of the Kathmandu, Bhaktapur, and Lalitpur districts was conducted. Of 30 farms (total flock size 104,200; range 3000-6000), prevalence of antibiotic use was 90% (95% CI: 73-98%). Six (22%) farms used antibiotics as prophylaxis, while 21 (78%) used it for therapeutics. Seven antibiotics from six classes (including quinolones, macrolides, and polymyxins) were used. The most commonly used antibiotics were tylosin (47%), colistin (47%), and dual therapies with neomycin and doxycycline (33%). A total of 50,000 grams of antibiotics (total weight including active and inactive ingredients) were used (0.5 grams/chicken/45 days of flock life) with eight (26%) farms using more than two antibiotics. No farms had records on clinical indications for prophylaxis or treatment. No post-mortem records of sick birds were available. Prevalence of antibiotic use in broiler farms of Kathmandu valley is high and includes "highest priority critically important antibiotics" for human use, with direct implications on public health.

Effects of Scale on Modeling West Nile Virus Disease Risk.

Modeling vector-borne diseases is best conducted when heterogeneity among interacting biotic and abiotic processes is captured. However, the successful integration of these complex processes is difficult, hindered by a lack of understanding of how these relationships influence disease transmission across varying scales. West Nile virus (WNV) is the most important mosquito-borne disease in the United States. Vectored by Culex mosquitoes and maintained in the environment by avian hosts, the virus can spill over into humans and horses, sometimes causing severe neuroinvasive illness. Several modeling studies have evaluated drivers of WNV disease risk, but nearly all have done so at broad scales and have reported mixed results of the effects of common explanatory variables. As a result, fine-scale relationships with common explanatory variables, particularly climatic, socioeconomic, and human demographic, remain uncertain across varying spatial extents. Using an interdisciplinary approach and an ongoing 12-year study of the Chicago region, this study evaluated the factors explaining WNV disease risk at high spatiotemporal resolution, comparing the human WNV model and covariate performance across three increasing spatial extents: ultrafine, local, and county scales. Our results demonstrate that as spatial extent increased, model performance increased. In addition, only six of the 23 assessed covariates were included in best-fit models of at least two scales. These results suggest that the mechanisms driving WNV ecology are scale-dependent and covariate importance increases as extent decreases. These tools may be particularly helpful for public health, mosquito, and disease control personnel in predicting and preventing disease within local and fine-scale jurisdictions, before spillover occurs.

Long-term return and donation pattern of those who begin donating at different ages: A retrospective cohort analysis of blood donors in Australia.

BACKGROUND: This study compared the likelihood of return to donate and donation rate ratio by age of donors at their first donation when followed up to 12 years. STUDY DESIGN AND METHODS: Donation history of two cohorts of first-time donors (those donating in 2007 and 2013) was extracted until March 2019 from Australian Red Cross Lifeblood's national database. Poisson regression analyses compared donor return and negative-binomial regression estimated the rate ratio of donations. RESULTS: A total of 120 469 and 95 381 donors were included in the 2007 and 2013 cohorts, respectively. Compared to donors aged 20-24 years, the likelihood of return in both cohorts increased consistently as age at first donation increased from 30-years and above. Average number of whole-blood and plasmapheresis donations increased as the age at first donation increased from 30-years onward. The whole-blood donation rate was highest for donors ≥60 years, while plasmapheresis donation rate was highest for donors aged 50-59 years. These patterns were largely consistent when stratified by sex. CONCLUSIONS: To continuously ensure the short- to mid-term sufficiency of blood supply in Australia, targeted recruitment of donors aged 30-years and above may be considered, however its feasibility and impact should be explored further given relatively smaller proportion of new donors are middle-aged and older under current policies. Future studies with a longer follow-up period are needed to examine whether the frequency of donation among those who start donating at a younger age increases later in their life when they are 30-years or over.