INTRODUCTION: Verbal autopsy (VA) methods have emerged to estimate causes of death in populations lacking robust civil registration and vital statistics (CRVS) systems. Despite World Health Organization endorsement of routine VA use, cost and efficiency concerns persist. Telephonic verbal autopsies (teleVAs) can reduce cost. Physician coding offers a valuable approach, but the expertise required makes it resource-intensive, often involving multiple coders for consensus. OBJECTIVE: To assess inter-coder agreement for cause of death (CoD) in South African teleVAs using Kappa statistics, evaluating if agreement surpasses a 0.8 cut-off (very high) potentially allowing single coders. METHODS: A cross-sectional study employed telephonic VA interviews on non-facility deaths in Cape Town (December 2020-September 2021). Trained fieldworkers administered a standard VA questionnaire. Each case's VA responses were reviewed independently by two physicians, medically certifying the CoD. A panel was used to solve disagreements. Cohen's kappa-statistic (k-statistic) tested agreement levels. RESULTS: Decedents were aged between 18 and 98 years. In total, 228 teleVAs (16.6% response rate) were conducted. Physician coding agreement was good overall (k-statistic: 0.63). Diabetes mellitus (47%) and other non-communicable disease (42%) had initial agreement between physician coders in less than 50% of cases in comparison to consensus totals. COVID-19 (89%) and acute cardiac disease (83%) showed initial agreement in more than 80% of cases compared to consensus totals. A chi-square test revealed a significant difference in the number of causes listed on death notification forms for cases with and without agreement in Part 1 (χ(2) = 14.71, p < 0.01), but not in Part 2 (χ(2) = 4.97, p = 0.17). CONCLUSION: CoD agreement might not be high enough to infer that single coders can be used instead of multiple coders. Challenges with co-morbidities and specific CoDs with multiple sequelae highlight the need for further research and refinement of VA methodologies for reliable CoD determination in routine practice.

BACKGROUND: Verbal autopsy (VA), though imperfect, serves as a vital tool to determine cause-of-death, particularly for out-of-facility deaths, but challenges persist in integrating VA into Civil Registration and Vital Statistics systems. OBJECTIVE: To describe the challenges and successes of collecting a national sample of verbal autopsy interviews in South Africa to obtain the cause of death profile in 2017/18. METHODS: We recruited next of kin from 27 randomly selected sub-districts (10.5%) across South Africa between September 2017 and April 2018. Trained fieldworkers conducted face-to-face interviews using the WHO2016 VA instrument, with physicians certifying underlying causes of death. Feasibility was evaluated based on response rates, participation, and data quality. RESULTS: Of the total 36,976 deaths registered, only 26% were identified during recruitment, with a 55% overall response rate for VA interviews. Physician-reviewed VA data were deemed of good quality for assigning underlying causes of death in 83% of cases. By comparing cause-specific mortality fractions, physician-reviewed VA identified 22.3% HIV/AIDS and InterVA-5 identified 18.5%, aligning with burden of disease estimates, while Statistics South Africa reported 4.9% HIV/AIDS. CONCLUSIONS: The study demonstrated the feasibility of using VA on a national scale, but immense challenges in identifying and recruiting next of kin highlight the importance of formalising VAs within the country's death notification system. | • Main findings: Next of kin of 9 730 decedents were approached at the time of registration of death and 55% consented to be approached later and agreed to do a VA interview by a trained field-worker; 83% of physician-reviewed VA data were considered high-quality for determining underlying causes and 22.3% of all the deaths were due to HIV/AIDS, much higher than the proportion reported in the national statistical office.• Added knowledge: Implementing the VA on a national scale was achievable but significant challenges in recruiting next of kin, emphasising a need to formalise VAs within the country’s death notification system.• Global health impact for policy and action: Accurate cause-of-death data are crucial for policymakers to make informed decisions about the country’s health system and could be supported by using VAs, particularly for the deaths that occur outside health facilities. | eng

Hepatitis B and hepatitis C are leading causes of cirrhosis and liver cancer and caused 1.3 million deaths worldwide in 2022. Hepatitis B is preventable with vaccination, and hepatitis C is curable with direct-acting antivirals. In 2015, in collaboration with CDC and other partners, Georgia, a country at the intersection of Europe and Asia, launched a hepatitis C elimination program to reduce the prevalence of chronic hepatitis C; at that time, the prevalence was 5.4%, more than five times the global average of 1.0%. In 2016, the World Health Assembly endorsed a goal for the elimination of viral hepatitis as a public health problem by 2030. In 2024, 89% of the Georgian adult population have received screening for hepatitis C, 83% of persons with current chronic HCV infection have received a diagnosis, and 86% of those with diagnosed hepatitis C have started treatment. During 2015-2023, vaccination coverage with the hepatitis B birth dose and with 3 doses of hepatitis B vaccine among infants exceeded 90% for most years. In 2021, the prevalence of hepatitis B surface antigen was 0.03% among children and adolescents aged 5-17 years and 2.7% among adults. Georgia has demonstrated substantial progress toward hepatitis B and hepatitis C elimination. Using lessons from the hepatitis C elimination program, scale-up of screening and treatment for hepatitis B among adults would prevent further viral hepatitis-associated morbidity and mortality in Georgia and would accelerate progress toward hepatitis B and hepatitis C elimination by 2030.

INTRODUCTION: The purpose of this review is to examine African Ebola outbreaks from their first discovery to the present, to determine how the medical and public health response has changed and identify the causes for those changes. We sought to describe what is now known about the epidemiology and spread of Ebola virus disease (EVD) from the significant outbreaks that have occurred and outbreak control methods applied under often challenging circumstances. Given the substantial role that the U.S. Government and the U.S. DoD have played in the 2014 to 2016 West African Ebola outbreak, the role of the DoD and the U.S. African Command in controlling EVD is described. MATERIALS AND METHODS: A descriptive method design was used to collect and analyze all available Ebola outbreak literature using the PubMed database. An initial literature search was conducted by searching for, obtaining, and reading original source articles on all major global Ebola outbreaks. To conduct a focused search, we used initial search terms "Ebola outbreak," "Ebola virus disease," "Ebola response," "Ebola countermeasures," and also included each country's name where Ebola cases are known to have occurred. From the 4,673 unique articles obtained from this search and subsequent article title review, 307 articles were identified for potential inclusion. Following abstract and article review, 45 original source articles were used to compile the history of significant Ebola outbreaks. From this compilation, articles focused on each respective subsection of this review to delineate and describe the history of EVD and response, identifying fundamental changes, were obtained and incorporated. RESULTS: We present known Ebola virus and disease attributes, including a general description, seasonality and location, transmission capacity, clinical symptoms, surveillance, virology, historical EVD outbreaks and response, international support for Ebola outbreak response, U.S. DoD support, medical countermeasures supporting outbreak response, remaining gaps to include policy limitations, regional instability, climate change, migration, and urbanization, public health education and infrastructure, and virus persistence and public awareness. CONCLUSIONS: The health and societal impacts of EVD on Africa has been far-reaching, with about 35,000 cases and over 15,000 deaths, with small numbers of cases spreading globally. However, the history of combatting EVD reveals that there is considerable hope for African nations to quickly and successfully respond to Ebola outbreaks, through use of endemic resources including Africa CDC and African Partner Outbreak Response Alliance and the U.S. African Command with greater DoD reachback. Although there remains much to be learned about the Ebola virus and EVD including whether the potential for novel strains to become deadly emerging infections, invaluable vaccines, antivirals, and public health measures are now part of the resources that can be used to combat this disease.

Analyses of National Health and Nutrition Examination Survey (NHANES) data suggested a significant decrease in sealant prevalence among children between 2011 to 2014 and 2015 to 2018. We explore whether this decrease could be associated with possible changes in 1) clinical sealant delivery, 2) dental materials (i.e., increased use of glass ionomer [GI] sealants resulting in an inability to detect sealant fragments that still provide preventive benefits or increased use of composite restorations leading to misclassifying sealants as restorations), and 3) examination sensitivity and specificity. We used NHANES data to estimate the prevalences of sealants, untreated caries, and restorations in ≥1 first permanent molar among children aged 7 to 10 y and used Medical Expenditure Panel Survey data to estimate the annual clinical delivery of sealants and fluoride treatments. We examined changes in outcomes between 2 periods (P < 0.05) controlling for selected sociodemographic characteristics. NHANES sealant examination quality was based on the reference examiner's replicate examinations. The adjusted prevalence of sealants decreased relatively by 27.5% (46.6% vs. 33.8%). Overall, untreated caries decreased. Untreated caries and restoration decreased among children without sealants. Annual clinical sealant delivery did not change, whereas fluoride treatment delivery increased. The decrease in sealant prevalence held when assessed for various age ranges and NHANES cycle combinations. While sealant examination specificity remained similar between the periods, sensitivity (weighted by the proportion of exams by each examiner) decreased relatively by 17.4% (0.92 vs. 0.76). These findings suggest that decreased sealant prevalence was not supported by decreased clinical sealant delivery nor increased use of composite restorations. Decreased examination sensitivity, which could be due to an increased use of GI sealants, could contribute to the decrease in sealant prevalence. The decrease in caries among children without sealants could suggest the increased use of GI sealants. However, we could not rule out that the decrease in caries could be attributable to increased fluoride treatment delivery.

BACKGROUND: Contrary to the World Health Organization's internationally recommended medical certificate of cause of death, the South African (SA) death notification form (DNF) does not allow for the reporting of the manner of death to permit accurate coding of external causes of injury deaths. OBJECTIVES: To describe the injury cause-of-death profile from forensic pathology records collected for the National Cause-of-Death Validation (NCoDV) Project and compare it with profiles from other sources of injury mortality data. In particular, the recording of firearm use in homicides is compared between sources. METHODS: The NCoDV Project was a cross-sectional study of deaths that occurred during a fixed period in 2017 and 2018, from a nationally representative sample of 27 health subdistricts in SA. Trained fieldworkers scanned forensic records for all deaths investigated at the forensic mortuaries serving the sampled subdistricts during the study period. Forensic practitioners reviewed the records and completed a medical certificate of cause of death for each decedent. Causes of death were coded to the International Statistical Classification of Diseases, 10th revision (ICD-10), using Iris automated coding software. Cause-specific mortality fractions for injury deaths were compared with Injury Mortality Survey 2017 (IMS 2017) and Statistics South Africa 2017 (Stats SA 2017) datasets. The cause profile for all firearm-related deaths was compared between the three datasets. RESULTS: A total of 5 315 records were available for analysis. Males accounted for 77.6% of cases, and most decedents were aged between 25 and 44 years. Homicide was the leading cause of death (34.7%), followed by transport injuries (32.6%) and suicide (14.7%). This injury cause profile was similar to IMS 2017 but differed markedly from the official statistics, which showed markedly lower proportions of these three causes (15.0%, 11.6% and 0.7%, respectively), and a much higher proportion of other unintentional causes. Investigation of firearm-related deaths revealed that most were homicides in NCoDV 2017/18 (88.5%) and IMS 2017 (93.1%), while in the Stats SA 2017 data, 98.7% of firearm deaths were classified as accidental. Approximately 7% of firearm-related deaths were suicides in NCoDV 2017/18 and IMS 2017, with only 0.3% in Stats SA 2017. CONCLUSION: The official cause-of-death data for injuries in SA in 2017 differed substantially from findings from the NCoDV 2017/18 study and IMS 2017. Accurate data sources would ensure that public health interventions are designed to reduce the high injury burden. Inclusion of the manner of death on the DNF, as is recommended internationally, is critically important to enable more accurate, reliable and valid reporting of the injury profile.

Background: Assessing the potential for mosquitoes to transmit medically important arboviruses is essential for understanding their threat to human populations. Currently, vector competence studies are typically performed by collecting saliva using a glass capillary tube system which involves sacrificing the mosquito at the time of saliva collection allowing only a single data point. These techniques also require handling infected mosquitoes and glass capillaries, constituting a safety risk. Materials and Methods: To improve the efficiency and safety of assessing vector competence, a novel containment and saliva collection approach for individually housed mosquitoes was developed. The improved housing, allowing longitudinal tracking of individual mosquitoes, consists of a 12-well Corning polystyrene plate sealed with a three-dimensional printed lid that holds organdy netting firmly against the rims of the wells. Results: This method provides excellent mosquito survival for five species of mosquitoes, with at least 79% of each species tested surviving for more than 2 weeks, comparable to the carton survival rates of ≥76%. When the plate housing system was used to assess vector infection, replication of West Nile virus (WNV) in mosquito tissues was similar to traditional containment mosquito housing. Mosquito saliva was collected using either blotting paper pads or traditional glass capillaries to assay viral transmission. The blotting paper collection showed similar or better sensitivity than the capillary method; in addition, longitudinal saliva samples could be collected from individual mosquitoes housed in the 12-well plates. Conclusions: The improved housing and saliva collection technique described herein provides a safer and more informative method for determining vector competence in mosquitoes.

Part 1 of this tutorial addressed how environmental contamination may be minimized by using proper personal analytical practices, sample preparation environmental suggestions, avoidance of glass and low purity quartz contact with samples and standards during sample collection and preparation, and appropriate choices of high purity solvents during sample collection and preparation. Part 2 continues the discussion in terms of minimizing sample contamination issues by using high purity polymer materials for sample collection and preparation, as well as discuss the differences between instrument and method limits of detection (LODs). Accepted and appropriate procedures for calculating method LODs are related to variability in instrument response and unavoidable environmental contamination during even the cleanest sample preparation. Adherence to such practices will help analysts avoid false positives and report results with a high level of confidence. © 2023 Advanstar Communications Inc.. All rights reserved.

Objectives The COVID-19 pandemic has had a substantial impact on health systems. The WHO Antimicrobial Resistance (AMR) Collaborating Centres Network conducted a survey to assess the effects of COVID-19 on AMR surveillance, prevention and control.Methods From October-December 2020, WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS) national focal points completed a questionnaire including Likert-scales and open-ended questions. Data were descriptively analysed, income/regional differences were assessed, and free-text questions were thematically analysed.Results Seventy-three countries across income levels participated. During the COVID-19 pandemic, 67% reported limited ability to work with AMR partnerships; decreases in funding were frequently reported by low- and middle-income countries (LMICs; p&lt;0.01). Reduced availability of nursing, medical and public health staff for AMR was reported by 71%, 69% and 64%, respectively, whereas 67% reported stable cleaning staff availability. The majority (58%) reported reduced reagents/consumables, particularly LMICs (p&lt;0.01). Decreased numbers of cultures, elective procedures, chronically ill admissions and outpatients and increased intensive care unit admissions reported could bias AMR data. Reported overall infection prevention and control (IPC) improvement could decrease AMR rates, whereas increases in selected inappropriate IPC practices and antibiotic prescribing could increase rates. Most did not yet have complete data on changing AMR rates due to COVID-19.Conclusions This was the first survey to explore the global impact of COVID-19 on AMR among GLASS countries. Responses revealed universal patterns but also captured country variability. Although focus is understandably on COVID-19, gains in detecting and controlling AMR, a global health priority, cannot afford to be lost.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was supported by a working group belonging to the WHO AMR Surveillance and Quality Assessment Collaborating Centres Network. It was led by the coordinator of the Network at the Robert Koch Institute in Berlin, Germany, who received funding from the Global Protection Programme (GHPP) at the German Federal Ministry of Health.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The anonymous survey was conducted as part of routine public health work by the WHO Antimicrobial Resistance (AMR) Surveillance and Quality Assessment Collaborating Centres Network. No human subjects, samples or data were involved for this research purpose. As per the policy in Germany, the survey protocol was reviewed and waived by the data protection institutional review board of the Network coordinator at Robert Koch Institute, Berlin, Germany.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThe aggregated data is avaiable on a case-by-case basis upon consultation with the WHO AMR Surveillance and Quality Assessment Collaborating Centres Network coordinator (Robert Koch Institute, Berlin, Germany)

The Costa Rican pygmy rice rat (Oligoryzomys costaricensis) is the primary reservoir of Choclo orthohantavirus (CHOV), the causal agent of hantavirus disease, pulmonary syndrome, and fever in humans in Panama. Since the emergence of CHOV in early 2000, we have systematically sampled and archived rodents from >150 sites across Panama to establish a baseline understanding of the host and virus, producing a permanent archive of holistic specimens that we are now probing in greater detail. We summarize these collections and explore preliminary habitat/virus associations to guide future wildlife surveillance and public health efforts related to CHOV and other zoonotic pathogens. Host sequences of the mitochondrial cytochrome b gene form a single monophyletic clade in Panama, despite wide distribution across Panama. Seropositive samples were concentrated in the central region of western Panama, consistent with the ecology of this agricultural commensal and the higher incidence of CHOV in humans in that region. Hantavirus seroprevalence in the pygmy rice rat was >15% overall, with the highest prevalence in agricultural areas (21%) and the lowest prevalence in shrublands (11%). Host-pathogen distribution, transmission dynamics, genomic evolution, and habitat affinities can be derived from the preserved samples, which include frozen tissues, and now provide a foundation for expanded investigations of orthohantaviruses in Panama.

The objective of this study is to evaluate a prototype local ventilation system (LVS) intended to reduce retail store workers' exposures to aerosols. The evaluation was carried out in a large aerosol test chamber where relatively uniform concentrations of polydisperse sodium chloride and glass-sphere particles were generated to test the system with nano- and micro-size particles. In addition, a cough simulator was constructed to mimic aerosols released by mouth breathing and coughing. Particle reduction efficiencies of the LVS were determined in four different experimental conditions using direct reading instruments and inhalable samplers. The particle reduction efficiency (%) depended on the position beneath the LVS, but the percentage was consistently high at the LVS center as follows: 1) > 98% particle reduction relative to background aerosols, 2) > 97% in the manikin's breathing zone relative to background aerosols, 3) > 97% during mouth breathing and coughing simulation, and 4) > 97% with a plexiglass barrier installation. Lower particle reduction (<70%) was observed when the LVS airflow was disturbed by background ventilation airflow. The lowest particle reduction (<20%) was observed when the manikin was closest to the simulator during coughing.

Objective: We performed a meta-analysis of epidemiological results for the association between occupational exposure as a firefighter and cancer as part of the broader evidence synthesis work of the IARC Monographs program. Methods: A systematic literature search was conducted to identify cohort studies of firefighters followed for cancer incidence and mortality. Studies were evaluated for the influence of key biases on results. Random-effects meta-analysis models were used to estimate the association between ever-employment and duration of employment as a firefighter and risk of 12 selected cancers. The impact of bias was explored in sensitivity analyses. Results: Among the 16 included cancer incidence studies, the estimated meta-rate ratio, 95% confidence interval (CI), and heterogeneity statistic (I2) for ever-employment as a career firefighter compared mostly to general populations were 1.58 (1.14–2.20, 8%) for mesothelioma, 1.16 (1.08–1.26, 0%) for bladder cancer, 1.21 (1.12–1.32, 81%) for prostate cancer, 1.37 (1.03–1.82, 56%) for testicular cancer, 1.19 (1.07–1.32, 37%) for colon cancer, 1.36 (1.15–1.62, 83%) for melanoma, 1.12 (1.01–1.25, 0%) for non-Hodgkin lymphoma, 1.28 (1.02–1.61, 40%) for thyroid cancer, and 1.09 (0.92–1.29, 55%) for kidney cancer. Ever-employment as a firefighter was not positively associated with lung, nervous system, or stomach cancer. Results for mesothelioma and bladder cancer exhibited low heterogeneity and were largely robust across sensitivity analyses. Conclusions: There is epidemiological evidence to support a causal relationship between occupational exposure as a firefighter and certain cancers. Challenges persist in the body of evidence related to the quality of exposure assessment, confounding, and medical surveillance bias. © 2023 Occupational Safety and Health Research Institute

BACKGROUND: The continued spread of insecticide resistance in mosquito vectors of malaria and arboviral diseases may lead to operational failure of insecticide-based interventions if resistance is not monitored and managed efficiently. This study aimed to develop and validate a new WHO glass bottle bioassay method as an alternative to the WHO standard insecticide tube test to monitor mosquito susceptibility to new public health insecticides with particular modes of action, physical properties or both. METHODS: A multi-centre study involving 21 laboratories worldwide generated data on the susceptibility of seven mosquito species (Aedes aegypti, Aedes albopictus, Anopheles gambiae sensu stricto [An. gambiae s.s.], Anopheles funestus, Anopheles stephensi, Anopheles minimus and Anopheles albimanus) to seven public health insecticides in five classes, including pyrethroids (metofluthrin, prallethrin and transfluthrin), neonicotinoids (clothianidin), pyrroles (chlorfenapyr), juvenile hormone mimics (pyriproxyfen) and butenolides (flupyradifurone), in glass bottle assays. The data were analysed using a Bayesian binomial model to determine the concentration-response curves for each insecticide-species combination and to assess the within-bioassay variability in the susceptibility endpoints, namely the concentration that kills 50% and 99% of the test population (LC(50) and LC(99), respectively) and the concentration that inhibits oviposition of the test population by 50% and 99% (OI(50) and OI(99)), to measure mortality and the sterilizing effect, respectively. RESULTS: Overall, about 200,000 mosquitoes were tested with the new bottle bioassay, and LC(50)/LC(99) or OI(50)/OI(99) values were determined for all insecticides. Variation was seen between laboratories in estimates for some mosquito species-insecticide combinations, while other test results were consistent. The variation was generally greater with transfluthrin and flupyradifurone than with the other compounds tested, especially against Anopheles species. Overall, the mean within-bioassay variability in mortality and oviposition inhibition were < 10% for most mosquito species-insecticide combinations. CONCLUSION: Our findings, based on the largest susceptibility dataset ever produced on mosquitoes, showed that the new WHO bottle bioassay is adequate for evaluating mosquito susceptibility to new and promising public health insecticides currently deployed for vector control. The datasets presented in this study have been used recently by the WHO to establish 17 new insecticide discriminating concentrations (DCs) for either Aedes spp. or Anopheles spp. The bottle bioassay and DCs can now be widely used to monitor baseline insecticide susceptibility of wild populations of vectors of malaria and Aedes-borne diseases worldwide.

In this study, we systematically characterized the airborne dust generated from grinding engineered and natural stone products using a laboratory testing system designed and operated to collect representative respirable dust samples. Four stone samples tested included two engineered stones consisting of crystalline silica in a polyester resin matrix (formulations differed with Stones A having up to 90wt% crystalline silica and Stone B up to 50wt% crystalline silica), an engineered stone consisting of recycled glass in a cement matrix (Stone C), and a granite. Aerosol samples were collected by respirable dust samplers, total dust samplers, and a Micro-Orifice Uniform Deposit Impactor. Aerosol samples were analyzed by gravimetric analysis and x-ray diffraction to determine dust generation rates, crystalline silica generation rates, and crystalline silica content. Additionally, bulk dust settled on the floor of the testing system was analyzed for crystalline silica content. Real-time particle size distributions were measured using an Aerodynamic Particle Sizer. All stone types generated similar trimodal lognormal number-weighted particle size distributions during grinding with the most prominent mode at an aerodynamic diameter of about 2.0-2.3 m, suggesting dust formation from grinding different stones is similar. Bulk dust from Stone C contained no crystalline silica. Bulk dust from Stone A, Stone B, and granite contained 60, 23, and 30wt% crystalline silica, respectively. In Stones A and B, the cristobalite form of crystalline silica was more plentiful than the quartz form. Only the quartz form was detected in granite. The bulk dust, respirable dust, and total dust for each stone had comparable amounts of crystalline silica, suggesting that crystalline silica content in the bulk dust could be representative of that in respirable dust generated during grinding. Granite generated more dust per unit volume of material removed than the engineered stones, which all had similar normalized dust generation rates. Stone A had the highest normalized generation rates of crystalline silica, followed by granite, Stone B, and Stone C (no crystalline silica), which likely leads to the same trend of respirable crystalline silica (RCS) exposure when working with these different stones. Manufacturing and adoption of engineered stone products with formulations such as Stone B or Stone C could potentially lower or eliminate RCS exposure risks. Combining all the effects of dust generation rate, size-dependent silica content, and respirable fraction, the highest normalized generation rate of RCS consistently occurs at 3.2-5.6 m for all the stones containing crystalline silica. Therefore, removing particles in this size range near the generation sources should be prioritized when developing engineering control measures.

A method for measuring peracetic acid vapors in air using impinger sampling and field-portable colorimetric analysis is presented. The capture efficiency of aqueous media in glass and plastic impingers was evaluated when used for peracetic acid vapor sampling. Measurement of peracetic acid was done using an N,N-diethyl-p-phenylenediamine colorimetric method with a field portable spectrometer. The linearity of the N,N-diethyl-p-phenylenediamine method was determined for peracetic acid both in-solution and captured from vapor phase using glass or plastic impingers. The Limits of Detection for the glass and plastic impingers were 0.24 mg/m(3) and 0.28 mg/m(3), respectively, for a 15 L air sample. The Limits of Quantitation were 0.79 mg/m(3) and 0.92 mg/m(3) for the glass and plastic impingers, respectively. Both metrics were below the American Conference of Governmental Industrial Hygienists Threshold Limit Value Short-Term Exposure Limit of 1.24 mg/m(3) (0.4 ppmv) during a 15-minute period. This impinger sampling method presented herein allows for an easy to use and rapid in-field measurement that can be used for evaluating occupational exposure to peracetic acid.

In response to the shortage of N95 filtering facepiece respirators for healthcare workers during the COVID-19 pandemic, the Centers for Disease Control and Prevention issued guidance for extended use and limited reuse of N95 FFRs to conserve supply. Previously worn N95 filtering facepiece respirators can serve as a source of pathogens, which can be transferred to the wearer while doffing and donning a respirator when practicing reuse. When practicing limited filtering facepiece respirators reuse, to reduce the risk of self-contamination, the Centers for Disease Control and Prevention recommends storing filtering facepiece respirators for five days between uses to allow for the decay of viable pathogens including SARS-CoV-2. This study assesses the persistence of the SARS-CoV-2 strain USA-WA1/2020 on N95 filtering facepiece respirators under controlled storage conditions for up to five days to inform the Centers for Disease Control and Prevention guidance. Coupons excised from six N95 filtering facepiece respirator models and glass slide coverslips were inoculated with the virus in a defined culture medium and in human saliva and stored at 20 °C and 20%, 45%, and 75% relative humidity. Statistically significant differences in SARS-CoV-2 half-lives were measured among the tested humidity levels with half-lives decreasing from an average of approximately 30 hours at 20% relative humidity to approximately 2 hours at 75% relative humidity. Significant differences in virus half-lives were also observed between the culture medium and saliva suspension media at 20% and 45% relative humidity with half lives up to 2.9 times greater when the virus was suspended in cell culture medium. The five-day storage strategy, assessed in this study, resulted in a minimum of 93.4% reduction in viable virus for the most challenging condition (20% relative humidity, cell culture medium) and exceeding 99% reduction in virus at all other conditions.

Worldwide, rotavirus is the leading pathogen causing severe diarrhea in children and a major cause of under 5 years mortality. In 1998, the first rotavirus vaccine, RotaShield, was licensed in the United States but a rare adverse event, intussusception, led to its withdrawal. Seven years passed before the next generation of vaccines became available, Rotarix (GSK) and Rotateq (Merck), and 11 years later, 2 additional vaccines from India, Rotavac (Bharat) and Rotasiil (Serum Institute), were recommended by World Health Organization for all children. Today, these vaccines are used in more than 100 countries and have contributed to marked decreases in hospitalizations and deaths from diarrhea. However, these live oral vaccines are less effective in low-income countries with high under 5 years mortality for reasons that are not understood. Efforts to develop new vaccines that avoid the oral route are in progress and will likely be needed to ultimately control rotavirus disease.

OBJECTIVES: The COVID-19 pandemic has had a substantial impact on health systems. The WHO Antimicrobial Resistance (AMR) Surveillance and Quality Assessment Collaborating Centres Network conducted a survey to assess the effects of COVID-19 on AMR surveillance, prevention and control. METHODS: From October to December 2020, WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS) national focal points completed a questionnaire, including Likert scales and open-ended questions. Data were descriptively analysed, income/regional differences were assessed and free-text questions were thematically analysed. RESULTS: Seventy-three countries across income levels participated. During the COVID-19 pandemic, 67% reported limited ability to work with AMR partnerships; decreases in funding were frequently reported by low- and middle-income countries (LMICs; P < 0.01). Reduced availability of nursing, medical and public health staff for AMR was reported by 71%, 69% and 64%, respectively, whereas 67% reported stable cleaning staff availability. The majority (58%) reported reduced reagents/consumables, particularly LMICs (P < 0.01). Decreased numbers of cultures, elective procedures, chronically ill admissions and outpatients and increased ICU admissions reported could bias AMR data. Reported overall infection prevention and control (IPC) improvement could decrease AMR rates, whereas increases in selected inappropriate IPC practices and antimicrobial prescribing could increase rates. Most did not yet have complete data on changing AMR rates due to COVID-19. CONCLUSIONS: This was the first survey to explore the global impact of COVID-19 on AMR among GLASS countries. Responses highlight important actions to help ensure that AMR remains a global health priority, including engaging with GLASS to facilitate reliable AMR surveillance data, seizing the opportunity to develop more sustainable IPC programmes, promoting integrated antibiotic stewardship guidance, leveraging increased laboratory capabilities and other system-strengthening efforts.

Fiber length is believed to be an important factor in determining various toxicological responses to asbestos and other bio-persistent fibers. Length classification of fibers thus is crucial for toxicological assessment. Nylon mesh screens have been shown to be effective in separating fibers by length. In this note, we report development of a purging flow system for harvesting fibers from a nylon net screen, with the aim of separating airborne fibers by length. We evaluated the performance of this purging flow system by examining the lengths of glass fibers collected on a screen. Fibers aerosolized by vortex shaking were provided to 10 µm and 20 µm mesh screens, and the fibers collected on each screen were purged periodically with a backflow. The length of the purged fibers was measured and compared to that of fibers washed from the screen. The mean length of fibers on the screen is larger than that of the fibers in the original test aerosol. The mean length of the backflow purged fibers is smaller than that of the fibers from the washed screen. The results indicate that the purging flow system with screens can harvest the longer fibers from the original aerosol. © U.S. Government work.

The development of cryopreservation protocols for Anopheles gambiae could significantly improve research and control efforts. Cryopreservation of any An. gambiae life stage has yet to be successful. The unique properties of embryos have proven to be resistant to any practical cryoprotectant loading. Therefore, we have chosen to investigate early non-feeding first instar larvae as a potential life stage for cryopreservation. In order to determine an appropriate cryoprotective compound, larvae were treated with progressively better glass-forming cryoprotective mixtures. Toxicity evaluation in combination with calorimetry-based water content and supercooling point depression assessments were used to determine the cryoprotectants that could be used for cryostorage of viable larvae. Approximately 35-75% of the larvae were viable after reasonably high osmotic and biochemical challenge. This study provides ample evidence for an active osmoregulatory response in the Anopheles larvae to counter the permeation of cryoprotectants from the surrounding medium. The data show a strong correlation between the larval mortality and water content, indicating an osmoregulatory crisis in the larva due to certain cryoprotectants such as the higher concentrations of ethane diol (ED). The observations also indicate that the ability of the larvae to regulate permeation and water balance ceases at or within 20 min of cryoprotectant exposure, but this is strongly influenced by the treatment temperature. Among the compound cryoprotectants tested, 25% ED + 10% dimethyl sulfoxide (DMSO) and 40% ED + 0.5 M trehalose seem to present a compromise between viability, larval water content, supercooling point depression, and glass forming abilities.

Outbreaks of vaccine-preventable diseases (VPDs) are a major threat to global health security. In 2018–2019, the Asia-Pacific region experienced large-scale outbreaks of circulating vaccine-derived poliovirus type 1, diphtheria, and measles [1]. The global resurgence of measles was accompanied by an 82% increase in incidence in the Western Pacific Region between 2016 and 2017. The Philippines reported 25,956 measles cases, including 381 deaths, in the first quarter of 2019 [1], and New Zealand reported 2185 cases between 1 January 2019 – 6 January 2020, with 768 (35.1%) hospitalisations [2]. Countries in the region, including the Philippines and New Zealand, have direct travel connectivity and several points of entry to many Pacific Island Countries and Territories (PICTs) including Samoa, Tonga, and Fiji – which reported measles outbreaks in 2019 [3].

The objective of this study was to investigate the efficacy of an aerodynamic separation scheme for obtaining aerosols with nearly monodisperse fiber lengths as test samples for mechanistic toxicological evaluations. The approach involved the separation of aerosolized glass fibers using an Aerodynamic Aerosol Classifier (AAC) or a multi-cyclone sampling array, followed by the collection of separated samples on filter substrates, and the measurement of each sample fiber length distribution. A glass fiber aerosol with a narrow range of aerodynamic sizes was selected and sampled with the AAC or multi-cyclone sampling array in two separate setups. The fiber length and diameter were measured using a field emission scanning electron microscope. The glass fiber aerosol was separated in distinct groups of eight with the AAC and of four with the multi-cyclone sampling array. The geometric standard deviations of the fiber length distributions of the separated aerosols ranged from 1.49 to 1.69 for the AAC and from 1.6 to 1.8 for multi-cyclone sampling array. While the separation of glass fiber aerosols with an AAC is likely to produce two different length fiber groups and the length resolution may be acceptable, the overall mass throughput of these separation schemes is limited.

BACKGROUND: The WHO elimination strategy for hepatitis C virus advocates scaling up screening and treatment to reduce global hepatitis C incidence by 80% by 2030, but little is known about how this reduction could be achieved and the costs of doing so. We aimed to evaluate the effects and cost of different strategies to scale up screening and treatment of hepatitis C in Pakistan and determine what is required to meet WHO elimination targets for incidence. METHODS: We adapted a previous model of hepatitis C virus transmission, treatment, and disease progression for Pakistan, calibrating using available data to incorporate a detailed cascade of care for hepatitis C with cost data on diagnostics and hepatitis C treatment. We modelled the effect on various outcomes and costs of alternative scenarios for scaling up screening and hepatitis C treatment in 2018-30. We calibrated the model to country-level demographic data for 1960-2015 (including population growth) and to hepatitis C seroprevalence data from a national survey in 2007-08, surveys among people who inject drugs (PWID), and hepatitis C seroprevalence trends among blood donors. The cascade of care in our model begins with diagnosis of hepatitis C infection through antibody screening and RNA confirmation. Diagnosed individuals are then referred to care and started on treatment, which can result in a sustained virological response (effective cure). We report the median and 95% uncertainty interval (UI) from 1151 modelled runs. FINDINGS: One-time screening of 90% of the 2018 population by 2030, with 80% referral to treatment, was projected to lead to 13.8 million (95% UI 13.4-14.1) individuals being screened and 350 000 (315 000-385 000) treatments started annually, decreasing hepatitis C incidence by 26.5% (22.5-30.7) over 2018-30. Prioritised screening of high prevalence groups (PWID and adults aged >/=30 years) and rescreening (annually for PWID, otherwise every 10 years) are likely to increase the number screened and treated by 46.8% and decrease incidence by 50.8% (95% UI 46.1-55.0). Decreasing hepatitis C incidence by 80% is estimated to require a doubling of the primary screening rate, increasing referral to 90%, rescreening the general population every 5 years, and re-engaging those lost to follow-up every 5 years. This approach could cost US$8.1 billion, reducing to $3.9 billion with lowest costs for diagnostic tests and drugs, including health-care savings, and implementing a simplified treatment algorithm. INTERPRETATION: Pakistan will need to invest about 9.0% of its yearly health expenditure to enable sufficient scale up in screening and treatment to achieve the WHO hepatitis C elimination target of an 80% reduction in incidence by 2030. FUNDING: UNITAID.

BACKGROUND: Data on the susceptibility of influenza viruses from South Africa to neuraminidase inhibitors (NAIs) are scarce, and no extensive analysis was done. OBJECTIVES: We aimed to determine oseltamivir and zanamivir susceptibility of influenza A and B virus neuraminidases (NAs), 2007-2013, South Africa. PATIENTS/METHODS: We enrolled participants through national influenza-like illness surveillance, 2007-2013. Influenza diagnosis was by virus isolation and quantitative polymerase chain reaction (qPCR). Drug susceptibility was determined by chemiluminescence-based NA-STAR/NA-XTD assay. Sanger sequencing was used to determine molecular markers of NAI resistance. RESULTS: Forty percent (6341/15 985) of participants were positive for influenza viruses using virus isolation (2007-2009) and qPCR (2009-2013) methods. A total of 1236/6341 (19.5%) virus isolates were generated of which 307/1236 (25%) were tested for drug susceptibility. During 2007-2008, the median 50% inhibitory concentration (IC50 ) of oseltamivir for seasonal influenza A(H1N1) increased from of 0.08 nmol/L (range 0.01-3.60) in 2007 to 73 nmol/L (range 1.56-305 nmol/L) in 2008. Influenza A isolates from 2009 to 2013 were susceptible to oseltamivir [A(H3N2) median IC50 = 0.05 nmol/L (range 0.01-0.08); A(H1N1)pdm09 = 0.11 nmol/L (range 0.01-0.78)] and zanamivir [A(H3N2) median IC50 = 0.56 nmol/L (range 0.47-0.66); A(H1N1)pdm09 = 0.35 nmol/L (range 0.27-0.533)]. Influenza B viruses were susceptible to both NAIs. NAI resistance-associated substitutions H275Y, E119V, and R150K (N1 numbering) were not detected in influenza A viruses that circulated in 2009-2013. CONCLUSIONS: We confirm replacement of NAI susceptible by resistant phenotype influenza A(H1N1) in 2008. Influenza A and B viruses (2009-2013) remained susceptible to NAIs; therefore, these drugs are useful for treating influenza-infected patients.

Aerodynamic behavior of airborne fibers including high-aspect ratio particles plays an important role in aerosol filtration and lung deposition. Fiber length is considered to be an important parameter in causing toxicological responses of elongate mineral particles, including asbestos, as well as one of the factors affecting lung deposition. In order to estimate the toxicity of fibers as a function of fiber length, it is required to separate fibers by length and understand mechanisms related to fiber separation for use in toxicology studies. In this study, we used nylon mesh screens with different pore sizes as a separation method to remove long fibers and measured screen collection efficiency of glass fibers (a surrogate for asbestos) as a function of aerodynamic diameter with the aim to prepare toxicology samples free of long fibers and/or harvest long fibers from the screen. Two screen configurations ([i] without a laminar flow entrance length, and [ii] with the entrance length) were tested to investigate the effect of screen pore size (10, 20, and 60 micro m) and screen configuration on collection efficiency of fibers. Screen collection efficiency (eta) was obtained based on measurements of downstream concentrations of a test chamber either without or with a screen. The results showed that screen collection efficiency increases as screen pore size decreases from 60 to 10 micro m for both cases with and without entrance lengths. For the screen configuration without entrance length, higher collection efficiency was obtained than the case with entrance length probably due to increased impaction caused by the close proximity of inlet to screen. In addition, the difference between the collection efficiencies for the different configurations was small in the aerodynamic size range below 3 micro m while it increased in the size range from 3 to about 7 micro m, indicating that as large aerodynamic diameter is associated with longer fibers, some differential selection of fibers is possible. Modified model collection efficiency for 10 and 20 micro m screens based on the interception predicts well the measured data for the case with entrance length, indicating that the fiber deposition on these screens occurs dominantly through the interception mechanism in the micrometer size range under a given flow condition.

Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgia and polyarthritis. Differentiation from other AFI is difficult due to the non-specific presentation and limited availability of diagnostics. This 3-year study identified independent clinical predictors by day post-illness onset (DPO) at presentation and age-group that distinguish chikungunya cases from two groups: other AFI and dengue. Specimens collected from participants with fever </=7 days were tested for chikungunya, dengue viruses 1-4, and 20 other pathogens. Of 8,996 participants, 18.2% had chikungunya, and 10.8% had dengue. Chikungunya cases were more likely than other groups to be older, report a chronic condition, and present <3 DPO. Regardless of timing of presentation, significant positive predictors for chikungunya versus other AFI were: joint pain, muscle, bone or back pain, skin rash, and red conjunctiva; with dengue as the comparator, red swollen joints (arthritis), joint pain, skin rash, any bleeding, and irritability were predictors. Chikungunya cases were less likely than AFI and dengue to present with thrombocytopenia, signs of poor circulation, diarrhea, headache, and cough. Among participants presenting <3 DPO, predictors for chikungunya versus other AFI included: joint pain, skin rash, and muscle, bone or back pain, and absence of thrombocytopenia, poor circulation and respiratory or gastrointestinal symptoms; when the comparator was dengue, joint pain and arthritis, and absence of thrombocytopenia, leukopenia, and nausea were early predictors. Among all groups presenting 3-5 DPO, pruritic skin became a predictor for chikungunya, joint, muscle, bone or back pain were no longer predictive, while arthritis became predictive in all age-groups. Absence of thrombocytopenia was a significant predictor regardless of DPO or comparison group. This study identified robust clinical indicators such as joint pain, skin rash and absence of thrombocytopenia that can allow early identification of and accurate differentiation between patients with chikungunya and other common causes of AFI.

The cloud and aerosol spectrometer (CAS) was calibrated to enable CAS sizing of coal dust for studies on flammable dust control. Coal dust sizes were determined by light-scattering theories for irregular particles that account for particle composition and morphology in computing coal dust diameters. Coal dust size computations were compared with test dust that was generated by cyclone separation and air-jet sieving and characterized by aerodynamic particle sizer (APS) and computer-controlled scanning electron microscopy (CCSEM) measurements. For test dust in the range of 0.5–32 μm, coal dust size distributions were consistent with cyclone-separated and sieve-segregated sizes. For the 3–20 μm size range, the coal dust size distribution had a mass median diameter that was 14% larger than that of the APS. This difference was reasonable considering that the basic calibration for glass spheres had 13% uncertainty. For the 20–32 μm and 32–45 μm test dusts, mass median diameters differed from CCSEM measurements by only 4% and 5%, respectively. Overall, the results suggest agreement between test dust sizes and computations for coal dust. Alternatively, using conventional Mie theory computations for spheres, coal dust mass median diameters were 35% and 40% larger than APS and CCSEM measurements, respectively.

OBJECTIVES: Following the launch of the Global Antimicrobial Resistance Surveillance System (GLASS), antimicrobial resistance (AMR) rates in many countries remain poorly described. This review provides an overview of published AMR data from Cambodia in the context of recently initiated national human and food-animal surveillance. METHODS: PubMed and the Cochrane Database of Systematic Reviews were searched for articles published from 2000 to 2018, which reported antimicrobial susceptibility testing (AST) data for GLASS specific organisms isolated from Cambodia. Articles were screened using strict inclusion/exclusion criteria. AST data was extracted, with medians and ranges of resistance rates calculated for specific bug-drug combinations. RESULTS: Twenty-four papers were included for final analysis, with 20 describing isolates from human populations. Escherichia coli was the most commonly described organism, with median resistance rates from human isolates of 92.8% (n=6 articles), 46.4% (n=4), 55.4% (n=8), and 46.4% (n=5) to ampicillin, 3(rd) generation cephalosporins, fluoroquinolones, and gentamicin respectively. CONCLUSIONS: Whilst resistance rates are high for several GLASS organisms, there were insufficient data to draw robust conclusions about the AMR situation in Cambodia. The recently implemented national AMR surveillance systems will begin to address this data gap.

Ebola virus (EBOV) remains a public health threat. We performed a longitudinal study of B cell responses to EBOV in four survivors of the 2014 West African outbreak. Infection induced lasting EBOV-specific immunoglobulin G (IgG) antibodies, but their subclass composition changed over time, with IgG1 persisting, IgG3 rapidly declining, and IgG4 appearing late. Striking changes occurred in the immunoglobulin repertoire, with massive recruitment of naive B cells that subsequently underwent hypermutation. We characterized a large panel of EBOV glycoprotein-specific monoclonal antibodies (mAbs). Only a small subset of mAbs that bound glycoprotein by ELISA recognized cell-surface glycoprotein. However, this subset contained all neutralizing mAbs. Several mAbs protected against EBOV disease in animals, including one mAb that targeted an epitope under evolutionary selection during the 2014 outbreak. Convergent antibody evolution was seen across multiple donors, particularly among VH3-13 neutralizing antibodies specific for the GP1 core. Our study provides a benchmark for assessing EBOV vaccine-induced immunity.

Poliovirus and rotavirus share notable similarities. Although rotavirus is not amenable to eradication because of animal reservoirs, live, attenuated oral vaccines have been the bedrock of both prevention and control programs, providing intestinal and humoral immunity. Both programs have also encountered safety concerns and suboptimal immune responses to oral vaccines in low-income settings that have been challenges, prompting the search for alternative solutions. In this paper, we review the progress made by polio prevention and eradication efforts over the past six decades. Specifically, we discuss the roles of the oral polio vaccine (OPV) and the inactivated polio vaccine (IPV) in achieving polio eradication, and explore potential application of these lessons to rotavirus. Recent scientific evidence has confirmed that a combined schedule of IPV and OPV adds synergistic value that may give the polio eradication effort the tools to end all poliovirus circulation worldwide. For rotavirus, oral vaccine is the only currently licensed and recommended vaccine for use in all children worldwide, providing heterologous protection against a broad range of strains. However, parenteral rotavirus vaccines are in the pre-clinical and clinical trial stage and insight from polio provides strong justification for accelerating the development of these vaccines. While challenges for parenteral rotavirus vaccines will need to be addressed, such as achieving protection against a broad range of strains, the principle of combined use of oral and parenteral rotavirus vaccines may provide the necessary humoral and intestinal immunity necessary to close the efficacy gaps between developing and developed countries, therefore controlling rotavirus worldwide. This strategy may also potentially reduce risk of intussusception.