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von Seidlein L. The wrongful indictment of pre-referral rectal artesunate further delays the roll-out of this lifesaving drug. THE LANCET. INFECTIOUS DISEASES 2022; 23:e208-e212. [PMID: 36549312 DOI: 10.1016/s1473-3099(22)00765-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/09/2022] [Accepted: 11/09/2022] [Indexed: 12/24/2022]
Abstract
Administering rectal artesunate suppositories to patients with severe malaria before they receive parenteral and oral consolidation therapy was found to reduce mortality more than a decade ago. The roll-out of rectal artesunate could combat the current global increase in malaria deaths. Instead, on Jan 27, 2022, WHO recommended a moratorium on the deployment of rectal artesunate and in doing so stopped the roll-out of a lifesaving intervention. This decision was based mainly on the results from an observational study that is part of a larger project being conducted in Nigeria, Uganda, and DR Congo. The Community Access to Rectal Artesunate for Malaria (CARAMAL) project was not set up to provide patient transport to referral health-care centres for parenteral artesunate administration or logistic support to assure the availability of parenteral and oral antimalarial consolidation therapy. Using a before-after study design, which is known to be prone to bias, the study found that case fatality rates of severe malaria increased instead of decreased after the roll-out of rectal artesunate. However, the study and its analysis have methodological flaws that provide an alternative explanation for study findings. Instead of further delaying the roll-out of rectal artesunate, there is an urgent need for a concerted effort to provide rectal artesunate as originally intended, where and when it is needed.
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Affiliation(s)
- Lorenz von Seidlein
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand.
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Van Be Bay P, Wain J, Phuong LT, Ho VA, Hien TT, Parry CM. OUP accepted manuscript. Trans R Soc Trop Med Hyg 2022; 116:736-744. [PMID: 35092688 PMCID: PMC9356000 DOI: 10.1093/trstmh/trac003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 11/02/2021] [Accepted: 01/10/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | - Le Thi Phuong
- Dong Thap Provincial Hospital, Cao Lanh, Dong Thap Province, Vietnam
| | - Vo Anh Ho
- Dong Thap Provincial Hospital, Cao Lanh, Dong Thap Province, Vietnam
| | - Tran Tinh Hien
- Well come Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam
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Stanaway JD, Reiner RC, Blacker BF, Goldberg EM, Khalil IA, Troeger CE, Andrews JR, Bhutta ZA, Crump JA, Im J, Marks F, Mintz E, Park SE, Zaidi AKM, Abebe Z, Abejie AN, Adedeji IA, Ali BA, Amare AT, Atalay HT, Avokpaho EFGA, Bacha U, Barac A, Bedi N, Berhane A, Browne AJ, Chirinos JL, Chitheer A, Dolecek C, El Sayed Zaki M, Eshrati B, Foreman KJ, Gemechu A, Gupta R, Hailu GB, Henok A, Hibstu DT, Hoang CL, Ilesanmi OS, Iyer VJ, Kahsay A, Kasaeian A, Kassa TD, Khan EA, Khang YH, Magdy Abd El Razek H, Melku M, Mengistu DT, Mohammad KA, Mohammed S, Mokdad AH, Nachega JB, Naheed A, Nguyen CT, Nguyen HLT, Nguyen LH, Nguyen NB, Nguyen TH, Nirayo YL, Pangestu T, Patton GC, Qorbani M, Rai RK, Rana SM, Ranabhat CL, Roba KT, Roberts NLS, Rubino S, Safiri S, Sartorius B, Sawhney M, Shiferaw MS, Smith DL, Sykes BL, Tran BX, Tran TT, Ukwaja KN, Vu GT, Vu LG, Weldegebreal F, Yenit MK, Murray CJL, Hay SI. The global burden of typhoid and paratyphoid fevers: a systematic analysis for the Global Burden of Disease Study 2017. THE LANCET. INFECTIOUS DISEASES 2019; 19:369-381. [PMID: 30792131 PMCID: PMC6437314 DOI: 10.1016/s1473-3099(18)30685-6] [Citation(s) in RCA: 379] [Impact Index Per Article: 75.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/17/2018] [Accepted: 11/01/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Efforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them. METHODS For this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers. FINDINGS Globally, 14·3 million (95% uncertainty interval [UI] 12·5-16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2-47·0) decline from 25·9 million (22·0-29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4-56·5), from 439·2 (376·7-507·7) per 100 000 person-years in 1990, to 197·8 (172·0-226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8-80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54-1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9-218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6-48·3) decline from 230·5 thousand (131·2-372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6-15·8) DALYs in 2017, down 43·0% (35·5-50·6) from 17·2 million (9·9-27·8) DALYs in 1990. INTERPRETATION Despite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease. FUNDING Bill & Melinda Gates Foundation.
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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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von Kalckreuth V, Konings F, Aaby P, Adu-Sarkodie Y, Ali M, Aseffa A, Baker S, Breiman RF, Bjerregaard-Andersen M, Clemens JD, Crump JA, Cruz Espinoza LM, Deerin JF, Gasmelseed N, Sow AG, Im J, Keddy KH, Cosmas L, May J, Meyer CG, Mintz ED, Montgomery JM, Olack B, Pak GD, Panzner U, Park SE, Rakotozandrindrainy R, Schütt-Gerowitt H, Soura AB, Warren MR, Wierzba TF, Marks F. The Typhoid Fever Surveillance in Africa Program (TSAP): Clinical, Diagnostic, and Epidemiological Methodologies. Clin Infect Dis 2016; 62 Suppl 1:S9-S16. [PMID: 26933028 DOI: 10.1093/cid/civ693] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND New immunization programs are dependent on data from surveillance networks and disease burden estimates to prioritize target areas and risk groups. Data regarding invasive Salmonella disease in sub-Saharan Africa are currently limited, thus hindering the implementation of preventive measures. The Typhoid Fever Surveillance in Africa Program (TSAP) was established by the International Vaccine Institute to obtain comparable incidence data on typhoid fever and invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa through standardized surveillance in multiple countries. METHODS Standardized procedures were developed and deployed across sites for study site selection, patient enrolment, laboratory procedures, quality control and quality assurance, assessment of healthcare utilization and incidence calculations. RESULTS Passive surveillance for bloodstream infections among febrile patients was initiated at thirteen sentinel sites in ten countries (Burkina Faso, Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar, Senegal, South Africa, Sudan, and Tanzania). Each TSAP site conducted case detection using these standardized methods to isolate and identify aerobic bacteria from the bloodstream of febrile patients. Healthcare utilization surveys were conducted to adjust population denominators in incidence calculations for differing healthcare utilization patterns and improve comparability of incidence rates across sites. CONCLUSIONS By providing standardized data on the incidence of typhoid fever and iNTS disease in sub-Saharan Africa, TSAP will provide vital input for targeted typhoid fever prevention programs.
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Affiliation(s)
| | - Frank Konings
- International Vaccine Institute, Seoul, Republic of Korea
| | - Peter Aaby
- Bandim Health Project, Bissau, Guinea-Bissau
| | - Yaw Adu-Sarkodie
- Kumasi Centre for Collaborative Research in Tropical Medicine School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Mohammad Ali
- International Vaccine Institute, Seoul, Republic of Korea Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Stephen Baker
- Oxford University Clinical Resarch Unit, Ho Chi Minh City, Vietnam
| | - Robert F Breiman
- Centers for Disease Control and Prevention, Nairobi, Kenya Global Health Institute, Emory University, Atlanta, Georgia
| | | | - John D Clemens
- International Vaccine Institute, Seoul, Republic of Korea International Centre for Diarrheal Disease Research, Dhaka, Bangladesh
| | - John A Crump
- Division of Infectious Diseases and International Health, Duke University Medical Center Duke Global Health Institute, Duke University, Durham, North Carolina Kilimanjaro Christian Medical Centre, Moshi, Tanzania Centre for International Health, University of Otago, Dunedin, New Zealand
| | | | | | | | - Amy Gassama Sow
- Institute Pasteur Senegal Université Cheikh Anta Diop de Dakar, Senegal
| | - Justin Im
- International Vaccine Institute, Seoul, Republic of Korea
| | - Karen H Keddy
- National Institute for Communicable Diseases School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Leonard Cosmas
- Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Jürgen May
- Department of Infection Epidemiology, Bernhard Nocht Institute for Tropical Medicine, Hamburg
| | - Christian G Meyer
- Institute of Tropical Medicine, Eberhard-Karls University Tübingen, Germany
| | - Eric D Mintz
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | - Ursula Panzner
- International Vaccine Institute, Seoul, Republic of Korea
| | - Se Eun Park
- International Vaccine Institute, Seoul, Republic of Korea
| | | | | | | | | | | | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
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Al-Emran HM, Hahn A, Baum J, Cruz Espinoza LM, Deerin J, Im J, Ibrango S, Kabore LP, von Kalckreuth V, Konings F, Marks F, Sampo E, Panzner U, Park SE, Pak GD, Schütt-Gerowitt H, Vinnemeier CD, Warren M, Soura AB. DiagnosingSalmonella entericaSerovar Typhi Infections by Polymerase Chain Reaction Using EDTA Blood Samples of Febrile Patients From Burkina Faso. Clin Infect Dis 2016; 62 Suppl 1:S37-41. [DOI: 10.1093/cid/civ770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Crump JA, Sjölund-Karlsson M, Gordon MA, Parry CM. Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections. Clin Microbiol Rev 2015; 28:901-37. [PMID: 26180063 PMCID: PMC4503790 DOI: 10.1128/cmr.00002-15] [Citation(s) in RCA: 623] [Impact Index Per Article: 69.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015.
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Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, Dunedin, Otago, New Zealand Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Maria Sjölund-Karlsson
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Christopher M Parry
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Luby SP, Saha S, Andrews JR. Towards sustainable public health surveillance for enteric fever. Vaccine 2015; 33 Suppl 3:C3-7. [PMID: 25912287 DOI: 10.1016/j.vaccine.2015.02.054] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/09/2015] [Accepted: 02/12/2015] [Indexed: 10/23/2022]
Abstract
Enteric fever that results from infection by the typhoidal Salmonellas (Salmonella Typhi and Salmonella Paratyphi A, B and C) is a life-threatening preventable illness. Surveillance of enteric fever is important to understand current burden of disease, to track changes in human health burden from increasing antimicrobial resistance and to assess the impact of efforts to reduce disease burden. Since enteric fever occurs predominantly in low income communities, expensive surveillance is not sustainable. Traditional hospital-based surveillance does not estimate population burden and intensive community-based cohort studies do not capture the severe disease that is crucial to policy decisions. While cohort studies have been considered the gold standard for incidence estimates, the resources required to conduct them are great; as a consequence, estimates of enteric fever burden have been highly geographically and temporally restricted. A hybrid approach combining laboratory diagnosis that is already being conducted in healthcare centers with community-based surveillance of health care facility use offers a low-cost, sustainable approach to generate policy relevant data.
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Affiliation(s)
- Stephen P Luby
- Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, United States.
| | - Samir Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Jason R Andrews
- Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, United States
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Abstract
Millions of people travel to the tropics each year and a significant minority of them become ill, either during their stay, or shortly after their return. Most have mild, self-limiting illnesses, but a few will have a life-threatening condition. This article outlines how to evaluate fever in the returning traveller and discusses important infection control and public health measures. A detailed travel history, which takes into account travel destinations, specific activities and risk factors in relation to the onset of symptoms, is essential for constructing a comprehensive list of differential diagnoses and guiding appropriate investigations. Importantly, all travellers returning from the tropics with a fever should be investigated for malaria, even if their return was 3 months ago or longer.
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Affiliation(s)
- Pasco Hearn
- is a Registrar in Infectious Diseases at the Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK. Competing interests: none-declared.,is a Senior Lecturer at the London School of Hygiene and Tropical Medicine, London, UK and a Consultant Physician at the Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK and North Middlesex University Hospital NHS Trust, London, UK. Competing interests: none declared
| | - Victoria Johnston
- is a Registrar in Infectious Diseases at the Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK. Competing interests: none-declared.,is a Senior Lecturer at the London School of Hygiene and Tropical Medicine, London, UK and a Consultant Physician at the Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK and North Middlesex University Hospital NHS Trust, London, UK. Competing interests: none declared
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10
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Parry CM, Wijedoru L, Arjyal A, Baker S. The utility of diagnostic tests for enteric fever in endemic locations. Expert Rev Anti Infect Ther 2014; 9:711-25. [DOI: 10.1586/eri.11.47] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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11
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Evaluation of an electricity-free, culture-based approach for detecting typhoidal Salmonella bacteremia during enteric fever in a high burden, resource-limited setting. PLoS Negl Trop Dis 2013; 7:e2292. [PMID: 23853696 PMCID: PMC3694822 DOI: 10.1371/journal.pntd.0002292] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/20/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In many rural areas at risk for enteric fever, there are few data on Salmonella enterica serotypes Typhi (S. Typhi) and Paratyphi (S. Paratyphi) incidence, due to limited laboratory capacity for microbiologic culture. Here, we describe an approach that permits recovery of the causative agents of enteric fever in such settings. This approach involves the use of an electricity-free incubator based upon use of phase-change materials. We compared this against conventional blood culture for detection of typhoidal Salmonella. METHODOLOGY/PRINCIPAL FINDINGS Three hundred and four patients with undifferentiated fever attending the outpatient and emergency departments of a public hospital in the Kathmandu Valley of Nepal were recruited. Conventional blood culture was compared against an electricity-free culture approach. Blood from 66 (21.7%) patients tested positive for a Gram-negative bacterium by at least one of the two methods. Sixty-five (21.4%) patients tested blood culture positive for S. Typhi (30; 9.9%) or S. Paratyphi A (35; 11.5%). From the 65 individuals with culture-confirmed enteric fever, 55 (84.6%) were identified by the conventional blood culture and 60 (92.3%) were identified by the experimental method. Median time-to-positivity was 2 days for both procedures. The experimental approach was falsely positive due to probable skin contaminants in 2 of 239 individuals (0.8%). The percentages of positive and negative agreement for diagnosis of enteric fever were 90.9% (95% CI: 80.0%-97.0%) and 96.0% (92.7%-98.1%), respectively. After initial incubation, Salmonella isolates could be readily recovered from blood culture bottles maintained at room temperature for six months. CONCLUSIONS/SIGNIFICANCE A simple culture approach based upon a phase-change incubator can be used to isolate agents of enteric fever. This approach could be used as a surveillance tool to assess incidence and drug resistance of the etiologic agents of enteric fever in settings without reliable local access to electricity or local diagnostic microbiology laboratories.
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12
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Buckle GC, Walker CLF, Black RE. Typhoid fever and paratyphoid fever: Systematic review to estimate global morbidity and mortality for 2010. J Glob Health 2012. [PMID: 23198130 PMCID: PMC3484760 DOI: 10.7189/jogh.02.010401] [Citation(s) in RCA: 227] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background Typhoid and paratyphoid fever remain important causes of morbidity worldwide. Accurate disease burden estimates are needed to guide policy decisions and prevention and control strategies. Methods We conducted a systematic literature review of the PubMed and Scopus databases using pre-defined criteria to identify population-based studies with typhoid fever incidence data published between 1980 and 2009. We also abstracted data from annual reports of notifiable diseases in countries with advanced surveillance systems. Typhoid and paratyphoid fever input data were grouped into regions and regional incidence and mortality rates were estimated. Incidence data were extrapolated across regions for those lacking data. Age-specific incidence rates were derived for regions where age-specific data were available. Crude and adjusted estimates of the global typhoid fever burden were calculated. Results Twenty-five studies were identified, all of which contained incidence data on typhoid fever and 12 on paratyphoid fever. Five advanced surveillance systems contributed data on typhoid fever; 2 on paratyphoid fever. Regional typhoid fever incidence rates ranged from <0.1/100 000 cases/y in Central and Eastern Europe and Central Asia to 724.6/100 000 cases/y in Sub-Saharan Africa. Regional paratyphoid incidence rates ranged from 0.8/100 000 cases/y in North Africa/Middle East to 77.4/100 000 cases/y in Sub-Saharan Africa and South Asia. The estimated total number of typhoid fever episodes in 2010 was 13.5 million (interquartile range 9.1–17.8 million). The adjusted estimate accounting for the low sensitivity of blood cultures for isolation of the bacteria was 26.9 million (interquartile range 18.3–35.7 million) episodes. These findings are comparable to the most recent analysis of global typhoid fever morbidity, which reported crude and adjusted estimates of 10.8 million and 21.7 million typhoid fever episodes globally in 2000. Conclusion Typhoid fever remains a significant health burden, especially in low- and middle-income countries. Despite the availability of more recent data on both enteric fevers, additional research is needed in many regions, particularly Africa, Latin America and other developing countries.
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Affiliation(s)
- Geoffrey C Buckle
- Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
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Buckle GC, Walker CLF, Black RE. Typhoid fever and paratyphoid fever: Systematic review to estimate global morbidity and mortality for 2010. J Glob Health 2012. [DOI: 10.7189/jogh.01.010401] [Citation(s) in RCA: 267] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Dong BQ, Yang J, Wang XY, Gong J, von Seidlein L, Wang ML, Lin M, Liao HZ, Ochiai RL, Xu ZY, Jodar L, Clemens JD. Trends and disease burden of enteric fever in Guangxi province, China, 1994-2004. Bull World Health Organ 2010; 88:689-96. [PMID: 20865074 PMCID: PMC2930361 DOI: 10.2471/blt.09.069310] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 02/13/2010] [Accepted: 02/15/2010] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To determine the burden of enteric fever through trends in morbidity and mortality, bacterial species and antimicrobial resistance in Guangxi, a southern, subtropical, coastal province of China with a disproportionally large burden of enteric fever. METHODS Data on morbidity and mortality caused by enteric fever between 1994 and 2004 were extracted from the Guangxi Center for Disease Control and Prevention. Laboratory-based surveillance and outbreak investigations were integrated with reports of notifiable infectious diseases to estimate the bacterial species-specific incidence of enteric fever. To adjust for underreporting, survey data were collected from three prefectures that represent the hyper-, moderate- and low-endemic regions of Guangxi province. FINDINGS In Guangxi province, enteric fever incidence rate varied over the study period, with a peak of 13.5 cases per 100 000 population in 1995 and a low of 6.5 in 2003. The disease occurred most frequently during the summer and autumn months and in the group aged 10-49 years. The incidence of enteric fever varied by region within Guangxi province. During the 11-year period covered by the study, 61 outbreaks of enteric fever were reported, and Salmonella paratyphi A (SPA) became the predominant causative agent in the province. CONCLUSION Prospective studies may provide a better understanding of the reason for the shifting epidemiology of enteric fever in Guangxi province. Given the emergence of resistance to first- and second-line antimicrobials for the treatment of enteric fever, a bivalent vaccine against both SPA and S. typhi would facilitate for disease control.
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Affiliation(s)
- Bai-Qing Dong
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | - Jin Yang
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | - Xuan-Yi Wang
- Institutes of Biomedical Sciences, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China
| | - Jian Gong
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | | | - Ming-Liu Wang
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | - Mei Lin
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | - He-Zhuang Liao
- Guangxi Center for Disease Control and Prevention, Nanning, Guangxi, China
| | - R Leon Ochiai
- International Vaccine Institute, Seoul, Republic of Korea
| | - Zhi-Yi Xu
- International Vaccine Institute, Seoul, Republic of Korea
| | - Luis Jodar
- International Vaccine Institute, Seoul, Republic of Korea
| | - John D Clemens
- International Vaccine Institute, Seoul, Republic of Korea
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Ley B, Mtove G, Thriemer K, Amos B, von Seidlein L, Hendriksen I, Mwambuli A, Shoo A, Malahiyo R, Ame SM, Kim DR, Ochiai LR, Clemens JD, Reyburn H, Wilfing H, Magesa S, Deen JL. Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies. BMC Infect Dis 2010; 10:180. [PMID: 20565990 PMCID: PMC2898821 DOI: 10.1186/1471-2334-10-180] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 06/22/2010] [Indexed: 11/16/2022] Open
Abstract
Background The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. Methods We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." Results We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. Conclusion Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of ≥ 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable.
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16
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Johnston V, Stockley JM, Dockrell D, Warrell D, Bailey R, Pasvol G, Klein J, Ustianowski A, Jones M, Beeching NJ, Brown M, Chapman ALN, Sanderson F, Whitty CJM. Fever in returned travellers presenting in the United Kingdom: recommendations for investigation and initial management. J Infect 2009; 59:1-18. [PMID: 19595360 DOI: 10.1016/j.jinf.2009.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Accepted: 05/20/2009] [Indexed: 01/23/2023]
Abstract
International travel is increasing. Most physicians and general practitioners will encounter returned travellers with fever and the majority of travel-related infection is associated with travel to the tropics. In those returning from the tropics malaria must always be excluded, and HIV considered, from all settings. Common causes of non-malarial fever include from Africa rickettsial diseases, amoebic liver abscess and Katayama syndrome; from South and South East Asia, enteric fever and arboviral infection; from the Middle East, brucellosis and from the Horn of Africa visceral leishmaniasis. Other rare but important diseases from particular geographical areas include leptospirosis, trypanosomiasis and viral haemorrhagic fever. North and South America, Europe and Australia also have infections which are geographically concentrated. Empirical treatment may have to be started based on epidemiological probability of infection whilst waiting for results to return. The evidence base for much of the management of tropical infections is limited. These recommendations provide a pragmatic approach to the initial diagnosis and management of fever in returned travellers, based on evidence where it is available and on consensus of expert opinion where it is not. With early diagnosis and treatment the majority of patients with a potentially fatal infection related to travel will make a rapid and full recovery.
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Affiliation(s)
- Victoria Johnston
- Hospital for Tropical Diseases, Mortimer Market Centre, Capper Street, London, UK.
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17
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Ochiai RL, Acosta CJ, Danovaro-Holliday MC, Baiqing D, Bhattacharya SK, Agtini MD, Bhutta ZA, Canh DG, Ali M, Shin S, Wain J, Page AL, Albert MJ, Farrar J, Abu-Elyazeed R, Pang T, Galindo CM, von Seidlein L, Clemens JD. A study of typhoid fever in five Asian countries: disease burden and implications for controls. Bull World Health Organ 2008; 86:260-8. [PMID: 18438514 DOI: 10.2471/blt.06.039818] [Citation(s) in RCA: 357] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 09/12/2007] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE To inform policy-makers about introduction of preventive interventions against typhoid, including vaccination. METHODS A population-based prospective surveillance design was used. Study sites where typhoid was considered a problem by local authorities were established in China, India, Indonesia, Pakistan and Viet Nam. Standardized clinical, laboratory, and surveillance methods were used to investigate cases of fever of >or= 3 days' duration for a one-year period. A total of 441,435 persons were under surveillance, 159,856 of whom were aged 5-15 years. FINDINGS A total of 21,874 episodes of fever were detected. Salmonella typhi was isolated from 475 (2%) blood cultures, 57% (273/475) of which were from 5-15 year-olds. The annual typhoid incidence (per 100,000 person years) among this age group varied from 24.2 and 29.3 in sites in Viet Nam and China, respectively, to 180.3 in the site in Indonesia; and to 412.9 and 493.5 in sites in Pakistan and India, respectively. Altogether, 23% (96/413) of isolates were multidrug resistant (chloramphenicol, ampicillin and trimethoprim-sulfamethoxazole). CONCLUSION The incidence of typhoid varied substantially between sites, being high in India and Pakistan, intermediate in Indonesia, and low in China and Viet Nam. These findings highlight the considerable, but geographically heterogeneous, burden of typhoid fever in endemic areas of Asia, and underscore the importance of evidence on disease burden in making policy decisions about interventions to control this disease.
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Affiliation(s)
- R Leon Ochiai
- International Vaccine Institute, Seoul, Republic of Korea.
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18
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Crump JA, Ram PK, Gupta SK, Miller MA, Mintz ED. Part I. Analysis of data gaps pertaining to Salmonella enterica serotype Typhi infections in low and medium human development index countries, 1984-2005. Epidemiol Infect 2008; 136:436-48. [PMID: 17686194 PMCID: PMC2870843 DOI: 10.1017/s0950268807009338] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2007] [Indexed: 11/05/2022] Open
Abstract
There are only 10 contemporary, population-based studies of typhoid fever that evaluate disease incidence using blood culture for confirmation of cases. Reported incidence ranged from 13 to 976/100 000 persons per year. These studies are likely to have been done preferentially in high- incidence sites which makes generalization of data difficult. Only five of these studies reported mortality. Of these the median (range) mortality was 0% (0-1.8%). Since study conditions usually involved enhanced clinical management of patients and the studies were not designed to evaluate mortality as an outcome, their usefulness for generalizing case-fatality rates is uncertain. No contemporary population-based studies reported rates of complications. Hospital-based typhoid fever studies reported median (range) complication rates of 2.8% (0.6-4.9%) for intestinal perforation and case-fatality rates of 2.0% (0-14.8%). Rates of complications other than intestinal perforation were not reported in contemporary hospital-based studies. Hospital-based studies capture information on the most severe illnesses among persons who have access to health-care services limiting their generalizability. Only two studies have informed the current understanding of typhoid fever age distribution curves. Extrapolation from population-based studies suggests that most typhoid fever occurs among young children in Asia. To reduce gaps in the current understanding of typhoid fever incidence, complications, and case-fatality rate, large population-based studies using blood culture confirmation of cases are needed in representative sites, especially in low and medium human development index countries outside Asia.
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Affiliation(s)
- J A Crump
- Enteric Diseases Epidemiology Branch, National Center for Zoonotic, Vectorborne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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19
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Abstract
OBJECTIVE To determine the efficacy of nested polymerase chain reaction (PCR) in detecting Salmonella typhi gene sequences in blood and urine specimens and to determine the cut-off titer of Widal test using PCR as gold standard test for diagnosis of typhoid fever. METHODS Study included 71 children between the ages of 8 months and 14 years; 52 of them were suspected cases of typhoid fever, 11 were febrile non-typhoid controls and 8 were apparently healthy children. Nested PCR in Blood and Urine, Blood culture, Widal test and Urine culture were done and their results analyzed. RESULTS Among suspected typhoid cases, PCR in blood and urine had positivity of 82.7% each. Blood culture, Widal test (at cut off titer TO and/or TH > 1:160) and urine culture had positivity of 26.9%, 50% and 3.8% respectively. In one case, urine PCR was positive and blood PCR was negative. Similarly, in another case, PCR in blood was positive however urine tested negative. Considering PCR as gold standard, the antibody cut off titer was evaluated. A cut-off titer of TO > 1:80 and/or TH > 1:160 had sensitivity and specificity of 72.7% and 84.2%, while the respective figures were 50% and 89.5% when the cut-off titer was TO and/or TH > 1:160. CONCLUSION The sensitivity, specificity, positive and negative predictive values, likelihood ratios were same for PCR based detection of S. typhi in blood and urine samples. Nested PCR had higher efficacy in detecting typhoid fever than Widal test, blood and urine cultures. A cut off titer of TO > 1:80 and/or TH > 1:160 was found to have better diagnostic value in this region.
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Affiliation(s)
- S R Ambati
- Miami Childrens Hospital, Miami, FL, USA.
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20
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Ochiai RL, Acosta CJ, Agtini M, Bhattacharya SK, Bhutta ZA, Do CG, Dong B, Chen X, Stanton B, Kaljee L, Nyamete A, Galindo CM, von Seidlein L, DeRoeck D, Jodar L, Clemens JD. The Use of Typhoid Vaccines in Asia: The DOMI Experience. Clin Infect Dis 2007; 45 Suppl 1:S34-8. [PMID: 17582567 DOI: 10.1086/518144] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Two currently licensed typhoid vaccines have been evaluated in Asia, yet few Asian countries have considered including typhoid vaccines in their vaccination programs. The Diseases of the Most Impoverished (DOMI) Program was initiated to provide evidence to decide on the introduction of typhoid vaccines in Asian countries. METHODS The centerpiece of the program is a multidisciplinary demonstration project with Vi vaccine in 5 Asian countries. The project includes epidemiologic, economic, sociobehavioral, and policy studies. RESULTS Policy makers want evidence on which to base their vaccine-related decisions. The DOMI Program has provided updated information on the typhoid fever burden at several Asian sites. Cost-of-illness studies found high costs to governments and individuals. Sociobehavioral studies indicated a positive attitude toward typhoid vaccines. The results of the demonstration projects indicate that mass-immunization campaigns are feasible and acceptable. CONCLUSIONS The DOMI Program has begun to provide momentum for the evidence-based, rational introduction of typhoid vaccines into the public health programs of several Asian countries.
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Affiliation(s)
- R Leon Ochiai
- International Vaccine Institute, Kwanak-gu, Seoul, Korea.
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Abstract
Typhoid fever is estimated to have caused 21.6 million illnesses and 216,500 deaths globally in 2000, affecting all ages. There is also one case of paratyphoid fever for every four of typhoid. The global emergence of multidrug-resistant strains and of strains with reduced susceptibility to fluoroquinolones is of great concern. We discuss the occurrence of poor clinical response to fluoroquinolones despite disc sensitivity. Developments are being made in our understanding of the molecular pathogenesis, and genomic and proteomic studies reveal the possibility of new targets for diagnosis and treatment. Further, we review guidelines for use of diagnostic tests and for selection of antimicrobials in varying clinical situations. The importance of safe water, sanitation, and immunisation in the presence of increasing antibiotic resistance is paramount. Routine immunisation of school-age children with Vi or Ty21a vaccine is recommended for countries endemic for typhoid. Vi vaccine should be used for 2-5 year-old children in highly endemic settings.
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Affiliation(s)
- M K Bhan
- All India Institute of Medical Sciences, New Delhi 110029, India.
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22
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Crump JA, Youssef FG, Luby SP, Wasfy MO, Rangel JM, Taalat M, Oun SA, Mahoney FJ. Estimating the incidence of typhoid fever and other febrile illnesses in developing countries. Emerg Infect Dis 2003; 9:539-44. [PMID: 12737736 PMCID: PMC2972755 DOI: 10.3201/eid0905.020428] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To measure the incidence of typhoid fever and other febrile illnesses in Bilbeis District, Egypt, we conducted a household survey to determine patterns of health seeking among persons with fever. Then we established surveillance for 4 months among a representative sample of health providers who saw febrile patients. Health providers collected epidemiologic information and blood (for culture and serologic testing) from eligible patients. After adjusting for the provider sampling scheme, test sensitivity, and seasonality, we estimated that the incidence of typhoid fever was 13/100,000 persons per year, and the incidence of brucellosis was 18/100,000 persons per year in the district. This surveillance tool could have wide applications for surveillance for febrile illness in developing countries.
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Affiliation(s)
- John A Crump
- Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Mailstop A38, 1600 Clifton Road NE, Atlanta, GA 30333, USA.
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23
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Affiliation(s)
- Christopher M Parry
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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24
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Abstract
BACKGROUND Typhoid is a common problem in developing countries. Cultivation of bacteria and serology (especially Widal test) give unacceptable levels of false-negative and false-positive results, respectively. PATIENTS AND METHODS In this study, a recently introduced polymerase chain reaction-based technique (which has 100% specificity for Salmonella typhi) was compared with blood culture and Widal test during the first week of illness of 82 suspected cases of typhoid. RESULTS The respective figures of positivity for PCR, blood culture and Widal test were 71.95%, 34.1%, and 36.5%. A control group of 20 healthy persons gave figures of 0%, 0%, and 33.3%, respectively. CONCLUSION We conclude that this PCR-based technique is not only absolutely specific, but also very sensitive and, therefore, much superior to blood culture and Widal test for the early diagnosis of typhoid.
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Affiliation(s)
- A Haque
- National Institute for Biotechnology and Genetic Engineering (NIBGE), and Department of Pathology, Punjab Medical College, Faisalabad, Pakistan
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25
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Calva E, Ordoñez LG, Fernandez-Mora M, Santana FJ, Bobadilla M, Puente JL. Distinctive IS200 insertion between gyrA and rcsC genes in Salmonella typhi. J Clin Microbiol 1997; 35:3048-53. [PMID: 9399492 PMCID: PMC230120 DOI: 10.1128/jcm.35.12.3048-3053.1997] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
While probing the vicinity of ompC, a copy of the IS200 insertion element was found between the gyrA and rcsC genes of Salmonella typhi, the causal agent of typhoid fever. This distinctive feature was conserved throughout 63 S. typhi isolates of different geographical origins and was absent from 46 other Salmonella serotypes, including those most associated with human infections, as well as from 19 other enteric bacteria. Furthermore, the location of this IS200 copy corresponds to a constant band, present throughout the 14 PstI S. typhi IS200 fingerprints, encompassing several Vi phage types. Interestingly, an apparently unrelated serotype not frequently associated with human disease, Salmonella weltevreden, contained an IS200 copy at the same position, although it was accompanied by an additional segment of cryptic DNA. On the basis of these findings, PCR assays were designed for molecular typing of S. typhi, and these are potentially useful in studying the epidemiology of typhoid fever.
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Affiliation(s)
- E Calva
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos.
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26
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Chaudhry R, Laxmi BV, Nisar N, Ray K, Kumar D. Standardisation of polymerase chain reaction for the detection of Salmonella typhi in typhoid fever. J Clin Pathol 1997; 50:437-9. [PMID: 9215131 PMCID: PMC499950 DOI: 10.1136/jcp.50.5.437] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To improve the diagnosis of Salmonella typhi infection, a polymerase chain reaction (PCR) assay was developed for the amplification of the dH flagellin gene of S typhi. Primers were designed from dH flagellin gene sequence which will give an amplification product of 486 base pairs. In tests to study the specificity of the assay, no amplification was seen in non-salmonella strains or salmonella strains with flagellar gene other than "d". Sensitivity tests determined that 28 pg of S typhi target DNA or 3 x 10(2) target bacteria could be detected by the PCR assay. Subsequently, the PCR technique was used for detection of S typhi in blood or clot cultures from 84 patients clinically suspected of having typhoid fever, and from 20 healthy control subjects. Twenty five of 84 samples from clinically suspected cases were positive by PCR; four of which were culture negative. No amplification was seen in samples from patients who were culture positive for organisms other than S typhi or from controls. The time taken for each sample for PCR analysis was less than 48 hours compared with three to five days for blood or clot culture. PCR appeared to be a promising diagnostic test for typhoid fever.
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Affiliation(s)
- R Chaudhry
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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27
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Szu SC, Taylor DN, Trofa AC, Clements JD, Shiloach J, Sadoff JC, Bryla DA, Robbins JB. Laboratory and preliminary clinical characterization of Vi capsular polysaccharide-protein conjugate vaccines. Infect Immun 1994; 62:4440-4. [PMID: 7927707 PMCID: PMC303128 DOI: 10.1128/iai.62.10.4440-4444.1994] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
To improve its immunogenicity for children and adults and to make it suitable for routine immunization of infants against typhoid fever, the capsular polysaccharide of Salmonella typhi (Vi) was bound to the B subunit of the heat-labile toxin (LT-B) of Escherichia coli or the recombinant exoprotein A (rEPA) of Pseudomonas aeruginosa. The conjugates elicited higher levels of antibodies (micrograms per milliliter of serum) in mice and in guinea pigs than did Vi and, unlike Vi alone, elicited booster antibody responses in both species. In adult volunteers, Vi-LT-B and Vi-rEPA, respectively, elicited higher levels of antibodies than Vi alone after the first injection (4.74 versus 1.77 and 4.91 versus 1.77; P < 0.005) and 26 weeks later (2.32 and 2.69 versus 0.54; P < 0.04); a second injection of the conjugates did not elicit a booster response of Vi antibodies. None of the 51 vaccinees had fever or significant local reactions. Vi-rEPA elicited slightly higher levels of Vi antibodies than did Vi-LT-B at all intervals after injection, but these differences were not significant. Each conjugate elicited antibodies to its carrier protein. The antibody responses elicited in adults by Vi bound to LT-B and rEPA are similar to those of other polysaccharide-protein conjugates. These conjugates promise to be an improved Vi vaccine. Studies of Vi conjugates with adults and infants in areas where typhoid is endemic are planned.
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Affiliation(s)
- S C Szu
- National Institute of Child Health and Human Development, Bethesda, Maryland 20892
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29
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Song JH, Cho H, Park MY, Na DS, Moon HB, Pai CH. Detection of Salmonella typhi in the blood of patients with typhoid fever by polymerase chain reaction. J Clin Microbiol 1993; 31:1439-43. [PMID: 8314983 PMCID: PMC265558 DOI: 10.1128/jcm.31.6.1439-1443.1993] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A polymerase chain reaction (PCR)-based test was developed for the detection of Salmonella typhi in the blood specimens from patients with typhoid fever. Two pairs of oligonucleotide primers were designed to amplify a 343-bp fragment of the flagellin gene of S. typhi. Amplified products were analyzed by agarose gel electrophoresis and Southern blot hybridization by using a 32P-labeled 40-base probe internal to the amplified DNA. The nested PCR with two pairs of primers could detect 10 organisms of S. typhi as determined by serial dilutions of DNA from S. typhi. The peripheral mononuclear cells from 11 of 12 patients with typhoid fever confirmed by blood culture were positive for DNA fragment of the flagellin gene of S. typhi, whereas 10 blood specimens of patients with other febrile diseases were negative. With the nested PCR, S. typhi DNAs were detected from blood specimens of four patients with suspected typhoid fever on the basis of clinical features but with negative cultures. We suggest that the PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture-negative cases.
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Affiliation(s)
- J H Song
- Department of Medicine, College of Medicine, University of Ulsan, Seoul, Korea
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30
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Abstract
Over five years the Bactec radiometric blood culture method yielded Salmonella typhi in 41 of 45 confirmed cases of typhoid fever, 90% of which were from the first culture set taken. Blood clot culture was positive in 18 (41%) of 44 confirmed cases and stool culture in 24 (59%) of 41. The yield from 2189 Widal clot cultures was only 0.03%. There were 68 positive results in 2258 unpaired Widal tests: 23 of them were falsely positive and 13 falsely negative, but in 11 out of 68 cases the Widal was the only positive laboratory test. It is concluded that routine clot culture is not cost effective if a sensitive blood culture method is used, and that the Widal test is useful only in selected patients.
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Affiliation(s)
- R Duthie
- Department of Microbiology, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
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31
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Rubin FA, McWhirter PD, Burr D, Punjabi NH, Lane E, Kumala S, Sudarmono P, Pulungsih SP, Lesmana M, Tjaniadi P. Rapid diagnosis of typhoid fever through identification of Salmonella typhi within 18 hours of specimen acquisition by culture of the mononuclear cell-platelet fraction of blood. J Clin Microbiol 1990; 28:825-7. [PMID: 2332479 PMCID: PMC267809 DOI: 10.1128/jcm.28.4.825-827.1990] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Detection of Salmonella typhi in blood by culture of the mononuclear cell-platelet layer was compared with other methods currently used for the diagnosis of typhoid fever. Colonies of S. typhi were present in all mononuclear cell-platelet layer-positive cultures within 18 h of plating and were identified within an additional 10 min by a coagglutination technique. In contrast, identification of all positive cultures by conventional blood culture required 3 days.
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Affiliation(s)
- F A Rubin
- Department of Bacterial Immunology, Walter Reed Army Institute of Research, Washington, D.C. 20307-5100
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Sippel J, Bukhtiari N, Awan MB, Krieg R, Duncan JF, Karamat KA, Malik IA, Igbal LM, Legters L. Indirect immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays (ELISAs) and IgM capture ELISA for detection of antibodies to lipopolysaccharide in adult typhoid fever patients in Pakistan. J Clin Microbiol 1989; 27:1298-302. [PMID: 2754002 PMCID: PMC267545 DOI: 10.1128/jcm.27.6.1298-1302.1989] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sera from 339 adult febrile patients in Pakistan were tested for antibodies to Salmonella typhi lipopolysaccharide by indirect immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assay (ELISA) and IgM capture ELISA. A total of 55 patients had S. typhi cultured from their blood, 20 had S. typhi cultured from their stool, 24 were blood or stool culture positive for S. paratyphi A, 41 were culture negative but clinically diagnosed as having enteric fever, 41 had gastrointestinal or urinary tract infections, 41 were clinically diagnosed as having malaria, 20 were smear-positive patients with malaria, 58 had respiratory infections, and the remaining 39 individuals were placed in a miscellaneous group who did not have Salmonella infection. The sensitivities of the indirect IgG ELISA, indirect IgM ELISA, and IgM capture ELISA determined with specimens obtained from the blood culture-positive patients with typhoid fever (positive controls) were 80, 64, and 62%, respectively. The specificities of the assays determined with sera from the patients with respiratory infections (negative controls) were 95, 95, and 97%, respectively. The percentage of smear-positive patients with malaria who were positive by these assays was lower than that in the negative control group. The percentages of individuals in the other patient categories who were positive by these tests were between those obtained with the positive and negative controls. Of the positive controls, 26 were positive by both IgM assays, 9 were IgM positive only by indirect ELISA, and 8 were IgM positive only by IgM capture ELISA. A total of 70% of the positive control patients who were tested for O agglutinins by the Widal tube agglutination assay were positive; however, 29% of the negative control patients were also positive. The indirect IgG ELISA was the single most effective test for the serodiagnosis of typhoid fever in this population.
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Affiliation(s)
- J Sippel
- Naval Medical Research Institute, Bethesda, Maryland 20814
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Rubin FA, McWhirter PD, Punjabi NH, Lane E, Sudarmono P, Pulungsih SP, Lesmana M, Kumala S, Kopecko DJ, Hoffman SL. Use of a DNA probe to detect Salmonella typhi in the blood of patients with typhoid fever. J Clin Microbiol 1989; 27:1112-4. [PMID: 2745686 PMCID: PMC267496 DOI: 10.1128/jcm.27.5.1112-1114.1989] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A DNA probe was used to detect Salmonella typhi from blood samples from 14 of 33 patients with culture-confirmed typhoid fever, using the equivalent of 2.5 ml of blood. In contrast, S. typhi was detected in 17 of the same 33 patients by culture of 8 ml of blood. The probe hybridized to blood samples of 4 of 47 patients from whom S. typhi was not isolated.
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Affiliation(s)
- F A Rubin
- Department of Bacterial Immunology, Walter Reed Army Institute of Research, Washington, D.C. 20307-5100
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34
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Simanjuntak CH, Hoffman SL, Darmowigoto R, Lesmana M, Soeprawoto, Edman DC. Streptokinase clot culture compared with whole blood culture for isolation of Salmonella typhi and S. paratyphi A from patients with enteric fever. Trans R Soc Trop Med Hyg 1988; 82:340-1. [PMID: 3055466 DOI: 10.1016/0035-9203(88)90471-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The sensitivities of whole blood and clot cultures were compared in 155 patients with typhoid or paratyphoid fever. Salmonella typhi or S. paratyphi A were isolated from 98.7% of 5 ml 1:10 blood:broth ratio blood cultures and 94.8% of 5 ml streptokinase clot cultures (P greater than 0.05). There was no difference in the speed of isolation. Whole blood culture and clot culture were of nearly equal sensitivity in this group of patients.
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Affiliation(s)
- C H Simanjuntak
- National Institute of Health Research and Development, Ministry of Health, Jakarta, Indonesia
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Acharya IL, Lowe CU, Thapa R, Gurubacharya VL, Shrestha MB, Cadoz M, Schulz D, Armand J, Bryla DA, Trollfors B. Prevention of typhoid fever in Nepal with the Vi capsular polysaccharide of Salmonella typhi. A preliminary report. N Engl J Med 1987; 317:1101-4. [PMID: 3657877 DOI: 10.1056/nejm198710293171801] [Citation(s) in RCA: 285] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We conducted a pilot study followed by a large clinical trial in Nepal of the use of the capsular polysaccharide of Salmonella typhi (Vi) as a vaccine to prevent typhoid fever. In the pilot study, involving 274 Nepalese, there were no significant side effects of the Vi vaccine; about 75 percent responded with a rise in serum antibodies of fourfold or more. In the clinical trial, residents of five villages were given intramuscular injections of either Vi or, as a control, pneumococcus vaccine dispensed in coded, randomly arranged, single-dose syringes. There were 6907 participants, of whom 6438 were members of the target population (5 to 44 years of age); each was visited every two days. Those with temperatures of 37.8 degrees C or higher for three consecutive days were examined and asked to give blood for culture. Typhoid was diagnosed as either blood culture-positive or clinically suspected on the basis of bradycardia, splenomegaly, and fever, with a negative blood culture. Seventeen months after vaccination, the codes were broken for the 71 patients meeting the criteria for either culture-positive or clinically suspected typhoid. The attack rate of typhoid was 16.2 per 1000 among the controls and 4.1 per 1000 among those immunized with Vi (P less than 0.00001). The efficacy of Vi was 72 percent in the culture-positive cases, 80 percent in the clinically suspected cases, and 75 percent in the two groups combined. These data provide evidence that Vi antibodies confer protection against typhoid. Surveillance continues to determine the duration of Vi-induced immunity.
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Affiliation(s)
- I L Acharya
- Infectious Disease Hospital and Central Health Laboratory, Teku, Nepal
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