ABSTRACT
Rationale: The global burden of sepsis is greatest in low-resource settings. Melioidosis, infection with the gram-negative bacterium Burkholderia pseudomallei, is a frequent cause of fatal sepsis in endemic tropical regions such as Southeast Asia. Objectives: To investigate whether plasma metabolomics would identify biological pathways specific to melioidosis and yield clinically meaningful biomarkers. Methods: Using a comprehensive approach, differential enrichment of plasma metabolites and pathways was systematically evaluated in individuals selected from a prospective cohort of patients hospitalized in rural Thailand with infection. Statistical and bioinformatics methods were used to distinguish metabolomic features and processes specific to patients with melioidosis and between fatal and nonfatal cases. Measurements and Main Results: Metabolomic profiling and pathway enrichment analysis of plasma samples from patients with melioidosis (n = 175) and nonmelioidosis infections (n = 75) revealed a distinct immuno-metabolic state among patients with melioidosis, as suggested by excessive tryptophan catabolism in the kynurenine pathway and significantly increased levels of sphingomyelins and ceramide species. We derived a 12-metabolite classifier to distinguish melioidosis from other infections, yielding an area under the receiver operating characteristic curve of 0.87 in a second validation set of patients. Melioidosis nonsurvivors (n = 94) had a significantly disturbed metabolome compared with survivors (n = 81), with increased leucine, isoleucine, and valine metabolism, and elevated circulating free fatty acids and acylcarnitines. A limited eight-metabolite panel showed promise as an early prognosticator of mortality in melioidosis. Conclusions: Melioidosis induces a distinct metabolomic state that can be examined to distinguish underlying pathophysiological mechanisms associated with death. A 12-metabolite signature accurately differentiates melioidosis from other infections and may have diagnostic applications.
Subject(s)
Burkholderia pseudomallei , Melioidosis , Sepsis , Humans , Melioidosis/diagnosis , Melioidosis/microbiology , Prospective Studies , MetabolomicsABSTRACT
In September 2021, a total of 25 patients diagnosed with COVID-19 developed acute melioidosis after (median 7 days) admission to a COVID-19 field hospital in Thailand. Eight nonpotable tap water samples and 6 soil samples were culture-positive for Burkholderia pseudomallei. Genomic analysis suggested contaminated tap water as the likely cause of illness.
Subject(s)
Burkholderia pseudomallei , COVID-19 , Melioidosis , Humans , Melioidosis/epidemiology , Thailand/epidemiology , Burkholderia pseudomallei/genetics , WaterABSTRACT
The soil bacterium Burkholderia pseudomallei is the causative agent of melioidosis and a significant cause of human morbidity and mortality in many tropical and subtropical countries. The species notoriously survives harsh environmental conditions but the genetic architecture for these adaptations remains unclear. Here we employed a powerful combination of genome-wide epistasis and co-selection studies (2,011 genomes), condition-wide transcriptome analyses (82 diverse conditions), and a gene knockout assay to uncover signals of "co-selection"-that is a combination of genetic markers that have been repeatedly selected together through B.Ā pseudomallei evolution. These enabled us to identify 13,061 mutation pairs under co-selection in distinct genes and noncoding RNA. Genes under co-selection displayed marked expression correlation when B.Ā pseudomallei was subjected to physical stress conditions, highlighting the conditions as one of the major evolutionary driving forces for this bacterium. We identified a putative adhesin (BPSL1661) as a hub of co-selection signals, experimentally confirmed a BPSL1661 role under nutrient deprivation, and explored the functional basis of co-selection gene network surrounding BPSL1661 in facilitating the bacterial survival under nutrient depletion. Our findings suggest that nutrient-limited conditions have been the common selection pressure acting on this species, and allelic variation of BPSL1661 may have promoted B.Ā pseudomallei survival during harsh environmental conditions by facilitating bacterial adherence to different surfaces, cells, or living hosts.
Subject(s)
Biological Evolution , Burkholderia pseudomallei , Adhesins, Bacterial , Alleles , Burkholderia pseudomallei/genetics , Burkholderia pseudomallei/physiology , Selection, Genetic , Stress, PhysiologicalABSTRACT
Non-academic partners can be vital in successful public engagement activities on antimicrobial resistance. With collaboration between academic and non-academic partners, we developed and launched an open-access web-based application, the 'antibiotic footprint calculator', in both Thai and English. The application focused on a good user experience, addressing antibiotic overuse and its impact, and encouraging immediate action. The application was unveiled in joint public engagement activities. From 1 Nov 2021 to 31 July 2022 (9 month period), 2554 players estimated their personal antibiotic footprint by using the application.
Subject(s)
Anti-Bacterial Agents , Drug Resistance, Bacterial , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Thailand , SoftwareABSTRACT
Vancomycin-resistant Enterococcus faecium (VREfm) is a leading cause of healthcare-associated infection. Reservoirs of VREfm are largely assumed to be nosocomial although there is a paucity of data on alternative sources. Here, we describe an integrated epidemiological and genomic analysis of E. faecium associated with bloodstream infection and isolated from wastewater. Treated and untreated wastewater from 20 municipal treatment plants in the East of England, United Kingdom was obtained and cultured to isolate E. faecium, ampicillin-resistant E. faecium (AREfm), and VREfm. VREfm was isolated from all 20 treatment plants and was released into the environment by 17/20 plants, the exceptions using terminal ultraviolet light disinfection. Median log10 counts of AREfm and VREfm in untreated wastewater from 10 plants in direct receipt of hospital sewage were significantly higher than 10 plants that were not. We sequenced and compared the genomes of 423 isolates from wastewater with 187 isolates associated with bloodstream infection at five hospitals in the East of England. Among 481 E. faecium isolates belonging to the hospital-adapted clade, we observed genetic intermixing between wastewater and bloodstream infection, with highly related isolates shared between a major teaching hospital in the East of England and 9/20 plants. We detected 28 antibiotic resistance genes in the hospital-adapted clade, of which 23 were represented in bloodstream, hospital sewage, and municipal wastewater isolates. We conclude that our findings are consistent with widespread distribution of hospital-adapted VREfm beyond acute healthcare settings with extensive release of VREfm into the environment in the East of England.
Subject(s)
Anti-Bacterial Agents/toxicity , Cross Infection/microbiology , Drug Resistance, Bacterial , Enterococcus faecium/isolation & purification , Genome, Bacterial , Vancomycin/toxicity , Wastewater/microbiology , England , Enterococcus faecium/drug effects , Enterococcus faecium/geneticsABSTRACT
Antimicrobial resistance (AMR) is a serious global health threat and is predicted to cause significant health and economic impacts, particularly in low- and middle-income countries (LMICs). AMR surveillance is critical in LMICs due to high burden of bacterial infections; however, conducting AMR surveillance in resource-limited settings is constrained by poorly functioning health systems, scarce financial resources, and lack of skilled personnel. In 2015, the United Nations World Health Assembly endorsed the World Health Organization's Global Action Plan to tackle AMR; thus, several countries are striving to improve their AMR surveillance capacity, including making significant investments and establishing and expanding surveillance networks. Initial data generated from AMR surveillance networks in LMICs suggest the high prevalence of resistance, but these data exhibit several shortcomings, such as a lack of representativeness, lack of standardized laboratory practices, and underutilization of microbiology services. Despite significant progress, AMR surveillance networks in LMICs face several challenges in expansion and sustainability due to limited financial resources and technical capacity. This review summarizes the existing health infrastructure affecting the establishment of AMR surveillance programs, the burden of bacterial infections demonstrating the need for AMR surveillance, and current progress and challenges in AMR surveillance efforts in eight South and Southeast Asian countries.
Subject(s)
Bacterial Infections/epidemiology , Drug Resistance, Bacterial , Health Facilities , Public Health Surveillance , Acinetobacter baumannii/drug effects , Asia, Southeastern , Asia, Western , Bacterial Infections/prevention & control , Developing Countries , Escherichia coli/drug effects , Humans , Klebsiella pneumoniae/drug effects , Neisseria gonorrhoeae/drug effects , Salmonella/drug effects , Shigella/drug effects , Staphylococcus aureus/drug effects , Streptococcus pneumoniae/drug effectsABSTRACT
BACKGROUND: Melioidosis, infection caused by Burkholderia pseudomallei, is a common cause of sepsis with high associated mortality in Southeast Asia. Identification of patients at high likelihood of clinical deterioration is important for guiding decisions about resource allocation and management. We sought to develop a biomarker-based model for 28-day mortality prediction in melioidosis. METHODS: In a derivation set (NĆ¢ĀĀ =Ć¢ĀĀ 113) of prospectively enrolled, hospitalized Thai patients with melioidosis, we measured concentrations of interferon-ĆĀ³, interleukin-1Ć, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-ĆĀ, granulocyte-colony stimulating factor, and interleukin-17A. We used least absolute shrinkage and selection operator (LASSO) regression to identify a subset of predictive biomarkers and performed logistic regression and receiver operating characteristic curve analysis to evaluate biomarker-based prediction of 28-day mortality compared with clinical variables. We repeated select analyses in an internal validation set (NĆ¢ĀĀ =Ć¢ĀĀ 78) and in a prospectively enrolled external validation set (NĆ¢ĀĀ =Ć¢ĀĀ 161) of hospitalized adults with melioidosis. RESULTS: All 8 cytokines were positively associated with 28-day mortality. Of these, interleukin-6 and interleukin-8 were selected by LASSO regression. A model consisting of interleukin-6, interleukin-8, and clinical variables significantly improved 28-day mortality prediction over a model of only clinical variables [AUC (95% confidence interval [CI]): 0.86 (.79-.92) vs 0.78 (.69-.87); PĆ¢ĀĀ =Ć¢ĀĀ .01]. In both the internal validation set (0.91 [0.84-0.97]) and the external validation set (0.81 [0.74-0.88]), the combined model including biomarkers significantly improved 28-day mortality prediction over a model limited to clinical variables. CONCLUSIONS: A 2-biomarker model augments clinical prediction of 28-day mortality in melioidosis.
Subject(s)
Cytokines/blood , Melioidosis , Adult , Biomarkers/blood , Burkholderia pseudomallei , Humans , Melioidosis/diagnosis , Melioidosis/mortality , ThailandABSTRACT
BACKGROUND: Treatment of melioidosis comprises intravenous drugs for at least 10 days, followed by oral trimethoprim-sulfamethoxazole (TMP-SMX) for 12 to 20 weeks. Oral TMP-SMX is recommended for 12 weeks in Australia and 20 weeks in Thailand. METHODS: For this open-label, pragmatic, multicenter, noninferiority, randomized controlled trial, we enrolled patients with culture-confirmed melioidosis who had received oral eradication treatment for 12 weeks and had no clinical evidence of active melioidosis. We randomly assigned patients to stop treatment (12-week regimen) or continue treatment for another 8 weeks (20-week regimen). The primary end point was culture-confirmed recurrent melioidosis within 1 year after enrollment. The noninferiority margin was a hazard ratio (HR) of 2.0. The secondary composite end point, combining overall recurrent melioidosis and mortality, was assessed post hoc. RESULTS: We enrolled 658 patients: 322 to the 12-week regimen and 336 to the 20-week regimen. There were 5 patients (2%) in the 12-week regimen and 2 patients (1%) in the 20-week regimen who developed culture-confirmed recurrent melioidosis (HR, 2.66; 95% confidence interval [CI], .52-13.69). The criterion for noninferiority of the primary event was not met (1-sided P = .37). However, all-cause mortality was significantly lower in the 12-week regimen group than in the 20-week regimen group (1 [.3%] vs 11 [3%], respectively; HR, 0.10; 95% CI, .01-.74). The criterion for noninferiority of the secondary composite end point, combining overall recurrent melioidosis and mortality, was met (1-sided P = .022). CONCLUSIONS: Based on the lower total mortality and noninferiority of the secondary composite end point observed, we recommend the 12-week regimen of TMP-SMX for oral eradication treatment of melioidosis. CLINICAL TRIALS REGISTRATION: NCT01420341.
Subject(s)
Melioidosis , Trimethoprim, Sulfamethoxazole Drug Combination , Administration, Oral , Australia , Humans , Melioidosis/drug therapy , Thailand , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic useABSTRACT
Melioidosis is a life-threatening infectious disease caused by the gram-negative bacillus Burkholderia pseudomallei. An effective vaccine is needed, but data on protective immune responses in human melioidosis are lacking. We used ELISA and an antibody-dependent cellular phagocytosis assay to identify the major features of protective antibodies in patients with acute melioidosis in Thailand. We found that high levels of B. pseudomallei-specific IgG2 are associated with protection against death in a multivariable logistic regression analysis adjusting for age, diabetes, renal disease, and neutrophil count. Serum from melioidosis survivors enhanced bacteria uptake into human monocytes expressing FcĆĀ³RIIa-H/R131, an intermediate-affinity IgG2-receptor, compared with serum from nonsurvivors. We did not find this enhancement when using monocytes carrying the low IgG2-affinity FcĆĀ³RIIa-R131 allele. The findings indicate the importance of IgG2 in protection against death in human melioidosis, a crucial finding for antibody-based therapeutics and vaccine development.
Subject(s)
Antibodies, Bacterial/immunology , Burkholderia pseudomallei , Immunoglobulin G/immunology , Melioidosis , Adult , Enzyme-Linked Immunosorbent Assay , Humans , Melioidosis/epidemiology , Melioidosis/immunology , ThailandABSTRACT
Delays in treating bacteremias with antibiotics to which the causative organism is susceptible are expected to adversely affect patient outcomes. Quantifying the impact of such delays to concordant treatment is important for decision-making about interventions to reduce the delays and for quantifying the burden of disease due to antimicrobial resistance. There are, however, potentially important biases to be addressed, including immortal time bias. We aimed to estimate the impact of delays in appropriate antibiotic treatment of patients with Acinetobacter species hospital-acquired bacteremia in Thailand on 30-day mortality by emulating a target trial using retrospective cohort data from Sunpasitthiprasong Hospital in 2003-2015. For each day, we defined treatment as concordant if the isolated organism was susceptible to at least 1 antibiotic given. Among 1,203 patients with Acinetobacter species hospital-acquired bacteremia, 682 had 1 or more days of delays to concordant treatment. Surprisingly, crude 30-day mortality was lower in patients with delays of ≥3 days compared with those who had 1-2 days of delays. Accounting for confounders and immortal time bias resolved this paradox. Emulating a target trial, we found that these delays were associated with an absolute increase in expected 30-day mortality of 6.6% (95% confidence interval: 0.2, 13.0), from 33.8% to 40.4%.
Subject(s)
Acinetobacter Infections/mortality , Anti-Bacterial Agents/therapeutic use , Bacteremia/mortality , Cross Infection/mortality , Time-to-Treatment/statistics & numerical data , Acinetobacter Infections/drug therapy , Adult , Aged , Bacteremia/drug therapy , Cross Infection/drug therapy , Female , Hospital Mortality , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic , Retrospective Studies , Thailand/epidemiologyABSTRACT
BACKGROUND: Burkholderia pseudomallei is the bacterial causative agent of melioidosis, a difficult disease to diagnose clinically with high mortality if not appropriately treated. Definitive diagnosis requires isolation and identification of the organism. With the increased adoption of MALDI-TOF MS for the identification of bacteria, we established a method for rapid identification of B. pseudomallei using the Vitek MS, a system that does not currently have B. pseudomallei in its in-vitro diagnostic database. RESULTS: A routine direct spotting method was employed to create spectra and SuperSpectra. An initial B. pseudomallei SuperSpectrum was created at Shoklo Malaria Research Unit (SMRU) from 17 reference isolates (46 spectra). When tested, this initial SMRU SuperSpectrum was able to identify 98.2 % (54/55) of Asian isolates, but just 46.7 % (35/75) of Australian isolates. Using spectra (430) from different reference and clinical isolates, two additional SMRU SuperSpectra were created. Using the combination of all SMRU SuperSpectra with seven existing SuperSpectra from Townsville, Australia 119 (100 %) Asian isolates and 31 (100 %) Australian isolates were correctly identified. In addition, no misidentifications were obtained when using these 11 SuperSpectra when tested with 34 isolates of other bacteria including the closely related species Burkholderia thailandensis and Burkholderia cepacia. CONCLUSIONS: This study has established a method for identification of B. pseudomallei using Vitek MS, and highlights the impact of geographical differences between strains for identification using this technique.
Subject(s)
Burkholderia pseudomallei/chemistry , Burkholderia pseudomallei/isolation & purification , Melioidosis/diagnosis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Bacteriological Techniques/instrumentation , Bacteriological Techniques/standards , Melioidosis/microbiology , Reproducibility of Results , Species SpecificityABSTRACT
Melioidosis is a neglected tropical disease with an estimated annual mortality rate of 89,000 in 45 countries across tropical regions. The causative agent is Burkholderia pseudomallei, a gram-negative soil-dwelling bacterium. In Thailand, B. pseudomallei can be found across multiple regions, along with the low-virulence B. thailandensis and the recently discovered B. thailandensis variant (BTCV), which expresses B. pseudomallei-like capsular polysaccharide. Comprehensive studies of human immune responses to B. thailandensis variants and cross-reactivity to B. pseudomallei are not complete. We evaluated human immune responses to B. pseudomallei, B. thailandensis, and BTCV in melioidosis patients and healthy persons in B. pseudomallei-endemic areas using a range of humoral and cellular immune assays. We found immune cross-reactivity to be strong for both humoral and cellular immunity among B. pseudomallei, B. thailandensis, and BTCV. Our findings suggest that environmental exposure to low-virulence strains may build cellular immunity to B. pseudomallei.
Subject(s)
Burkholderia/immunology , Melioidosis/epidemiology , Adult , Aged , Aged, 80 and over , Burkholderia/pathogenicity , Cohort Studies , Cross Reactions , Female , Humans , Immunity , Male , Melioidosis/microbiology , Middle Aged , Prospective Studies , Thailand/epidemiology , Virulence , Young AdultABSTRACT
We evaluated effectiveness of personal protective measures against severe acute respiratory disease coronavirus 2 (SARS-CoV-2) infection. Our case-control study included 211 cases of coronavirus disease (COVID-19) and 839 controls in Thailand. Cases were defined as asymptomatic contacts of COVID-19 patients who later tested positive for SARS-CoV-2; controls were asymptomatic contacts who never tested positive. Wearing masks all the time during contact was independently associated with lower risk for SARS-CoV-2 infection compared with not wearing masks; wearing a mask sometimes during contact did not lower infection risk. We found the type of mask worn was not independently associated with infection and that contacts who always wore masks were more likely to practice social distancing. Maintaining >1 m distance from a person with COVID-19, having close contact for <15 minutes, and frequent handwashing were independently associated with lower risk for infection. Our findings support consistent wearing of masks, handwashing, and social distancing to protect against COVID-19.
Subject(s)
Betacoronavirus , Coronavirus Infections/prevention & control , Disease Transmission, Infectious/prevention & control , Masks/statistics & numerical data , Pandemics/prevention & control , Personal Protective Equipment/statistics & numerical data , Pneumonia, Viral/prevention & control , Adult , Aged , COVID-19 , Case-Control Studies , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Female , Hand Disinfection , Humans , Male , Middle Aged , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Risk Factors , Risk Reduction Behavior , SARS-CoV-2 , Thailand/epidemiologyABSTRACT
Diabetes mellitus (DM) is a serious global health problem currently affecting over 450Ā million people worldwide. Defining its interaction with major global infections is an international public health priority. Melioidosis is caused by Burkholderia pseudomallei, an exemplar pathogen for studying intracellular bacterial infection in the context of DM due to the 12-fold increased risk in this group. We characterized immune correlates of survival in peripheral blood of acute melioidosis patients with and without DM and highlight different immune response patterns. We demonstrate the importance of circulating NK cells and show that CX3CR1 expression on lymphocytes is a novel correlate of survival from acute melioidosis. Furthermore, excessive serum levels of IL-15 and IL-18BP contribute to poor outcome independent of DM comorbidity. CD8+ TĀ cells and granzyme B expression in NK cells are important for survival of non-DM patients, whereas high antibody titers against B. pseudomallei and double-negative TĀ cells are linked to survival of DM patients. Recall responses support a role of ĆĀ³ĆĀ“ T-cell-derived IFN-ĆĀ³ in the establishment of protective immunity in the DM group. Defining the hallmarks of protection in people with DM is crucial for the design of new therapies and vaccines targeting this rapidly expanding risk group.
Subject(s)
Biomarkers/metabolism , Burkholderia pseudomallei/physiology , CX3C Chemokine Receptor 1/metabolism , Diabetes Mellitus/immunology , Killer Cells, Natural/immunology , Melioidosis/immunology , T-Lymphocytes/immunology , Acute Disease , Adult , Aged , Antibodies, Bacterial/blood , Cells, Cultured , Diabetes Mellitus/epidemiology , Diabetes Mellitus/mortality , Female , Humans , Immunity , Intercellular Signaling Peptides and Proteins/blood , Interleukin-15/blood , Male , Melioidosis/epidemiology , Melioidosis/mortality , Middle Aged , Survival AnalysisABSTRACT
BACKGROUND: Few studies of biomarkers as predictors of outcome in infection have been performed in tropical, low- and middle-income countries where the burden of sepsis is highest. We evaluated whether selected biomarkers could predict 28-day mortality in infected patients in rural Thailand. METHODS: Four thousand nine hundred eighty-nine adult patients admitted with suspected infection to a referral hospital in northeast Thailand were prospectively enrolled within 24 h of admission. In a secondary analysis of 760 patients, interleukin-8 (IL-8), soluble tumor necrosis factor receptor 1 (sTNFR-1), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and soluble triggering receptor expressed by myeloid cells 1 (sTREM-1) were measured in the plasma. Association with 28-day mortality was evaluated using regression; a parsimonious biomarker model was selected using the least absolute shrinkage and selection operator (LASSO) method. Discrimination of mortality was assessed by receiver operating characteristic curve analysis and verified by multiple methods. RESULTS: IL-8, sTNFR-1, Ang-2, and sTREM-1 concentrations were strongly associated with death. LASSO identified a three-biomarker model of sTREM-1, Ang-2, and IL-8, but sTREM-1 alone provided comparable mortality discrimination (p = 0.07). sTREM-1 alone was comparable to a model of clinical variables (area under receiver operating characteristic curve [AUC] 0.81, 95% confidence interval [CI] 0.77-0.85 vs AUC 0.79, 95% CI 0.74-0.84; p = 0.43). The combination of sTREM-1 and clinical variables yielded greater mortality discrimination than clinical variables alone (AUC 0.83, 95% CI 0.79-0.87; p = 0.004). CONCLUSIONS: sTREM-1 predicts mortality from infection in a tropical, middle-income country comparably to a model derived from clinical variables and, when combined with clinical variables, can further augment mortality prediction. TRIAL REGISTRATION: The Ubon-sepsis study was registered on ClinicalTrials.gov ( NCT02217592 ), 2014.
Subject(s)
Biomarkers/blood , Cross Infection/diagnosis , Triggering Receptor Expressed on Myeloid Cells-1/genetics , Adult , Aged , Female , Humans , Male , Middle Aged , Mortality , Tropical ClimateABSTRACT
BACKGROUND: Reporting cumulative antimicrobial susceptibility testing data on a regular basis is crucial to inform antimicrobial resistance (AMR) action plans at local, national, and global levels. However, analyzing data and generating a report are time consuming and often require trained personnel. OBJECTIVE: This study aimed to develop and test an application that can support a local hospital to analyze routinely collected electronic data independently and generate AMR surveillance reports rapidly. METHODS: An offline application to generate standardized AMR surveillance reports from routinely available microbiology and hospital data files was written in the R programming language (R Project for Statistical Computing). The application can be run by double clicking on the application file without any further user input. The data analysis procedure and report content were developed based on the recommendations of the World Health Organization Global Antimicrobial Resistance Surveillance System (WHO GLASS). The application was tested on Microsoft Windows 10 and 7 using open access example data sets. We then independently tested the application in seven hospitals in Cambodia, Lao People's Democratic Republic, Myanmar, Nepal, Thailand, the United Kingdom, and Vietnam. RESULTS: We developed the AutoMated tool for Antimicrobial resistance Surveillance System (AMASS), which can support clinical microbiology laboratories to analyze their microbiology and hospital data files (in CSV or Excel format) onsite and promptly generate AMR surveillance reports (in PDF and CSV formats). The data files could be those exported from WHONET or other laboratory information systems. The automatically generated reports contain only summary data without patient identifiers. The AMASS application is downloadable from https://www.amass.website/. The participating hospitals tested the application and deposited their AMR surveillance reports in an open access data repository. CONCLUSIONS: The AMASS is a useful tool to support the generation and sharing of AMR surveillance reports.
Subject(s)
Drug Resistance, Bacterial/drug effects , Hospitals/statistics & numerical data , Epidemiological Monitoring , Humans , Proof of Concept StudyABSTRACT
Background: Infection with the gram-negative bacillus Burkholderia pseudomallei (melioidosis) is an important cause of pneumosepsis in Southeast Asia and has a mortality of up to 40%. We aimed to assess the role of platelets in the host response against B. pseudomallei infection. Methods: Association between platelet counts and mortality was determined in 1160 patients with culture-proven melioidosis. Mice treated with (low- or high-dose) platelet-depleting antibody were inoculated intranasally with B. pseudomallei and killed. Additional studies using functional glycoprotein Ibα-deficient mice were conducted. Results: Thrombocytopenia was present in 31% of patients at admission and predicted mortality in melioidosis patients even after adjustment for confounders. In our murine-melioidosis model, platelet counts decreased, and mice treated with a platelet-depleting antibody showed enhanced mortality and higher bacterial loads compared to mice with normal platelet counts. Low platelet counts had a modest impact on early-pulmonary neutrophil influx. Reminiscent of their role in hemostasis, platelet depletion impaired vascular integrity, resulting in early lung bleeding. Glycoprotein Ibα-deficient mice had reduced platelet counts during B. pseudomallei infection together with an impaired local host defense in the lung. Conclusions: Thrombocytopenia predicts mortality in melioidosis patients and, during experimental melioidosis, platelets play a protective role in both innate immunity and vascular integrity.
Subject(s)
Burkholderia pseudomallei/immunology , Melioidosis/complications , Melioidosis/pathology , Thrombocytopenia/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Asia, Southeastern , Disease Models, Animal , Female , Humans , Male , Melioidosis/immunology , Melioidosis/mortality , Mice , Middle Aged , Prospective Studies , Survival Analysis , Thrombocytopenia/immunology , Young AdultABSTRACT
BACKGROUND: Every year, 90,000 people may die from melioidosis. Vaccine candidates have not proceeded past animal studies, partly due to uncertainty around the potential market size. This study aims to estimate the potential impact, cost-effectiveness and market size for melioidosis vaccines. METHODS: Age-structured decision tree models with country-specific inputs were used to estimate net costs and health benefits of vaccination, with health measured in quality-adjusted life years (QALYs). Four target groups of people living in endemic regions were considered: (i) people aged over 45 years with chronic renal disease, (ii) people aged over 45 years with diabetes, (iii) people aged over 45 years with diabetes and/or chronic renal disease, (iv) everyone aged over 45 years. Melioidosis risk was estimated using Bayesian evidence synthesis of 12 observational studies. In the base case, vaccines were assumed to have 80% efficacy, to have 5-year mean protective duration and to cost USD10.20-338.20 per vaccine. RESULTS: Vaccination could be cost-effective (with incremental cost-effectiveness ratio below GDP per capita) in 61/83 countries/territories with local melioidosis transmission. In these 61 countries/territories, vaccination could avert 68,000 lost QALYs, 8300 cases and 4400 deaths per vaccinated age cohort, at an incremental cost of USD59.6 million. Strategy (ii) was optimal in most regions. The vaccine market may be worth USD268 million per year at its threshold cost-effective price in each country/territory. CONCLUSIONS: There is a viable melioidosis vaccine market, with cost-effective vaccine strategies in most countries/territories with local transmission.
Subject(s)
Melioidosis/drug therapy , Vaccination/economics , Cost-Benefit Analysis , Female , Humans , Male , Melioidosis/pathology , Middle AgedABSTRACT
BACKGROUND: There is a pressing need to understand better the extent and distribution of antimicrobial resistance on a global scale, to inform development of effective interventions. Collation of datasets for meta-analysis, mathematical modelling and temporo-spatial analysis is hampered by the considerable variability in clinical sampling, variable quality in laboratory practice and inconsistencies in antimicrobial susceptibility testing and reporting. METHODS: The Microbiology Investigation Criteria for Reporting Objectively (MICRO) checklist was developed by an international working group of clinical and laboratory microbiologists, infectious disease physicians, epidemiologists and mathematical modellers. RESULTS: In keeping with the STROBE checklist, but applicable to all study designs, MICRO defines items to be included in reports of studies involving human clinical microbiology data. It provides a concise and comprehensive reference for clinicians, researchers, reviewers and journals working on, critically appraising, and publishing clinical microbiology datasets. CONCLUSIONS: Implementation of the MICRO checklist will enhance the quality and scientific reporting of clinical microbiology data, increasing data utility and comparability to improve surveillance, grade data quality, facilitate meta-analyses and inform policy and interventions from local to global levels.
Subject(s)
Clinical Laboratory Services , Data Accuracy , Data Interpretation, Statistical , Microbiological Techniques , Research Design , Checklist/standards , Clinical Laboratory Services/standards , Clinical Laboratory Services/statistics & numerical data , Datasets as Topic , Humans , Microbiological Techniques/methods , Microbiological Techniques/standards , Microbiological Techniques/statistics & numerical data , Practice Guidelines as Topic , Publishing/standards , Research Design/standards , Research Report/standardsABSTRACT
Community-acquired (CA) sepsis is a major public health problem worldwide, yet the etiology remains unknown for >50% of the patients. Here we applied metagenomic next-generation sequencing (mNGS) to characterize the human virome in 492 clinical samples (384 sera, 92 pooled nasal and throat swabs, 10 stools, and 6 cerebrospinal fluid samples) from 386 patients (213 adults and 173 children) presenting with CA sepsis who were recruited from 6 hospitals across Vietnam between 2013 and 2015. Specific monoplex PCRs were used subsequently to confirm the presence of viral sequences detected by mNGS. We found sequences related to 47 viral species belonging to 21 families in 358 of 386 (93%) patients, including viruses known to cause human infections. After PCR confirmation, human viruses were found in 52 of 386 patients (13.4%); picornavirus (enteroviruses [n = 14], rhinovirus [n = 5], and parechovirus [n = 2]), hepatitis B virus (n = 10), cytomegalovirus (n = 9), Epstein-Barr virus (n = 5), and rotavirus A (n = 3) were the most common viruses detected. Recently discovered viruses were also found (gemycircularvirus [n = 5] and WU polyomavirus, Saffold virus, salivirus, cyclovirus-VN, and human pegivirus 2 [HPgV2] [n, 1 each]), adding to the growing literature about the geographic distribution of these novel viruses. Notably, sequences related to numerous viruses not previously reported in human tissues were also detected. To summarize, we identified 21 viral species known to be infectious to humans in 52 of 386 (13.4%) patients presenting with CA sepsis of unknown cause. The study, however, cannot directly impute sepsis causation to the viruses identified. The results highlight the fact that it remains a challenge to establish the causative agents in CA sepsis patients, especially in tropical settings such as Vietnam.