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Styczynski A, Amin MB, Hoque KI, Parveen S, Md Pervez AF, Zeba D, Akhter A, Pitchik H, Islam MA, Hossain MI, Saha SR, Gurley ES, Luby S. Perinatal colonization with extended-spectrum beta-lactamase-producing and carbapenem-resistant Gram-negative bacteria: a hospital-based cohort study. Antimicrob Resist Infect Control 2024; 13:13. [PMID: 38281974 PMCID: PMC10823664 DOI: 10.1186/s13756-024-01366-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/03/2024] [Indexed: 01/30/2024] Open
Abstract
BACKGROUND Antimicrobial resistance (AMR) is a growing global health threat that contributes to substantial neonatal mortality. Bangladesh has reported some of the highest rates of AMR among bacteria causing neonatal sepsis. As AMR colonization among newborns can predispose to infection with these bacteria, we aimed to characterize the frequency of and risk factors for colonization of mothers and newborns during hospitalization for delivery. METHODS We enrolled pregnant women presenting for delivery to a tertiary care hospital in Faridpur, Bangladesh. We collected vaginal and rectal swabs from mothers pre- and post-delivery, rectal swabs from newborns, and swabs from the hospital environment. Swabs were plated on agars selective for extended-spectrum-beta-lactamase producing bacteria (ESBL-PB) and carbapenem-resistant bacteria (CRB). We performed logistic regression to determine factors associated with ESBL-PB/CRB colonization. RESULTS We enrolled 177 women and their newborns during February-October 2020. Prior to delivery, 77% of mothers were colonized with ESBL-PB and 15% with CRB. 79% of women underwent cesarean deliveries (C-section). 98% of women received antibiotics. Following delivery, 98% of mothers and 89% of newborns were colonized with ESBL-PB and 89% of mothers and 72% of newborns with CRB. Of 290 environmental samples, 77% were positive for ESBL-PB and 69% for CRB. Maternal pre-delivery colonization was associated with hospitalization during pregnancy (RR for ESBL-PB 1.24, 95% CI 1.10-1.40; CRB 2.46, 95% CI 1.39-4.37). Maternal post-delivery and newborn colonization were associated with C-section (RR for maternal CRB 1.31, 95% CI 1.08-1.59; newborn ESBL-PB 1.34, 95% CI 1.09-1.64; newborn CRB 1.73, 95% CI 1.20-2.47). CONCLUSIONS In this study, we observed high rates of colonization with ESBL-PB/CRB among mothers and newborns, with pre-delivery colonization linked to prior healthcare exposure. Our results demonstrate this trend may be driven by intense use of antibiotics, frequent C-sections, and a contaminated hospital environment. These findings highlight that greater attention should be given to the use of perinatal antibiotics, improved surgical stewardship for C-sections, and infection prevention practices in healthcare settings to reduce the high prevalence of colonization with AMR organisms.
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Affiliation(s)
- Ashley Styczynski
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Palo Alto, CA, USA.
| | - Mohammed Badrul Amin
- Laboratory of Food Safety and One Health, Laboratory Sciences and Services Division, icddr,b, Dhaka, Bangladesh
| | - Kazi Injamamul Hoque
- Laboratory of Food Safety and One Health, Laboratory Sciences and Services Division, icddr,b, Dhaka, Bangladesh
| | - Shahana Parveen
- Programme on Emerging Infections, icddr,b, Dhaka, Bangladesh
| | - Abu Faisal Md Pervez
- Department of Pediatrics, Bangabandhu Sheikh Mujib Medical College, Faridpur, Bangladesh
| | - Dilruba Zeba
- Department of Obstetrics and Gynaecology, Bangabandhu Sheikh Mujib Medical College, Faridpur, Bangladesh
| | - Akhi Akhter
- Department of Obstetrics and Gynaecology, Bangabandhu Sheikh Mujib Medical College, Faridpur, Bangladesh
| | - Helen Pitchik
- Division of Epidemiology, School of Public Health, University of California Berkeley, Berkeley, CA, USA
| | - Mohammad Aminul Islam
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Muhammed Iqbal Hossain
- Laboratory of Food Safety and One Health, Laboratory Sciences and Services Division, icddr,b, Dhaka, Bangladesh
| | - Sumita Rani Saha
- Laboratory of Food Safety and One Health, Laboratory Sciences and Services Division, icddr,b, Dhaka, Bangladesh
| | - Emily S Gurley
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Palo Alto, CA, USA
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Aguilar GR, Swetschinski LR, Weaver ND, Ikuta KS, Mestrovic T, Gray AP, Chung E, Wool EE, Han C, Hayoon AG, Araki DT, Abdollahi A, Abu-Zaid A, Adnan M, Agarwal R, Dehkordi JA, Aravkin AY, Areda D, Azzam AY, Berezin EN, Bhagavathula AS, Bhutta ZA, Bhuyan SS, Browne AJ, Castañeda-Orjuela CA, Chandrasekar EK, Ching PR, Dai X, Darmstadt GL, De la Hoz FP, Diao N, Diaz D, Mombaque dos Santos W, Eyre D, Garcia C, Haines-Woodhouse G, Hassen MB, Henry NJ, Hopkins S, Hossain MM, Iregbu KC, Iwu CC, Jacobs JA, Janko MM, Jones R, Karaye IM, Khalil IA, Khan IA, Khan T, Khubchandani J, Khusuwan S, Kisa A, Koyaweda GW, Krapp F, Kumaran EA, Kyu HH, Lim SS, Liu X, Luby S, Maharaj SB, Maronga C, Martorell M, May J, McManigal B, Mokdad AH, Moore CE, Mostafavi E, Murillo-Zamora E, Mussi-Pinhata MM, Nanavati R, Nassereldine H, Natto ZS, Qamar FN, Nuñez-Samudio V, Ochoa TJ, Ojo-Akosile TR, Olagunju AT, Olivas-Martinez A, Ortiz-Brizuela E, Ounchanum P, Paredes JL, Patthipati VS, Pawar S, Pereira M, Pollard A, Ponce-De-Leon A, Sady Prates EJ, Qattea I, Reyes LF, Roilides E, Rosenthal VD, Rudd KE, Sangchan W, Seekaew S, Seylani A, Shababi N, Sham S, Sifuentes-Osornio J, Singh H, Stergachis A, Tasak N, Tat NY, Thaiprakong A, Valdez PR, Yada DY, Yunusa I, Zastrozhin MS, Hay SI, Dolecek C, Sartorius B, Murray CJ, Naghavi M. The burden of antimicrobial resistance in the Americas in 2019: a cross-country systematic analysis. Lancet Reg Health Am 2023; 25:100561. [PMID: 37727594 PMCID: PMC10505822 DOI: 10.1016/j.lana.2023.100561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/22/2023] [Accepted: 07/10/2023] [Indexed: 09/21/2023]
Abstract
Background Antimicrobial resistance (AMR) is an urgent global health challenge and a critical threat to modern health care. Quantifying its burden in the WHO Region of the Americas has been elusive-despite the region's long history of resistance surveillance. This study provides comprehensive estimates of AMR burden in the Americas to assess this growing health threat. Methods We estimated deaths and disability-adjusted life-years (DALYs) attributable to and associated with AMR for 23 bacterial pathogens and 88 pathogen-drug combinations for countries in the WHO Region of the Americas in 2019. We obtained data from mortality registries, surveillance systems, hospital systems, systematic literature reviews, and other sources, and applied predictive statistical modelling to produce estimates of AMR burden for all countries in the Americas. Five broad components were the backbone of our approach: the number of deaths where infection had a role, the proportion of infectious deaths attributable to a given infectious syndrome, the proportion of infectious syndrome deaths attributable to a given pathogen, the percentage of pathogens resistant to an antibiotic class, and the excess risk of mortality (or duration of an infection) associated with this resistance. We then used these components to estimate the disease burden by applying two counterfactual scenarios: deaths attributable to AMR (compared to an alternative scenario where resistant infections are replaced with susceptible ones), and deaths associated with AMR (compared to an alternative scenario where resistant infections would not occur at all). We generated 95% uncertainty intervals (UIs) for final estimates as the 25th and 975th ordered values across 1000 posterior draws, and models were cross-validated for out-of-sample predictive validity. Findings We estimated 569,000 deaths (95% UI 406,000-771,000) associated with bacterial AMR and 141,000 deaths (99,900-196,000) attributable to bacterial AMR among the 35 countries in the WHO Region of the Americas in 2019. Lower respiratory and thorax infections, as a syndrome, were responsible for the largest fatal burden of AMR in the region, with 189,000 deaths (149,000-241,000) associated with resistance, followed by bloodstream infections (169,000 deaths [94,200-278,000]) and peritoneal/intra-abdominal infections (118,000 deaths [78,600-168,000]). The six leading pathogens (by order of number of deaths associated with resistance) were Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Together, these pathogens were responsible for 452,000 deaths (326,000-608,000) associated with AMR. Methicillin-resistant S. aureus predominated as the leading pathogen-drug combination in 34 countries for deaths attributable to AMR, while aminopenicillin-resistant E. coli was the leading pathogen-drug combination in 15 countries for deaths associated with AMR. Interpretation Given the burden across different countries, infectious syndromes, and pathogen-drug combinations, AMR represents a substantial health threat in the Americas. Countries with low access to antibiotics and basic health-care services often face the largest age-standardised mortality rates associated with and attributable to AMR in the region, implicating specific policy interventions. Evidence from this study can guide mitigation efforts that are tailored to the needs of each country in the region while informing decisions regarding funding and resource allocation. Multisectoral and joint cooperative efforts among countries will be a key to success in tackling AMR in the Americas. Funding Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund.
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Zhang S, Shi J, Li X, Luby S, Coin L, O'Brien J, Sivakumar M, Hai F, Jiang G. Triplex qPCR assay for Campylobacter jejuni and Campylobacter coli monitoring in wastewater. Sci Total Environ 2023:164574. [PMID: 37268129 DOI: 10.1016/j.scitotenv.2023.164574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 05/27/2023] [Accepted: 05/29/2023] [Indexed: 06/04/2023]
Abstract
Campylobacter spp. is one of the most frequent pathogens of bacterial gastroenteritis recorded worldwide. Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) are the two major disease-associated species, accounting for >95 % of infections, and thus have been selected for disease surveillance. Monitoring temporal variations in pathogen concentration and diversity excreted from community wastewater allows the early detection of outbreaks. Multiplex real-time/quantitative PCR (qPCR) enables multi-target quantification of pathogens in various types of samples including wastewater. Also, an internal amplification control (IAC) is required for each sample when adopting PCR-based methods for pathogen detection and quantification in wastewater to exclude the inhibition of the wastewater matrix. To achieve reliable quantification of C. jejuni and C. coli towards wastewater samples, this study developed and optimized a triplex qPCR assay by combining three qPCR primer-probe sets targeting Campylobacter jejuni subsp. jejuni, Campylobacter coli, and Campylobacter sputorum biovar sputorum (C. sputorum), respectively. This triplex qPCR assay not only can directly and simultaneously detect the concentration of C. jejuni and C. coli in wastewater but also can achieve the PCR inhibition control using C. sputorum primer-probe set. This is the first developed triplex qPCR assay with IAC for C. jejuni and C. coli, to be used in the wastewater-based epidemiology (WBE) applications. The optimized triplex qPCR assay enables the detection limit of the assay (ALOD100%) and wastewater (PLOD80%) as 10 gene copy/μL and 2 log10 cells/mL (2 gene copies/μL of extracted DNA), respectively. The application of this triplex qPCR to 52 real raw wastewater samples from 13 wastewater treatment plants demonstrated its potential as a high-throughput and economically viable tool for the long-term monitoring of C. jejuni and C. coli prevalence in communities and the surrounding environments. This study provided an accessible methodology and a solid foundation for WBE-based monitoring of Campylobacter spp. relevant diseases and paved the road for future WBE back-estimation of C. jejuni and C. coli prevalence.
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Affiliation(s)
- Shuxin Zhang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Jiahua Shi
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia; School of Medical, Indigenous and Health Sciences, University of Wollongong, Australia
| | - Xuan Li
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Stephen Luby
- Stanford Center for Innovation in Global Health, Stanford Woods Institute for the Environment, Stanford University, Stanford, CA 94305, United States
| | - Lachlan Coin
- Division of Medicine, Dentistry and Health Sciences, The University of Melbourne, Australia
| | - Jake O'Brien
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
| | - Muttucumaru Sivakumar
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Faisal Hai
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Guangming Jiang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia.
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Guo Y, Li X, Luby S, Jiang G. Vertical outbreak of COVID-19 in high-rise buildings: The role of sewer stacks and prevention measures. Curr Opin Environ Sci Health 2022; 29:100379. [PMID: 35856009 PMCID: PMC9279164 DOI: 10.1016/j.coesh.2022.100379] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/27/2022] [Accepted: 07/04/2022] [Indexed: 05/25/2023]
Abstract
COVID-19 outbreaks in high-rise buildings suggested the transmission route of fecal-aerosol-inhalation due to the involvement of viral aerosols in sewer stacks. The vertical transmission is likely due to the failure of water traps that allow viral aerosols to spread through sewer stacks. This process can be further facilitated by the chimney effect in vent stack, extract ventilation in bathrooms, or wind-induced air pressure fluctuations. To eliminate the risk of such vertical disease spread, the installation of protective devices is highly encouraged in high-rise buildings. Although the mechanism of vertical pathogen spread through drainage pipeline has been illustrated by tracer gas or microbial experiments and numerical modeling, more research is needed to support the update of regulatory and design standards for sewerage facilities.
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Affiliation(s)
- Ying Guo
- School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Xuan Li
- School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA 94305, USA
| | - Guangming Jiang
- School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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Islam MT, Date K, Khan AI, Bhuiyan TR, Khan ZH, Ahmed S, Hossain M, Khaton F, Zaman K, McMillan NAJ, Anand A, An Q, Zhang C, Weldon WC, Yu A, Luby S, Qadri F. Co-administration of Oral Cholera Vaccine With Oral Polio Vaccine Among Bangladeshi Young Children: A Randomized Controlled Open Label Trial to Assess Interference. Clin Infect Dis 2022; 76:263-270. [PMID: 36136760 PMCID: PMC9839191 DOI: 10.1093/cid/ciac782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/19/2022] [Accepted: 09/19/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Cholera remains a public health threat for low- and middle-income countries, particularly in Asia and Africa. Shanchol™, an inactivated oral cholera vaccine (OCV) is currently in use globally. OCV and oral poliovirus vaccines (OPV) could be administered concomitantly, but the immunogenicity and safety of coadministration among children aged 1-3 years is unknown. METHODS We undertook an open-label, randomized, controlled, inequality trial in Dhaka city, Bangladesh. Healthy children aged 1-3 years were randomly assigned to 1 of 3 groups: bivalent OPV (bOPV)-alone, OCV-alone, or combined bOPV + OCV and received vaccines on the day of enrollment and 28 days later. Blood samples were collected on the day of enrollment, day 28, and day 56. Serum poliovirus neutralizing antibodies and vibriocidal antibodies against Vibrio cholerae O1 were assessed using microneutralization assays. RESULTS A total of 579 children aged 1‒3 years were recruited, 193 children per group. More than 90% of the children completed visits at day 56. Few adverse events following immunization were recorded and were equivalent among study arms. On day 28, 60% (90% confidence interval: 53%-67%) and 54% (46%-61%) of participants with co-administration of bOPV + OCV responded to polioviruses type 1 and 3, respectively, compared to 55% (47%-62%) and 46% (38%-53%) in the bOPV-only group. Additionally, >50% of participants showed a ≥4-fold increase in vibriocidal antibody titer responses on day 28, comparable to the responses observed in OCV-only arm. CONCLUSIONS Co-administration of bOPV and OCV is safe and effective in children aged 1-3 years and can be cost-beneficial. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov (NCT03581734).
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Affiliation(s)
| | - Kashmira Date
- Current affiliation: Global Medical Affairs Lead for Vaccines, Global Public Health at Johnson & Johnson
| | - Ashraful Islam Khan
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Taufiqur Rahman Bhuiyan
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Zahid Hasan Khan
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shamim Ahmed
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Motaher Hossain
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Fatema Khaton
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - K Zaman
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Nigel A J McMillan
- Infectious Diseases and Immunology, Menzies Health Institute Queensland and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Australia
| | - Abhijeet Anand
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Qian An
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Chenhua Zhang
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - William C Weldon
- Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Alexander Yu
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Firdausi Qadri
- Correspondence: F. Qadri, Mucosal Immunology and Vaccinology Unit, Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68, Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh ()
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Zhang S, Li X, Shi J, Sivakumar M, Luby S, O'Brien J, Jiang G. Analytical performance comparison of four SARS-CoV-2 RT-qPCR primer-probe sets for wastewater samples. Sci Total Environ 2022; 806:150572. [PMID: 34582851 PMCID: PMC8464025 DOI: 10.1016/j.scitotenv.2021.150572] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 05/18/2023]
Abstract
Current studies have confirmed the feasibility of SARS-CoV-2 RNA detection by RT-qPCR assays in wastewater samples as an effective surveillance tool of COVID-19 prevalence in a community. Analytical performance of various RT-qPCR assays has been compared against wastewater samples based on the positive ratio. However, there is no systematic comparison work has been conducted for both analytical sensitivity and quantitative reliability against wastewater, which are essential factors for WBE. In this study, the detection performance of four RT-qPCR primer-probe sets, including CCDC-N, CDC-N1, N-Sarbeco, and E-Sarbeco, was systematically evaluated with pure synthetized plasmids, spiked wastewater mocks and raw wastewater samples. In addition to confirm RT-qPCR results, Nanopore sequencing was employed to delineate at molecular level for the analytical sensitivity and reproducibility of those primer-probe sets. CCDC-N showed high sensitivity and the broadest linearity range for wastewater samples. It was thus recommended to be the most efficient tool in the quantitative analysis of SARS-CoV-2 in wastewater. CDC-N1 had the highest sensitivity for real wastewater and thus would be suitable for the screening of wastewater for the presence of SARS-CoV-2. When applying the primer-probe sets to wastewater samples collected from different Australian catchments, increased active clinical cases were observed with the augment of SARS-CoV-2 RNA quantified by RT-qPCR in wastewater in low prevalence communities.
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Affiliation(s)
- Shuxin Zhang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Xuan Li
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Jiahua Shi
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Muttucumaru Sivakumar
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Stephen Luby
- Woods Institute for the Environment, Stanford University, United States
| | - Jake O'Brien
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Australia
| | - Guangming Jiang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia.
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French MA, Fiona Barker S, Taruc RR, Ansariadi A, Duffy GA, Saifuddaolah M, Zulkifli Agussalim A, Awaluddin F, Zainal Z, Wardani J, Faber PA, Fleming G, Ramsay EE, Henry R, Lin A, O'Toole J, Openshaw J, Sweeney R, Sinharoy SS, Kolotelo P, Jovanovic D, Schang C, Higginson EE, Prescott MF, Burge K, Davis B, Ramirez-Lovering D, Reidpath D, Greening C, Allotey P, Simpson JA, Forbes A, Chown SL, McCarthy D, Johnston D, Wong T, Brown R, Clasen T, Luby S, Leder K. A planetary health model for reducing exposure to faecal contamination in urban informal settlements: Baseline findings from Makassar, Indonesia. Environ Int 2021; 155:106679. [PMID: 34126296 DOI: 10.1016/j.envint.2021.106679] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The intense interactions between people, animals and environmental systems in urban informal settlements compromise human and environmental health. Inadequate water and sanitation services, compounded by exposure to flooding and climate change risks, expose inhabitants to environmental contamination causing poor health and wellbeing and degrading ecosystems. However, the exact nature and full scope of risks and exposure pathways between human health and the environment in informal settlements are uncertain. Existing models are limited to microbiological linkages related to faecal-oral exposures at the individual level, and do not account for a broader range of human-environmental variables and interactions that affect population health and wellbeing. METHODS We undertook a 12-month health and environmental assessment in 12 flood-prone informal settlements in Makassar, Indonesia. We obtained caregiver-reported health data, anthropometric measurements, stool and blood samples from children < 5 years, and health and wellbeing data for children 5-14 years and adult respondents. We collected environmental data including temperature, mosquito and rat species abundance, and water and sediment samples. Demographic, built environment and household asset data were also collected. We combined our data with existing literature to generate a novel planetary health model of health and environment in informal settlements. RESULTS Across the 12 settlements, 593 households and 2764 participants were enrolled. Two-thirds (64·1%) of all houses (26·3-82·7% per settlement) had formal land tenure documentation. Cough, fever and diarrhoea in the week prior to the survey were reported among an average of 34.3%, 26.9% and 9.7% of children aged < 5 years, respectively; although proportions varied over time, prevalence among these youngest children was consistently higher than among children 5-14 years or adult respondents. Among children < 5 years, 44·3% experienced stunting, 41·1% underweight, 12.4% wasting, and 26.5% were anaemic. There was self- or carer-reported poor mental health among 16.6% of children aged 5-14 years and 13.9% of adult respondents. Rates of potential risky exposures from swimming in waterways, eating uncooked produce, and eating soil or dirt were high, as were exposures to flooding and livestock. Just over one third of households (35.3%) had access to municipal water, and contamination of well water with E. coli and nitrogen species was common. Most (79·5%) houses had an in-house toilet, but no houses were connected to a piped sewer network or safe, properly constructed septic tank. Median monthly settlement outdoor temperatures ranged from 26·2 °C to 29.3 °C, and were on average, 1·1 °C warmer inside houses than outside. Mosquito density varied over time, with Culex quinquefasciatus accounting for 94·7% of species. Framed by a planetary health lens, our model includes four thematic domains: (1) the physical/built environment; (2) the ecological environment; (3) human health; and (4) socio-economic wellbeing, and is structured at individual, household, settlement, and city/beyond spatial scales. CONCLUSIONS Our planetary health model includes key risk factors and faecal-oral exposure pathways but extends beyond conventional microbiological faecal-oral enteropathogen exposure pathways to comprehensively account for a wider range of variables affecting health in urban informal settlements. It includes broader ecological interconnections and planetary health-related variables at the household, settlement and city levels. It proposes a composite framework of markers to assess water and sanitation challenges and flood risks in urban informal settlements for optimal design and monitoring of interventions.
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Affiliation(s)
- Matthew A French
- Monash Sustainable Development Institute, Monash University, Victoria 3800, Australia
| | - S Fiona Barker
- School of Public Health and Preventive Medicine, Monash University, Victoria 3004, Australia
| | - Ruzka R Taruc
- RISE Program, Faculty of Public Health, Hasanuddin University, Makassar, Indonesia
| | | | - Grant A Duffy
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | | | | | - Fitriyanty Awaluddin
- RISE Program, Faculty of Public Health, Hasanuddin University, Makassar, Indonesia
| | - Zainal Zainal
- RISE Program, Faculty of Public Health, Hasanuddin University, Makassar, Indonesia
| | - Jane Wardani
- Monash Sustainable Development Institute, Monash University, Victoria 3800, Australia
| | - Peter A Faber
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Genie Fleming
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Emma E Ramsay
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Rebekah Henry
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Victoria 3800, Australia
| | - Audrie Lin
- School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Joanne O'Toole
- School of Public Health and Preventive Medicine, Monash University, Victoria 3004, Australia
| | - John Openshaw
- Woods Institute and the Freeman Spogli Institute, Stanford University, Stanford, CA 94305, USA
| | - Rohan Sweeney
- Centre for Health Economics, Monash Business School, Monash University, Victoria 3145, Australia
| | - Sheela S Sinharoy
- Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Peter Kolotelo
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Victoria 3800, Australia
| | - Dusan Jovanovic
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Victoria 3800, Australia
| | - Christelle Schang
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Victoria 3800, Australia
| | - Ellen E Higginson
- Cambridge Institute for Therapeutic Immunology and Infectious Disease, University of Cambridge, Cambridge, UK
| | - Michaela F Prescott
- Informal Cities Lab, Monash Art Design & Architecture, Monash University, Victoria 3145, Australia
| | - Kerrie Burge
- Monash Sustainable Development Institute, Monash University, Victoria 3800, Australia
| | - Brett Davis
- Monash Sustainable Development Institute, Monash University, Victoria 3800, Australia
| | - Diego Ramirez-Lovering
- Informal Cities Lab, Monash Art Design & Architecture, Monash University, Victoria 3145, Australia
| | - Daniel Reidpath
- The International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh; Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Chris Greening
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Pascale Allotey
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia; International Institute for Global Health, United Nations University, Kuala Lumpur, Malaysia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Andrew Forbes
- School of Public Health and Preventive Medicine, Monash University, Victoria 3004, Australia
| | - Steven L Chown
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - David McCarthy
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Victoria 3800, Australia
| | - David Johnston
- Centre for Health Economics, Monash Business School, Monash University, Victoria 3145, Australia
| | - Tony Wong
- Water Sensitive Cities Institute, Monash University, Victoria 3800, Australia
| | - Rebekah Brown
- Monash Sustainable Development Institute, Monash University, Victoria 3800, Australia
| | - Thomas Clasen
- Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Stephen Luby
- School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Karin Leder
- School of Public Health and Preventive Medicine, Monash University, Victoria 3004, Australia.
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8
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Li X, Kulandaivelu J, Zhang S, Shi J, Sivakumar M, Mueller J, Luby S, Ahmed W, Coin L, Jiang G. Data-driven estimation of COVID-19 community prevalence through wastewater-based epidemiology. Sci Total Environ 2021; 789:147947. [PMID: 34051491 PMCID: PMC8141262 DOI: 10.1016/j.scitotenv.2021.147947] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/01/2021] [Accepted: 05/18/2021] [Indexed: 05/21/2023]
Abstract
Wastewater-based epidemiology (WBE) has been regarded as a potential tool for the prevalence estimation of coronavirus disease 2019 (COVID-19) in the community. However, the application of the conventional back-estimation approach is currently limited due to the methodological challenges and various uncertainties. This study systematically performed meta-analysis for WBE datasets and investigated the use of data-driven models for the COVID-19 community prevalence in lieu of the conventional WBE back-estimation approach. Three different data-driven models, i.e. multiple linear regression (MLR), artificial neural network (ANN), and adaptive neuro fuzzy inference system (ANFIS) were applied to the multi-national WBE dataset. To evaluate the robustness of these models, predictions for sixteen scenarios with partial inputs were compared against the actual prevalence reports from clinical testing. The performance of models was further validated using unseen data (data sets not included for establishing the model) from different stages of the COVID-19 outbreak. Generally, ANN and ANFIS models showed better accuracy and robustness over MLR models. Air and wastewater temperature played a critical role in the prevalence estimation by data-driven models, especially MLR models. With unseen datasets, ANN model reasonably estimated the prevalence of COVID-19 (cumulative cases) at the initial phase and forecasted the upcoming new cases in 2-4 days at the post-peak phase of the COVID-19 outbreak. This study provided essential information about the feasibility and accuracy of data-driven estimation of COVID-19 prevalence through the WBE approach.
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Affiliation(s)
- Xuan Li
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia
| | | | - Shuxin Zhang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Jiahua Shi
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Muttucumaru Sivakumar
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia
| | - Jochen Mueller
- Queensland Alliance for Environmental Health Science (QAEHS), The University of Queensland, 4102 Brisbane, Australia
| | - Stephen Luby
- Stanford Center for Innovation in Global Health, Stanford Woods Institute for the Environment, Stanford University, Stanford, CA 94305, United States
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Qld 4102, Australia
| | - Lachlan Coin
- Division of Medicine, Dentistry and Health Sciences, The University of Melbourne, Australia
| | - Guangming Jiang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia.
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9
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Carey ME, MacWright WR, Im J, Meiring JE, Gibani MM, Park SE, Longley A, Jeon HJ, Hemlock C, Yu AT, Soura A, Aiemjoy K, Owusu-Dabo E, Terferi M, Islam S, Lunguya O, Jacobs J, Gordon M, Dolecek C, Baker S, Pitzer VE, Yousafzai MT, Tonks S, Clemens JD, Date K, Qadri F, Heyderman RS, Saha SK, Basnyat B, Okeke IN, Qamar FN, Voysey M, Luby S, Kang G, Andrews J, Pollard AJ, John J, Garrett D, Marks F. The Surveillance for Enteric Fever in Asia Project (SEAP), Severe Typhoid Fever Surveillance in Africa (SETA), Surveillance of Enteric Fever in India (SEFI), and Strategic Typhoid Alliance Across Africa and Asia (STRATAA) Population-based Enteric Fever Studies: A Review of Methodological Similarities and Differences. Clin Infect Dis 2021; 71:S102-S110. [PMID: 32725221 PMCID: PMC7388711 DOI: 10.1093/cid/ciaa367] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Building on previous multicountry surveillance studies of typhoid and others salmonelloses such as the Diseases of the Most Impoverished program and the Typhoid Surveillance in Africa Project, several ongoing blood culture surveillance studies are generating important data about incidence, severity, transmission, and clinical features of invasive Salmonella infections in sub-Saharan Africa and South Asia. These studies are also characterizing drug resistance patterns in their respective study sites. Each study answers a different set of research questions and employs slightly different methodologies, and the geographies under surveillance differ in size, population density, physician practices, access to healthcare facilities, and access to microbiologically safe water and improved sanitation. These differences in part reflect the heterogeneity of the epidemiology of invasive salmonellosis globally, and thus enable generation of data that are useful to policymakers in decision-making for the introduction of typhoid conjugate vaccines (TCVs). Moreover, each study is evaluating the large-scale deployment of TCVs, and may ultimately be used to assess post-introduction vaccine impact. The data generated by these studies will also be used to refine global disease burden estimates. It is important to ensure that lessons learned from these studies not only inform vaccination policy, but also are incorporated into sustainable, low-cost, integrated vaccine-preventable disease surveillance systems.
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Affiliation(s)
- Megan E Carey
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - Justin Im
- International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - James E Meiring
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom.,Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Malick M Gibani
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Infectious Diseases, Imperial College London, London, United Kingdom
| | - Se Eun Park
- International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - Ashley Longley
- Global Immunization Division, Centers for Disease Control Foundation, Atlanta, Georgia, USA
| | - Hyon Jin Jeon
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - Caitlin Hemlock
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA
| | - Alexander T Yu
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Abdramane Soura
- Institut Supérieur des Sciences de la Population, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Kristen Aiemjoy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Ellis Owusu-Dabo
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Sahidul Islam
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Octavie Lunguya
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Melita Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - Christiane Dolecek
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Stephen Baker
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
| | | | - Susan Tonks
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - John D Clemens
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.,Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California, USA
| | - Kashmira Date
- Global Immunization Division, Centers for Disease Control Foundation, Atlanta, Georgia, USA
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Robert S Heyderman
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Samir K Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Buddha Basnyat
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Iruka N Okeke
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Idaban, Nigeria
| | - Farah N Qamar
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Merryn Voysey
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | | | - Jason Andrews
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Andrew J Pollard
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - Jacob John
- Christian Medical College, Vellore, India
| | - Denise Garrett
- Sabin Vaccine Institute, Washington, District of Columbia, USA
| | - Florian Marks
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
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10
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Date K, Shimpi R, Luby S, N R, Haldar P, Katkar A, Wannemuehler K, Mogasale V, Pallas S, Song D, Kunwar A, Loharikar A, Yewale V, Ahmed D, Horng L, Wilhelm E, Bahl S, Harvey P, Dutta S, Bhatnagar P. Decision Making and Implementation of the First Public Sector Introduction of Typhoid Conjugate Vaccine-Navi Mumbai, India, 2018. Clin Infect Dis 2021; 71:S172-S178. [PMID: 32725235 DOI: 10.1093/cid/ciaa597] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Typhoid fever prevention and control efforts are critical in an era of rising antimicrobial resistance among typhoid pathogens. India remains one of the highest typhoid disease burden countries, although a highly efficacious typhoid conjugate vaccine (TCV), prequalified by the World Health Organization in 2017, has been available since 2013. In 2018, the Navi Mumbai Municipal Corporation (NMMC) introduced TCV into its immunization program, targeting children aged 9 months to 14 years in 11 of 22 areas (Phase 1 campaign). We describe the decision making, implementation, and delivery costing to inform TCV use in other settings. METHODS We collected information on the decision making and campaign implementation in addition to administrative coverage from NMMC and partners. We then used a microcosting approach from the local government (NMMC) perspective, using a new Microsoft Excel-based tool to estimate the financial and economic vaccination campaign costs. RESULTS The planning and implementation of the campaign were led by NMMC with support from multiple partners. A fixed-post campaign was conducted during weekends and public holidays in July-August 2018 which achieved an administrative vaccination coverage of 71% (ranging from 46% in high-income to 92% in low-income areas). Not including vaccine and vaccination supplies, the average financial cost and economic cost per dose of TCV delivery were $0.45 and $1.42, respectively. CONCLUSION The first public sector TCV campaign was successfully implemented by NMMC, with high administrative coverage in slums and low-income areas. Delivery cost estimates provide important inputs to evaluate the cost-effectiveness and affordability of TCV vaccination through public sector preventive campaigns.
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Affiliation(s)
- Kashmira Date
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Rahul Shimpi
- World Health Organization, India Country Office, New Delhi, India
| | | | - Ramaswami N
- Navi Mumbai Municipal Corporation, Navi Mumbai, India
| | - Pradeep Haldar
- Ministry of Health and Family Welfare, Government of India, India
| | - Arun Katkar
- World Health Organization, India Country Office, New Delhi, India
| | - Kathleen Wannemuehler
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Sarah Pallas
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Dayoung Song
- International Vaccine Institute, Republic of Korea
| | - Abhishek Kunwar
- World Health Organization, India Country Office, New Delhi, India
| | - Anagha Loharikar
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Vijay Yewale
- Dr. Yewale Multispecialty Hospital, Navi Mumbai, India
| | - Danish Ahmed
- World Health Organization, India Country Office, New Delhi, India
| | - Lily Horng
- Stanford University, Stanford, California, USA
| | - Elisabeth Wilhelm
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sunil Bahl
- World Health Organization, Regional Office for South-East Asia, New Delhi, India
| | - Pauline Harvey
- World Health Organization, India Country Office, New Delhi, India
| | - Shanta Dutta
- National Institute of Cholera and Enteric Diseases-Indian Council for Medical Research, Kolkata, India
| | - Pankaj Bhatnagar
- World Health Organization, India Country Office, New Delhi, India
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11
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Goshua A, Gomez J, Erny B, Burke M, Luby S, Sokolow S, LaBeaud AD, Auerbach P, Gisondi MA, Nadeau K. Addressing Climate Change and Its Effects on Human Health: A Call to Action for Medical Schools. Acad Med 2021; 96:324-328. [PMID: 33239537 DOI: 10.1097/acm.0000000000003861] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Human health is increasingly threatened by rapid and widespread changes in the environment and climate, including rising temperatures, air and water pollution, disease vector migration, floods, and droughts. In the United States, many medical schools, the American Medical Association, and the National Academy of Sciences have published calls for physicians and physicians-in-training to develop a basic knowledge of the science of climate change and an awareness of the associated health risks. The authors-all medical students and educators-argue for the expeditious redesign of medical school curricula to teach students to recognize, diagnose, and treat the many health conditions exacerbated by climate change as well as understand public health issues. In this Invited Commentary, the authors briefly review the health impacts of climate change, examine current climate change course offerings and proposals, and describe the rationale for promptly and comprehensively including climate science education in medical school curricula. Efforts in training physicians now will benefit those physicians' communities whose health will be impacted by a period of remarkable climate change. The bottom line is that the health effects of climate reality cannot be ignored, and people everywhere must adapt as quickly as possible.
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Affiliation(s)
- Anna Goshua
- A. Goshua is a second-year medical student, Stanford University School of Medicine, Stanford, California
| | - Jason Gomez
- J. Gomez is a second-year medical student, Stanford University School of Medicine, Stanford, California
| | - Barbara Erny
- B. Erny is medical liaison for international programs, American Society of Cataract and Refractive Surgery Foundation, Fairfax, Virginia, and a member, Environmental Health Committee, Physicians for Social Responsibility, Washington, DC
| | - Marshall Burke
- M. Burke is associate professor, Department of Earth System Science and Center on Food Security and the Environment, Stanford University, Stanford, California
| | - Stephen Luby
- S. Luby is professor of medicine and associate dean of global health research, Stanford University, Stanford, California
| | - Susanne Sokolow
- S. Sokolow is senior research scientist, Stanford Woods Institute for the Environment, Stanford University, Stanford, California
| | - A Desiree LaBeaud
- A.D. LaBeaud is professor of pediatrics, Stanford University School of Medicine, and a senior fellow, Stanford Woods Institute for the Environment, Stanford, California
| | - Paul Auerbach
- P. Auerbach is the Redlich Family Professor Emeritus, Department of Emergency Medicine, Stanford University School of Medicine, Stanford, California
| | - Michael A Gisondi
- M.A. Gisondi is associate professor and vice chair of education, Department of Emergency Medicine, Stanford University, Stanford, California
| | - Kari Nadeau
- K. Nadeau is the Naddisy Family Foundation Professor of Allergy and director, Sean N. Parker Center for Allergy and Asthma Research at Stanford University, Stanford, California
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12
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Lee KH, Nikolay B, Sazzad HMS, Hossain MJ, Khan AKMD, Rahman M, Satter SM, Nichol ST, Klena JD, Pulliam JRC, Kilpatrick AM, Sultana S, Afroj S, Daszak P, Luby S, Cauchemez S, Salje H, Gurley ES. Changing Contact Patterns Over Disease Progression: Nipah Virus as a Case Study. J Infect Dis 2021; 222:438-442. [PMID: 32115627 DOI: 10.1093/infdis/jiaa091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/27/2020] [Indexed: 01/30/2023] Open
Abstract
Contact patterns play a key role in disease transmission, and variation in contacts during the course of illness can influence transmission, particularly when accompanied by changes in host infectiousness. We used surveys among 1642 contacts of 94 Nipah virus case patients in Bangladesh to determine how contact patterns (physical and with bodily fluids) changed as disease progressed in severity. The number of contacts increased with severity and, for case patients who died, peaked on the day of death. Given transmission has only been observed among fatal cases of Nipah virus infection, our findings suggest that changes in contact patterns during illness contribute to risk of infection.
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Affiliation(s)
- Kyu Han Lee
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Birgit Nikolay
- Mathematical Modelling of Infectious Diseases Unit Institut Pasteur, Paris, France
| | - Hossain M S Sazzad
- Infectious Disease Division, icddr,b, Dhaka, Bangladesh.,Kirby Institute, University of New South Wales, Sydney, Australia
| | - M Jahangir Hossain
- Infectious Disease Division, icddr,b, Dhaka, Bangladesh.,Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | | | - Mahmudur Rahman
- Infectious Disease Division, icddr,b, Dhaka, Bangladesh.,Institute of Epidemiology Disease Control and Research, Dhaka, Bangladesh
| | | | - Stuart T Nichol
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - John D Klena
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Sharmin Sultana
- Institute of Epidemiology Disease Control and Research, Dhaka, Bangladesh
| | - Sayma Afroj
- Infectious Disease Division, icddr,b, Dhaka, Bangladesh
| | | | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Simon Cauchemez
- Mathematical Modelling of Infectious Diseases Unit Institut Pasteur, Paris, France
| | - Henrik Salje
- Mathematical Modelling of Infectious Diseases Unit Institut Pasteur, Paris, France
| | - Emily S Gurley
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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13
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Styczynski A, Amin MB, Parveen S, Pervez MA, Zeba D, Akhter A, Gurley ES, Luby S. 1377. Perinatal Transmission Dynamics of Antimicrobial Resistance. Open Forum Infect Dis 2020. [PMCID: PMC7777229 DOI: 10.1093/ofid/ofaa439.1559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Antimicrobial resistance (AMR) is a global health threat that disproportionately affects low- and middle-income countries. An ongoing study of childhood mortality in Bangladesh revealed a common cause of death among neonates is sepsis from Gram-negative multi-drug-resistant organisms.
Methods
To ascertain factors leading to neonatal exposure, we enrolled 100 women presenting for delivery to Faridpur Hospital during February-March 2020. We collected vaginal and rectal swabs from mothers on presentation and at least 24 hours after delivery as well as rectal swabs from newborns. Swabs were plated on chromogenic agars selective for extended-spectrum-beta-lactamase-(ESBL) producing organisms and carbapenem-resistant Enterobacteriaceae (CRE).
Results
Eight-five percent of women underwent C-section. Prior to delivery, ESBL organisms were isolated from 15% of vaginal and 63% of rectal swabs. CRE was detected in 2% of vaginal and 8% of rectal swabs. Following delivery, colonization exceeded 90% (ESBL) and 70% (CRE) in both swab sets. Similarly, among newborns, 85% were colonized with ESBL and 67% with CRE. Maternal AMR colonization on admission did not correlate with income, education, parity, prenatal care, or prior antibiotic use, but was associated with hospitalization during pregnancy (rectal CRE OR 11.9, p< 0.01). Maternal colonization at discharge was positively associated with membrane stripping (vaginal ESBL OR 9.0, p< 0.01; rectal CRE OR 5.0, p=0.03), C-section (OR 4.0-15.4, p< 0.05), and administration of third-generation cephalosporins (OR 5.0-10.1, p< 0.05). Newborn colonization correlated with maternal colonization on discharge (p< 0.005) but not on admission. Among newborns delivered by C-section, there was an 8-9-fold increased risk of ESBL and CRE colonization (p< 0.01).
Conclusion
These results demonstrate that AMR is driven by nosocomial factors in the perinatal setting, and invasive procedures and perinatal antibiotic use increase risk of AMR colonization. These findings emphasize the urgent need for enhanced antibiotic stewardship and infection prevention and control practices to preserve the benefits of hospital-based deliveries.
Disclosures
All Authors: No reported disclosures
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Affiliation(s)
| | | | | | - Md Abu Pervez
- Faridpur Medical College Hospital, Faridpur, Dhaka, Bangladesh
| | - Dilruba Zeba
- Faridpur Medical College Hospital, Faridpur, Dhaka, Bangladesh
| | - Akhi Akhter
- Faridpur Medical College Hospital, Faridpur, Dhaka, Bangladesh
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14
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Lewis G, Jordan JL, Relman DA, Koblentz GD, Leung J, Dafoe A, Nelson C, Epstein GL, Katz R, Montague M, Alley EC, Filone CM, Luby S, Church GM, Millett P, Esvelt KM, Cameron EE, Inglesby TV. The biosecurity benefits of genetic engineering attribution. Nat Commun 2020; 11:6294. [PMID: 33293537 PMCID: PMC7722838 DOI: 10.1038/s41467-020-19149-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 09/28/2020] [Indexed: 11/23/2022] Open
Abstract
Biology can be misused, and the risk of this causing widespread harm increases in step with the rapid march of technological progress. A key security challenge involves attribution: determining, in the wake of a human-caused biological event, who was responsible. Recent scientific developments have demonstrated a capability for detecting whether an organism involved in such an event has been genetically modified and, if modified, to infer from its genetic sequence its likely lab of origin. We believe this technique could be developed into powerful forensic tools to aid the attribution of outbreaks caused by genetically engineered pathogens, and thus protect against the potential misuse of synthetic biology.
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Affiliation(s)
- Gregory Lewis
- Future of Humanity Institute, Oxford University, Oxford, UK.
- Alt. Technology Labs, Inc., Berkeley, CA, USA.
| | | | - David A Relman
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Microbiology & Immunology, Stanford University School of Medicine; and Center for International Security and Cooperation, Stanford University, Stanford, CA, USA
| | - Gregory D Koblentz
- Schar School of Policy and Government, George Mason University, Washington, DC, USA
| | - Jade Leung
- Future of Humanity Institute, Oxford University, Oxford, UK
| | - Allan Dafoe
- Future of Humanity Institute, Oxford University, Oxford, UK
| | - Cassidy Nelson
- Future of Humanity Institute, Oxford University, Oxford, UK
| | - Gerald L Epstein
- Center for the Study of Weapons of Mass Destruction, National Defense University, Washington, DC, USA
| | - Rebecca Katz
- Center for Global Health Science and Security, Georgetown University, Washington, DC, USA
| | - Michael Montague
- Center for Health Security, Johns Hopkins University, Baltimore, MD, USA
| | - Ethan C Alley
- Alt. Technology Labs, Inc., Berkeley, CA, USA
- Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | | | - Stephen Luby
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - George M Church
- Alt. Technology Labs, Inc., Berkeley, CA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Piers Millett
- Future of Humanity Institute, Oxford University, Oxford, UK
- International Genetically Engineered Machine Competition, Boston, MA, USA
| | - Kevin M Esvelt
- Alt. Technology Labs, Inc., Berkeley, CA, USA
- Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Thomas V Inglesby
- Center for Health Security, Johns Hopkins University, Baltimore, MD, USA
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Yu AT, Shakya R, Adhikari B, Tamrakar D, Vaidya K, Maples S, Date K, Bogoch II, Bern C, Qamar F, Yousafzai MT, Garrett DO, Longley AT, Hemlock C, Luby S, Aiemjoy K, Andrews JR. A Cluster-based, Spatial-sampling Method for Assessing Household Healthcare Utilization Patterns in Resource-limited Settings. Clin Infect Dis 2020; 71:S239-S247. [PMID: 33258933 PMCID: PMC7705878 DOI: 10.1093/cid/ciaa1310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Implementation of population-based surveys is resource intensive and logistically demanding, especially in areas with rapidly changing demographics and incomplete or no enumeration of the underlying population and their residences. To remove the need for pre-enumeration and to simplify field logistics for the population healthcare utilization survey used for the Surveillance for Enteric Fever in Asia Project in Nepal, we incorporated a geographic information system-based geosurvey and field mapping system into a single-stage cluster sampling approach. METHODS A survey was administered to ascertain healthcare-seeking behavior in individuals with recent suspected enteric fever. Catchment areas were based on residential addresses of enteric fever patients using study facilities; clusters were randomly selected from digitally created grids using available satellite images and all households within clusters were offered enrollment. A tablet-compatible geosurvey and mapping system that allowed for data-syncing and use in areas without cellular data was created using the ArcGIS suite of software. RESULTS Between January 2017 and November 2018, we surveyed 25 521 households in Nepal (16 769 in urban Kathmandu and 8752 in periurban Kavrepalanchok), representing 84 202 individuals. Overall, the survey participation rate was 90.9%, with geographic heterogeneity in participation rates within each catchment area. Areas with higher average household wealth had lower participation rates. CONCLUSION A geographic information system-based geosurvey and field mapping system allowed creation of a virtual household map at the same time as survey administration, enabling a single-stage cluster sampling method to assess healthcare utilization in Nepal for the Surveillance for Enteric Fever in Asia Project . This system removed the need for pre-enumeration of households in sampling areas, simplified logistics and could be replicated in future community surveys.
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Affiliation(s)
- Alexander T Yu
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Rajani Shakya
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Nepal
| | - Bikram Adhikari
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Nepal
| | - Dipesh Tamrakar
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Nepal
| | - Krista Vaidya
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Nepal
| | - Stace Maples
- Stanford Geospatial Center, Stanford University, Stanford, California, USA
| | - Kashmira Date
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Isaac I Bogoch
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Caryn Bern
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | | | | | - Denise O Garrett
- Applied Epidemiology, Sabin Vaccine Institute, Washington, DC, USA
| | - Ashley T Longley
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- National Foundation for the Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Caitlin Hemlock
- Applied Epidemiology, Sabin Vaccine Institute, Washington, DC, USA
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Kristen Aiemjoy
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
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Tamrakar D, Vaidya K, Yu AT, Aiemjoy K, Naga SR, Cao Y, Bern C, Shrestha R, Karmacharya BM, Pradhan S, Qamar FN, Saha S, Date K, Longley AT, Hemlock C, Luby S, Garrett DO, Bogoch II, Andrews JR. Spatial Heterogeneity of Enteric Fever in 2 Diverse Communities in Nepal. Clin Infect Dis 2020; 71:S205-S213. [PMID: 33258932 PMCID: PMC7705881 DOI: 10.1093/cid/ciaa1319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Typhoid fever is endemic in the urban Kathmandu Valley of Nepal; however, there have been no population-based studies of typhoid outside of this community in the past 3 decades. Whether typhoid immunization should be prioritized in periurban and rural communities has been unclear. METHODS We performed population-based surveillance for enteric fever in 1 urban catchment (Kathmandu) and 1 periurban and rural catchment (Kavrepalanchok) as part of the Surveillance for Enteric Fever in Asia Project (SEAP). We recruited individuals presenting to outpatient and emergency departments at 2 study hospitals with suspected enteric fever and performed blood cultures. Additionally, we conducted a household survey in each catchment area to characterize care seeking for febrile illness. We evaluated spatial heterogeneity in febrile illness, care seeking, and enteric fever incidence. RESULTS Between September 2016 and September 2019, we enrolled 5736 participants with suspected enteric fever at 2 study hospitals. Among these, 304 (5.3%) were culture positive for Salmonella Typhi (249 [81.9%]) or Paratyphi A (55 [18.1%]). Adjusted typhoid incidence in Kathmandu was 484 per 100 000 person-years and in Kavrepalanchok was 615 per 100 000 person-years. While all geographic areas for which estimates could be made had incidence >200 per 100 000 person-years, we observed spatial heterogeneity with up to 10-fold variation in incidence between communities. CONCLUSIONS In urban, periurban, and rural communities in and around Kathmandu, we measured a high but heterogenous incidence of typhoid. These findings provide some support for the introduction of conjugate vaccines in Nepal, including outside urban areas, alongside other measures to prevent enteric fever.
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Affiliation(s)
- Dipesh Tamrakar
- Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchok, Nepal
| | - Krista Vaidya
- Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchok, Nepal
| | - Alexander T Yu
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Kristen Aiemjoy
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Shiva Ram Naga
- Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchok, Nepal
| | - Yanjia Cao
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Caryn Bern
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, USA
| | - Rajeev Shrestha
- Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchok, Nepal
| | | | - Sailesh Pradhan
- Kathmandu Medical College and Teaching Hospital, Kathmandu, Nepal
| | - Farah Naz Qamar
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Samir Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children’s) Hospital, Dhaka, Bangladesh
| | - Kashmira Date
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ashley T Longley
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- National Foundation for the Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Caitlin Hemlock
- Applied Epidemiology, Sabin Vaccine Institute, Washington, DC, USA
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
| | - Denise O Garrett
- Applied Epidemiology, Sabin Vaccine Institute, Washington, DC, USA
| | - Isaac I Bogoch
- Department of Medicine, University of Toronto, Toronto, Canada
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, School of Medicine, Stanford University, Stanford, California, USA
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Baker S, Ali M, Deerin JF, Eltayeb MA, Cruz Espinoza LM, Gasmelseed N, Im J, Panzner U, Kalckreuth VV, Keddy KH, Pak GD, Park JK, Park SE, Sooka A, Sow AG, Tall A, Luby S, Meyer CG, Marks F. The Typhoid Fever Surveillance in Africa Program: Geospatial Sampling Frames for Household-based Studies: Lessons Learned From a Multicountry Surveillance Network in Senegal, South Africa, and Sudan. Clin Infect Dis 2020; 69:S474-S482. [PMID: 31665783 PMCID: PMC6821174 DOI: 10.1093/cid/ciz755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background Robust household sampling, commonly applied for population-based investigations, requires sampling frames or household lists to minimize selection bias. We have applied Google Earth Pro satellite imagery to constitute structure-based sampling frames at sites in Pikine, Senegal; Pietermaritzburg, South Africa; and Wad-Medani, Sudan. Here we present our experiences in using this approach and findings from assessing its applicability by determining positional accuracy. Methods Printouts of satellite imagery combined with Global Positioning System receivers were used to locate and to verify the locations of sample structures (simple random selection; weighted-stratified sampling). Positional accuracy was assessed by study site and administrative subareas by calculating normalized distances (meters) between coordinates taken from the sampling frame and on the ground using receivers. A higher accuracy in conjunction with smaller distances was assumed. Kruskal-Wallis and Dunn multiple pairwise comparisons were performed to evaluate positional accuracy by setting and by individual surveyor in Pietermaritzburg. Results The median normalized distances and interquartile ranges were 0.05 and 0.03–0.08 in Pikine, 0.09 and 0.05–0.19 in Pietermaritzburg, and 0.05 and 0.00–0.10 in Wad-Medani, respectively. Root mean square errors were 0.08 in Pikine, 0.42 in Pietermaritzburg, and 0.17 in Wad-Medani. Kruskal-Wallis and Dunn comparisons indicated significant differences by low- and high-density setting and interviewers who performed the presented approach with high accuracy compared to interviewers with poor accuracy. Conclusions The geospatial approach presented minimizes systematic errors and increases robustness and representativeness of a sample. However, the findings imply that this approach may not be applicable at all sites and settings; its success also depends on skills of surveyors working with aerial data. Methodological modifications are required, especially for resource-challenged sites that may be affected by constraints in data availability and area size.
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Affiliation(s)
- Stephen Baker
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Department of Medicine, University of Cambridge, United Kingdom
| | | | | | | | | | - Nagla Gasmelseed
- Faculty of Medicine at the University of Gezira, Wad-Medani, Sudan
- Faculty of Science, University of Hafr Al Batin, Saudi Arabia
| | - Justin Im
- International Vaccine Institute, Seoul, Republic of Korea
| | - Ursula Panzner
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Karen H Keddy
- Faculty of Health Sciences, University of the Witwatersrand
| | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | - Jin Kyung Park
- International Vaccine Institute, Seoul, Republic of Korea
| | - Se Eun Park
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- International Vaccine Institute, Seoul, Republic of Korea
| | - Arvinda Sooka
- National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Amy Gassama Sow
- Institut Pasteur de Dakar, Senegal
- Université Cheikh Anta Diop de Dakar, Senegal
| | | | - Stephen Luby
- Infectious Diseases and Geographic Medicine, Stanford University, California
| | - Christian G Meyer
- Institute of Tropical Medicine, Eberhard Karls University, Tübingen, Germany
- Duy Tan University, Da Nang, Vietnam
| | - Florian Marks
- Department of Medicine, University of Cambridge, United Kingdom
- International Vaccine Institute, Seoul, Republic of Korea
- Correspondence: F. Marks, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea ()
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Ryckman T, Luby S, Owens DK, Bendavid E, Goldhaber-Fiebert JD. Methods for Model Calibration under High Uncertainty: Modeling Cholera in Bangladesh. Med Decis Making 2020; 40:693-709. [PMID: 32639859 DOI: 10.1177/0272989x20938683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background. Published data on a disease do not always correspond directly to the parameters needed to simulate natural history. Several calibration methods have been applied to computer-based disease models to extract needed parameters that make a model's output consistent with available data. Objective. To assess 3 calibration methods and evaluate their performance in a real-world application. Methods. We calibrated a model of cholera natural history in Bangladesh, where a lack of active surveillance biases available data. We built a cohort state-transition cholera natural history model that includes case hospitalization to reflect the passive surveillance data-generating process. We applied 3 calibration techniques: incremental mixture importance sampling, sampling importance resampling, and random search with rejection sampling. We adapted these techniques to the context of wide prior uncertainty and many degrees of freedom. We evaluated the resulting posterior parameter distributions using a range of metrics and compared predicted cholera burden estimates. Results. All 3 calibration techniques produced posterior distributions with a higher likelihood and better fit to calibration targets as compared with prior distributions. Incremental mixture importance sampling resulted in the highest likelihood and largest number of unique parameter sets to better inform joint parameter uncertainty. Compared with naïve uncalibrated parameter sets, calibrated models of cholera in Bangladesh project substantially more cases, many of which are not detected by passive surveillance, and fewer deaths. Limitations. Calibration cannot completely overcome poor data quality, which can leave some parameters less well informed than others. Calibration techniques may perform differently under different circumstances. Conclusions. Incremental mixture importance sampling, when adapted to the context of high uncertainty, performs well. By accounting for biases in data, calibration can improve model projections of disease burden.
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Affiliation(s)
- Theresa Ryckman
- Center for Health Policy and Center for Primary Care & Outcomes Research, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen Luby
- Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - Douglas K Owens
- VA Palo Alto Healthcare System, Palo Alto, CA, USA.,Center for Health Policy and Center for Primary Care & Outcomes Research, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Eran Bendavid
- Division of Primary Care and Population Health, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.,Center for Health Policy and Center for Primary Care & Outcomes Research, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Jeremy D Goldhaber-Fiebert
- Center for Health Policy and Center for Primary Care & Outcomes Research, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Humphrey J, Pickering A, Null C, Winch P, Mangwadu G, Arnold B, Prendergast A, Njenga S, Rahman M, Ntozini R, Benjamin-Chung J, Stewart C, Huda T, Moulton L, Colford J, Luby S. The WASH Benefits and SHINE Trials. Interpretation of Findings on Linear Growth and Diarrhoea and Implications for Policy: Perspective of the Investigative Teams (P10-136-19). Curr Dev Nutr 2019. [DOI: 10.1093/cdn/nzz034.p10-136-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Objectives
We recently completed 3 efficacy trials (Bangladesh, Kenya, Zimbabwe) testing the independent and combined effects of improved complementary feeding (CF) and intensive household water quality, sanitation, and hygiene (WASH) on child diarrhea and length-for-age-Z-score (LAZ) at 18 to 24 mo. Intervention uptake was high. In all three trials: CF increased LAZ but WASH had no effect on LAZ. WASH reduced diarrhea in Bangladesh but not in Kenya or Zimbabwe. We present a synthesis of trial findings and their implications.
Methods
Reviews of the literature and reanalyses of trial data were conducted.
Results
WASH and stunting: Copious observational studies have demonstrated a strong association between household-level WASH and child LAZ. We conducted an observational anlaysis (nested birth cohort) from our control arms. In adjusted analyses of all three trials, having an improved latrine when the pregnant woman was enrolled was associated with ∼0.2LAZ increase in her child at 18–24 mo. The frequently reported association between household WASH indicators and child growth may be confounded and drawing causal inferance misguided.
WASH and diarrhea: Promoters visited intervention households 6 times per month in Bangladesh and monthly in Kenya and Zimbabwe. We conducted a systematic literature review: virtually all evidence that household water chlorination and handwashing reduce diarrhea comes from studies with daily to fortnightly intervention contact. In studies with follow-up after the trial ending, behaviors steeply declined and the effect on child diarrhea disappeared. Household water chlorination and handwashing promotion implemented through sporadic message delivery may not reduce child diarrhea.
Enteropathogen transmission: Despite achieving substantial contrast between WASH and non-WASH households, children in the WASH arms still experienced high enteropathogen transmission, illustrating the recalcitrance of pervasive fecal contamination in rural low-income communities to even intense intervention.
Conclusions
Household WASH interventions are unlikely to reduce child stunting and may not reduce child diarrhea. We call for substantial investment in research to identify and in programming to deliver much more efficacious interventions.
Funding Sources
Bill & Melinda Gates Foundation, USAID, DFID/UKAID, Wellcome Trust.
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Affiliation(s)
| | - Amy Pickering
- Civil and Environmental Engineering, Tufts University
| | | | - Peter Winch
- Johns Hopkins Bloomberg School of Public Health
| | | | - Ben Arnold
- School of Public Health, University of California Berkeley
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Titu AMN, Rahman M, Unicomb L, Doza S, Ahmed KMU, Selim S, Anand S, Chang H, Luby S, Clasen T, Gribble M, Narayan KMV. Abstract P224: Urinary Excretion of Sodium, Potassium, Calcium and Magnesium and Blood Pressure Among a Population of ≥ 20-Year-Olds: Evidence From Southwest Coastal Bangladesh. Hypertension 2018. [DOI: 10.1161/hyp.72.suppl_1.p224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We analyzed data from a stepped wedge randomized trial to evaluate how urinary Na, K, Ca and Mg excretion are associated with the change in blood pressure (BP) among the adult population. We followed up a cohort of 1,191 participants (>20 years old) from 540 households in 16 communities of southwest coastal Bangladesh for five visits during December 2016 - April 2017 when they were exposed to high salinity drinking water. In all visits, we measured participants’ BP (N=5,746) and 24-hour urinary Na, K, Ca and Mg. We used multilevel linear regression models to determine the association among change in urinary excretion of Na, K, Ca and Mg with differences in mean systolic blood pressure (SBP) and diastolic blood pressure (DBP). Models included participant-, household-, and community-level random intercepts and were adjusted for age, sex, BMI, physical activity, smoking status, and household wealth. We restricted analysis among participants who had complete 24-hour urine collection based on measured versus expected urinary creatinine ratio of >=0.7 (N=5,103). The median urinary 24 hours Na excretion was 164 mmol, K was 34 mmol, Ca was 126 mg, and Mg was 83 mg in visit 1. The mean population SBP was 115.6 mmHg in visit 1 and 110.2 in visit 5, and the mean DBP was 68.9 mmHg in visit 1 and 65.9 in visit 5. Compared to visit 1, we found 85% higher urinary Ca in visit 3 and 57% higher urinary Mg in visit 5. We found 100 mmol per 24 hours increase in urinary Na was associated with 1.74 (95% CI: 0.85, 2.62) mmHg higher SBP and 0.51 (95% CI: -0.06, 1.08) mmHg higher DBP, and 50 mmol per 24 hours increase in urinary K was associated with 2.39 (95% CI: 0.84, 3.94) mmHg lower SBP and 0.79 (95% CI: -1.76, 0.17) mmHg lower DBP. We found 100 mg per 24 hours increase in urinary Ca was associated with 0.29 (95% CI: 0.02, 0.60) mmHg lower SBP and 0.32 (0.07, 0.57) mmHg lower DBP, and 100 mg per 24 hours increase in urinary Mg was associated with 1.09 (95% CI: 0.55, 1.64) mmHg lower SBP and 0.41 (0.07, 0.76) mmHg lower DBP. We found SBP lowering effect of urinary Mg increased if urinary Ca was lower (p = 0.048). We found urinary K, Ca, and Mg are associated with lower BP in coastal Bangladesh. Our results suggest a high intake of these beneficial minerals alongside Na reduction may successfully lower mean BP of the population.
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Affiliation(s)
- Abu Mohd Naser Titu
- Dept of Environmental Health Sciences, Rollins Sch of Public Health, Emory Univ, Atlanta, GA
| | - Mahbubur Rahman
- International Cntr for Diarrhoeal Disease Rsch, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Leanne Unicomb
- International Cntr for Diarrhoeal Disease Rsch, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Solaiman Doza
- International Cntr for Diarrhoeal Disease Rsch, Bangladesh (icddr,b), Dhaka, Bangladesh
| | | | - Shahjada Selim
- Dept of Endocrinology, Bangabandhu Sheikh Mujib Med Univ, Dhaka, Bangladesh
| | - Shuchi Anand
- Div of Nephrology, Stanford Sch of Medicine, Stanford Univ, Stanford, CA
| | - Howard Chang
- Dept of Biostatistics and Bioinformatics, Rollins Sch of Public Health, Emory Univ, Atlanta, GA
| | - Stephen Luby
- Woods Institute for the Environment, Stanford Univ, Stanford, California, Stanford, CA
| | - Thomas Clasen
- Dept of Environmental Health Sciences, Rollins Sch of Public Health, Emory Univ, Atlanta, GA
| | - Matthew Gribble
- Dept of Environmental Health Sciences, Rollins Sch of Public Health, Emory Univ, Atlanta, GA
| | - KM Venkat Narayan
- Emory Global Diabetes Rsch Cntr, Hubert Dept of Global Health, Rollins Sch of Public Health, Emory Univ, Atlanta, GA
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Harris AR, Islam MA, Unicomb L, Boehm AB, Luby S, Davis J, Pickering AJ. Fecal Contamination on Produce from Wholesale and Retail Food Markets in Dhaka, Bangladesh. Am J Trop Med Hyg 2018; 98:287-294. [PMID: 29165214 PMCID: PMC5928698 DOI: 10.4269/ajtmh.17-0255] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/17/2017] [Indexed: 11/07/2022] Open
Abstract
Fresh produce items can become contaminated with enteric pathogens along the supply chain at the preharvest (e.g., irrigation water, soil, fertilizer) or postharvest (e.g., vendor handling or consumer handling) stages. This study assesses the concentrations of fecal indicator bacteria Escherichia coli, enterococci (ENT), and Bacteriodales on surfaces of carrots, eggplants, red amaranth leaves, and tomatoes obtained from both a wholesale market (recently harvested) and neighborhood retail markets in Dhaka, Bangladesh. We detected E. coli in 100% of carrot and red amaranth rinses, 92% of eggplant rinses, and 46% of tomato rinses. Using a molecular microbial source tracking assay, we found that 32% of produce samples were positive for ruminant fecal contamination. Fecal indicator bacteria were more likely to be detected on produce collected in retail markets compared with that in the wholesale market; retail market produce were 1.25 times more likely to have E. coli detected (P = 0.03) and 1.24 times more likely to have ENT detected (P = 0.03) as compared with wholesale market produce. Bacteriodales was detected in higher concentrations in retail market produce samples compared with wholesale market produce samples (0.40 log10 gene copies per 100 cm2 higher, P = 0.03). Our results suggest that ruminant and general fecal contamination of produce in markets in Dhaka is common, and suggest that unsanitary conditions in markets are an important source of produce fecal contamination postharvest.
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Affiliation(s)
- Angela R. Harris
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University, Stanford, California
| | - Mohammad Aminul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Leanne Unicomb
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Alexandria B. Boehm
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University, Stanford, California
| | - Stephen Luby
- Woods Institute for the Environment, Stanford University, Stanford, California
| | - Jennifer Davis
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University, Stanford, California
- Woods Institute for the Environment, Stanford University, Stanford, California
| | - Amy J. Pickering
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University, Stanford, California
- Civil and Environmental Engineering, Tufts University, Medford, Massachusetts
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22
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Rolfes MA, Goswami D, Sharmeen AT, Yeasmin S, Parvin N, Nahar K, Rahman M, Barends M, Ahmed D, Rahman MZ, Bresee J, Luby S, Moulton LH, Santosham M, Fry AM, Brooks WA. Efficacy of trivalent influenza vaccine against laboratory-confirmed influenza among young children in a randomized trial in Bangladesh. Vaccine 2017; 35:6967-6976. [PMID: 29100706 PMCID: PMC5723570 DOI: 10.1016/j.vaccine.2017.10.074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 11/27/2022]
Abstract
There is limited data on efficacy of yearly influenza vaccination in children aged <2 years. Influenza vaccination was found to be safe and significantly reduced influenza in young children. These findings support yearly influenza vaccination of young children.
Background Few trials have evaluated influenza vaccine efficacy (VE) in young children, a group particularly vulnerable to influenza complications. We aimed to estimate VE against influenza in children aged <2 years in Bangladesh; a subtropical setting, where influenza circulation can be irregular. Methods Children aged 6–23 months were enrolled 1:1 in a parallel, double-blind, randomized controlled trial of trivalent inactivated influenza vaccine (IIV3) versus inactivated polio vaccine (IPV); conducted August 2010–March 2014 in Dhaka, Bangladesh. Children received two pediatric doses of vaccine, one month apart, and were followed for one year for febrile and respiratory illness. Field assistants conducted weekly home-based, active surveillance and ill children were referred to the study clinic for clinical evaluation and nasopharyngeal wash specimen collection. Analysis included all children who received a first vaccine dose and compared yearly incidence of reverse transcription polymerase chain reaction (RT-PCR)-confirmed influenza between trial arms. The VE was estimated as 1 − (rate ratio of illness) × 100%, using unadjusted Poisson regression. The trial was registered with ClinicalTrials.gov, number NCT01319955. Results Across four vaccination rounds, 4081 children were enrolled and randomized, contributing 2576 child-years of observation to the IIV3 arm and 2593 child-years to the IPV arm. Influenza incidence was 10 episodes/100 child-years in the IIV3 arm and 15 episodes/100 child-years in the IPV arm. Overall, the VE was 31% (95% confidence interval 18, 42%) against any RT-PCR-confirmed influenza. The VE varied by season, but was similar by influenza type/subtype and participant age and sex. Conclusions Vaccination of young children with IIV3 provided a significant reduction in laboratory-confirmed influenza; however, exploration of additional influenza vaccine strategies, such as adjuvanted vaccines or standard adult vaccine doses, is warranted to find more effective influenza vaccines for young children in low-income countries.
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Affiliation(s)
- Melissa A Rolfes
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA, USA; Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | | | | | | | | | | | | | | | | | | - Joseph Bresee
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | | | | | | - Alicia M Fry
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - W Abdullah Brooks
- Icddr,b, Dhaka, Bangladesh; Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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Epstein J, Anthony S, Islam A, Kilpatrick A, Khan SA, Ross N, Smith I, Barr J, Zambrana-Torrelio C, Tao Y, Islam A, Quan P, Olival K, Gurley E, Hossain M, Field H, Fielder M, Briese T, Rahman M, Crameri G, Wang LF, Luby S, Lipkin W, Daszak P. Nipah virus ecology and infection dynamics in its bat reservoir, Pteropus medius, in Bangladesh. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.11.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Horng L, Dutta NC, Ahmed S, Rabbani A, Luby S, Uddin MJ. Peer Networking to Improve Knowledge of Child Health and Immunization Services Among Recently Relocated Mothers in Slums of Dhaka, Bangladesh. Open Forum Infect Dis 2016. [DOI: 10.1093/ofid/ofw172.488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lily Horng
- Stanford University School of Medicine, Stanford, California
| | - Notan Chandra Dutta
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shahabuddin Ahmed
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Stephen Luby
- Stanford University School of Medicine, Stanford, California
| | - Md Jasim Uddin
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
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Hoy-Schulz YE, Jannat K, Roberts T, Zaidi S, Rahman MM, Unicomb L, Luby S, Parsonnet J. Colonization of Probiotics in Bangladeshi Infants After Different Administration Regimens. Open Forum Infect Dis 2016. [DOI: 10.1093/ofid/ofw172.1056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yana Emmy Hoy-Schulz
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, School of Medicine, Stanford, CA
| | - Kaniz Jannat
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Saira Zaidi
- Stanford University School of Medicine, Stanford, CA
| | - Md. Mostafizur Rahman
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Leanne Unicomb
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Stephen Luby
- Stanford University School of Medicine, Stanford, CA
| | - Julie Parsonnet
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA
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Harris AR, Pickering AJ, Harris M, Doza S, Islam MS, Unicomb L, Luby S, Davis J, Boehm AB. Ruminants Contribute Fecal Contamination to the Urban Household Environment in Dhaka, Bangladesh. Environ Sci Technol 2016; 50:4642-9. [PMID: 27045990 DOI: 10.1021/acs.est.5b06282] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In Dhaka, Bangladesh, the sensitivity and specificity of three human, three ruminant, and one avian source-associated QPCR microbial source tracking assays were evaluated using fecal samples collected on site. Ruminant-associated assays performed well, whereas the avian and human assays exhibited unacceptable cross-reactions with feces from other hosts. Subsequently, child hand rinses (n = 44) and floor sponge samples (n = 44) from low-income-households in Dhaka were assayed for fecal indicator bacteria (enterococci, Bacteroidales, and Escherichia coli) and a ruminant-associated bacterial target (BacR). Mean enterococci concentrations were of 100 most probable number (MPN)/2 hands and 1000 MPN/225 cm(2) floor. Mean concentrations of Bacteroidales were 10(6) copies/2 hands and 10(5) copies/225 cm(2) floor. E. coli were detected in a quarter of hand rinse and floor samples. BacR was detected in 18% of hand rinse and 27% of floor samples. Results suggest that effective household fecal management should account not only for human sources of contamination but also for animal sources. The poor performance of the human-associated assays in the study area calls into the question the feasibility of developing a human-associated marker in urban slum environments, where domestic animals are exposed to human feces that have been disposed in pits and open drains.
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Affiliation(s)
- Angela R Harris
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
| | - Amy J Pickering
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Michael Harris
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University , Stanford, California 94305, United States
| | | | | | | | - Stephen Luby
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Jennifer Davis
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Alexandria B Boehm
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
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Singer T, Moore F, Luby S. Potential effects of increased global temperatures on neurological development factors in children under 5 years in east Africa: a modelling study. The Lancet Global Health 2016. [DOI: 10.1016/s2214-109x(16)30026-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Hoy-Schulz YE, Jannat K, Roberts T, Zaidi SH, Unicomb L, Luby S, Parsonnet J. Safety and acceptability of Lactobacillus reuteri DSM 17938 and Bifidobacterium longum subspecies infantis 35624 in Bangladeshi infants: a phase I randomized clinical trial. BMC Complement Altern Med 2016; 16:44. [PMID: 26832746 PMCID: PMC4736167 DOI: 10.1186/s12906-016-1016-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/23/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Probiotics have rarely been studied in young healthy infants from low-income countries. This phase I study investigated the safety and acceptability of two probiotics in Bangladesh. METHODS Healthy infants aged four to twelve weeks from urban slums in Bangladesh were randomized to one of three different intervention dosing arms (daily, weekly, biweekly - once every two weeks) of Lactobacillus reuteri DSM 17938 and Bifidobacterium longum subspecies infantis 35624 over one month or to a fourth arm that received no probiotics. All subjects were followed for two additional months. Reported gastrointestinal and respiratory symptoms as well as breastfeeding rates, hospitalizations, differential withdrawals, and caretakers' perception of probiotic use were compared among arms. RESULTS In total, 160 infants were randomized (40 to each arm) with 137 (Daily n = 35, Weekly n = 35, Biweekly n = 35, Control n = 32) followed up for a median of twelve weeks; 113 completed the study. Illness and breastfeeding rates were similar across all arms. Ten hospitalizations unrelated to probiotic use occurred. Forty eight percent of the caretakers of infants in intervention arms believed that probiotics improved their baby's health. CONCLUSIONS These two commonly used probiotics appeared safe and well-accepted by Bangladeshi families. TRIAL REGISTRATION ClinicalTrials.gov NCT01899378 . Registered July 10, 2013.
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Hoy-Schulz YE, Jannat K, Roberts T, Zaidi S, Rahman MM, Alauddin M, Unicomb L, Luby S, Parsonnet J. Effect of Probiotics on Markers of Gut Health in Bangladeshi Infants. Open Forum Infect Dis 2015. [DOI: 10.1093/ofid/ofv133.1175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Horng L, Unicomb L, Alam MU, Halder A, Ghosh P, Luby S. Health Worker and Family Caregiver Hand Hygiene in Bangladesh Healthcare Facilities: Results From a Nationally Representative Survey. Open Forum Infect Dis 2015. [DOI: 10.1093/ofid/ofv133.1174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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31
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Hoy-Schulz YE, Jannat K, Roberts T, Rahman M, Zaidi S, Unicomb L, Luby S, Parsonnet J. 970Safety of Bifidobacterium longum infantis and Lactobacillus reuteri in Bangladeshi Infants. Open Forum Infect Dis 2014. [PMCID: PMC5782250 DOI: 10.1093/ofid/ofu052.678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Kaniz Jannat
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Mostafizur Rahman
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Saira Zaidi
- Stanford University School of Medicine, Stanford, CA
- University of California, Berkeley School of Public Health, Berkeley, CA
| | - Leanne Unicomb
- Center for Communicable Diseases, International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Stephen Luby
- Stanford University School of Medicine, Stanford, CA
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Lederman E, Khan SU, Luby S, Zhao H, Braden Z, Gao J, Karem K, Damon I, Reynolds M, Li Y. Zoonotic parapoxviruses detected in symptomatic cattle in Bangladesh. BMC Res Notes 2014; 7:816. [PMID: 25410770 PMCID: PMC4246640 DOI: 10.1186/1756-0500-7-816] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 10/21/2014] [Indexed: 11/13/2022] Open
Abstract
Background Application of molecular diagnostic methods to the determination of etiology in suspected poxvirus-associated infections of bovines is important both for the diagnosis of the individual case and to form a more complete understanding of patterns of strain occurrence and spread. The objective of this study was to identify and characterize bovine-associated zoonotic poxviruses in Bangladesh which are relevant to animal and human health. Findings Investigators from the International Center Diarrhoeal Disease Research (icddr,b), the US Centers for Disease Control and Prevention (CDC), and the Bangladesh Department of Livestock Services traveled to three districts in Bangladesh—Siranjganj, Rangpur and Bhola–to collect diagnostic specimens from dairy cattle and buffalo that had symptoms consistent with poxvirus-associated infections. Bovine papular stomatitis virus (BPSV) DNA was obtained from lesion material (teat) and an oral swab collected from an adult cow and calf (respectively) from a dairy production farm in Siranjganj. Pseudocowpox virus (PCPV) DNA signatures were obtained from a scab and oral swab collected from a second dairy cow and her calf from Rangpur. Conclusions We report the first detection of zoonotic poxviruses from Bangladesh and show phylogenetic comparisons between the Bangladesh viruses and reference strains based on analyses of the B2L and J6R loci (vaccinia orthologs). Understanding the range and diversity of different species and strains of parapoxvirus will help to spotlight unusual patterns of occurrence that could signal events of significance to the agricultural and public health sectors.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Yu Li
- Poxvirus and Rabies Branch, US Centers for Disease Control and Prevention, Atlanta, USA.
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Haynes AK, Manangan AP, Iwane MK, Sturm-Ramirez K, Homaira N, Brooks WA, Luby S, Rahman M, Klena JD, Zhang Y, Yu H, Zhan F, Dueger E, Mansour AM, Azazzy N, McCracken JP, Bryan JP, Lopez MR, Burton DC, Bigogo G, Breiman RF, Feikin DR, Njenga K, Montgomery J, Cohen AL, Moyes J, Pretorius M, Cohen C, Venter M, Chittaganpitch M, Thamthitiwat S, Sawatwong P, Baggett HC, Luber G, Gerber SI. Respiratory syncytial virus circulation in seven countries with Global Disease Detection Regional Centers. J Infect Dis 2014; 208 Suppl 3:S246-54. [PMID: 24265484 DOI: 10.1093/infdis/jit515] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in young children globally, with the highest burden in low- and middle-income countries where the association between RSV activity and climate remains unclear. METHODS Monthly laboratory-confirmed RSV cases and associations with climate data were assessed for respiratory surveillance sites in tropical and subtropical areas (Bangladesh, China, Egypt, Guatemala, Kenya, South Africa, and Thailand) during 2004-2012. Average monthly minimum and maximum temperatures, relative humidity, and precipitation were calculated using daily local weather data from the US National Climatic Data Center. RESULTS RSV circulated with 1-2 epidemic periods each year in site areas. RSV seasonal timing and duration were generally consistent within country from year to year. Associations between RSV and weather varied across years and geographic locations. RSV usually peaked in climates with high annual precipitation (Bangladesh, Guatemala, and Thailand) during wet months, whereas RSV peaked during cooler months in moderately hot (China) and arid (Egypt) regions. In South Africa, RSV peaked in autumn, whereas no associations with seasonal weather trends were observed in Kenya. CONCLUSIONS Further understanding of RSV seasonality in developing countries and various climate regions will be important to better understand the epidemiology of RSV and for timing the use of future RSV vaccines and immunoprophylaxis in low- and middle-income countries.
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Affiliation(s)
- Amber K Haynes
- Division of Viral Diseases, National Center for Immunizations and Respiratory Diseases
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Capone S, Manera MG, Taurino A, Siciliano P, Rella R, Luby S, Benkovicova M, Siffalovic P, Majkova E. Fe3O4/γ-Fe2O3 nanoparticle multilayers deposited by the Langmuir-Blodgett technique for gas sensors application. Langmuir 2014; 30:1190-1197. [PMID: 24410195 DOI: 10.1021/la404542u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Fe3O4/γ-Fe2O3 nanoparticles (NPs) based thin films were used as active layers in solid state resistive chemical sensors. NPs were synthesized by high temperature solution phase reaction. Sensing NP monolayers (ML) were deposited by Langmuir-Blodgett (LB) techniques onto chemoresistive transduction platforms. The sensing ML were UV treated to remove NP insulating capping. Sensors surface was characterized by scanning electron microscopy (SEM). Systematic gas sensing tests in controlled atmosphere were carried out toward NO2, CO, and acetone at different concentrations and working temperatures of the sensing layers. The best sensing performance results were obtained for sensors with higher NPs coverage (10 ML), mainly for NO2 gas showing interesting selectivity toward nitrogen oxides. Electrical properties and conduction mechanisms are discussed.
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Affiliation(s)
- S Capone
- Institute of Microelectronics and Microsystems (C.N.R.-I.M.M.), via Monteroni, Campus Ecotekne, 73100 Lecce, Italy
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Bowen A, Agboatwalla M, Luby S, Tobery T, Ayers T, Hoekstra RM. Association between intensive handwashing promotion and child development in Karachi, Pakistan: a cluster randomized controlled trial. ACTA ACUST UNITED AC 2013; 166:1037-44. [PMID: 22986783 DOI: 10.1001/archpediatrics.2012.1181] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To evaluate associations between handwashing promotion and child growth and development. DESIGN Cluster randomized controlled trial. SETTING Informal settlements in Karachi, Pakistan. PARTICIPANTS A total of 461 children who were enrolled in a trial of household-level handwashing promotion in 2003 and were younger than 8 years at reassessment in 2009. INTERVENTIONS In 2003, neighborhoods were randomized to control (n = 9), handwashing promotion (n = 9), or handwashing promotion and drinking water treatment (n = 10); intervention households received free soap and weekly handwashing promotion for 9 months. MAIN OUTCOME MEASURES Anthropometrics and developmental quotients measured with the Battelle Developmental Inventory II at 5 to 7 years of age. RESULTS Overall, 24.9% (95% CI, 20.0%-30.6%) and 22.1% (95% CI, 18.0%-26.8%) of children had z scores that were more than 2 SDs below the expected z scores for height and body mass index for age, respectively; anthropometrics did not differ significantly across study groups. Global developmental quotients averaged 104.4 (95% CI, 101.9-107.0) among intervention children and 98.3 (95% CI, 93.1-103.4) among control children (P = .04). Differences of similar magnitude were measured across adaptive, personal-social, communication, cognitive, and motor domains. CONCLUSIONS Although growth was similar across groups, children randomized to the handwashing promotion during their first 30 months of age attained global developmental quotients 0.4 SDs greater than those of control children at 5 to 7 years of age. These gains are comparable to those of at-risk children enrolled in publicly funded preschools in the United States and suggest that handwashing promotion could improve child well-being and societal productivity. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01538953.
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Affiliation(s)
- Anna Bowen
- Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Roy M, Harris J, Afreen S, Deak E, Gade L, Balajee SA, Park B, Chiller T, Luby S. Aflatoxin contamination in food commodities in Bangladesh. Food Addit Contam Part B Surveill 2012; 6:17-23. [PMID: 24786620 DOI: 10.1080/19393210.2012.720617] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
During September 2009, we performed a rapid cross-sectional study to investigate the extent of aflatoxin contamination among common Bangladeshi foods. We collected eight common human food commodities (rice, lentils, wheat flour, dates, betelnut, red chili powder, ginger and groundnuts) and poultry feed samples from two large markets in each of three cities in Bangladesh. We quantified aflatoxin levels from pooled subsamples using fluorescence high-performance liquid chromatography. Aflatoxin levels were highest in dates and groundnuts (maximum 623 and 423 ng/g), respectively. Samples of betelnut (mean 30.6 ng/g), lentils (mean 21.2 ng/g) and red chili powder (>20 ng/g) also had elevated levels. The mean aflatoxin level among poultry feed samples was 73.0 ng/g. Aflatoxin levels were above the US maximum regulatory levels of 20 ng/g in five of eight commonly ingested human food commodities tested.
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Affiliation(s)
- Monika Roy
- a Centers for Disease Control and Prevention , Mycotic Diseases Branch , Atlanta , GA , USA
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Sultana R, Nahar N, Rimi N, Azad S, Islam MS, Gurley E, Luby S. Backyard poultry raising in Bangladesh: a valued resource for the villagers and a setting for zoonotic transmission of avian influenza. A qualitative study. Rural Remote Health 2012. [DOI: 10.22605/rrh1927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Jergel M, Vegso K, Siffalovic P, Benkovicova M, Kocsis T, Luby S, Majkova E, Nygård K, Konovalov O. In situGISAXS study of a nanoparticle Langmuir film formation for plasmonic applications. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312095402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Vegso K, Siffalovic P, Jergel M, Weis M, Benkovicova M, Majkova E, Luby S, Kocsis T, Capek I. Silver nanoparticle monolayer-to-bilayer transition at the air/water interface as studied by the GISAXS technique: application of a new paracrystal model. Langmuir 2012; 28:9395-9404. [PMID: 22662960 DOI: 10.1021/la301577a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
An original diffraction model for the analysis of grazing-incidence small-angle X-ray scattering (GISAXS) from the nanoparticle Langmuir films was developed. This model relies on the concept of the 2D hexagonal paracrystal and employs the distorted-wave Born approximation that is relevant for GISAXS measurements at the air/water interface when the angle of incidence is close to the critical value. The model comprises the cases of the close-packed nanoparticle monolayer and bilayer with the AB-type layer stacking. In this way, both the lateral (along the interface) and vertical (normal to the interface) correlations of the nanoparticle positions can be analyzed. The model was applied to an in situ GISAXS study of the formation of a silver nanoparticle Langmuir film during compression at the air/water interface in the Langmuir-Blodgett trough. Spherical nanoparticles of 5.8 ± 0.6 nm diameter were employed. Different compression stages starting from the submonolayer up to the monolayer collapse via bilayer formation were analyzed in terms of the mean lateral interparticle distance, degree of paracrystal disorder, interlayer distance, vertical disorder, and layer-stacking type in the bilayer as well as the ratio between the monolayer and bilayer coverage in the final film. The model developed is applicable to any nanoparticle Langmuir film formed at the air/liquid interface to extract structural parameters on the nanoscale. The particular results obtained have direct implications on the preparation of silver plasmonic templates with "hot spots" for surface-enhanced Raman scattering.
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Affiliation(s)
- K Vegso
- Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 84511 Bratislava, Slovakia.
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Luoto J, Mahmud M, Albert J, Luby S, Najnin N, Unicomb L, Levine DI. Learning to dislike safe water products: results from a randomized controlled trial of the effects of direct and peer experience on willingness to pay. Environ Sci Technol 2012; 46:6244-6251. [PMID: 22563851 DOI: 10.1021/es2027967] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Low-cost point-of-use (POU) safe water products have the potential to reduce waterborne illness, but adoption by the global poor remains low. We performed an eight-month randomized trial of four low-cost household water treatment products in Dhaka, Bangladesh. Intervention households (n = 600) received repeated educational messages about the importance of drinking safe water along with consecutive two-month free trials with each of four POU products in random order. Households randomly assigned to the control group (n = 200) did not receive free products or repeated educational messages. Households' willingness to pay for these products was quite low on average (as measured by bids in an incentive-compatible real-money auction), although a modest share was willing to pay the actual or expected retail price for low-cost chlorine-based products. Furthermore, contrary to our hypotheses that both one's own personal experience and the influence of one's peers would increase consumers' willingness to pay, direct experience significantly decreased mean bids by 18-55% for three of the four products and had no discernible effect on the fourth. Neighbor experience also did not increase bids. Widespread dissemination of safe water products is unlikely until we better understand the preferences and aspirations of these at-risk populations.
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Affiliation(s)
- Jill Luoto
- RAND, Santa Monica, California, United States.
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Vegso K, Siffalovic P, Benkovicova M, Jergel M, Luby S, Majkova E, Capek I, Kocsis T, Perlich J, Roth SV. GISAXS analysis of 3D nanoparticle assemblies--effect of vertical nanoparticle ordering. Nanotechnology 2012; 23:045704. [PMID: 22222583 DOI: 10.1088/0957-4484/23/4/045704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report on grazing-incidence small-angle x-ray scattering (GISAXS) study of 3D nanoparticle arrays prepared by two different methods from colloidal solutions-layer-by-layer Langmuir-Schaefer deposition and spontaneous self-assembling during the solvent evaporation. GISAXS results are evaluated within the distorted wave Born approximation (DWBA) considering the multiple scattering effects and employing a simplified multilayer model to reduce the computing time. In the model, particular layers are represented by nanoparticle chains where the positions of individual nanoparticles are generated following a model of cumulative disorder. The nanoparticle size dispersion is considered as well. Three model cases are distinguished-no shift between the neighboring chains (AA stacking), a shift equal to half of the mean interparticle distance (AB stacking) and random shift between the chains. The first two cases correspond to vertically correlated nanoparticle positions across different chains. A comparison of the experimental GISAXS patterns with the model cases enabled us to distinguish important differences between the 3D arrays prepared by the two methods. In particular, laterally ordered layers without vertical correlation of the nanoparticle positions were found in the nanoparticle multilayers prepared by the Langmuir-Schaefer method. On the other hand, the solvent evaporation under particular conditions produced highly ordered 3D nanoparticle assemblies where both laterally and vertically correlated nanoparticle positions were found.
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Affiliation(s)
- K Vegso
- Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia.
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Halahovets Y, Siffalovic P, Jergel M, Senderak R, Majkova E, Luby S, Kostic I, Szymanski B, Stobiecki F. Scanning magneto-optical Kerr microscope with auto-balanced detection scheme. Rev Sci Instrum 2011; 82:083706. [PMID: 21895250 DOI: 10.1063/1.3625687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have developed a scanning magneto-optical Kerr microscope dedicated to localization and measurement of the in-plane magnetization of ultra-thin layered magnetic nanostructures with high sensitivity and signal-to-noise ratio. The novel light detection scheme is based on a differential photodetector with automatic common mode noise rejection system with a high noise suppression up to 50 dB. The sensitivity of the developed detection scheme was tested by measurement of a single Co layer and a giant magnetoresistance (GMR) multilayer stack. The spatial resolution of the Kerr microscope was demonstrated by mapping an isolated 5×5 μm spin-valve pillar.
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Affiliation(s)
- Y Halahovets
- Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia.
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Abstract
Although promotion of safe hygiene is the single most cost-effective means of preventing infectious disease, investment in hygiene is low both in the health and in the water and sanitation sectors. Evidence shows the benefit of improved hygiene, especially for improved handwashing and safe stool disposal. A growing understanding of what drives hygiene behaviour and creative partnerships are providing fresh approaches to change behaviour. However, some important gaps in our knowledge exist. For example, almost no trials of the effectiveness of interventions to improve food hygiene in developing countries are available. We also need to figure out how best to make safe hygiene practices matters of daily routine that are sustained by social norms on a mass scale. Full and active involvement of the health sector in getting safe hygiene to all homes, schools, and institutions will bring major gains to public health.
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Affiliation(s)
- Val Curtis
- The Hygiene Centre, London School of Hygiene and Tropical Medicine, London, UK.
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Chushkin Y, Chitu L, Luby S, Majkova E, Satka A, Holy V, Ivan J, Giersig M, Hilgendorff M, Metzger TH, Konovalov O. Formation of 2-D and 3-D Arrays of Colloidal Co Magnetic Nanoparticles. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-877-s6.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractOrdering of Co nanoparticles (∼11 nm in diameter) into 2-D and 3-D arrays on Si/Si3N4 substrates in external magnetic field and without field is reported. Arrays of particles were studied by TEM, SEM and GISAXS. The GISAXS measurements were performed at the wavelengths 0.155 nm and 0.336 nm and the spectra were simulated using distorted wave Born approximation approach. From results it follows that 2-D ordered monolayers of particles are composed of hexagonal close-packed mosaic blocks. 3-D arrays – rods are formed along magnetic field direction, being parallel or perpendicular to the substrate surface, when the colloid was more concentrated. Distribution of particles in rods was analyzed only by GISAXS and it was described by close packing of hard spheres. Their effective diameter was 14.7 nm.
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Siffalovic P, Chitu L, Vegso K, Majkova E, Jergel M, Weis M, Luby S, Capek I, Keckes J, Maier GA, Satka A, Perlich J, Roth SV. Towards strain gauges based on a self-assembled nanoparticle monolayer--SAXS study. Nanotechnology 2010; 21:385702. [PMID: 20739738 DOI: 10.1088/0957-4484/21/38/385702] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An in situ small-angle x-ray scattering study of the nanoparticle displacement in a self-assembled monolayer as a function of a supporting membrane strain is presented. The average nanoparticle spacing is 6.7 nm in the unstrained state and increases in the applied force direction, following linearly the membrane strain which reaches the maximum value of 11%. The experimental results suggest a continuous mutual shift of the nanoparticles and their gradual separation with the growing stress rather than nanoparticle islands formation. No measurable shift of the nanoparticles was observed in the direction perpendicular to the applied stress.
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Affiliation(s)
- P Siffalovic
- Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia.
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Kendall EA, LaRocque RC, Bui DM, Galloway R, Ari MD, Goswami D, Breiman RF, Luby S, Brooks WA. Leptospirosis as a cause of fever in urban Bangladesh. Am J Trop Med Hyg 2010; 82:1127-30. [PMID: 20519612 DOI: 10.4269/ajtmh.2010.09-0574] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We tested paired sera from 584 febrile persons in an low-income urban community in Bangladesh for evidence of Leptospira infection. A total of 8.4% of the persons met criteria for definite or probable infection. Persons with leptospirosis were older than those with undifferentiated fever in this population. The dominant infecting serogroups in Bangladesh differed from serogroups commonly reported in nearby regions.
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Affiliation(s)
- Emily A Kendall
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
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Zaman K, Yunus M, Faruque ASG, El Arifeen S, Hossain I, Azim T, Rahman M, Podder G, Roy E, Luby S, Sack DA. Surveillance of rotavirus in a rural diarrhoea treatment centre in Bangladesh, 2000-2006. Vaccine 2010; 27 Suppl 5:F31-4. [PMID: 19931715 DOI: 10.1016/j.vaccine.2009.08.063] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Rotavirus was detected in 33% of 4519 children less than 5 years of age admitted with diarrhoea to treatment centres at Matlab in rural Bangladesh from 2000 to 2006. Highest rotavirus detection rates were in children aged 6-11 months with 56% being less than 1 year old. The peak seasonal detection was in July-September and December-February. The population-based incidence rates of rotavirus ranged from 10.8 to 19.6/1000 children less than 5 years of age. G1 serotype predominated between June 2002-May 2005 and June 2005-May 2006 the predominant type was G2 (41%) followed by G1 (22%) and G9 (22%). Rotavirus is an important cause of childhood diarrhoea in rural Bangladesh and this burden may be reduced with a rotavirus vaccination programme.
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Affiliation(s)
- K Zaman
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Mohakhali, Dhaka 1212, Bangladesh.
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Clasen T, Bartram J, Colford J, Luby S, Quick R, Sobsey M. Comment on "Household water treatment in poor populations: is there enough evidence for scaling up now?". Environ Sci Technol 2009; 43:5542-5546. [PMID: 19708394 DOI: 10.1021/es9008147] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Azmi I, Aslam M, Mondol A, Ahmed D, Luby S, Watanabe H, Endtz H, Cravioto A, Talukder K. P23 Mechanism of fluoroquinolone resistance in Salmonella Typhi. Int J Antimicrob Agents 2009. [DOI: 10.1016/s0924-8579(09)70242-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Zaman K, Sack D, Yunus M, Arifeen S, Podder G, Azim T, Luby S, Breiman R, Neuzil K, Datta S, Delem A, Suryakiran P, Bock H. Successful co-administration of a human rotavirus and oral poliovirus vaccines in Bangladeshi infants in a 2-dose schedule at 12 and 16 weeks of age. Vaccine 2009; 27:1333-9. [DOI: 10.1016/j.vaccine.2008.12.059] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 12/24/2008] [Accepted: 12/28/2008] [Indexed: 11/16/2022]
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