ABSTRACT
BACKGROUND: The primary vector control interventions in Zambia are long-lasting insecticidal nets and indoor residual spraying. Challenges with these interventions include insecticide resistance and the outdoor biting and resting behaviours of many Anopheles mosquitoes. Therefore, new vector control tools targeting additional mosquito behaviours are needed to interrupt transmission. Attractive targeted sugar bait (ATSB) stations, which exploit the sugar feeding behaviours of mosquitoes, may help in this role. This study evaluated the residual laboratory bioefficacy of Westham prototype ATSB® Sarabi v.1.2.1 Bait Station (Westham Ltd., Hod-Hasharon, Israel) in killing malaria vectors in Western Province, Zambia, during the first year of a large cluster randomized phase-III trial (Clinical Trials.gov Identifier: NCT04800055). METHODS: This was a repeat cross-sectional study conducted within three districts, Nkeyema, Kaoma, and Luampa, in Western Province, Zambia. The study was conducted in 12 intervention clusters among the 70 trial clusters (35 interventions, 35 controls) between December 2021 and June 2022. Twelve undamaged bait stations installed on the outer walls of households were collected monthly (one per cluster per month) for bioassays utilizing adult female and male Anopheles gambiae sensu stricto (Kisumu strain) mosquitoes from a laboratory colony. RESULTS: A total of 84 field-deployed ATSB stations were collected, and 71 ultimately met the study inclusion criteria for remaining in good condition. Field-deployed stations that remained in good condition (intact, non-depleted of bait, and free of dirt as well as mold) retained high levels of bioefficacy (mean induced mortality of 95.3% in males, 71.3% in females, 83.9% combined total) over seven months in the field but did induce lower mortality rates than non-deployed ATSB stations (mean induced mortality of 96.4% in males, 87.0% in females, 91.4% combined total). There was relatively little variation in corrected mortality rates between monthly rounds for those ATSB stations that had been deployed to the field. CONCLUSION: While field-deployed ATSB stations induced lower mortality rates than non-deployed ATSB stations, these stations nonetheless retained relatively high and stable levels of bioefficacy across the 7-month malaria transmission season. While overall mean mosquito mortality rates exceeded 80%, mean mortality rates for females were 24 percentage points lower than among males and these differences merit attention and further evaluation in future studies. The duration of deployment was not associated with lower bioefficacy. Westham prototype ATSB stations can still retain bioefficacy even after deployment in the field for 7 months, provided they do not meet predetermined criteria for replacement.
Subject(s)
Anopheles , Mosquito Control , Mosquito Vectors , Zambia , Animals , Mosquito Control/methods , Anopheles/drug effects , Anopheles/physiology , Mosquito Vectors/drug effects , Mosquito Vectors/physiology , Female , Male , Cross-Sectional Studies , Malaria/prevention & control , Malaria/transmission , Seasons , Insecticides/pharmacology , Sugars , Humans , Feeding BehaviorABSTRACT
BACKGROUND: Attractive Targeted Sugar Baits (ATSBs) offer a complementary vector control strategy to interventions targeting blood feeding or larval control by attacking the sugar feeding behaviour of adult mosquitoes using an attract-and-kill approach. Western Zambia was the first location to receive and deploy ATSB Sarabi version 1.2 stations in a Phase III cluster randomized controlled trial. This paper describes ATSB station installation, monitoring, removal, and disposal, quantifies ATSB station coverage, and reports major reasons for ATSB station replacement. METHODS: ATSB stations were deployed during two annual transmission seasons, through scheduled installation and removal campaigns. During deployment, monitoring was conducted per protocol to maintain high coverage of the ATSB stations in good condition. Routine monitoring visits during the trial captured details on ATSB station damage necessitating replacement following pre-defined replacement criteria. Annual cross-sectional household surveys measured ATSB station coverage during peak malaria transmission. RESULTS: A total of 67,945 ATSB stations were installed in Year 1 (41,695 initially installed+ 26,250 installed during monitoring) and 69,494 ATSB stations were installed in Year 2 (41,982 initially installed+ 27,512 installed during monitoring) across 35 intervention clusters to maintain high coverage of two ATSB stations in good condition per eligible household structure. The primary reasons for ATSB station replacement due to damage were holes/tears and presence of mold. Cross-sectional household surveys documented high coverage of ATSB stations across Year 1 and Year 2 with 93.1% of eligible structures having ≥ 2 ATSB stations in any condition. DISCUSSION: ATSB station deployment and monitoring efforts were conducted in the context of a controlled cRCT to assess potential product efficacy. Damage to ATSB stations during deployment required replacement of a subset of stations. High coverage of eligible structures was maintained over the two-year study despite replacement requirements. Additional research is needed to better understand the impact of damage on ATSB station effectiveness under programmatic conditions, including thresholds of threats to physical integrity and biological deterioration on product efficacy. CONCLUSIONS: Optimizing ATSB stations to address causes of damage and conducting implementation research to inform optimal delivery and cost-effective deployment will be important to facilitate scale-up of ATSB interventions.
Subject(s)
Mosquito Control , Zambia , Mosquito Control/methods , Humans , Animals , Female , Malaria/prevention & control , Sugars , Cross-Sectional Studies , Mosquito Vectors/physiology , Anopheles/physiology , MaleABSTRACT
BACKGROUND: Attractive targeted sugar bait (ATSB) stations are a novel tool with potential to complement current approaches to malaria vector control. To assess the public health value of ATSB station deployment in areas of high coverage with standard vector control, a two-arm cluster-randomized controlled trial (cRCT) of Sarabi ATSB® stations (Westham Ltd., Hod-Hasharon, Israel) was conducted in Western Province, Zambia, a high-burden location were Anopheles funestus is the dominant vector. The trial included 70 clusters and was designed to measure the effect of ATSBs on case incidence and infection prevalence over two 7-month deployments. Reported here are results of the vector surveillance component of the study, conducted in a subset of 20 clusters and designed to provide entomological context to guide overall interpretation of trial findings. METHODS: Each month, 200 paired indoor-outdoor human landing catch (HLC) and 200 paired light trap (LT) collections were conducted to monitor An. funestus parity, abundance, biting rates, sporozoite prevalence, and entomological inoculation rates (EIR). RESULTS: During the study 20,337 female An. funestus were collected, 11,229 from control and 9,108 from intervention clusters. A subset of 3,131 HLC specimens were assessed for parity: The mean non-parous proportion was 23.0% (95% CI 18.2-28.7%, total n = 1477) in the control and 21.2% (95% CI 18.8-23.9%, total n = 1654) in the intervention arm, an OR = 1.05 (95% CI 0.82-1.34; p = 0.688). A non-significant reduction in LT abundance (RR = 0.65 [95% CI 0.30-1.40, p = 0.267]) was associated with ATSB deployment. HLC rates were highly variable, but model results indicate a similar non-significant trend with a RR = 0.68 (95%CI 0.22-2.00; p = 0.479). There were no effects on sporozoite prevalence or EIR. CONCLUSIONS: Anopheles funestus parity did not differ across study arms, but ATSB deployment was associated with a non-significant 35% reduction in vector LT density, results that are consistent with the epidemiological impact reported elsewhere. Additional research is needed to better understand how to maximize the potential impact of ATSB approaches in Zambia and other contexts. TRIAL REGISTRATION NUMBER: This trial was registered with Clinicaltrials.gov (NCT04800055, 16 March 2021).
Subject(s)
Anopheles , Mosquito Control , Mosquito Vectors , Zambia , Anopheles/physiology , Animals , Mosquito Vectors/physiology , Mosquito Control/methods , Female , Humans , Sugars , Malaria/prevention & controlABSTRACT
Wastewater-based epidemiology has expanded as a tool for collecting COVID-19 surveillance data, but there is limited information on the feasibility of this form of surveillance within decentralized wastewater systems (e.g., septic systems). This study assessed SARS-CoV-2 RNA concentrations in wastewater samples from a septic system servicing a mobile home park (66 households) and from two pumping stations serving a similarly sized (71 households) and a larger (1,000 households) neighborhood within a nearby sewershed over 35 weeks in 2020. Also, raw wastewater from a hospital in the same sewershed was sampled. The mobile home park samples had the highest detection frequency (39/39 days) and mean concentration of SARS-CoV-2 RNA (2.7 × 107 gene copies/person/day for the N1) among the four sampling sites. N1 gene and N2 gene copies were highly correlated across mobile home park samples (Pearson's r = 0.93, p < 0.0001). In the larger neighborhood, new COVID-19 cases were reported every week during the sampling period; however, we detected SARS-CoV-2 RNA in 12% of the corresponding wastewater samples. The results of this study suggest that sampling from decentralized wastewater infrastructure can be used for continuous monitoring of SARS-CoV-2 infections.
Subject(s)
COVID-19 , RNA, Viral , SARS-CoV-2 , Wastewater , Wastewater/virology , COVID-19/epidemiology , COVID-19/virology , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , RNA, Viral/genetics , RNA, Viral/analysis , RNA, Viral/isolation & purification , Humans , Wastewater-Based Epidemiological Monitoring , Sewage/virologyABSTRACT
Objectives. To compare 4 COVID-19 surveillance metrics in a major metropolitan area. Methods. We analyzed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater influent and primary solids in Raleigh, North Carolina, from April 10 through December 13, 2020. We compared wastewater results with lab-confirmed COVID-19 cases and syndromic COVID-like illness (CLI) cases to answer 3 questions: (1) Did they correlate? (2) What was the temporal alignment of the different surveillance systems? (3) Did periods of significant change (i.e., trends) align? Results. In the Raleigh sewershed, wastewater influent, wastewater primary solids, lab-confirmed cases, and CLI were strongly or moderately correlated. Trends in lab-confirmed cases and wastewater influent were observed earlier, followed by CLI and, lastly, wastewater primary solids. All 4 metrics showed sustained increases in COVID-19 in June, July, and November 2020 and sustained decreases in August and September 2020. Conclusions. In a major metropolitan area in 2020, the timing of and trends in municipal wastewater, lab-confirmed case, and syndromic case surveillance of COVID-19 were in general agreement. Public Health Implications. Our results provide evidence for investment in SARS-CoV-2 wastewater and CLI surveillance to complement information provided through lab-confirmed cases. (Am J Public Health. 2023;113(1):79-88. https://doi.org/10.2105/AJPH.2022.307108).
Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , SARS-CoV-2 , Wastewater , North Carolina/epidemiology , Sentinel Surveillance , RNA, ViralABSTRACT
BACKGROUND: Attractive targeted sugar bait (ATSB) stations are a promising new approach to malaria vector control that could compliment current tools by exploiting the natural sugar feeding behaviors of mosquitoes. Recent proof of concept work with a prototype ATSB® Sarabi Bait Station (Westham Co., Hod-Hasharon, Israel) has demonstrated high feeding rates and significant reductions in vector density, human biting rate, and overall entomological inoculation rate for Anopheles gambiae sensu lato (s.l.) in the tropical savannah of western Mali. The study reported here was conducted in the more temperate, rainier region of Western Province, Zambia and was designed to confirm the primary vector species in region and to estimate corresponding rates of feeding from prototype attractive sugar bait (ASB) Sarabi Bait Stations. METHODS: The product evaluated was the Sarabi v1.1.1 ASB station, which did not include insecticide but did include 0.8% uranine as a dye allowing for the detection, using UV fluorescence light microscopy, of mosquitoes that have acquired a sugar meal from the ASB. A two-phase, crossover study design was conducted in 10 village-based clusters in Western Province, Zambia. One study arm initially received 2 ASB stations per eligible structure while the other initially received 3. Primary mosquito sampling occurred via indoor and outdoor CDC Miniature UV Light Trap collection from March 01 through April 09, 2021 (Phase 1) and from April 19 to May 28, 2021 (Phase 2). RESULTS: The dominant vector in the study area is Anopheles funestus s.l., which was the most abundant species group collected (31% of all Anophelines; 45,038/144,5550), had the highest sporozoite rate (3.16%; 66 positives out of 2,090 tested), and accounted for 94.3% (66/70) of all sporozoite positive specimens. Of those An. funestus specimens further identified to species, 97.2% (2,090/2,150) were An. funestus sensu stricto (s.s.). Anopheles gambiae s.l. (96.8% of which were Anopheles arabiensis) is a likely secondary vector and Anopheles squamosus may play a minor role in transmission. Overall, 21.6% (9,218/42,587) of An. funestus specimens and 10.4% (201/1,940) of An. gambiae specimens collected were positive for uranine, translating into an estimated daily feeding rate of 8.9% [7.7-9.9%] for An. funestus (inter-cluster range of 5.5% to 12.7%) and 3.9% [3.3-4.7%] for An. gambiae (inter-cluster range of 1.0-5.2%). Feeding rates were no different among mosquitoes collected indoors or outdoors, or among mosquitoes from clusters with 2 or 3 ASBs per eligible structure. Similarly, there were no correlations observed between feeding rates and the average number of ASB stations per hectare or with weekly rainfall amounts. CONCLUSIONS: Anopheles funestus and An. gambiae vector populations in Western Province, Zambia readily fed from the prototype Sarabi v1.1.1 ASB sugar bait station. Observed feeding rates are in line with those thought to be required for ATSB stations to achieve reductions in malaria transmission when used in combination with conventional control methods (IRS or LLIN). These results supported the decision to implement a large-scale, epidemiological cluster randomized controlled trial of ATSB in Zambia, deploying 2 ATSB stations per eligible structure.
Subject(s)
Anopheles , Malaria , Humans , Animals , Sugars , Zambia , Cross-Over Studies , Fluorescein , Malaria/prevention & control , Mosquito VectorsABSTRACT
Measuring Escherichia coli in a single-grab sample of stored drinking water is often used to characterize drinking water quality. However, if water quality exhibits variability temporally, then one-time measurement schemes may be insufficient to adequately characterize the quality of water that people consume. This study uses longitudinal data collected from 193 households in peri-urban Tanzania to assess variability in stored water quality and to characterize uncertainty with different data collection schemes. Households were visited 5 times over the course of a year. At each visit, information was collected on water management practices, and a sample of stored drinking water was collected for E. coli enumeration. Water quality was poor for households, with 80% having highly contaminated (>100 CFU per 100 mL) water during at least one visit. There was substantial variability of water quality for households, with only 3% of households having the same category (low, medium, or high) of water quality for all five visits. These data suggest a single sample would inaccurately characterize a household's drinking water quality over the course of a year and lead to misestimates of population level access to safe drinking water.
Subject(s)
Drinking Water , Water Quality , Humans , Water Supply , Tanzania , Escherichia coliABSTRACT
BACKGROUND & AIMS: Understanding the mechanisms by which tumors adapt to therapy is critical for developing effective combination therapeutic approaches to improve clinical outcomes for patients with cancer. METHODS: To identify promising and clinically actionable targets for managing colorectal cancer (CRC), we conducted a patient-centered functional genomics platform that includes approximately 200 genes and paired this with a high-throughput drug screen that includes 262 compounds in four patient-derived xenografts (PDXs) from patients with CRC. RESULTS: Both screening methods identified exportin 1 (XPO1) inhibitors as drivers of DNA damage-induced lethality in CRC. Molecular characterization of the cellular response to XPO1 inhibition uncovered an adaptive mechanism that limited the duration of response in TP53-mutated, but not in TP53-wild-type CRC models. Comprehensive proteomic and transcriptomic characterization revealed that the ATM/ATR-CHK1/2 axes were selectively engaged in TP53-mutant CRC cells upon XPO1 inhibitor treatment and that this response was required for adapting to therapy and escaping cell death. Administration of KPT-8602, an XPO1 inhibitor, followed by AZD-6738, an ATR inhibitor, resulted in dramatic antitumor effects and prolonged survival in TP53-mutant models of CRC. CONCLUSIONS: Our findings anticipate tremendous therapeutic benefit and support the further evaluation of XPO1 inhibitors, especially in combination with DNA damage checkpoint inhibitors, to elicit an enduring clinical response in patients with CRC harboring TP53 mutations.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Biomarkers, Tumor/genetics , Colorectal Neoplasms/drug therapy , Karyopherins/antagonists & inhibitors , Mutation , Protein Kinase Inhibitors/administration & dosage , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Animals , Ataxia Telangiectasia Mutated Proteins/metabolism , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Databases, Genetic , HCT116 Cells , HT29 Cells , Humans , Indoles/administration & dosage , Karyopherins/metabolism , Mice , Morpholines/administration & dosage , Piperazines/administration & dosage , Pyridines/administration & dosage , Pyrimidines/administration & dosage , Receptors, Cytoplasmic and Nuclear/metabolism , Sulfonamides/administration & dosage , Xenograft Model Antitumor Assays , Exportin 1 ProteinABSTRACT
Low- and middle-income countries (LMICs) bear the largest mortality burden of antibiotic-resistant infections. Small-scale animal production and free-roaming domestic animals are common in many LMICs, yet data on zoonotic exchange of gut bacteria and antibiotic resistance genes (ARGs) in low-income communities are sparse. Differences between rural and urban communities with regard to population density, antibiotic use, and cohabitation with animals likely influence the frequency of transmission of gut bacterial communities and ARGs between humans and animals. Here, we determined the similarity in gut microbiomes, using 16S rRNA gene amplicon sequencing, and resistomes, using long-read metagenomics, between humans, chickens, and goats in a rural community compared to an urban community in Bangladesh. Gut microbiomes were more similar between humans and chickens in the rural (where cohabitation is more common) than the urban community, but there was no difference for humans and goats in the rural versus the urban community. Human and goat resistomes were more similar in the urban community, and ARG abundance was higher in urban animals than rural animals. We identified substantial overlap of ARG alleles in humans and animals in both settings. Humans and chickens had more overlapping ARG alleles than humans and goats. All fecal hosts from the urban community and rural humans carried ARGs on chromosomal contigs classified as potentially pathogenic bacteria, including Escherichia coli, Campylobacter jejuni, Clostridioides difficile, and Klebsiella pneumoniae. These findings provide insight into the breadth of ARGs circulating within human and animal populations in a rural compared to urban community in Bangladesh. IMPORTANCE While the development of antibiotic resistance in animal gut microbiomes and subsequent transmission to humans has been demonstrated in intensive farming environments and high-income countries, evidence of zoonotic exchange of antibiotic resistance in LMIC communities is lacking. This research provides genomic evidence of overlap of antibiotic resistance genes between humans and animals, especially in urban communities, and highlights chickens as important reservoirs of antibiotic resistance. Chicken and human gut microbiomes were more similar in rural Bangladesh, where cohabitation is more common. Incorporation of long-read metagenomics enabled characterization of bacterial hosts of resistance genes, which has not been possible in previous culture-independent studies using only short-read sequencing. These findings highlight the importance of developing strategies for combatting antibiotic resistance that account for chickens being reservoirs of ARGs in community environments, especially in urban areas.
Subject(s)
Microbiota , Rural Population , Animals , Anti-Bacterial Agents/pharmacology , Bacteria/genetics , Bangladesh , Chickens/genetics , Escherichia coli/genetics , Genes, Bacterial , Humans , Microbiota/genetics , RNA, Ribosomal, 16S/geneticsABSTRACT
The Joint Monitoring Programme estimated that 71% of people globally had access to "safely managed" drinking water in 2017. However, typical data collection practices focus only on a household's primary water source, yet some households in low- and middle-income countries (LMICs) engage in multiple water source use, including supplementing improved water supplies with unimproved water throughout the year. Monte Carlo simulations and previously published data were used to simulate exposure to fecal contamination (as measured by E. coli) along a range of supplemental unimproved source use rates (e.g., 0-100% improved water use, with the remainder made up with unimproved water). The model results revealed a statistically significant increase in annual exposure to E. coli when individuals supplement their improved water with unimproved water just 2 days annually. Additionally, our analysis identified scenarios-realistic for the data set study setting-where supplementing with unimproved water counterintuitively decreases exposure to E. coli. These results highlight the need for evaluating the temporal dynamics in water quality and availability of drinking water sources in LMICs as well as capturing the use of multiple water sources for monitoring global access to safe drinking water.
Subject(s)
Drinking Water , Escherichia coli , Feces , Humans , Water Microbiology , Water Quality , Water SupplyABSTRACT
The Urban Heat Island effect has been the focus of several studies concerned with the effects of urbanisation on human and ecosystem health. Humidity, however, remains much less studied, although it is useful for characterising human thermal comfort, the Urban Dryness Island effect and vegetation development. Furthermore, variability in microscale climate due to differences in land cover is increasingly crucial for understanding urbanisation effects on the health and wellbeing of living organisms. We used regression analysis to investigate the spatial and temporal dynamics of temperature, humidity and heat index in the tropical African city of Kampala, Uganda. We gathered data during the wet to dry season transition from 22 locations that represent the wide range of urban morphological differences in Kampala. Our analysis showed that the advancement of the dry season increased variability of climate in Kampala and that the most built-up locations experienced the most profound seasonal changes in climate. This work stresses the need to account for water availability and humidity to improve our understanding of human and ecosystem health in cities.
Subject(s)
Ecosystem , Hot Temperature , Cities , Humans , Seasons , Tropical Climate , UgandaABSTRACT
The Joint Monitoring Programme (JMP) 2017 Update and Sustainable Development Goals (SDGs) Baselines report classified 71% of the global population as having access to 'safely managed' drinking water. Current global monitoring efforts to track access to safely managed drinking water rely on collecting information on the 'primary' source of drinking water. However, there is evidence that households often rely on multiple sources to meet their water needs in many low- and middle-income countries (LMICs). This systematic review was designed to compile the literature related to the practice of multiple water source use (MWSU) for drinking water in LMICs. A total of 5,318 studies were collected, and after abstract and full-text review, 74 articles were identified for inclusion. Studies reviewed reported from 4 to 100% of the study populations practicing MWSU. Additionally, the practice of supplemental unimproved source use was reported globally, representing households with improved primary source water also accessing unimproved water sources throughout the year. These findings expose gaps in current global water monitoring efforts, revealing potential inflation of reports of 'safe drinking water access' and unaccounted exposure to drinking water from unimproved sources.
Subject(s)
Drinking Water , Water Supply , Developing Countries , Drinking Water/analysis , Poverty , Water QualityABSTRACT
Marginalized communities lack full participation in social, economic, and political life, and they disproportionately bear the burden of environmental and health risks. This special issue of Environmental Engineering Science, the official journal of the Association of Environmental Engineering and Science Professors (AEESP), reports research on the unique environmental challenges faced by historically marginalized communities around the world. The results of community-based participatory research with an Afro-descendant community in Columbia, Native American communities in Alaska, United States, villagers in the Philippines, disadvantaged communities in California, United States, rural communities in Mexico and Costa Rica, homeless encampments in the San Diego River (United States) watershed entrepreneurs in Durban, South Africa, and remote communities in the island nation of Fiji are presented. The research reported in this special issue is transdisciplinary, bringing engineers together with anthropologists, sociologists, economists, and public health experts. In the 13 articles in this special issue, some of the topics covered include inexpensive technologies for water treatment, novel agricultural strategies for reversing biodiversity losses, and strategies for climate change adaptation. In addition, one article covered educational strategies for teaching ethics to prepare students for humanitarian engineering, including topics of poverty, sustainability, social justice, and engineering decisions under uncertainty. Finally, an article presented ways that environmental engineering professors can engage and promote the success of underrepresented minority students and enable faculty engaged in community-based participatory research.
ABSTRACT
The growth of rice is a sequence of three different phenological phases. This sequence of change in rice phenology implies that the condition of the plant during the vegetative phase relates directly to the health of leaves functioning during the reproductive and ripening phases. As such, accurate monitoring is important towards understanding rice growth dynamics. Leaf Area Index (LAI) is an important indicator of rice yields and the availability of this information during key phenological phases can support more informed farming decisions. Satellite remote sensing has been adopted as a proxy to field measurements of LAI and with the launch of freely available high resolution Satellite images such as Sentinel-2, it is imperative that accurate retrieval methods are adopted towards monitoring LAI at irrigated rice fields. Here, we evaluate the potential of a hybrid radiative transfer model (i.e., PROSAIL - Gaussian Process Regression (GPR), for estimating the phenological dynamics of irrigated rice LAI using imager derived from the Sentinel-2 multispectral instrument. LAI field measurements were obtained from an experimental rice field in Nasarawa state, Nigeria during the dry season. We used the PROSAIL radiative transfer model to create a look up table (LUT) that was subsequently used to train a GPR model. Afterwards, we evaluated the potential of the hybrid modelling approach by assessing the overall model accuracy and the extent to which LAI was able to accurately predict LAI during key rice phenological phases. We compared the predicted hybrid GPR LAI values with LAI values generated from the SNAP toolbox, based on a hybrid Artificial Neural Network (ANN) modelling approach. Our results show that the overall predictive accuracy of the hybrid GPR model (R2 = 0.82, RMSE = 1.65) was more accurate than that of the hybrid ANN model (R2 = 0.66, RMSE = 3.89) for retrieving LAI values from Sentinel-2 imagery. Both models underestimated LAI values during the reproductive and ripening phases . However, the accuracy during the phenological phases were more significant when using the hybrid GPR model (P < 0.05). During the different phenological phases, the hybrid GPR model predicted LAI more accurately during the reproductive (R2 = 0.7) and ripening (R2 = 0.59) phases compared to the hybrid ANN reproductive and ripening phases. When monitoring LAI phenological profiles of both hybrid models, the hybrid GPR and ANN models underestimated LAI during the reproductive and ripening phases. However, the ANN model underestimations were statistically significantly greater than those for the hybrid GPR model (P < 0.05). Our results highlight the potential of hybrid GPR models for estimating the phenological dynamics of irrigated rice LAI from Sentinel-2 data. They provided more accurate estimation of LAI patterns from varying nitrogen and water applications than hybrid ANN models.
ABSTRACT
In September 2018, Hurricane Florence caused extreme flooding in eastern North Carolina, USA, a region highly dense in concentrated animal production, especially swine and poultry. In this study, floodwater samples (n = 96) were collected as promptly post-hurricane as possible and for up to approximately 30 days and selectively enriched for Campylobacter using Bolton broth enrichment and isolation on modified charcoal cefoperazone deoxycholate agar (mCCDA) microaerobically at 42°C. Only one sample yielded Campylobacter, which was found to be Campylobacter jejuni with the novel sequence type 2866 (ST-2866). However, the methods employed to isolate Campylobacter readily yielded Arcobacter from 73.5% of the floodwater samples. The Arcobacter isolates failed to grow on Mueller-Hinton agar at 25, 30, 37, or 42°C microaerobically or aerobically but could be readily subcultured on mCCDA at 42°C microaerobically. Multilocus sequence typing of 112 isolates indicated that all were Arcobacter butzleri The majority (85.7%) of the isolates exhibited novel sequence types (STs), with 66 novel STs identified. Several STs, including certain novel ones, were detected in diverse waterbody types (channel, isolated ephemeral pools, floodplain) and from multiple watersheds, suggesting the potential for regionally dominant strains. The genotypes were clearly partitioned into two major clades, one with high representation of human and ruminant isolates and another with an abundance of swine and poultry isolates. Surveillance of environmental waters and food animal production systems in this animal agriculture-dense region is needed to assess potential regional prevalence and temporal stability of the observed A. butzleri strains as well as their potential association with specific types of food animal production.IMPORTANCE Climate change and associated extreme weather events can have massive impacts on the prevalence of microbial pathogens in floodwaters. However, limited data are available on foodborne zoonotic pathogens such as Campylobacter or Arcobacter in hurricane-associated floodwaters in rural regions with intensive animal production. With a high density of intensive animal production as well as pronounced vulnerability to hurricanes, eastern North Carolina presents unique opportunities in this regard. Our findings revealed widespread incidence of the emerging zoonotic pathogen Arcobacter butzleri in floodwaters from Hurricane Florence. We encountered high and largely unexplored diversity while also noting the potential for regionally abundant and persistent clones. We noted pronounced partitioning of the floodwater genotypes into two source-associated clades. The data will contribute to elucidating the poorly understood ecology of this emerging pathogen and highlight the importance of surveillance of floodwaters associated with hurricanes and other extreme weather events for Arcobacter and other zoonotic pathogens.
Subject(s)
Arcobacter/isolation & purification , Cyclonic Storms , Genotype , Rivers/microbiology , Arcobacter/genetics , Campylobacter jejuni/isolation & purification , Floods , Multilocus Sequence Typing , North CarolinaABSTRACT
AIMS: To examine perceptions of occupational stress in Emergency Department (ED) nurses and measure the impact of interventions to address them. BACKGROUND: Cross-sectional studies internationally have established that Emergency Department (ED) nursing staff experience high levels of occupational stress. Few however have examined changes in perceptions of stress over time or the impact of interventions to address them. EVALUATION: A structured questionnaire completed by volunteer nursing staff in one United Kingdom ED assessing perceptions of occupational stress and job satisfaction. Questionnaire rounds were administered in 2014 (T1), 2015 (T2) and 2017 (T3) at 18-month intervals. Statistical analyses were conducted using multivariate regression, t-tests and Mann-Whitney U tests. KEY ISSUE: Statistically significant improvements in effort-reward balance, relational justice and job satisfaction were seen between T2 and T3 for nurses completing questionnaires at all three time points, but not for other stressors. CONCLUSION: This study suggests that organisational interventions, supported by robust research data and consistent departmental leadership can positively influence perceptions of organisational stress in ED nurses. Our approach is generic, internationally applicable and can be adopted in all EDs. IMPLICATIONS OF NURSING MANAGEMENT: These occupational stressors are common to all EDs. Nurse managers should know their distribution amongst their staff. Such data can inform interventions to achieve maximal benefits for staff wellbeing and may be of value when targeting resources in times of financial pressure.
Subject(s)
Emergency Service, Hospital/standards , Nursing Staff/psychology , Occupational Stress/etiology , Adult , Cross-Sectional Studies , Emergency Service, Hospital/organization & administration , Emergency Service, Hospital/statistics & numerical data , Female , Focus Groups/methods , Humans , Longitudinal Studies , Male , Middle Aged , Multivariate Analysis , Nursing Staff/statistics & numerical data , Occupational Stress/classification , Occupational Stress/psychology , Qualitative Research , Statistics, Nonparametric , Surveys and Questionnaires , SwedenABSTRACT
In response to the 2016 Zika outbreak, Aedes aegypti mosquitoes from 38 locations across Puerto Rico were screened using Centers for Disease Control and Prevention bottle bioassays for sensitivity to insecticides used for mosquito control. All populations were resistant to pyrethroids. Naled, an organophosphate, was the most effective insecticide, killing all mosquitoes tested.
Subject(s)
Aedes , Insecticides , Mosquito Control/methods , Zika Virus Infection/prevention & control , Animals , Female , Humans , Insecticide Resistance , Naled , Puerto Rico/epidemiologyABSTRACT
Patients with end-stage renal disease (ESRD) are at elevated risk of acquiring infectious diseases, including tuberculosis (TB). Inflammation and uremia negatively impact immune function in this population, but specific pathways involved in TB immunity have not been identified. Although γδ T cells are known to contribute to protection from TB, their phenotype and function in patients with ESRD is relatively unknown. To determine this we recruited 20 patients with and 20 without ESRD (controls), with or without latent TB infection to assess γδ T cell frequency, surface phenotype, and cytokine production by flow cytometry in response to stimulation. γδ T cells derived from patients with ESRD exhibited significantly lower expression of CCR5, CXCR3, and CD26 compared to controls. Furthermore, patients with ESRD, particularly the group with latent TB infection, exhibited poor IFNγ, TNFα, and GMCSF responses to stimulation with either phosphoantigen HMB-PP, IL-12/IL-18, E. coli, or phorbol myristate acetate and ionomycin. Similar dysfunctional responses were observed in patients with active TB. Surprisingly, neither the γδ phenotype nor its function was associated with plasma markers of inflammation or microbial translocation. Thus, there is significant perturbation of the γδ T-cell population in patients with ESRD, particularly in those with latent TB infection.
Subject(s)
Cytokines/metabolism , Intraepithelial Lymphocytes/immunology , Kidney Failure, Chronic/immunology , Latent Tuberculosis/immunology , Mycobacterium tuberculosis/pathogenicity , Adult , Aged , Cytokines/immunology , Diphosphates , Disease Susceptibility/immunology , Disease Susceptibility/microbiology , Female , Flow Cytometry , Humans , Intraepithelial Lymphocytes/metabolism , Kidney Failure, Chronic/urine , Latent Tuberculosis/microbiology , Lymphocyte Activation/immunology , Male , Middle Aged , Mycobacterium tuberculosis/isolation & purification , Uremia/immunology , Uremia/urineABSTRACT
LX2761 is a potent sodium/glucose cotransporter 1 inhibitor restricted to the intestinal lumen after oral administration. Studies presented here evaluated the effect of orally administered LX2761 on glycemic control in preclinical models. In healthy mice and rats treated with LX2761, blood glucose excursions were lower and plasma total glucagon-like peptide-1 (GLP-1) levels higher after an oral glucose challenge; these decreased glucose excursions persisted even when the glucose challenge occurred 15 hours after LX2761 dosing in ad lib-fed mice. Further, treating mice with LX2761 and the dipeptidyl-peptidase 4 inhibitor sitagliptin synergistically increased active GLP-1 levels, suggesting increased LX2761-mediated release of GLP-1 into the portal circulation. LX2761 also lowered postprandial glucose, fasting glucose, and hemoglobin A1C, and increased plasma total GLP-1, during long-term treatment of mice with either early- or late-onset streptozotocin-diabetes; in the late-onset cohort, LX2761 treatment improved survival. Mice and rats treated with LX2761 occasionally had diarrhea; this dose-dependent side effect decreased in severity and frequency over time, and LX2761 doses were identified that decreased postprandial glucose excursions without causing diarrhea. Further, the frequency of LX2761-associated diarrhea was greatly decreased in mice either by gradual dose escalation or by pretreatment with resistant starch 4, which is slowly digested to glucose in the colon, a process that primes the colon for glucose metabolism by selecting for glucose-fermenting bacterial species. These data suggest that clinical trials are warranted to determine if LX2761 doses and dosing strategies exist that provide improved glycemic control combined with adequate gastrointestinal tolerability in people living with diabetes.
Subject(s)
Benzhydryl Compounds/pharmacology , Blood Glucose/drug effects , Blood Glucose/metabolism , Glucagon-Like Peptide 1/antagonists & inhibitors , Glucagon-Like Peptide 1/blood , Hypoglycemic Agents/pharmacology , Thioglycosides/pharmacology , Animals , Benzhydryl Compounds/chemistry , Dose-Response Relationship, Drug , Glycemic Index/drug effects , Glycemic Index/physiology , Hypoglycemic Agents/chemistry , Male , Mice , Mice, Inbred C57BL , Random Allocation , Rats , Rats, Sprague-Dawley , Thioglycosides/chemistryABSTRACT
Increasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future disease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti's adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population(s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, historical human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analysis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti.