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Wen L, Cui Y, Huang L, Wei C, Wang G, Zhang J, Jiang Y, Wei Y, Shen P. Changes of composition and antibiotic resistance of fecal coliform bacteria in municipal wastewater treatment plant. J Environ Sci (China) 2024; 146:241-250. [PMID: 38969452 DOI: 10.1016/j.jes.2023.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/07/2023] [Accepted: 09/10/2023] [Indexed: 07/07/2024]
Abstract
The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria (FCB) in a typical wastewater treatment plant (WWTP) were investigated concerning the seasonal changes. Results showed that WWTP could remove the FCB concentration by 3∼5 logs within the effluent of 104∼105 CFU/L, but the antibiotic resistant rate of FCB species increased significantly after WWTP. The dominant FCB changed from Escherichia coli in the influent (∼73.0%) to Klebsiella pneumoniae in the effluent (∼53.3%) after WWTP, where the Escherichia coli was removed the most, while Klebsiella pneumoniae was the most persistent. The secondary tank removed the most of FCB (by 3∼4 logs) compared to other processes, but increased all the concerned antibiotic resistant rate. The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP. The FCB showed the highest multiple antibiotic resistance (92.9%) in total which even increased to 100% in the effluent. Klebsiella has the highest antibiotic resistant rate in FCB, with a multiple antibiotic resistance rate of 98.4%. These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.
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Affiliation(s)
- Luoyao Wen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Life Science and Technology, Guangxi University, Nanning 530005, China
| | - Yunwei Cui
- College of Life Science and Technology, Guangxi University, Nanning 530005, China
| | - Luodong Huang
- College of Life Science and Technology, Guangxi University, Nanning 530005, China
| | - Chunzhong Wei
- Nanning Engineering & Technology Research Center for Water Safety, Guangxi Beitou Environmental Protection & Water Group Co., LTD., Nanning 530025, China
| | - Gangan Wang
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany
| | - Junya Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yanbo Jiang
- Nanning Engineering & Technology Research Center for Water Safety, Guangxi Beitou Environmental Protection & Water Group Co., LTD., Nanning 530025, China; International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Yuansong Wei
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peihong Shen
- College of Life Science and Technology, Guangxi University, Nanning 530005, China.
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2
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Ahmmed F, Khanam F, Islam MT, Kim DR, Kang S, Firoj MG, Aziz AB, Hoque M, Liu X, Jeon HJ, Kanungo S, Chowdhury F, Khan AI, Zaman K, Marks F, Kim JH, Qadri F, Clemens JD, Tadesse BT, Im J. Spatial and temporal clustering of typhoid fever in an urban slum of Dhaka City: Implications for targeted typhoid vaccination. PLoS Negl Trop Dis 2024; 18:e0012273. [PMID: 38913735 PMCID: PMC11226105 DOI: 10.1371/journal.pntd.0012273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 07/05/2024] [Accepted: 06/06/2024] [Indexed: 06/26/2024] Open
Abstract
BACKGROUND Salmonella enterica serotype Typhi (Salmonella Typhi) causes severe and occasionally life-threatening disease, transmitted through contaminated food and water. Humans are the only reservoir, inadequate water, sanitation, and hygiene infrastructure increases risk of typhoid. High-quality data to assess spatial and temporal relationships in disease dynamics are scarce. METHODS We analyzed data from a prospective cohort conducted in an urban slum area of Dhaka City, Bangladesh. Passive surveillance at study centers identified typhoid cases by microbiological culture. Each incident case (index case) was matched to two randomly selected index controls, and we measured typhoid incidence in the population residing in a geographically defined region surrounding each case and control. Spatial clustering was evaluated by comparing the typhoid incidence in residents of geometric rings of increasing radii surrounding the index cases and controls over 28 days. Temporal clustering was evaluated by separately measuring incidence in the first and second 14-day periods following selection. Incidence rate ratios (IRRs) were calculated using Poisson regression models. RESULTS We evaluated 141 typhoid index cases. The overall typhoid incidence was 0.44 per 100,000 person-days (PDs) (95% CI: 0.40, 0.49). In the 28 days following selection, the highest typhoid incidence (1.2 per 100,000 PDs [95% CI: 0.8, 1.6]) was in the innermost cluster surrounding index cases. The IRR in this innermost cluster was 4.9 (95% CI: 2.4, 10.3) relative to the innermost control clusters. Neither typhoid incidence rates nor relative IRR between index case and control populations showed substantive differences in the first and second 14-day periods after selection. CONCLUSION In the absence of routine immunization programs, geographic clustering of typhoid cases suggests a higher intensity of typhoid risk in the population immediately surrounding identified cases. Further studies are needed to understand spatial and temporal trends and to evaluate the effectiveness of targeted vaccination in disrupting typhoid transmission.
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Affiliation(s)
- Faisal Ahmmed
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Farhana Khanam
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Md Taufiqul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Deok Ryun Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - Sophie Kang
- International Vaccine Institute, Seoul, Republic of Korea
| | - Md Golam Firoj
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Masuma Hoque
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Xinxue Liu
- Oxford Vaccine Group, Department of Pediatrics, University of Oxford, Oxford, United Kingdom
| | - Hyon Jin Jeon
- International Vaccine Institute, Seoul, Republic of Korea
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Suman Kanungo
- ICMR- National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Fahima Chowdhury
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Ashraful Islam Khan
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Khalequ Zaman
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Madagascar Institute for Vaccine Research, University of Antananarivo, Antananarivo, Madagascar
- Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany
| | - Jerome H. Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - John D. Clemens
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- International Vaccine Institute, Seoul, Republic of Korea
- UCLA Fielding School of Public Health, Los Angeles, California, United States of America
- Vaccine Innovation Center, Korea University School of Medicine, Seoul, Republic of Korea
| | | | - Justin Im
- RIGHT Foundation, Seoul, Republic of Korea
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Kim C, Goucher GR, Tadesse BT, Lee W, Abbas K, Kim JH. Associations of water, sanitation, and hygiene with typhoid fever in case-control studies: a systematic review and meta-analysis. BMC Infect Dis 2023; 23:562. [PMID: 37644449 PMCID: PMC10464135 DOI: 10.1186/s12879-023-08452-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/11/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Water, sanitation, and hygiene (WASH) play a pivotal role in controlling typhoid fever, as it is primarily transmitted through oral-fecal pathways. Given our constrained resources, staying current with the most recent research is crucial. This ensures we remain informed about practical insights regarding effective typhoid fever control strategies across various WASH components. We conducted a systematic review and meta-analysis of case-control studies to estimate the associations of water, sanitation, and hygiene exposures with typhoid fever. METHODS We updated the previous review conducted by Brockett et al. We included new findings published between June 2018 and October 2022 in Web of Science, Embase, and PubMed. We used the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) tool for risk of bias (ROB) assessment. We classified WASH exposures according to the classification provided by the WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation, and Hygiene (JMP) update in 2015. We conducted the meta-analyses by only including studies that did not have a critical ROB in both Bayesian and frequentist random-effects models. RESULTS We identified 8 new studies and analyzed 27 studies in total. Our analyses showed that while the general insights on the protective (or harmful) impact of improved (or unimproved) WASH remain the same, the pooled estimates of OR differed. Pooled estimates of limited hygiene (OR = 2.26, 95% CrI: 1.38 to 3.64), untreated water (OR = 1.96, 95% CrI: 1.28 to 3.27) and surface water (OR = 2.14, 95% CrI: 1.03 to 4.06) showed 3% increase, 18% decrease, and 16% increase, respectively, from the existing estimates. On the other hand, improved WASH reduced the odds of typhoid fever with pooled estimates for improved water source (OR = 0.54, 95% CrI: 0.31 to 1.08), basic hygiene (OR = 0.6, 95% CrI: 0.38 to 0.97) and treated water (OR = 0.54, 95% CrI: 0.36 to 0.8) showing 26% decrease, 15% increase, and 8% decrease, respectively, from the existing estimates. CONCLUSIONS The updated pooled estimates of ORs for the association of WASH with typhoid fever showed clear changes from the existing estimates. Our study affirms that relatively low-cost WASH strategies such as basic hygiene or water treatment can be an effective tool to provide protection against typhoid fever in addition to other resource-intensive ways to improve WASH. TRIAL REGISTRATION PROSPERO 2021 CRD42021271881.
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Affiliation(s)
- Chaelin Kim
- International Vaccine Institute, Seoul, South Korea
| | | | | | - Woojoo Lee
- Graduate School of Public Health, Seoul National University, Seoul, South Korea
| | - Kaja Abbas
- London School of Hygiene & Tropical Medicine, London, UK
| | - Jong-Hoon Kim
- International Vaccine Institute, Seoul, South Korea.
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4
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You S, Huang X, Xing L, Lesperance M, LeBlanc C, Moccia LP, Mercier V, Shao X, Pan Y, Zhang X. Dynamics of fecal coliform bacteria along Canada's coast. MARINE POLLUTION BULLETIN 2023; 189:114712. [PMID: 36827773 DOI: 10.1016/j.marpolbul.2023.114712] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/15/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
The vast coastline provides Canada with a flourishing seafood industry including bivalve shellfish production. To sustain a healthy bivalve molluscan shellfish production, the Canadian Shellfish Sanitation Program was established to monitor the health of shellfish harvesting habitats, and fecal coliform bacteria data have been collected at nearly 15,000 marine sample sites across six coastal provinces in Canada since 1979. We applied Functional Principal Component Analysis and subsequent correlation analyses to find annual variation patterns of bacteria levels at sites in each province. The overall magnitude and the seasonality of fecal contamination were modelled by functional principal component one and two, respectively. The amplitude was related to human and warm-blooded animal activities; the seasonality was strongly correlated with river discharge driven by precipitation and snow melt in British Columbia, but such correlation in provinces along the Atlantic coast could not be properly evaluated due to lack of data during winter.
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Affiliation(s)
- Shuai You
- University of Victoria, 3800 Finnerty Road, Victoria, BC V8W 2Y2, Canada.
| | - Xiaolin Huang
- University of Victoria, 3800 Finnerty Road, Victoria, BC V8W 2Y2, Canada.
| | - Li Xing
- University of Saskatchewan, 105 Administration Place, Saskatoon, Saskatchewan S7N 5A2, Canada.
| | - Mary Lesperance
- University of Victoria, 3800 Finnerty Road, Victoria, BC V8W 2Y2, Canada.
| | - Charles LeBlanc
- Shellfish Water Classification Program - Atlantic Region, Environment and Climate Change Canada, Government of Canada, 443 University Ave., Moncton, NB E1A 3E9, Canada.
| | - L Paul Moccia
- Shellfish Water Classification Program - Pacific Region, Environment and Climate Change Canada, Government of Canada, 2645 Dollarton Highway, Vancouver, BC V7H 1B1, Canada.
| | - Vincent Mercier
- National Coordination, Environment and Climate Change Canada, Government of Canada, 443 University Ave., Moncton, NB E1A 3E9, Canada.
| | - Xiaojian Shao
- Digital Technologies Research Centre, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada.
| | - Youlian Pan
- Digital Technologies Research Centre, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada.
| | - Xuekui Zhang
- University of Victoria, 3800 Finnerty Road, Victoria, BC V8W 2Y2, Canada.
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Hoffman SA, Sikorski MJ, Levine MM. Chronic Salmonella Typhi carriage at sites other than the gallbladder. PLoS Negl Trop Dis 2023; 17:e0011168. [PMID: 36952437 PMCID: PMC10035749 DOI: 10.1371/journal.pntd.0011168] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
Typhoid fever caused by infection with Salmonella enterica subspecies enterica serotype Typhi (S. Typhi), an important public health problem in many low- and middle-income countries, is transmitted by ingestion of water or food contaminated by feces or urine from individuals with acute or chronic S. Typhi infection. Most chronic S. Typhi carriers (shedding for ≥12 months) harbor infection in their gallbladder wherein preexisting pathologies, particularly cholelithiasis, provide an environment that fosters persistence. Much less appreciated is the existence of non-gallbladder hepatobiliary chronic S. Typhi carriers and urinary carriers. The former includes parasitic liver flukes as a chronic carriage risk factor. Chronic urinary carriers typically have pathology of their urinary tract, with or without renal or bladder stones. Even as the prevalence of multidrug-resistant and extensively drug-resistant S. Typhi strains is rising, global implementation of highly effective typhoid vaccines is increasing. There is also renewed interest in identifying, monitoring, and (where possible) treating chronic carriers who comprise the long-term reservoir of S. Typhi.
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Affiliation(s)
- Seth A Hoffman
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Michael J Sikorski
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Myron M Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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Outbreak of Paratyphoid Fever Caused by Contaminated Street-Vended Food at Qingyang Town, China, 2016. Disaster Med Public Health Prep 2022; 17:e205. [PMID: 36537008 DOI: 10.1017/dmp.2022.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In 2016, an outbreak of paratyphoid fever occurred in 40 cases at Qingyang town, in China. A case-control study was carried out to determine the source of this outbreak. Case-control study was conducted to identify the risk factors of this outbreak. The cases were identified as patients with isolation of S. Paratyphi, controls were confirmed cases' healthy classmates, colleagues or neighbors and matched by age (±5 y) and gender. Pulsed-field gel electrophoresis was performed to source tracking. Totally, 40 cases were reported: 24 cases were students, and 20 (20/24) of them were Qingyang High School students. For the case-control study, consuming Chinese egg pancakes was detected as a risk factor (OR1:1 = 5.000; 95% CI: 1.710-14.640), and hand-washing before meals was protective behavior compared with seldom hand-washing (OR1:1 = 23.256; 95% CI: 2.451-200.000). S. Paratyphi was cultured from a well water sample used for washing contents of the pancakes. Isolates from well water and paratyphoid cases showed the same PFGE patterns. Contaminated well water and Chinese egg pancakes were likely source and vehicle of this outbreak. Health education, especially handwashing, and food safety supervision should be promoted particularly in schools.
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7
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Sikorski MJ, Ma J, Hazen TH, Desai SN, Tupua S, Nimarota-Brown S, Sialeipata M, Rambocus S, Ballard SA, Valcanis M, Thomsen RE, Robins-Browne RM, Howden BP, Naseri TK, Levine MM, Rasko DA. Spatial-temporal and phylogenetic analyses of epidemiologic data to help understand the modes of transmission of endemic typhoid fever in Samoa. PLoS Negl Trop Dis 2022; 16:e0010348. [PMID: 36251704 PMCID: PMC9612817 DOI: 10.1371/journal.pntd.0010348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 10/27/2022] [Accepted: 09/15/2022] [Indexed: 11/05/2022] Open
Abstract
Salmonella enterica serovar Typhi (S. Typhi) is either widely distributed or proximally transmitted via fecally-contaminated food or water to cause typhoid fever. In Samoa, where endemic typhoid fever has persisted over decades despite water quality and sanitation improvements, the local patterns of S. Typhi circulation remain unclear. From April 2018-June 2020, epidemiologic data and GPS coordinates were collected during household investigations of 260 acute cases of typhoid fever, and 27 asymptomatic shedders of S. Typhi were detected among household contacts. Spatial and temporal distributions of cases were examined using Average Nearest Neighbor and space-time hotspot analyses. In rural regions, infections occurred in sporadic, focal clusters contrasting with persistent, less clustered cases in the Apia Urban Area. Restrictions to population movement during nationwide lockdowns in 2019-2020 were associated with marked reductions of cases. Phylogenetic analyses of isolates with whole genome sequences (n = 186) revealed one dominant genotype 3.5.4 (n = 181/186) that contains three Samoa-exclusive sub-lineages: 3.5.4.1, 3.5.4.2, and 3.5.4.3. Variables of patient sex, age, and geographic region were examined by phylogenetic groupings, and significant differences (p<0.05) associated genetically-similar isolates in urban areas with working ages (20-49 year olds), and in rural areas with age groups typically at home (<5, 50+). Isolates from asymptomatic shedders were among all three sub-lineages. Whole genome sequencing provided evidence of bacterial genetic similarity, which corroborated 10/12 putative epidemiologic linkages among cases and asymptomatic shedders, as well as 3/3 repeat positives (presumed relapses), with a median of one single nucleotide polymorphism difference. These findings highlight various patterns of typhoid transmission in Samoa that differ between urban and rural regions as well as genomic subtypes. Asymptomatic shedders, detectable only through household investigations, are likely an important reservoir and mobile agent of infection. This study advances a "Samoan S. Typhi framework" that supports current and future typhoid surveillance and control efforts in Samoa.
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Affiliation(s)
- Michael J. Sikorski
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jianguo Ma
- Department of Geographical Sciences, University of Maryland, College Park, Maryland, United States of America
| | - Tracy H. Hazen
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sachin N. Desai
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Siaosi Tupua
- Ministry of Health, Government of Samoa, Apia, Samoa
| | | | | | - Savitra Rambocus
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Susan A. Ballard
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mary Valcanis
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | | | - Roy M. Robins-Browne
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia,Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Benjamin P. Howden
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | | | - Myron M. Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David A. Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America,* E-mail:
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Khaliq A, Yousafzai MT, Haq S, Yaseen R, Qureshi S, Rind F, Padhani ZA, Khan A, Kazi AM, Qamar FN. A review of toolkits and case definitions for detecting enteric fever outbreaks in Asian and African countries from 1965-2019. J Glob Health 2021; 11:04031. [PMID: 34131486 PMCID: PMC8183158 DOI: 10.7189/jogh.11.04031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background This review assessed the case definitions, diagnostic criteria, antimicrobial resistance, and methods used for enteric fever outbreaks and utilization of any unified outbreak score or checklist for early identification and response in Asia and Africa from 1965-2019. Methods We searched enteric fever outbreaks using PubMed, Google Scholar, and the Cochrane library. Studies describing a single outbreak event of enteric fever in Asia and Africa from 1965-2019 were reviewed. We excluded case reports, letter to editors, studies reporting typhoid in conjunction with other diseases, the Centers for Disease Control and Prevention (CDC) trip reports, the World Health Organization (WHO) bulletins report, data from mathematical modeling and simulation studies, reviews and ProMed alert. Also, non-typhoidal salmonella outbreaks were excluded. Results A total of 5063 articles were identified using the key terms and 68 studies were selected for data extraction. Most (48, 71%) outbreaks were from Asian countries, 20 (29%) were reported from Africa. Only 15 studies reported the case definition used for case identification during an outbreak and 8 of those were from Asia. A third (20, 29%) of the studies described antibiotic resistance pattern. 43 (63%) studies contained information regarding the source of the outbreak. Outcomes (hospitalization and deaths) were reported in a quarter of studies. Only 23 (29%) of the studies reported outbreak control strategies while none reported any unified outbreak score or a checklist to identify the outbreak. Conclusion This review highlights the variability in detection and reporting methods for enteric fever outbreaks in Asia and Africa. No standardized case definitions or laboratory methods were reported. Only a few studies reported strategies for outbreak control. There is a need for the development of a unified outbreak score or a checklist to identify and report enteric fever outbreaks globally.
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Affiliation(s)
- Asif Khaliq
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan.,School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Mohammad Tahir Yousafzai
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan.,Kirby Institute, University of New South Wales, Australia
| | - Salman Haq
- Ziauddin Medical College, Ziauddin University Karachi, Pakistan
| | - Rahima Yaseen
- Ziauddin Medical College, Ziauddin University Karachi, Pakistan
| | - Sonia Qureshi
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan
| | - Fahad Rind
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan
| | - Zahra A Padhani
- Institute of Global Health and Development, Aga Khan University Hospital, Karachi
| | - Ayub Khan
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan
| | - Abdul Momin Kazi
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan
| | - Farah Naz Qamar
- Department of Pediatrics and Child Health, The Aga Khan University Hospital, Aga Khan University Karachi, Pakistan
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Andrews JR, Yu AT, Saha S, Shakya J, Aiemjoy K, Horng L, Qamar F, Garrett D, Baker S, Saha S, Luby SP. Environmental Surveillance as a Tool for Identifying High-risk Settings for Typhoid Transmission. Clin Infect Dis 2021; 71:S71-S78. [PMID: 32725227 PMCID: PMC7446943 DOI: 10.1093/cid/ciaa513] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Enteric fever remains a major cause of morbidity in developing countries with poor sanitation conditions that enable fecal contamination of water distribution systems. Historical evidence has shown that contamination of water systems used for household consumption or agriculture are key transmission routes for Salmonella Typhi and Salmonella Paratyphi A. The World Health Organization now recommends that typhoid conjugate vaccines (TCV) be used in settings with high typhoid incidence; consequently, governments face a challenge regarding how to prioritize typhoid against other emerging diseases. A key issue is the lack of typhoid burden data in many low- and middle-income countries where TCV could be deployed. Here we present an argument for utilizing environmental sampling for the surveillance of enteric fever organisms to provide data on community-level typhoid risk. Such an approach could complement traditional blood culture-based surveillance or even replace it in settings where population-based clinical surveillance is not feasible. We review historical studies characterizing the transmission of enteric fever organisms through sewage and water, discuss recent advances in the molecular detection of typhoidal Salmonella in the environment, and outline challenges and knowledge gaps that need to be addressed to establish environmental sampling as a tool for generating actionable data that can inform public health responses to enteric fever.
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Affiliation(s)
- Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Alexander T Yu
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Senjuti Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Jivan Shakya
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Nepal
| | - Kristen Aiemjoy
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Lily Horng
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Farah Qamar
- Department of Pediatrics and Child Health, Aga Khan University Hospital Karachi, Karachi, Pakistan
| | | | - Stephen Baker
- Department of Medicine, Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID) University of Cambridge, Cambridge, United Kingdom
| | - Samir Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
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10
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Matrajt G, Lillis L, Meschke JS. Review of Methods Suitable for Environmental Surveillance of Salmonella Typhi and Paratyphi. Clin Infect Dis 2021; 71:S79-S83. [PMID: 32725228 PMCID: PMC7388719 DOI: 10.1093/cid/ciaa487] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Typhoid fever is an enteric disease caused by the pathogens Salmonella Typhi and Salmonella Paratyphi. Clinical surveillance networks are lacking in many affected areas, thus presenting a need to understand transmission and population prevalence. Environmental surveillance (ES) has been suggested as a potentially effective method in the absence of (or in supplement to) clinical surveillance. This review summarizes methods identified in the literature for sampling and detection of typhoidal Salmonella from environmental samples including drinking water, wastewater, irrigation water, and surface waters. Methods described use a trap or grab sampling approach combined with various selective culture and molecular methods. The level to which the performance of identified methods is characterized for ES in the literature is variable, thus arguing for the optimization and standardization of ES techniques.
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Affiliation(s)
- Graciela Matrajt
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington, USA
| | | | - J Scott Meschke
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington, USA
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11
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Appiah GD, Chung A, Bentsi-Enchill AD, Kim S, Crump JA, Mogasale V, Pellegrino R, Slayton RB, Mintz ED. Typhoid Outbreaks, 1989-2018: Implications for Prevention and Control. Am J Trop Med Hyg 2020; 102:1296-1305. [PMID: 32228795 PMCID: PMC7253085 DOI: 10.4269/ajtmh.19-0624] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Typhoid fever remains an important public health problem in low- and middle-income countries, with large outbreaks reported from Africa and Asia. Although the WHO recommends typhoid vaccination for control of confirmed outbreaks, there are limited data on the epidemiologic characteristics of outbreaks to inform vaccine use in outbreak settings. We conducted a literature review for typhoid outbreaks published since 1990. We found 47 publications describing 45,215 cases in outbreaks occurring in 25 countries from 1989 through 2018. Outbreak characteristics varied considerably by WHO region, with median outbreak size ranging from 12 to 1,101 cases, median duration from 23 to 140 days, and median case fatality ratio from 0% to 1%. The largest number of outbreaks occurred in WHO Southeast Asia, 13 (28%), and African regions, 12 (26%). Among 43 outbreaks reporting a mode of disease transmission, 24 (56%) were waterborne, 17 (40%) were foodborne, and two (5%) were by direct contact transmission. Among the 34 outbreaks with antimicrobial resistance data, 11 (32%) reported Typhi non-susceptible to ciprofloxacin, 16 (47%) reported multidrug-resistant (MDR) strains, and one reported extensively drug-resistant strains. Our review showed a longer median duration of outbreaks caused by MDR strains (148 days versus 34 days for susceptible strains), although this difference was not statistically significant. Control strategies focused on water, sanitation, and food safety, with vaccine use described in only six (13%) outbreaks. As typhoid conjugate vaccines become more widely used, their potential role and impact in outbreak control warrant further evaluation.
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Affiliation(s)
- Grace D Appiah
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Alexandria Chung
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, United Kingdom
| | - Adwoa D Bentsi-Enchill
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Sunkyung Kim
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand.,Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, North Carolina
| | - Vittal Mogasale
- Policy and Economic Research Department, Development and Delivery Unit, International Vaccine Institute, Seoul, South Korea
| | | | - Rachel B Slayton
- Division of Healthcare Quality and Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric D Mintz
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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12
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Brockett S, Wolfe MK, Hamot A, Appiah GD, Mintz ED, Lantagne D. Associations among Water, Sanitation, and Hygiene, and Food Exposures and Typhoid Fever in Case-Control Studies: A Systematic Review and Meta-Analysis. Am J Trop Med Hyg 2020; 103:1020-1031. [PMID: 32700668 DOI: 10.4269/ajtmh.19-0479] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Typhoid fever transmission occurs through ingestion of food or water contaminated with Salmonella Typhi, and case-control studies are often conducted to identify outbreak sources and transmission vehicles. However, there is no current summary of the associations among water, sanitation, and hygiene (WASH); and food exposures and typhoid from case-control studies. We conducted a systematic review and meta-analysis of case-control studies to evaluate the associations among typhoid fever and predicted WASH or food exposure risk factors (13), and protective factors (7). Overall, 19 manuscripts describing 22 case-control studies were included. Two studies were characterized as having low risk of bias, one as medium risk, and 19 as high risk. In total, nine of 13 predicted risk factors were associated with increased odds of typhoid (odds ratio [OR] = 1.4-2.4, I 2 = 30.5-74.8%.), whereas five of seven predicted protective factors were associated with lower odds of typhoid (OR = 0.52-0.73, I 2 = 38.7-84.3%). In five types of sensitivity analyses, two (8%) of 26 summary associations changed significance from the original analysis. Results highlight the following: the importance of household hygiene transmission pathways, the need for further research around appropriate food interventions and the risk of consuming specific foods and beverages outside the home, and the absence of any observed association between sanitation exposures and typhoid fever. We recommend that typhoid interventions focus on interrupting household transmission routes and that future studies provide more detailed information about WASH and food exposures to inform better targeted interventions.
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Affiliation(s)
- Sarah Brockett
- Tufts University School of Medicine, Boston, Massachusetts
| | - Marlene K Wolfe
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California.,Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts
| | - Asa Hamot
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts
| | - Grace D Appiah
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric D Mintz
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Daniele Lantagne
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts
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13
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Abstract
We combine methodology from history and genetics to reconstruct the biosocial history of antimicrobial resistance (AMR) in the bacterium Salmonella enterica serovar Typhi (S. Typhi). We show how evolutionary divergence in S. Typhi was driven by rising global antibiotic use and by the neglect of typhoid outside of high-income countries. Although high-income countries pioneered 1960s precautionary antibiotic regulations to prevent selection for multidrug resistance, new antibiotic classes, typhoid's cultural status as a supposedly ancient disease of "undeveloped" countries, limited international funding, and narrow biosecurity agendas helped fragment effective global collective action for typhoid control. Antibiotic-intensive compensation for weak water and healthcare systems subsequently fueled AMR selection in low- and middle-income countries but often remained invisible due to lacking surveillance capabilities. The recent rise of extensively drug-resistant typhoid bears the biosocial footprint of more than half a century of antibiotic-intensive international neglect.
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Affiliation(s)
- Claas Kirchhelle
- Wellcome Unit for the History of Medicine/Oxford Martin School, University of Oxford, Addenbrooke’s Hospital, United Kingdom
| | - Zoe Anne Dyson
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, United Kingdom
| | - Gordon Dougan
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, United Kingdom
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14
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Environmental Foundations of Typhoid Fever in the Fijian Residential Setting. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16132407. [PMID: 31284613 PMCID: PMC6651141 DOI: 10.3390/ijerph16132407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 11/16/2022]
Abstract
Proximal characteristics and conditions in the residential setting deserve greater attention for their potential to influence typhoid transmission. Using a case-control design in Central Division, Republic of Fiji, we examined bacterial (coliform and Escherichia coli) contamination and chemical composition of water and soil as potential vehicles of exposure to Salmonella Typhi, combining observational analysis of residential living conditions, geospatial analysis of household locations, and factor analysis to explore multivariate associations with the risk of developing typhoid fever. Factors positively associated with typhoid infection related to drainage [phosphate (OR 4.235, p = 0.042) and E. coli concentrations (OR 2.248, p = 0.029) in toilet drainage soil, housing [external condition (OR 3.712, p < 0.001)], drinking water contamination (OR 2.732, p = 0.003) and sanitary condition (OR 1.973, p = 0.031). These five factors explained 42.5% of the cumulative variance and were significant in predicting typhoid infection. Our results support the hypothesis that a combination of spatial and biophysical attributes of the residential setting influence the probability of typhoid transmission; in this study, factors associated with poor drainage, flooding, and sanitary condition increase local exposure to contaminated water and soil, and thereby infection. These findings extend testing of causal assumptions beyond the immediate domestic domain, enhance the scope of traditional case control epidemiology and allow greater specificity of interventions at the scale of the residential setting.
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15
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16
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Abstract
Salmonella enterica subspecies enterica serovar Typhi (Salmonella Typhi) is the cause of typhoid fever and a human host-restricted organism. Our understanding of the global burden of typhoid fever has improved in recent decades, with both an increase in the number and geographic representation of high-quality typhoid fever incidence studies, and greater sophistication of modeling approaches. The 2017 World Health Organization Strategic Advisory Group of Experts on Immunization recommendation for the introduction of typhoid conjugate vaccines for infants and children aged >6 months in typhoid-endemic countries is likely to require further improvements in our understanding of typhoid burden at the global and national levels. Furthermore, the recognition of the critical and synergistic role of water and sanitation improvements in concert with vaccine introduction emphasize the importance of improving our understanding of the sources, patterns, and modes of transmission of Salmonella Typhi in diverse settings.
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Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
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Typhoid fever in Santiago, Chile: Insights from a mathematical model utilizing venerable archived data from a successful disease control program. PLoS Negl Trop Dis 2018; 12:e0006759. [PMID: 30188904 PMCID: PMC6143279 DOI: 10.1371/journal.pntd.0006759] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/18/2018] [Accepted: 08/16/2018] [Indexed: 12/04/2022] Open
Abstract
Typhoid fever is endemic in many developing countries. In the early 20th century, newly industrializing countries including the United States successfully controlled typhoid as water treatment (chlorination/sand filtration) and improved sanitation became widespread. Enigmatically, typhoid remained endemic through the 1980s in Santiago, Chile, despite potable municipal water and widespread household sanitation. Data were collected across multiple stages of endemicity and control in Santiago, offering a unique resource for gaining insight into drivers of transmission in modern settings. We developed an individual-based mathematical model of typhoid transmission, with model components including distinctions between long-cycle and short-cycle transmission routes. Data used to fit the model included the prevalence of chronic carriers, seasonality, longitudinal incidence, and age-specific distributions of typhoid infection and disease. Our model captured the dynamics seen in Santiago across endemicity, vaccination, and environmental control. Both vaccination and diminished exposure to seasonal amplified long-cycle transmission contributed to the observed declines in typhoid incidence, with the vaccine estimated to elicit herd effects. Vaccines are important tools for controlling endemic typhoid, with even limited coverage eliciting herd effects in this setting. Removing the vehicles responsible for amplified long-cycle transmission and assessing the role of chronic carriers in endemic settings are additional key elements in designing programs to achieve accelerated control of endemic typhoid. Typhoid fever was successfully controlled in Santiago, Chile, after a series of interventions including vaccination with a live oral vaccine (Ty21a), and an environmental sanitation improvement, when a ban was put on the irrigation of salad vegetable crops with untreated sewage. Data collected during this period inform seasonality, age distribution and longitudinal trends of disease. We developed an individual-based, mathematical model to both simulate the dynamics of typhoid seen in Santiago, as well as to investigate relative impacts of the vaccine and sanitation interventions. We found that herd immunity resulted from field trials of the Ty21a vaccine and that chronic carriers were a likely driver of sustained transmission at low incidence levels. Modeling typhoid fever in areas that have demonstrated successful control provides insight for control strategies in modern settings.
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Estimating Typhoid Fever Risk Associated with Lack of Access to Safe Water: A Systematic Literature Review. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2018; 2018:9589208. [PMID: 30174699 PMCID: PMC6076975 DOI: 10.1155/2018/9589208] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/28/2018] [Indexed: 11/17/2022]
Abstract
Background Unsafe water is a well-known risk for typhoid fever, but a pooled estimate of the population-level risk of typhoid fever resulting from exposure to unsafe water has not been quantified. An accurate estimation of the risk from unsafe water will be useful in demarcating high-risk populations, modeling typhoid disease burden, and targeting prevention and control activities. Methods We conducted a systematic literature review and meta-analysis of observational studies that measured the risk of typhoid fever associated with drinking unimproved water as per WHO-UNICEF's definition or drinking microbiologically unsafe water. The mean value for the pooled odds ratio from case-control studies was calculated using a random effects model. In addition to unimproved water and unsafe water, we also listed categories of other risk factors from the selected studies. Results The search of published studies from January 1, 1990, to December 31, 2013 in PubMed, Embase, and World Health Organization databases provided 779 publications, of which 12 case-control studies presented the odds of having typhoid fever for those exposed to unimproved or unsafe versus improved drinking water sources. The odds of typhoid fever among those exposed to unimproved or unsafe water ranged from 1.06 to 9.26 with case weighted mean of 2.44 (95% CI: 1.65–3.59). Besides water-related risk, the studies also identified other risk factors related to socioeconomic aspects, type of food consumption, knowledge and awareness about typhoid fever, and hygiene practices. Conclusions In this meta-analysis, we have quantified the pooled risk of typhoid fever among people exposed to unimproved or unsafe water which is almost two and a half times more than people who were not exposed to unimproved or unsafe water. However, caution should be exercised in applying the findings from this study in modeling typhoid fever disease burden at country, regional, and global levels as improved water does not always equate to safe water.
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Environmental Survey of Drinking Water Sources in Kampala, Uganda, during a Typhoid Fever Outbreak. Appl Environ Microbiol 2017; 83:AEM.01706-17. [PMID: 28970225 DOI: 10.1128/aem.01706-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 08/30/2017] [Indexed: 11/20/2022] Open
Abstract
In 2015, a typhoid fever outbreak began in downtown Kampala, Uganda, and spread into adjacent districts. In response, an environmental survey of drinking water source types was conducted in areas of the city with high case numbers. A total of 122 samples was collected from 12 source types and tested for Escherichia coli, free chlorine, and conductivity. An additional 37 grab samples from seven source types and 16 paired large volume (20 liter) samples from wells and springs were also collected and tested for the presence of Salmonella enterica serovar Typhi. Escherichia coli was detected in 60% of kaveras (drinking water sold in plastic bags) and 80% of refilled water bottles; free chlorine was not detected in either source type. Most jerry cans (68%) contained E. coli and had free chlorine residuals below the WHO-recommended level of 0.5 mg/liter during outbreaks. Elevated conductivity readings for kaveras, refilled water bottles, and jerry cans (compared to treated surface water supplied by the water utility) suggested that they likely contained untreated groundwater. All unprotected springs and wells and more than 60% of protected springs contained E. coli Water samples collected from the water utility were found to have acceptable free chlorine levels and no detectable E. coli While S Typhi was not detected in water samples, Salmonella spp. were detected in samples from two unprotected springs, one protected spring, and one refilled water bottle. These data provided clear evidence that unregulated vended water and groundwater represented a risk for typhoid transmission.IMPORTANCE Despite the high incidence of typhoid fever globally, relatively few outbreak investigations incorporate drinking water testing. During waterborne disease outbreaks, measurement of physical-chemical parameters, such as free chlorine residual and electrical conductivity, and of microbiological parameters, such as the presence of E. coli or the implicated etiologic agent, in drinking water samples can identify contaminated sources. This investigation indicated that unregulated vended water and groundwater sources were contaminated and were therefore a risk to consumers during the 2015 typhoid fever outbreak in Kampala. Identification of contaminated drinking water sources and sources that do not contain adequate disinfectant levels can lead to rapid targeted interventions.
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Implementation of DMAs in Intermittent Water Supply Networks Based on Equity Criteria. WATER 2017. [DOI: 10.3390/w9110851] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Ahsan MS, Akber MA, Islam MA, Kabir MP, Hoque MI. Monitoring bacterial contamination of piped water supply in rural coastal Bangladesh. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:597. [PMID: 29086037 DOI: 10.1007/s10661-017-6316-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
Safe drinking water is scarce in southwest coastal Bangladesh because of unavailability of fresh water. Given the high salinity of both groundwater and surface water in this area, harvested rainwater and rain-fed pond water became the main sources of drinking water. Both the government and non-government organizations have recently introduced pipe water supply in the rural coastal areas to ensure safe drinking water. We assessed the bacteriological quality of water at different points along the piped water distribution system (i.e., the source, treatment plant, household taps, street hydrants, and household storage containers) of Mongla municipality under Mongla Upazila in Bagerhat district. Water samples were collected at 2-month interval from May 2014 to March 2015. Median E. coli and total coliform counts at source, treatment plant, household taps, street hydrants, and household storage containers were respectively 225, 4, 7, 7, and 15 cfu/100 ml and 42,000, 545, 5000, 6150, and 18,800 cfu/100 ml. Concentrations of both of the indicator bacteria reduced after treatment, although it did not satisfy the WHO drinking water standards. However, re-contamination in distribution systems and household storage containers indicate improper maintenance of distribution system and lack of personal hygiene.
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Affiliation(s)
- Md Sabbir Ahsan
- Environmental Science Discipline, Khulna University, Khulna, Bangladesh
| | - Md Ali Akber
- Environmental Science Discipline, Khulna University, Khulna, Bangladesh
| | - Md Atikul Islam
- Environmental Science Discipline, Khulna University, Khulna, Bangladesh.
| | - Md Pervez Kabir
- Environmental Science Discipline, Khulna University, Khulna, Bangladesh
| | - Md Ikramul Hoque
- Department of Building Engineering and Construction Management, Khulna University of Engineering and Technology, Khulna, Bangladesh
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A cross-sectional seroepidemiological survey of typhoid fever in Fiji. PLoS Negl Trop Dis 2017; 11:e0005786. [PMID: 28727726 PMCID: PMC5549756 DOI: 10.1371/journal.pntd.0005786] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 08/08/2017] [Accepted: 07/06/2017] [Indexed: 12/26/2022] Open
Abstract
Fiji, an upper-middle income state in the Pacific Ocean, has experienced an increase in confirmed case notifications of enteric fever caused by Salmonella enterica serovar Typhi (S. Typhi). To characterize the epidemiology of typhoid exposure, we conducted a cross-sectional sero-epidemiological survey measuring IgG against the Vi antigen of S. Typhi to estimate the effect of age, ethnicity, and other variables on seroprevalence. Epidemiologically relevant cut-off titres were established using a mixed model analysis of data from recovering culture-confirmed typhoid cases. We enrolled and assayed plasma of 1787 participants for anti-Vi IgG; 1,531 of these were resident in mainland areas that had not been previously vaccinated against S. Typhi (seropositivity 32.3% (95%CI 28.2 to 36.3%)), 256 were resident on Taveuni island, which had been previously vaccinated (seropositivity 71.5% (95%CI 62.1 to 80.9%)). The seroprevalence on the Fijian mainland is one to two orders of magnitude higher than expected from confirmed case surveillance incidence, suggesting substantial subclinical or otherwise unreported typhoid. We found no significant differences in seropositivity prevalences by ethnicity, which is in contrast to disease surveillance data in which the indigenous iTaukei Fijian population are disproportionately affected. Using multivariable logistic regression, seropositivity was associated with increased age (odds ratio 1.3 (95% CI 1.2 to 1.4) per 10 years), the presence of a pit latrine (OR 1.6, 95%CI 1.1 to 2.3) as opposed to a septic tank or piped sewer, and residence in settlements rather than residential housing or villages (OR 1.6, 95% CI 1.0 to 2.7). Increasing seropositivity with age is suggestive of low-level endemic transmission in Fiji. Improved sanitation where pit latrines are used and addressing potential transmission routes in settlements may reduce exposure to S. Typhi. Widespread unreported infection suggests there may be a role for typhoid vaccination in Fiji, in addition to public health management of cases and outbreaks. Fiji has experienced a decade-long increase in typhoid fever cases, a potentially life-threatening systemic bacterial disease caused by Salmonella Typhi. We undertook a representative blood-serum community survey to measure antibodies (IgG) against the Vi antigen of Salmonella Typhi using a rigorous survey design. We found one in three residents of mainland, unvaccinated Fiji had detectable antibody against Vi. This was higher than would be expected from confirmed case notifications received by the national surveillance system. Additionally, similar antibody responses were detected in Fijians of all ethnicities, which contrasts to surveillance cases in which indigenous iTaukei Fijians were disproportionately affected. Serology on a Fijian island where a significant proportion of the population has been vaccinated found that three-quarters of residents were seropositive three years after the Vi-polysaccharide typhoid vaccination campaign. Importantly, in mainland participants, seroprevalence increased with age, suggesting long-standing, low-level, endemic transmission. Pit latrines were associated with seropositivity when compared with septic tanks, and settlements compared with residential housing. Very high antibody titres in a small percentage of participants may suggest carriage of Salmonella Typhi. The seroprevalence findings suggest eliminating typhoid from Fiji by focussing on cases and outbreaks alone will be challenging. Our results support typhoid vaccination and further development of water, sanitation and hygiene infrastructure in Fiji.
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Subramanian VS, Cho MJ, Tan SZ, Fayzieva D, Sebaly C. Spatial Distribution and Trends of Waterborne Diseases in Tashkent Province. Cent Asian J Glob Health 2017; 6:277. [PMID: 29138738 DOI: 10.5195/cajgh.2017.277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Introduction The cumulative effect of limited investment in public water systems, inadequate public health infrastructure, and gaps in infectious disease prevention increased the incidence of waterborne diseases in Uzbekistan. The objectives of this study were: (1) to spatially analyze the distribution of the diseases in Tashkent Province, (2) to identify the intensity of spatial trends in the province, (3) to identify urban-rural characteristics of the disease distribution, and (4) to identify the differences in disease incidence between pediatric and adult populations of the province. Methods Data on four major waterborne diseases and socio-demographics factors were collected in Tashkent Province from 2011 to 2014. Descriptive epidemiological methods and spatial-temporal methods were used to investigate the distribution and trends, and to identify waterborne diseases hotspots and vulnerable population groups in the province. Results Hepatitis A and enterobiasis had a high incidence in most of Tashkent Province, with higher incidences in the eastern and western districts. Residents of rural areas, including children, were found to be more vulnerable to the waterborne diseases compared to other populations living in the province. Conclusions This pilot study calls for more scientific investigations of waterborne diseases and their effect on public health in the region, which could facilitate targeted public health interventions in vulnerable regions of Uzbekistan.
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Affiliation(s)
| | - Min Jung Cho
- Department of political and cultural change, Center for Development Research, University of Bonn, Germany
| | - Siwei Zoe Tan
- Department of political and cultural change, Center for Development Research, University of Bonn, Germany
| | - Dilorom Fayzieva
- Research Institute of Irrigation and Water Problems, Tashkent, Uzbekistan
| | - Christian Sebaly
- Department of political and cultural change, Center for Development Research, University of Bonn, Germany
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Bivins AW, Sumner T, Kumpel E, Howard G, Cumming O, Ross I, Nelson K, Brown J. Estimating Infection Risks and the Global Burden of Diarrheal Disease Attributable to Intermittent Water Supply Using QMRA. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7542-7551. [PMID: 28582618 DOI: 10.1021/acs.est.7b01014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Intermittent water supply (IWS) is prevalent throughout low and middle-income countries. IWS is associated with increased microbial contamination and potentially elevated risk of waterborne illness. We used existing data sets to estimate the population exposed to IWS, assess the probability of infection using quantitative microbial risk assessment, and calculate the subsequent burden of diarrheal disease attributable to consuming fecally contaminated tap water from an IWS. We used reference pathogens Campylobacter, Cryptosporidium, and rotavirus as conservative risk proxies for infections via bacteria, protozoa, and viruses, respectively. Results indicate that the median daily risk of infection is an estimated 1 in 23 500 for Campylobacter, 1 in 5 050 000 for Cryptosporidium, and 1 in 118 000 for rotavirus. Based on these risks, IWS may account for 17.2 million infections causing 4.52 million cases of diarrhea, 109 000 diarrheal DALYs, and 1560 deaths each year. The burden of diarrheal disease associated with IWS likely exceeds the WHO health-based normative guideline for drinking water of 10-6 DALYs per person per year. Our results underscore the importance water safety management in water supplies and the potential benefits of point-of-use treatment to mitigate risks.
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Affiliation(s)
- Aaron W Bivins
- School of Civil & Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Trent Sumner
- School of Civil & Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Emily Kumpel
- Civil & Environmental Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Guy Howard
- Department for International Development, London, U.K
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene and Tropical Medicine , London, U.K
| | - Ian Ross
- Oxford Policy Management, Oxford, U.K
| | - Kara Nelson
- Civil & Environmental Engineering, University of California Berkeley , Berkeley, California 94720, United States
| | - Joe Brown
- School of Civil & Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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Celik I, Tamimi LMA, Al-Khatib IA, Apul DS. Management of rainwater harvesting and its impact on the health of people in the Middle East: case study from Yatta town, Palestine. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:271. [PMID: 28512715 DOI: 10.1007/s10661-017-5970-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 04/21/2017] [Indexed: 06/07/2023]
Abstract
Water-related diseases are a primary problem in Palestine where many residents revert to harvested rainwater as their primary water source due to water shortages within the area. From an environmental engineering perspective, it is already well known that certain situations (e.g., cross contamination) reduce drinking water quality and ultimately cause diseases in a population. In this study, we investigated the social practices and situations that may lead to lower disease occurrence. Towards this goal, we surveyed 382 residents in Yatta to collect data on the water-related diseases that they experienced and the specific situations that might affect the disease occurrences such as the residents' practices (i) for maintaining a high quality of cistern water, (ii) for maintaining the environment around the cistern, and (iii) for managing the wastewater. In addition, we measured the physicochemical and microbiological parameters in cisterns to support the qualitative survey data. The measured parameters, including turbidity, salinity, free available chlorine, total Coliforms, and fecal Coliforms, were above Palestinian Standard Institution (PSI) and World Health Organization (WHO) guideline levels, suggesting a potential infectious hazard. The poor quality of the water was also observed by residents based on change in taste and by visually noting floating impurities, turbidity, and green coloration. Survey results showed that observations of the poor quality in cisterns and surrounding environment had statistically significant correlation with most of the water-related diseases. Additionally, frequently emptying the septic tank contributes to improving the observed water qualities. Therefore, residents should be encouraged to continue to observe the water quality in the cistern, improve the surrounding environment of cistern, and empty their septic tank frequently, to keep the water diseases away from their households.
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Affiliation(s)
- Ilke Celik
- Department of Civil Engineering, University of Toledo, 2801W. Bancroft St., MS 307, Toledo, OH, 43606, USA
| | - Lina M A Tamimi
- Faculty of Graduate Studies, Birzeit University, Birzeit, West Bank, Palestine
| | - Issam A Al-Khatib
- Institute of Environmental and Water Studies, Birzeit University, Birzeit, West Bank, Palestine.
| | - Defne S Apul
- Department of Civil Engineering, University of Toledo, 2801W. Bancroft St., MS 307, Toledo, OH, 43606, USA
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Antillón M, Warren JL, Crawford FW, Weinberger DM, Kürüm E, Pak GD, Marks F, Pitzer VE. The burden of typhoid fever in low- and middle-income countries: A meta-regression approach. PLoS Negl Trop Dis 2017; 11:e0005376. [PMID: 28241011 PMCID: PMC5344533 DOI: 10.1371/journal.pntd.0005376] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/09/2017] [Accepted: 01/31/2017] [Indexed: 11/26/2022] Open
Abstract
Background Upcoming vaccination efforts against typhoid fever require an assessment of the baseline burden of disease in countries at risk. There are no typhoid incidence data from most low- and middle-income countries (LMICs), so model-based estimates offer insights for decision-makers in the absence of readily available data. Methods We developed a mixed-effects model fit to data from 32 population-based studies of typhoid incidence in 22 locations in 14 countries. We tested the contribution of economic and environmental indices for predicting typhoid incidence using a stochastic search variable selection algorithm. We performed out-of-sample validation to assess the predictive performance of the model. Results We estimated that 17.8 million cases of typhoid fever occur each year in LMICs (95% credible interval: 6.9–48.4 million). Central Africa was predicted to experience the highest incidence of typhoid, followed by select countries in Central, South, and Southeast Asia. Incidence typically peaked in the 2–4 year old age group. Models incorporating widely available economic and environmental indicators were found to describe incidence better than null models. Conclusions Recent estimates of typhoid burden may under-estimate the number of cases and magnitude of uncertainty in typhoid incidence. Our analysis permits prediction of overall as well as age-specific incidence of typhoid fever in LMICs, and incorporates uncertainty around the model structure and estimates of the predictors. Future studies are needed to further validate and refine model predictions and better understand year-to-year variation in cases. Typhoid fever is a bacterial enteric infection that continues to pose a considerable burden to the 5.5 billion people living in low- and middle-income countries (LMICs). We developed and validated a model incorporating widely available indicators of economic and social development and the environment to estimate the burden of typhoid fever across LMICs. Our analysis uses all available data to estimate the incidence of typhoid in key age groups, which is important for the design and implementation of optimal vaccination strategies, and it identifies regions of the world that have the most uncertainty in typhoid incidence. Across all LMICs, we estimated that the expected number of typhoid fever cases per year is 17.8 million (95% CI: 6.9–48.4 million). We also present the probability that incidence surpasses the criteria for low, medium, high, and very high incidence in each country, which could help guide policy in the face of uncertainty.
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Affiliation(s)
- Marina Antillón
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- * E-mail:
| | - Joshua L. Warren
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Forrest W. Crawford
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Daniel M. Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Esra Kürüm
- Department of Statistics, University of California Riverside, Riverside, California, United States of America
| | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
| | - Virginia E. Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
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Abraham MR, Susan TB. Water contamination with heavy metals and trace elements from Kilembe copper mine and tailing sites in Western Uganda; implications for domestic water quality. CHEMOSPHERE 2017; 169:281-287. [PMID: 27883913 DOI: 10.1016/j.chemosphere.2016.11.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 11/01/2016] [Accepted: 11/15/2016] [Indexed: 05/19/2023]
Abstract
The mining and processing of copper in Kilembe, Western Uganda, from 1956 to 1982 left over 15 Mt of cupriferous and cobaltiferous pyrite dumped within a mountain river valley, in addition to mine water which is pumped to the land surface. This study was conducted to assess the sources and concentrations of heavy metals and trace elements in Kilembe mine catchment water. Multi-element analysis of trace elements from point sources and sinks was conducted which included mine tailings, mine water, mine leachate, Nyamwamba River water, public water sources and domestic water samples using ICP-MS. The study found that mean concentrations (mg kg-1) of Co (112), Cu (3320), Ni (131), As (8.6) in mine tailings were significantly higher than world average crust and were being eroded and discharged into water bodies within the catchment. Underground mine water and leachate contained higher mean concentrations (μg L-1) of Cu (9470), Co (3430) and Ni (590) compared with background concentrations (μg L-1) in un contaminated water of 1.9, 0.21 and 0.67 for Cu, Co and Ni respectively. Over 25% of household water samples exceeded UK drinking water thresholds for Al of 200 μg L-1, Co exceeded Winsconsin (USA drinking) water thresholds of 40 μg L-1 in 40% of samples while Fe in 42% of samples exceeded UK thresholds of 200 μg L-1. The study however found that besides mining activities, natural processes of geological weathering also contributed to Al, Fe, and Mn water contamination in a number of public water sources.
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Affiliation(s)
- Mwesigye R Abraham
- School of Forestry, Environment and Geographical Sciences, Makerere University Uganda, P.O. Box 7062, Kampala, Uganda.
| | - Tumwebaze B Susan
- School of Forestry, Environment and Geographical Sciences, Makerere University Uganda, P.O. Box 7062, Kampala, Uganda
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Kabwama SN, Bulage L, Nsubuga F, Pande G, Oguttu DW, Mafigiri R, Kihembo C, Kwesiga B, Masiira B, Okullo AE, Kajumbula H, Matovu JKB, Makumbi I, Wetaka M, Kasozi S, Kyazze S, Dahlke M, Hughes P, Sendagala JN, Musenero M, Nabukenya I, Hill VR, Mintz E, Routh J, Gómez G, Bicknese A, Zhu BP. A large and persistent outbreak of typhoid fever caused by consuming contaminated water and street-vended beverages: Kampala, Uganda, January - June 2015. BMC Public Health 2017; 17:23. [PMID: 28056940 PMCID: PMC5216563 DOI: 10.1186/s12889-016-4002-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 12/23/2016] [Indexed: 11/15/2022] Open
Abstract
Background On 6 February 2015, Kampala city authorities alerted the Ugandan Ministry of Health of a “strange disease” that killed one person and sickened dozens. We conducted an epidemiologic investigation to identify the nature of the disease, mode of transmission, and risk factors to inform timely and effective control measures. Methods We defined a suspected case as onset of fever (≥37.5 °C) for more than 3 days with abdominal pain, headache, negative malaria test or failed anti-malaria treatment, and at least 2 of the following: diarrhea, nausea or vomiting, constipation, fatigue. A probable case was defined as a suspected case with a positive TUBEX® TF test. A confirmed case had blood culture yielding Salmonella Typhi. We conducted a case-control study to compare exposures of 33 suspected case-patients and 78 controls, and tested water and juice samples. Results From 17 February–12 June, we identified 10,230 suspected, 1038 probable, and 51 confirmed cases. Approximately 22.58% (7/31) of case-patients and 2.56% (2/78) of controls drank water sold in small plastic bags (ORM-H = 8.90; 95%CI = 1.60–49.00); 54.54% (18/33) of case-patients and 19.23% (15/78) of controls consumed locally-made drinks (ORM-H = 4.60; 95%CI: 1.90–11.00). All isolates were susceptible to ciprofloxacin and ceftriaxone. Water and juice samples exhibited evidence of fecal contamination. Conclusion Contaminated water and street-vended beverages were likely vehicles of this outbreak. At our recommendation authorities closed unsafe water sources and supplied safe water to affected areas. Electronic supplementary material The online version of this article (doi:10.1186/s12889-016-4002-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Steven Ndugwa Kabwama
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda.
| | - Lilian Bulage
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Fred Nsubuga
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Gerald Pande
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - David Were Oguttu
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Richardson Mafigiri
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Christine Kihembo
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Benon Kwesiga
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Ben Masiira
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Allen Eva Okullo
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Henry Kajumbula
- Makerere University College of Health Science Microbiology Laboratory, Kampala, Uganda
| | | | - Issa Makumbi
- Public Health Emergency Operations Center, Ministry of Health, Kampala, Uganda
| | - Milton Wetaka
- Public Health Emergency Operations Center, Ministry of Health, Kampala, Uganda
| | - Sam Kasozi
- Public Health Emergency Operations Center, Ministry of Health, Kampala, Uganda
| | - Simon Kyazze
- Public Health Emergency Operations Center, Ministry of Health, Kampala, Uganda
| | - Melissa Dahlke
- Public Health Emergency Operations Center, Ministry of Health, Kampala, Uganda
| | | | | | - Monica Musenero
- Epidemiology and Surveillance Division, Ministry of Health, Kampala, Uganda
| | | | - Vincent R Hill
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Eric Mintz
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Janell Routh
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Gerardo Gómez
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Amelia Bicknese
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Bao-Ping Zhu
- US Centers for Disease Control and Prevention, Atlanta, Georgia, USA.,US Centers for Disease Control and Prevention, Kampala, Uganda
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Jenkins AP, Jupiter S, Mueller U, Jenney A, Vosaki G, Rosa V, Naucukidi A, Mulholland K, Strugnell R, Kama M, Horwitz P. Health at the Sub-catchment Scale: Typhoid and Its Environmental Determinants in Central Division, Fiji. ECOHEALTH 2016; 13:633-651. [PMID: 27557784 DOI: 10.1007/s10393-016-1152-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/11/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
The impact of environmental change on transmission patterns of waterborne enteric diseases is a major public health concern. This study concerns the burden and spatial nature of enteric fever, attributable to Salmonella Typhi infection in the Central Division, Republic of Fiji at a sub-catchment scale over 30-months (2013-2015). Quantitative spatial analysis suggested relationships between environmental conditions of sub-catchments and incidence and recurrence of typhoid fever. Average incidence per inhabited sub-catchment for the Central Division was high at 205.9/100,000, with cases recurring in each calendar year in 26% of sub-catchments. Although the numbers of cases were highest within dense, urban coastal sub-catchments, the incidence was highest in low-density mountainous rural areas. Significant environmental determinants at this scale suggest increased risk of exposure where sediment yields increase following runoff. The study suggests that populations living on large systems that broaden into meandering mid-reaches and floodplains with alluvial deposition are at a greater risk compared to small populations living near small, erosional, high-energy headwaters and small streams unconnected to large hydrological networks. This study suggests that anthropogenic alteration of land cover and hydrology (particularly via fragmentation of riparian forest and connectivity between road and river networks) facilitates increased transmission of typhoid fever and that environmental transmission of typhoid fever is important in Fiji.
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Affiliation(s)
- Aaron Peter Jenkins
- Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
| | | | - Ute Mueller
- Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
| | - Adam Jenney
- Fiji National University, Suva, Fiji
- Murdoch Childrens Research Institute, Parkville, Australia
| | | | | | | | - Kim Mulholland
- Murdoch Childrens Research Institute, Parkville, Australia
- London School of Hygiene and Tropical Medicine, London, England
| | | | - Mike Kama
- Fiji Ministry of Health and Medical Services, Suva, Fiji
| | - Pierre Horwitz
- Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
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Abstract
INTRODUCTION Typhoid fever (TF), caused by Salmonella enterica serovar Typhi, is the most common cause of enteric fever, responsible for an estimated 129,000 deaths and more than 11 million cases annually. Although several reviews have provided global and regional TF disease burden estimates, major gaps in our understanding of TF epidemiology remain. Areas covered: We provide an overview of the gaps in current estimates of TF disease burden and offer suggestions for addressing them, so that affected communities can receive the full potential of disease prevention offered by vaccination and water, sanitation, and hygiene interventions. Expert commentary: Current disease burden estimates for TF do not capture cases from certain host populations, nor those with atypical presentations of TF, which may lead to substantial underestimation of TF cases and deaths. These knowledge gaps pose major obstacles to the informed use of current and new generation typhoid vaccines.
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Affiliation(s)
- Stephen K Obaro
- a Department of Pediatrics , University of Nebraska Medical Center , Omaha , NE , USA
| | - Pui-Ying Iroh Tam
- b Department of Pediatrics , University of Minnesota Masonic Children's Hospital , Minneapolis , MN , USA
| | - Eric Daniel Mintz
- c Division of Foodborne, Waterborne and Environmental Diseases , Centers for Disease Control and Prevention , Atlanta , GA , USA
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Intermittent Domestic Water Supply: A Critical Review and Analysis of Causal-Consequential Pathways. WATER 2016. [DOI: 10.3390/w8070274] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Network Capacity Assessment and Increase in Systems with Intermittent Water Supply. WATER 2016. [DOI: 10.3390/w8040126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kumpel E, Nelson KL. Intermittent Water Supply: Prevalence, Practice, and Microbial Water Quality. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:542-553. [PMID: 26670120 DOI: 10.1021/acs.est.5b03973] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Intermittent water supplies (IWS), in which water is provided through pipes for only limited durations, serve at least 300 million people around the world. However, providing water intermittently can compromise water quality in the distribution system. In IWS systems, the pipes do not supply water for periods of time, supply periods are shortened, and pipes experience regular flow restarting and draining. These unique behaviors affect distribution system water quality in ways that are different than during normal operations in continuous water supplies (CWS). A better understanding of the influence of IWS on mechanisms causing contamination can help lead to incremental steps that protect water quality and minimize health risks. This review examines the status and nature of IWS practices throughout the world, the evidence of the effect of IWS on water quality, and how the typical contexts in which IWS systems often exist-low-income countries with under-resourced utilities and inadequate sanitation infrastructure-can exacerbate mechanisms causing contamination. We then highlight knowledge gaps for further research to improve our understanding of water quality in IWS.
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Affiliation(s)
- Emily Kumpel
- Civil and Environmental Engineering, University of California , Berkeley, California 94720, United States
- The Aquaya Institute, Nairobi, Kenya
| | - Kara L Nelson
- Civil and Environmental Engineering, University of California , Berkeley, California 94720, United States
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Karkey A, Jombart T, Walker AW, Thompson CN, Torres A, Dongol S, Tran Vu Thieu N, Pham Thanh D, Tran Thi Ngoc D, Voong Vinh P, Singer AC, Parkhill J, Thwaites G, Basnyat B, Ferguson N, Baker S. The Ecological Dynamics of Fecal Contamination and Salmonella Typhi and Salmonella Paratyphi A in Municipal Kathmandu Drinking Water. PLoS Negl Trop Dis 2016; 10:e0004346. [PMID: 26735696 PMCID: PMC4703202 DOI: 10.1371/journal.pntd.0004346] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/09/2015] [Indexed: 11/20/2022] Open
Abstract
One of the UN sustainable development goals is to achieve universal access to safe and affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming to understand the public health implications of water quality in Kathmandu we subjected weekly water samples from 10 sources for one year to a range of chemical and bacteriological analyses. We additionally aimed to detect the etiological agents of typhoid fever and longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the majority of water sources exhibited chemical and bacterial contamination exceeding WHO guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution, symptomatic of highly localized fecal contamination. Rainfall was found to be a key driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S. Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples, respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the contaminated water, forming complex communities again displaying location-specific temporal signatures. Our data signify that the municipal water in Kathmandu is a predominant vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality in the Kathmandu Valley. Aiming to understand the ecology of municipal drinking water and measure the potential exposure to pathogens that cause typhoid fever (Salmonella Typhi and Salmonella Paratyphi A) in Kathmandu, Nepal, we collected water samples from 10 water sources weekly for one year and subjected them to comprehensive chemical, bacteriological and molecular analyses. We found that Kathmandu drinking water exhibits longitudinal fecal contamination in excess of WHO guidelines. The chemical composition of water indicated site-specific pollution profiles, which were likely driven by localized contamination with human fecal material. We additionally found that Salmonella Typhi and Salmonella Paratyphi A could be detected throughout the year in every water sampling location, but specifically peaked after the monsoons. A microbiota analysis (a method for studying bacterial diversity in biological samples) revealed the water to be contaminated by complex populations of fecal bacteria, which again exhibited a unique profile by both location and time. This study shows that Salmonella Typhi and Salmonella Paratyphi A can be longitudinally detected in drinking water in Kathmandu and represents the first major investigation of the spatiotemporal dynamics of drinking water pollution in an endemic typhoid setting.
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Affiliation(s)
- Abhilasha Karkey
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Thibaut Jombart
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Alan W. Walker
- The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
- Microbiology Group, The Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Corinne N. Thompson
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
| | - Andres Torres
- Grupo de Investigación Ciencia e Ingeniería del Agua y el Ambiente, Facultad de Ingeniería, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Nga Tran Vu Thieu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Duy Pham Thanh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Dung Tran Thi Ngoc
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Phat Voong Vinh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Andrew C. Singer
- NERC Centre for Ecology and Hydrology, Wallingford, Oxfordshire, United Kingdom
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Guy Thwaites
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
| | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Neil Ferguson
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
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Akullian A, Ng’eno E, Matheson AI, Cosmas L, Macharia D, Fields B, Bigogo G, Mugoh M, John-Stewart G, Walson JL, Wakefield J, Montgomery JM. Environmental Transmission of Typhoid Fever in an Urban Slum. PLoS Negl Trop Dis 2015; 9:e0004212. [PMID: 26633656 PMCID: PMC4669139 DOI: 10.1371/journal.pntd.0004212] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/14/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Enteric fever due to Salmonella Typhi (typhoid fever) occurs in urban areas with poor sanitation. While direct fecal-oral transmission is thought to be the predominant mode of transmission, recent evidence suggests that indirect environmental transmission may also contribute to disease spread. METHODS Data from a population-based infectious disease surveillance system (28,000 individuals followed biweekly) were used to map the spatial pattern of typhoid fever in Kibera, an urban informal settlement in Nairobi Kenya, between 2010-2011. Spatial modeling was used to test whether variations in topography and accumulation of surface water explain the geographic patterns of risk. RESULTS Among children less than ten years of age, risk of typhoid fever was geographically heterogeneous across the study area (p = 0.016) and was positively associated with lower elevation, OR = 1.87, 95% CI (1.36-2.57), p <0.001. In contrast, the risk of typhoid fever did not vary geographically or with elevation among individuals more than ten years of age [corrected]. CONCLUSIONS Our results provide evidence of indirect, environmental transmission of typhoid fever among children, a group with high exposure to fecal pathogens in the environment. Spatially targeting sanitation interventions may decrease enteric fever transmission.
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Affiliation(s)
- Adam Akullian
- University of Washington, School of Public Health and Community Medicine, Department of Epidemiology, Seattle, Washington, United States of America
| | - Eric Ng’eno
- Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya
| | - Alastair I. Matheson
- University of Washington, School of Public Health and Community Medicine, Department of Epidemiology, Seattle, Washington, United States of America
| | - Leonard Cosmas
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
| | - Daniel Macharia
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
| | - Barry Fields
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
| | - Godfrey Bigogo
- Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya
| | - Maina Mugoh
- Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya
| | - Grace John-Stewart
- Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Judd L. Walson
- Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Jonathan Wakefield
- University of Washington, Department of Statistics and Biostatistics, Seattle, Washington, United States of America
| | - Joel M. Montgomery
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
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Mogasale V, Maskery B, Ochiai RL, Lee JS, Mogasale VV, Ramani E, Kim YE, Park JK, Wierzba TF. Burden of typhoid fever in low-income and middle-income countries: a systematic, literature-based update with risk-factor adjustment. LANCET GLOBAL HEALTH 2015; 2:e570-80. [PMID: 25304633 DOI: 10.1016/s2214-109x(14)70301-8] [Citation(s) in RCA: 336] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk. METHODS We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confirmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates. FINDINGS The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9-14·7) cases with 129 000 (75 000-208 000) deaths. By comparison, the estimated risk-unadjusted burden was 20·6 million (17·5-24·2) cases and 223 000 (131 000-344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of differences between the current estimate and past estimates. INTERPRETATION The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk differences, it will allow assessment of the effect at the population level and will facilitate cost-effectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine.
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Affiliation(s)
| | | | | | | | | | - Enusa Ramani
- International Vaccine Institute, Seoul, South Korea
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Crump JA. Updating and refining estimates of typhoid fever burden for public health action. LANCET GLOBAL HEALTH 2015; 2:e551-3. [PMID: 25304622 PMCID: PMC4404498 DOI: 10.1016/s2214-109x(14)70306-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
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Upgrading a piped water supply from intermittent to continuous delivery and association with waterborne illness: a matched cohort study in urban India. PLoS Med 2015; 12:e1001892. [PMID: 26505897 PMCID: PMC4624240 DOI: 10.1371/journal.pmed.1001892] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 09/17/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India. METHODS AND FINDINGS We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children <5 y old, with four longitudinal visits over 15 mo (Nov 2010-Feb 2012) to record caregiver-reported health outcomes (diarrhea, highly credible gastrointestinal illness, bloody diarrhea, typhoid fever, cholera, hepatitis, and deaths of children <2 y old) and, at the final visit, to measure weight for age for children <5 y old. We also collected caregiver-reported data on negative control outcomes (cough/cold and scrapes/bruises) to assess potential bias from residual confounding or differential measurement error. Continuous supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83-1.04, p = 0.19), bloody diarrhea (PR = 0.78, 95% CI: 0.60-1.01, p = 0.06), or weight-for-age z-scores (Δz = 0.01, 95% CI: -0.07-0.09, p = 0.79) in children <5 y old. In prespecified subgroup analyses by socioeconomic status, children <5 y old in lower-income continuous supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46-0.87, p-value for interaction = 0.03) than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence ratio [CIR] = 0.58, 95% CI: 0.41-0.78, p = 0.001) than intermittent supply areas. There was no significant association with hepatitis, cholera, or mortality of children <2 y old; however, our results were indicative of lower mortality of children <2 y old (CIR = 0.51, 95% CI: 0.22-1.07, p = 0.10) in continuous supply areas. The major limitations of our study were the potential for unmeasured confounding given the observational design and measurement bias from differential reporting of health symptoms given the nonblinded treatment. However, there was no significant difference in the prevalence of the negative control outcomes between study groups that would suggest undetected confounding or measurement bias. CONCLUSIONS Continuous water supply had no significant overall association with diarrheal disease or ponderal growth in children <5 y old in Hubli-Dharwad; this might be due to point-of-use water contamination from continuing household storage and exposure to diarrheagenic pathogens through nonwaterborne routes. Continuous supply was associated with lower prevalence of dysentery in children in low-income households and lower typhoid fever incidence, suggesting that intermittently operated piped water systems are a significant transmission mechanism for Salmonella typhi and dysentery-causing pathogens in this urban population, despite centralized water treatment. Continuous supply was associated with reduced transmission, especially in the poorer higher-risk segments of the population.
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Abstract
Control of typhoid fever relies on clinical information, diagnosis, and an understanding for the epidemiology of the disease. Despite the breadth of work done so far, much is not known about the biology of this human-adapted bacterial pathogen and the complexity of the disease in endemic areas, especially those in Africa. The main barriers to control are vaccines that are not immunogenic in very young children and the development of multidrug resistance, which threatens efficacy of antimicrobial chemotherapy. Clinicians, microbiologists, and epidemiologists worldwide need to be familiar with shifting trends in enteric fever. This knowledge is crucial, both to control the disease and to manage cases. Additionally, salmonella serovars that cause human infection can change over time and location. In areas of Asia, multidrug-resistant Salmonella enterica serovar Typhi (S Typhi) has been the main cause of enteric fever, but now S Typhi is being displaced by infections with drug-resistant S enterica serovar Paratyphi A. New conjugate vaccines are imminent and new treatments have been promised, but the engagement of local medical and public health institutions in endemic areas is needed to allow surveillance and to implement control measures.
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Affiliation(s)
- John Wain
- Norwich Medical School, University of East Anglia, Norwich, UK.
| | - Rene S Hendriksen
- National Food Institute, Technical University of Denmark, WHO Collaborating Centre for Antimicrobial Resistance in Foodborne Pathogens and European Union Reference Laboratory for Antimicrobial Resistance, Kongens Lyngby, Denmark
| | - Matthew L Mikoleit
- National Enteric Reference Laboratory Team, Enteric Diseases Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Karen H Keddy
- Centre for Enteric Diseases, National Institute for Communicable Diseases, Division in the National Health Laboratory Service (NHLS), Johannesburg, South Africa; Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Dworkin J, Saeed R, Mykhan H, Kanan S, Farhad D, Ali KO, Abdulwahab RHK, Palardy J, Neill MA. Burden of typhoid fever in Sulaimania, Iraqi Kurdistan. Int J Infect Dis 2014; 27:70-3. [DOI: 10.1016/j.ijid.2014.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/23/2014] [Accepted: 07/02/2014] [Indexed: 11/24/2022] Open
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Prüss-Ustün A, Bartram J, Clasen T, Colford JM, Cumming O, Curtis V, Bonjour S, Dangour AD, De France J, Fewtrell L, Freeman MC, Gordon B, Hunter PR, Johnston RB, Mathers C, Mäusezahl D, Medlicott K, Neira M, Stocks M, Wolf J, Cairncross S. Burden of disease from inadequate water, sanitation and hygiene in low- and middle-income settings: a retrospective analysis of data from 145 countries. Trop Med Int Health 2014; 19:894-905. [PMID: 24779548 PMCID: PMC4255749 DOI: 10.1111/tmi.12329] [Citation(s) in RCA: 439] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To estimate the burden of diarrhoeal diseases from exposure to inadequate water, sanitation and hand hygiene in low- and middle-income settings and provide an overview of the impact on other diseases. METHODS For estimating the impact of water, sanitation and hygiene on diarrhoea, we selected exposure levels with both sufficient global exposure data and a matching exposure-risk relationship. Global exposure data were estimated for the year 2012, and risk estimates were taken from the most recent systematic analyses. We estimated attributable deaths and disability-adjusted life years (DALYs) by country, age and sex for inadequate water, sanitation and hand hygiene separately, and as a cluster of risk factors. Uncertainty estimates were computed on the basis of uncertainty surrounding exposure estimates and relative risks. RESULTS In 2012, 502,000 diarrhoea deaths were estimated to be caused by inadequate drinking water and 280,000 deaths by inadequate sanitation. The most likely estimate of disease burden from inadequate hand hygiene amounts to 297,000 deaths. In total, 842,000 diarrhoea deaths are estimated to be caused by this cluster of risk factors, which amounts to 1.5% of the total disease burden and 58% of diarrhoeal diseases. In children under 5 years old, 361,000 deaths could be prevented, representing 5.5% of deaths in that age group. CONCLUSIONS This estimate confirms the importance of improving water and sanitation in low- and middle-income settings for the prevention of diarrhoeal disease burden. It also underscores the need for better data on exposure and risk reductions that can be achieved with provision of reliable piped water, community sewage with treatment and hand hygiene.
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Affiliation(s)
- Annette Prüss-Ustün
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Jamie Bartram
- Gillings School of Global Public Health, University of North Carolina at Chapel HillChapel Hill, NC, USA
| | - Thomas Clasen
- Rollins School of Public Health, Emory UniversityAtlanta, GA, USA
| | - John M Colford
- School of Public Health, University of California, BerkeleyBerkeley, CA, USA
| | - Oliver Cumming
- London School of Hygiene and Tropical MedicineLondon, UK
| | - Valerie Curtis
- London School of Hygiene and Tropical MedicineLondon, UK
| | - Sophie Bonjour
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Alan D Dangour
- London School of Hygiene and Tropical MedicineLondon, UK
| | - Jennifer De France
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Lorna Fewtrell
- Centre for Research into Environment and Health, Aberystwyth UniversityAberystwyth, UK
| | | | - Bruce Gordon
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Paul R Hunter
- Norwich Medical School, University of East AngliaNorwich, UK
- Department of Environmental Health, Tshware University of TechnologyPretoria, South Africa
| | - Richard B Johnston
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
- EAWAG, Swiss Federal Institute of Aquatic Science and TechnologyDübendorf, Switzerland
| | - Colin Mathers
- Department of Health Statistics and Information Systems, World Health OrganizationGeneva, Switzerland
| | - Daniel Mäusezahl
- Swiss Tropical and Public Health InstituteBasel, Switzerland
- University of BaselBasel, Switzerland
| | - Kate Medlicott
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Maria Neira
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
| | - Meredith Stocks
- Rollins School of Public Health, Emory UniversityAtlanta, GA, USA
| | - Jennyfer Wolf
- Department of Public Health and Environment, World Health OrganizationGeneva, Switzerland
- Swiss Tropical and Public Health InstituteBasel, Switzerland
- University of BaselBasel, Switzerland
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Wedgworth JC, Brown J, Johnson P, Olson JB, Elliott M, Forehand R, Stauber CE. Associations between perceptions of drinking water service delivery and measured drinking water quality in rural Alabama. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:7376-92. [PMID: 25046635 PMCID: PMC4113882 DOI: 10.3390/ijerph110707376] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/03/2014] [Accepted: 06/30/2014] [Indexed: 01/28/2023]
Abstract
Although small, rural water supplies may present elevated microbial risks to consumers in some settings, characterizing exposures through representative point-of-consumption sampling is logistically challenging. In order to evaluate the usefulness of consumer self-reported data in predicting measured water quality and risk factors for contamination, we compared matched consumer interview data with point-of-survey, household water quality and pressure data for 910 households served by 14 small water systems in rural Alabama. Participating households completed one survey that included detailed feedback on two key areas of water service conditions: delivery conditions (intermittent service and low water pressure) and general aesthetic characteristics (taste, odor and color), providing five condition values. Microbial water samples were taken at the point-of-use (from kitchen faucets) and as-delivered from the distribution network (from outside flame-sterilized taps, if available), where pressure was also measured. Water samples were analyzed for free and total chlorine, pH, turbidity, and presence of total coliforms and Escherichia coli. Of the 910 households surveyed, 35% of participants reported experiencing low water pressure, 15% reported intermittent service, and almost 20% reported aesthetic problems (taste, odor or color). Consumer-reported low pressure was associated with lower gauge-measured pressure at taps. While total coliforms (TC) were detected in 17% of outside tap samples and 12% of samples from kitchen faucets, no reported water service conditions or aesthetic characteristics were associated with presence of TC. We conclude that consumer-reported data were of limited utility in predicting potential microbial risks associated with small water supplies in this setting, although consumer feedback on low pressure—a risk factor for contamination—may be relatively reliable and therefore useful in future monitoring efforts.
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Affiliation(s)
- Jessica C Wedgworth
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35487, USA.
| | - Joe Brown
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, USA.
| | - Pauline Johnson
- Department of Civil and Environmental Engineering, University of Alabama, 245 7th Avenue, Tuscaloosa, AL 35487, USA.
| | - Julie B Olson
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35487, USA.
| | - Mark Elliott
- Department of Civil and Environmental Engineering, University of Alabama, 245 7th Avenue, Tuscaloosa, AL 35487, USA.
| | - Rick Forehand
- Barge Waggoner Sumner and Cannon Inc., 2047 West Main Street, Suite 1, Dothan, AL 36301, USA.
| | - Christine E Stauber
- Division of Environmental Health, School of Public Health, Georgia State University, P.O. Box 3995, Atlanta, GA 30302, USA.
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Kaftyreva LA, Egorova SA, Makarova MA, Zabrovskaya AV, Matveeva ZN, Suzhaeva LV, Voitenkova EV. DIVERSITY OF ANTIMICROBIAL RESISTANCE MECHANISMS IN SALMONELLA. RUSSIAN JOURNAL OF INFECTION AND IMMUNITY 2014. [DOI: 10.15789/2220-7619-2011-4-303-310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Abstract. Current review presents information on the antimicrobial resistance of Salmonella of various serotypes. The phenotypes of resistance and the main resistance mechanisms to the antimicrobials of various groups are described. Comparison data on the resistance to antimicrobials of Salmonella serological variants, which circulate worldwide including the Russian Federation (S. Typhimurium DT104, S. Newport, S. Virchow, S. Enteritidis) are shown. Moreover, epidemiological characteristics of transmission factors related to these pathogens are discussed. Special attention is given to genetic determinants, which encode the resistance of Enterobacteriaceae, as well as mobile genetic elements (integrons, plasmids, pathogenicity islands), which are involved in the spread of resistance.
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Kumpel E, Nelson KL. Mechanisms affecting water quality in an intermittent piped water supply. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:2766-2775. [PMID: 24459990 DOI: 10.1021/es405054u] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Drinking water distribution systems throughout the world supply water intermittently, leaving pipes without pressure between supply cycles. Understanding the multiple mechanisms that affect contamination in these intermittent water supplies (IWS) can be used to develop strategies to improve water quality. To study these effects, we tested water quality in an IWS system with infrequent and short water delivery periods in Hubli-Dharwad, India. We continuously measured pressure and physicochemical parameters and periodically collected grab samples to test for total coliform and E. coli throughout supply cycles at 11 sites. When the supply was first turned on, water with elevated turbidity and high concentrations of indicator bacteria was flushed out of pipes. At low pressures (<10 psi), elevated indicator bacteria were frequently detected even when there was a chlorine residual, suggesting persistent contamination had occurred through intrusion or backflow. At pressures between 10 and 17 psi, evidence of periodic contamination suggested that transient intrusion, backflow, release of particulates, or sloughing of biofilms from pipe walls had occurred. Few total coliform and no E. coli were detected when water was delivered with a chlorine residual and at pressures >17 psi.
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Affiliation(s)
- Emily Kumpel
- Civil and Environmental Engineering, University of California , Berkeley
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Waddington CS, Darton TC, Pollard AJ. The challenge of enteric fever. J Infect 2014; 68 Suppl 1:S38-50. [DOI: 10.1016/j.jinf.2013.09.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2013] [Indexed: 11/27/2022]
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Karkey A, Thompson CN, Tran Vu Thieu N, Dongol S, Le Thi Phuong T, Voong Vinh P, Arjyal A, Martin LB, Rondini S, Farrar JJ, Dolecek C, Basnyat B, Baker S. Differential epidemiology of Salmonella Typhi and Paratyphi A in Kathmandu, Nepal: a matched case control investigation in a highly endemic enteric fever setting. PLoS Negl Trop Dis 2013; 7:e2391. [PMID: 23991240 PMCID: PMC3749961 DOI: 10.1371/journal.pntd.0002391] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/17/2013] [Indexed: 01/08/2023] Open
Abstract
Background Enteric fever, a systemic infection caused by the bacteria Salmonella Typhi and Salmonella Paratyphi A, is endemic in Kathmandu, Nepal. Previous work identified proximity to poor quality water sources as a community-level risk for infection. Here, we sought to examine individual-level risk factors related to hygiene and sanitation to improve our understanding of the epidemiology of enteric fever in this setting. Methodology and principal findings A matched case-control analysis was performed through enrollment of 103 blood culture positive enteric fever patients and 294 afebrile community-based age and gender-matched controls. A detailed questionnaire was administered to both cases and controls and the association between enteric fever infection and potential exposures were examined through conditional logistic regression. Several behavioral practices were identified as protective against infection with enteric fever, including water storage and hygienic habits. Additionally, we found that exposures related to poor water and socioeconomic status are more influential in the risk of infection with S. Typhi, whereas food consumption habits and migration play more of a role in risk of S. Paratyphi A infection. Conclusions and significance Our work suggests that S. Typhi and S. Paratyphi A follow different routes of infection in this highly endemic setting and that sustained exposure to both serovars probably leads to the development of passive immunity. In the absence of a polyvalent vaccine against S. Typhi and S. Paratyphi A, we advocate better systems for water treatment and storage, improvements in the quality of street food, and vaccination with currently available S. Typhi vaccines. Enteric fever, caused by ingestion of bacteria Salmonella Typhi or Salmonella Paratyphi A, is common in regions with poor water quality and sanitation. We sought to identify individual-level risks for infection in Kathmandu, Nepal, a region endemic for enteric fever. In this study, we enrolled patients presenting to hospital who were blood-culture positive for enteric fever and a series of community controls matched for age, gender and residential ward. Our findings suggest that while some risks for infection with S. Typhi and S. Paratyphi A overlap, these organisms also have distinctive routes of infection in this setting; poor water and socioeconomic status seemed more influential in infection with S. Typhi, whereas food consumption habits and migratory status were shown to play a larger role in infection with S. Paratyphi A. Additionally, serological evaluation of IgG levels against the Vi (Salmonella Typhi) and the O:2 (Salmonella Paratyphi A) antigens demonstrated high titers against both antigens throughout life, suggesting frequent and constant exposure to these organisms in Kathmandu. As major improvements in sanitation infrastructure are unlikely in this setting, we recommend water treatment and storage-based prevention strategies, as well as street food quality regulation, and the promotion of vaccination with existing typhoid vaccines.
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Affiliation(s)
- Abhilasha Karkey
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Corinne N. Thompson
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
| | - Nga Tran Vu Thieu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Tu Le Thi Phuong
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Phat Voong Vinh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Amit Arjyal
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | | | - Simona Rondini
- Novartis Institute Vaccines for Global Health, Siena, Italy
| | - Jeremy J. Farrar
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
| | | | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
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Sima LC, Elimelech M. More than a drop in the bucket: decentralized membrane-based drinking water refill stations in southeast Asia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:7580-7588. [PMID: 23725533 DOI: 10.1021/es304384n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Decentralized membrane-based water treatment and refill stations represent a viable and growing business model in Southeast Asia, which rely upon the purchase of water from refill stations by consumers. This feature article discusses these water treatment and refill stations, including the appropriateness of the technology, the suitability of the business models employed, and the long-term environmental and operational sustainability of these systems. We also provide an outlook for the sector, highlighting key technical challenges that need to be addressed in order to improve the capacity of these systems, such that they can become an effective and financially viable solution.
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Affiliation(s)
- Laura C Sima
- Department of Chemical and Environmental Engineering, Yale University , New Haven, Connecticut 06520-8286, USA
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Baker S, Holt KE, Clements ACA, Karkey A, Arjyal A, Boni MF, Dongol S, Hammond N, Koirala S, Duy PT, Nga TVT, Campbell JI, Dolecek C, Basnyat B, Dougan G, Farrar JJ. Combined high-resolution genotyping and geospatial analysis reveals modes of endemic urban typhoid fever transmission. Open Biol 2013; 1:110008. [PMID: 22645647 PMCID: PMC3352080 DOI: 10.1098/rsob.110008] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 10/03/2011] [Indexed: 11/16/2022] Open
Abstract
Typhoid is a systemic infection caused by Salmonella Typhi and Salmonella Paratyphi A, human-restricted bacteria that are transmitted faeco-orally. Salmonella Typhi and S. Paratyphi A are clonal, and their limited genetic diversity has precluded the identification of long-term transmission networks in areas with a high disease burden. To improve our understanding of typhoid transmission we have taken a novel approach, performing a longitudinal spatial case–control study for typhoid in Nepal, combining single-nucleotide polymorphism genotyping and case localization via global positioning. We show extensive clustering of typhoid occurring independent of population size and density. For the first time, we demonstrate an extensive range of genotypes existing within typhoid clusters, and even within individual households, including some resulting from clonal expansion. Furthermore, although the data provide evidence for direct human-to-human transmission, we demonstrate an overwhelming contribution of indirect transmission, potentially via contaminated water. Consistent with this, we detected S. Typhi and S. Paratyphi A in water supplies and found that typhoid was spatially associated with public water sources and low elevation. These findings have implications for typhoid-control strategies, and our innovative approach may be applied to other diseases caused by other monophyletic or emerging pathogens.
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Affiliation(s)
- Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 190 Ben Ham Tu, Quan 5, Ho Chi Minh City, Vietnam.
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Corner RJ, Dewan AM, Hashizume M. Modelling typhoid risk in Dhaka metropolitan area of Bangladesh: the role of socio-economic and environmental factors. Int J Health Geogr 2013; 12:13. [PMID: 23497202 PMCID: PMC3610306 DOI: 10.1186/1476-072x-12-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/03/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Developing countries in South Asia, such as Bangladesh, bear a disproportionate burden of diarrhoeal diseases such as cholera, typhoid and paratyphoid. These seem to be aggravated by a number of social and environmental factors such as lack of access to safe drinking water, overcrowdedness and poor hygiene brought about by poverty. Some socioeconomic data can be obtained from census data whilst others are more difficult to elucidate. This study considers a range of both census data and spatial data from other sources, including remote sensing, as potential predictors of typhoid risk. Typhoid data are aggregated from hospital admission records for the period from 2005 to 2009. The spatial and statistical structures of the data are analysed and principal axis factoring is used to reduce the degree of co-linearity in the data. The resulting factors are combined into a quality of life index, which in turn is used in a regression model of typhoid occurrence and risk. RESULTS The three principal factors used together explain 87% of the variance in the initial candidate predictors, which eminently qualifies them for use as a set of uncorrelated explanatory variables in a linear regression model. Initial regression result using ordinary least squares (OLS) were disappointing, this was explainable by analysis of the spatial autocorrelation inherent in the principal factors. The use of geographically weighted regression caused a considerable increase in the predictive power of regressions based on these factors. The best prediction, determined by analysis of the Akaike information criterion (AIC) was found when the three factors were combined into a quality of life index, using a method previously published by others, and had a coefficient of determination of 73%. CONCLUSIONS The typhoid occurrence/risk prediction equation was used to develop the first risk map showing areas of Dhaka metropolitan area whose inhabitants are at greater or lesser risk of typhoid infection. This, coupled with seasonal information on typhoid incidence also reported in this paper, has the potential to advise public health professionals on developing prevention strategies such as targeted vaccination.
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Affiliation(s)
- Robert J Corner
- Department of Spatial Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia
| | - Ashraf M Dewan
- Department of Spatial Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia
- Department of Geography & Environment, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Masahiro Hashizume
- Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
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