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Mylona E, Hefele L, Tran Vu Thieu N, Trinh Van T, Nguyen Ngoc Minh C, Tran Tuan A, Karkey A, Dongol S, Basnyat B, Voong Vinh P, Ho Ngoc Dan T, Russell P, Charles RC, Parry CM, Baker S. The Identification of Enteric Fever-Specific Antigens for Population-Based Serosurveillance. J Infect Dis 2024; 229:833-844. [PMID: 37403670 PMCID: PMC10938218 DOI: 10.1093/infdis/jiad242] [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: 01/25/2023] [Revised: 06/21/2023] [Accepted: 07/04/2023] [Indexed: 07/06/2023] Open
Abstract
BACKGROUND Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A, is a major public health problem in low- and middle-income countries. Moderate sensitivity and scalability of current methods likely underestimate enteric fever burden. Determining the serological responses to organism-specific antigens may improve incidence measures. METHODS Plasma samples were collected from blood culture-confirmed enteric fever patients, blood culture-negative febrile patients over the course of 3 months, and afebrile community controls. A panel of 17 Salmonella Typhi and Paratyphi A antigens was purified and used to determine antigen-specific antibody responses by indirect ELISAs. RESULTS The antigen-specific longitudinal antibody responses were comparable between enteric fever patients, patients with blood culture-negative febrile controls, and afebrile community controls for most antigens. However, we found that IgG responses against STY1479 (YncE), STY1886 (CdtB), STY1498 (HlyE), and the serovar-specific O2 and O9 antigens were greatly elevated over a 3-month follow up period in S. Typhi/S. Paratyphi A patients compared to controls, suggesting seroconversion. CONCLUSIONS We identified a set of antigens as good candidates to demonstrate enteric fever exposure. These targets can be used in combination to develop more sensitive and scalable approaches to enteric fever surveillance and generate invaluable epidemiological data for informing vaccine policies. CLINICAL TRIAL REGISTRATION ISRCTN63006567.
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Affiliation(s)
- Elli Mylona
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Lisa Hefele
- Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Grand Duchy of Luxembourg
| | - Nga Tran Vu Thieu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tan Trinh Van
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Chau Nguyen Ngoc Minh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Anh Tran Tuan
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Abhilasha Karkey
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Phat Voong Vinh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Thanh Ho Ngoc Dan
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Paula Russell
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | | | - Christopher M Parry
- Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
- Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- IAVI Human Immunology Laboratory, Imperial College London, London, UK
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Vij S, Thakur R, Singh RP, Kumar R, Pathania P, Gupta V, Suri CR, Rishi P. Dual immunization with CdtB protein and flagellin epitope offers augmented protection against enteric fever in mice. Life Sci 2023; 334:122216. [PMID: 37918629 DOI: 10.1016/j.lfs.2023.122216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/17/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023]
Abstract
AIMS Present study has explored the protective response of dual immunization using two different antigenic entities (i.e. flagellin epitope and cytolethal distending toxin subunit B (CdtB) protein) against lethal challenge of typhoidal serovars in a murine model. MAIN METHODS In-vitro immunogenicity of flagellin epitope-BSA conjugate and CdtB protein was confirmed using Indirect ELISA of typhoid positive patients' sera. Further, both entities were administered intraperitoneally in mice individually or in combination, followed by lethal challenge of typhoidal Salmonellae. Various parameters were analysed such as bacterial burden, mice survival, histopathological analysis, cytokine analysis and immunophenotyping. Serum samples obtained from the immunized mice were used for passive immunization studies, wherein mice survival and mechanism of action of the generated antibodies was studied. KEY FINDINGS Active immunization studies using the combination of both entities demonstrated improved mice survival after lethal challenge with typhoidal Salmonellae, reduced bacterial burden in organs, expression of immunophenotypic markers in splenocytes and restored tissue histoarchitecture. When used in combination, the effective doses of both the candidates reduced which may be attributed to multiprong approach used by the immune system to recognize Salmonella. Passive immunization studies further determined the protective efficacy of generated antibodies by different mechanisms such as complement mediated bactericidal action, swarming inhibition and increased phagocytic uptake. SIGNIFICANCE Present study is the first phase of the proof-of-concept which may prove to be beneficial in developing an effective bi-functional vaccine candidate to render protection against both Vi-positive as well as Vi-negative Salmonella strains.
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Affiliation(s)
- Shania Vij
- Department of Microbiology, Panjab University, Chandigarh 160014, India.
| | - Reena Thakur
- Department of Microbiology, Panjab University, Chandigarh 160014, India
| | | | - Rashmi Kumar
- CSIR-Institute of Microbial Technology (IMTech), Chandigarh 160036, India
| | - Preeti Pathania
- CSIR-Institute of Microbial Technology (IMTech), Chandigarh 160036, India
| | - Varsha Gupta
- Department of Microbiology, Government Medical College and Hospital (GMCH), Sector 32, Chandigarh 160030, India
| | - Chander Raman Suri
- CSIR-Institute of Microbial Technology (IMTech), Chandigarh 160036, India
| | - Praveen Rishi
- Department of Microbiology, Panjab University, Chandigarh 160014, India.
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Pokhrel N, Chapagain R, Thakur CK, Basnet A, Amatya I, Singh R, Ghimire R. Salmonella infection among the pediatric population at a tertiary care children's hospital in central Nepal: a retrospective study. Front Microbiol 2023; 14:1218864. [PMID: 37840726 PMCID: PMC10570616 DOI: 10.3389/fmicb.2023.1218864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/10/2023] [Indexed: 10/17/2023] Open
Abstract
Background Typhoid fever, an infective bacterial disease, is capable of causing fatal systemic infection in humans, and in an era of antimicrobial resistance, it has become of public health importance. This study aimed to investigate the laboratory diagnosis of Salmonella bloodstream infection, its serotype, antimicrobial resistance pattern, and seasonal variation at a tertiary care children's hospital. Methods We undertook a retrospective, cross-sectional study by reviewing hospital-based laboratory records of patients whose blood culture samples were submitted from the outpatient department to the laboratory of a tertiary care children's hospital in Kathmandu, Nepal, from January 2017 to January 2019. Results Among the total blood culture samples obtained (n = 39,771), bacterial isolates (n = 1,055, 2.65%) belonged either to the Genus Enterobacteriaceae or Genus Acinetobacter. Altogether (n = 91, 8.63%), isolates were positive for Salmonella spp., which were further identified as Salmonella enterica subsp. enterica ser. Typhi (n = 79, 7.49%), Salmonella enterica subsp. enterica ser. Paratyphi A (n = 11, 1.04%), and Salmonella enterica subsp. enterica ser. Paratyphi B (n = 1, 0.1%). The median age of patients was 6 years (IQR: 4-9), with male and female patients constituting (n = 53, 58.24%; OR, 1.0; 95% CI, 0.60-1.67) and (n = 38, 41.76%; OR, 0.98; 95% CI, 0.49-2.05) cases, respectively. The disease was observed throughout the year, with a high prevalence toward the spring season (March-May). An antibiogram showed resistance more toward nalidixic acid with S. Typhi, comprising half the isolates (n = 52, 65.82%; p = 0.11). Resistance toward β-lactams with β-lactamase inhibitors (amoxicillin/clavulanate; 1.27%) was seen in a single isolate of S. Typhi. The multidrug resistance pattern was not pronounced. The multiple antibiotic resistance (MAR) index was in the range between 0.14 and 0.22 in S. Typhi and 0.22 and 0.23 in S. Paratyphi. Conclusion Salmonella Typhi was the predominant ser. Infection was common among children between 1 and 5 years of age, showing male predominance and with the spring season contributing to a fairly higher number of cases. Antimicrobial susceptibility testing of S. Typhi showed more resistance toward nalidixic acid, with only a single isolate resistant to β-lactamase inhibitors (amoxicillin/clavulanate). Alarming multidrug resistance patterns were not observed. The MAR index in this study indicates the importance of the judicious use of antimicrobials and hospital infection prevention and control practices.
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Affiliation(s)
| | - Ramhari Chapagain
- Department of Pediatrics, Kanti Children’s Hospital, Kathmandu, Nepal
| | | | - Ajaya Basnet
- Shi-Gan International College of Science and Technology, Kathmandu, Nepal
| | - Isha Amatya
- Nepal Health Research Council, Kathmandu, Nepal
| | | | - Raghav Ghimire
- Department of Pediatric Cardiology, Shahid Gangalal National Heart Centre, Kathmandu, Nepal
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Olaru ID, Chingono RMS, Bottomley C, Kandiye FR, Mhino F, Nyamayaro CA, Manyau S, Vere M, Chitando P, Chonzi P, Darton TC, Dixon J, Kranzer K. The effect of a comprehensive typhoid conjugate vaccine campaign on antimicrobial prescribing in children in Harare, Zimbabwe: a mixed methods study. Lancet Glob Health 2023; 11:e1422-e1431. [PMID: 37591588 PMCID: PMC7616073 DOI: 10.1016/s2214-109x(23)00319-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 08/19/2023]
Abstract
BACKGROUND Vaccines prevent infections and could subsequently reduce antimicrobial use. A 1-week mass vaccination campaign was done with Typbar-TCV (Bharat Biotech, Hyderabad, India) between Feb 25 and March 4, 2019. We investigated whether this typhoid conjugate vaccine campaign could affect antimicrobial prescribing in children presenting to primary care in Harare, Zimbabwe. METHODS In this mixed methods study, data for acute paediatric outpatient consultations between Jan 1, 2018, and March 31, 2020, were collected from five clinics in Harare. Interrupted time series analysis was done to compare prescription data before and after the campaign. To contextualise findings, qualitative data were collected between April 20, 2021, and July 20, 2022, comprising ethnographic research (ie, workshops, surveys, observations, and interviews) in 14 clinics. Ethnographic data were used for thematic analysis. The primary outcome was monthly antimicrobial prescriptions in children aged 6 months to 15 years, normalised by the number of trauma events in all age groups. FINDINGS In the data collection period, 27 107 paediatric consultations were recorded. 17 951 (66·2%) of 27 107 children were prescribed antimicrobials. Despite the perceived reduction in typhoid cases and a decreasing trend in the prescription of antimicrobials commonly used to treat typhoid (ie, ciprofloxacin and azithromycin), mass vaccination with Typbar-TCV did not affect the total rate of antimicrobials (adjusted rate ratio, 1·20, 95% CI 0·70-2·05, p=0·51) or the rate of typhoid antimicrobials prescribed (0·93, 0·44-1·96, p=0·85). Unsafe water sources and insufficient diagnostic services were reported to contribute to the continued disease burden and antimicrobial prescription. INTERPRETATION Non-specific febrile illness caused by confirmed or suspected typhoid is a common cause of antimicrobial use in endemic areas. Although effective in preventing typhoid fever, we were unable to identify any effect of Typbar-TCV on antimicrobial prescribing. Ethnographic research showed the effect of contextual factors on antimicrobial prescribing, including concerns regarding safe water access, appropriate sewage disposal, health-care and diagnostic availability. To realise effects beyond disease burden reduction, holistic approaches addressing these concerns are needed so that the value of vaccines mitigating the effects of antimicrobial use as a driver of antimicrobial resistance is fully achieved. FUNDING Wellcome Trust. TRANSLATION For the Shona translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Ioana D Olaru
- Biomedical Research and Training Institute, Harare, Zimbabwe; Clinical Research Department, London School of Hygiene & Tropical Medicine, London, UK; Institute of Medical Microbiology, University Hospital Münster, Münster, Germany.
| | | | - Christian Bottomley
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Faith R Kandiye
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Fadzaishe Mhino
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | | | - Salome Manyau
- Biomedical Research and Training Institute, Harare, Zimbabwe; Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK
| | - Michael Vere
- Department of Health, Harare City Council, Rowan Martin Building, Harare, Zimbabwe
| | - Phillomina Chitando
- Department of Health, Harare City Council, Rowan Martin Building, Harare, Zimbabwe
| | - Prosper Chonzi
- Department of Health, Harare City Council, Rowan Martin Building, Harare, Zimbabwe
| | - Thomas C Darton
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Justin Dixon
- Biomedical Research and Training Institute, Harare, Zimbabwe; Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK
| | - Katharina Kranzer
- Biomedical Research and Training Institute, Harare, Zimbabwe; Clinical Research Department, London School of Hygiene & Tropical Medicine, London, UK; Division of Infectious and Tropical Medicine, Medical Centre of the University of Munich, Munich, Germany
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Bansal SB, Ramasubramanian V, Prasad N, Saraf N, Soman R, Makharia G, Varughese S, Sahay M, Deswal V, Jeloka T, Gang S, Sharma A, Rupali P, Shah DS, Jha V, Kotton CN. South Asian Transplant Infectious Disease Guidelines for Solid Organ Transplant Candidates, Recipients, and Donors. Transplantation 2023; 107:1910-1934. [PMID: 36749281 DOI: 10.1097/tp.0000000000004521] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
These guidelines discuss the epidemiology, screening, diagnosis, posttransplant prophylaxis, monitoring, and management of endemic infections in solid organ transplant (SOT) candidates, recipients, and donors in South Asia. The guidelines also provide recommendations for SOT recipients traveling to this region. These guidelines are based on literature review and expert opinion by transplant physicians, surgeons, and infectious diseases specialists, mostly from South Asian countries (India, Pakistan, Bangladesh, Nepal, and Sri Lanka) as well as transplant experts from other countries. These guidelines cover relevant endemic bacterial infections (tuberculosis, leptospirosis, melioidosis, typhoid, scrub typhus), viral infections (hepatitis A, B, C, D, and E; rabies; and the arboviruses including dengue, chikungunya, Zika, Japanese encephalitis), endemic fungal infections (mucormycosis, histoplasmosis, talaromycosis, sporotrichosis), and endemic parasitic infections (malaria, leishmaniasis, toxoplasmosis, cryptosporidiosis, strongyloidiasis, and filariasis) as well as travelers' diarrhea and vaccination for SOT candidates and recipients including travelers visiting this region. These guidelines are intended to be an overview of each topic; more detailed reviews are being published as a special supplement in the Indian Journal of Transplantation .
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Affiliation(s)
- Shyam Bihari Bansal
- Department of Nephrology and Kidney Transplantation, Medanta Institute of Kidney and Urology Medanta-Medicity, Gurgaon, India
| | | | - Narayan Prasad
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Neeraj Saraf
- Department of Hepatology, Medanta, Medicity, Gurgaon, India
| | - Rajeev Soman
- Department of Infectious Diseases, Jupiter Hospital, Pune, India
| | - Govind Makharia
- Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Santosh Varughese
- Department of Nephrology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Manisha Sahay
- Department of Nephrology, Osmania Medical College, and Hospital, Hyderabad, India
| | - Vikas Deswal
- Department of Infectious Diseases, Medanta, Medicity, Gurgaon, India
| | - Tarun Jeloka
- Department of Infectious Diseases, Jupiter Hospital, Pune, India
| | - Sishir Gang
- Department of Nephrology, Muljibhai Patel Urological Hospital, Nadiad, Gujrat, India
| | - Ashish Sharma
- Department of Renal Transplant Surgery, PGIMER, Chandigarh, India
| | - Priscilla Rupali
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | - Dibya Singh Shah
- Department of Nephrology and Transplant Medicine, Institute of Medicine, Tribhuvan University of Teaching hospital, Kathmandu, Nepal
| | | | - Camille Nelson Kotton
- Transplant and Immunocompromised Host Infectious Diseases Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA
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Johnston PI, Bogue P, Chirambo AC, Mbewe M, Prakash R, Kandoole-Kabwere V, Lester R, Darton T, Baker S, Gordon MA, Meiring JE. Bacterial shedding and serologic responses following an outbreak of Salmonella Typhi in an endemic cohort. BMC Infect Dis 2023; 23:416. [PMID: 37340341 DOI: 10.1186/s12879-023-08385-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/08/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Salmonella enterica serovar Typhi (Salmonella Typhi) is the cause of typhoid fever. Salmonella Typhi may be transmitted through shedding in the stool, which can continue after recovery from acute illness. Shedding is detected by culturing stool, which is challenging to co-ordinate at scale. We hypothesised that sero-surveillance would direct us to those shedding Salmonella Typhi in stool following a typhoid outbreak. METHODS In 2016 a typhoid outbreak affected one in four residents of a Nursing School in Malosa, Malawi. The Department of Health asked for assistance to identify nursing students that might spread the outbreak to other health facilities. We measured IgG antibody titres against Vi capsular polysaccharide (anti-Vi IgG) and IgM / IgG antibodies against H:d flagellin (anti-H:d) three and six months after the outbreak. We selected participants in the highest and lowest deciles for anti-Vi IgG titre (measured at visit one) and obtained stool for Salmonella culture and PCR. All participants reported whether they had experienced fever persisting for three days or more during the outbreak (in keeping with the WHO definitions of 'suspected typhoid'). We tested for salmonellae in the Nursing School environment. RESULTS We obtained 320 paired serum samples from 407 residents. We cultured stool from 25 residents with high anti-Vi IgG titres and 24 residents with low titres. We did not recover Salmonella Typhi from stool; four stool samples yielded non-typhoidal salmonellae; one sample produced a positive PCR amplification for a Salmonella Typhi target. Median anti-Vi and anti-H:d IgG titres fell among participants who reported persistent fever. There was a smaller fall in anti-H:d IgG titres among participants who did not report persistent fever. Non-typhoidal salmonellae were identified in water sampled at source and from a kitchen tap. CONCLUSION High titres of anti-Vi IgG did not identify culture-confirmed shedding of Salmonella Typhi. There was a clear serologic signal of recent typhoid exposure in the cohort, represented by waning IgG antibody titres over time. The presence of non-typhoidal salmonellae in drinking water indicates sub-optimal sanitation. Developing methods to detect and treat shedding remains an important priority to complement typhoid conjugate vaccination in efforts to achieve typhoid elimination.
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Affiliation(s)
- Peter I Johnston
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK.
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
| | - Patrick Bogue
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Angeziwa Chunga Chirambo
- Department of Medical Laboratory Sciences, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Maurice Mbewe
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Reenesh Prakash
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | - Rebecca Lester
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Thomas Darton
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, South Yorkshire, UK
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge, Cambridge, UK
| | - Melita A Gordon
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - James E Meiring
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, South Yorkshire, UK
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Geteneh A, Tadesse S, Biset S, Girma L, Fissiha P. Rapid stool antigenic test for typhoid fever among suspected cases, Northeast, Ethiopia. Sci Rep 2023; 13:649. [PMID: 36635427 PMCID: PMC9837061 DOI: 10.1038/s41598-023-27909-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 01/10/2023] [Indexed: 01/14/2023] Open
Abstract
Typhoid fever continued to be the key cause of morbidity and mortality in developing countries with poor hygienic practices and limited access to safe drinking water. The Widal card agglutination test is the main diagnostic tool in Ethiopia, which is limited in differentiating the overlapping symptoms with other acute febrile illnesses such as malaria and viral enteritis. This eventually leds to unnecessary antibiotic use and eventual drug resistance. Therefore this study wants to assess the burden and associated potential risk factors of typhoid fever among suspected cases using the typhoid rapid stool antigen test in Northeast Ethiopia. A hospital-based cross-sectional study was conducted at Gaint and Meket Shediho primary hospitals from May to July 2021. A total of 255 patients clinically suspected of typhoid fever, and willing to grant informed consent were included systematically. The demographic and hygiene-related variables were collected using a pre-tested structured questionnaire. The rapid stool antigenic test and xylose-lysine-deoxycholate agar (XLD) stool culture were evaluated for the level of agreement. The present study indicated that the prevalence of typhoid fever was 15.3%. This displayed that the human-restricted infectious disease, typhoid fever remained a challenge to Ethiopians. Washing hands with soap, history of typhoid fever, having previous history of hospitalization, and chronic underlying disease was the significant potential factor for typhoid fever. The higher agreement of the rapid stool antigenic test with the stool culture can indicate the factual burden of typhoid fever in the suspected population. This could minimize empiric treatment and the possible emergence of drug resistance. Thus, resource-poor settings may need to look for a rapid and reliable stool antigenic test.
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Affiliation(s)
- Alene Geteneh
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia, Ethiopia.
| | - Selamyhun Tadesse
- grid.507691.c0000 0004 6023 9806Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia, Ethiopia
| | - Sirak Biset
- grid.59547.3a0000 0000 8539 4635Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, University of Gondar, Gondar, Ethiopia
| | - Lencho Girma
- Department of Medical Laboratory Science, Mizan Aman College of Health Sciences, Aman, Ethiopia
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Igiri BE, Okoduwa SIR, Munirat SA, Otu-Bassey IB, Bashir A, Onyiyioza OM, Enang IA, Okoduwa UJ. Diversity in Enteric Fever Diagnostic Protocols and Recommendation for Composite Reference Standard. IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY 2023; 17:22-38. [DOI: 10.30699/ijmm.17.1.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Muacevic A, Adler JR. Clinical and Laboratory Features of Enteric Fever in Children and Antibiotic Sensitivity Pattern in a Tertiary Care Hospital of a Low- and Middle-Income Country. Cureus 2022; 14:e30784. [PMID: 36320797 PMCID: PMC9614183 DOI: 10.7759/cureus.30784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Globally, enteric fever (EF) significantly gives rise to an appalling death toll. It is an endemic illness in Bangladesh and South Asia. The condition manifests in a wide range of clinical features in children. Nowadays, antibiotic resistance is an international stumbling block that hampers the appropriate treatment and outcome of EF. OBJECTIVE The study evaluated the clinical and laboratory characteristics and antibiotic sensitivity pattern of Salmonella enterica in children. METHODS This prospective research was conducted at Delta Medical College and Hospital, Dhaka, Bangladesh, from January 2017 to December 2019. A total of 200 pediatric cases of EF were included in this study who were either culture positive or had significantly raised Widal test titer for Salmonella with suggestive clinical features. RESULTS All the patients had a fever, and most had coated tongue, vomiting, abdominal pain, organomegaly, and diarrhea. Among the selected 200 cases of EF, 43.5% were Salmonella typhi culture-positive. A high erythrocyte sedimentation rate (ESR) was observed in a substantial number (53%) of patients. Ceftriaxone was the most sensitive (100%) antibiotic through laboratory analysis, followed by cefotaxime (95.1%). Among the oral antibiotics used, cefixime (92.8%) was the most sensitive. CONCLUSION EF in children can present with varied clinical manifestations. Selective antibiotic treatment according to sensitivity patterns is crucial for effective illness management and will reduce morbidity and mortality in the pediatric population.
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Multiplex PCR assay to detect high risk lineages of Salmonella Typhi and Paratyphi A. PLoS One 2022; 17:e0267805. [PMID: 35867662 PMCID: PMC9307194 DOI: 10.1371/journal.pone.0267805] [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: 10/11/2021] [Accepted: 04/14/2022] [Indexed: 11/19/2022] Open
Abstract
Enteric fever infections remain a significant public health issue, with up to 20 million infections per year. Increasing rates of antibiotic resistant strains have rendered many first-line antibiotics potentially ineffective. Genotype 4.3.1 (H58) is the main circulating lineage of S. Typhi in many South Asian countries and is associated with high levels of antibiotic resistance. The emergence and spread of extensively drug resistant (XDR) typhoid strains has increased the need for a rapid molecular test to identify and track these high-risk lineages for surveillance and vaccine prioritisation. Current methods require samples to be cultured for several days, followed by DNA extraction and sequencing to determine the specific lineage. We designed and evaluated the performance of a new multiplex PCR assay, targeting S. Paratyphi A as well as the H58 and XDR lineages of S. Typhi on a collection of bacterial strains. Our assay was 100% specific for the identification of lineage specific S. Typhi and S. Paratyphi A, when tested with a mix of non-Typhi Salmonella and non-Salmonella strains. With additional testing on clinical and environmental samples, this assay will allow rapid lineage level detection of typhoid of clinical significance, at a significantly lower cost to whole-genome sequencing. To our knowledge, this is the first report of a SNP-based multiplex PCR assay for the detection of lineage specific serovars of Salmonella Typhi.
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Kariuki S, Kering K, Wairimu C, Onsare R, Mbae C. Antimicrobial Resistance Rates and Surveillance in Sub-Saharan Africa: Where Are We Now? Infect Drug Resist 2022; 15:3589-3609. [PMID: 35837538 PMCID: PMC9273632 DOI: 10.2147/idr.s342753] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/16/2022] [Indexed: 01/03/2023] Open
Abstract
Introduction Although antimicrobials have traditionally been used to treat infections and improve health outcomes, resistance to commonly used antimicrobials has posed a major challenge. An estimated 700,000 deaths occur globally every year as a result of infections caused by antimicrobial-resistant pathogens. Antimicrobial resistance (AMR) also contributes directly to the decline in the global economy. In 2019, sub-Saharan Africa (SSA) had the highest mortality rate (23.5 deaths per 100,000) attributable to AMR compared to other regions. Methods We searched PubMed for articles relevant to AMR in pathogens in the WHO-GLASS list and in other infections of local importance in SSA. In this review, we focused on AMR rates and surveillance of AMR for these priority pathogens and some of the most encountered pathogens of public health significance. In addition, we reviewed the implementation of national action plans to mitigate against AMR in countries in SSA. Results and Discussion The SSA region is disproportionately affected by AMR, in part owing to the prevailing high levels of poverty, which result in a high burden of infectious diseases, poor regulation of antimicrobial use, and a lack of alternatives to ineffective antimicrobials. The global action plan as a strategy for prevention and combating AMR has been adopted by most countries, but fewer countries are able to fully implement country-specific action plans, and several challenges exist in many settings. Conclusion A concerted One Health approach will be required to ramp up implementation of action plans in the region. In addition to AMR surveillance, effective implementation of infection prevention and control, water, sanitation, and hygiene, and antimicrobial stewardship programs will be key cost-effective strategies in helping to tackle AMR.
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Affiliation(s)
- Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya,Correspondence: Samuel Kariuki, Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya, Email
| | - Kelvin Kering
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Celestine Wairimu
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Robert Onsare
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Cecilia Mbae
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
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12
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Ashraf Hussain M, Ahmed I, Akram S, Khan MA, Ali S, Amir M. Extensively Drug-Resistant Typhoidal Salmonellae: Are These Bugs Swarming Into Suburban and Rural Areas of Pakistan? Cureus 2022; 14:e26189. [PMID: 35891850 PMCID: PMC9306454 DOI: 10.7759/cureus.26189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2022] [Indexed: 11/05/2022] Open
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13
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Kim CL, Cruz Espinoza LM, Vannice KS, Tadesse BT, Owusu-Dabo E, Rakotozandrindrainy R, Jani IV, Teferi M, Bassiahi Soura A, Lunguya O, Steele AD, Marks F. The Burden of Typhoid Fever in Sub-Saharan Africa: A Perspective. Res Rep Trop Med 2022; 13:1-9. [PMID: 35308424 PMCID: PMC8932916 DOI: 10.2147/rrtm.s282461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/12/2022] [Indexed: 11/23/2022] Open
Abstract
While typhoid fever has largely been eliminated in high-income regions which have developed modern water, sanitation, and hygiene facilities, it remains a significant public health burden resulting in morbidity and mortality among millions of individuals in resource-constrained settings. Prevention and control efforts are needed that integrate several high-impact interventions targeting facilities and infrastructure, including those addressing improvements in sanitation, access to safe water, and planned urbanization, together with parallel efforts directed at effective strategies for use of typhoid conjugate vaccines (TCV). The use of TCVs is a critical tool with the potential of having a rapid impact on typhoid fever disease burden; their introduction will also serve as an important strategy to combat evolving antimicrobial resistance to currently available typhoid fever treatments. Well-designed epidemiological surveillance studies play a critical role in establishing the need for, and monitoring the impact of, typhoid fever control and prevention strategies implemented by public health authorities. Here, we present a perspective based on a narrative review of the impact of typhoid fever on morbidity and mortality in sub-Saharan Africa and discuss ongoing surveillance activities and the role of vaccination in prevention and control efforts.
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Affiliation(s)
- Cara Lynn Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Kirsten S Vannice
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Birkneh Tilahun Tadesse
- International Vaccine Institute, Seoul, Republic of Korea
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Center for Innovative Drug Development and Therapeutic Trials for Africa, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ellis Owusu-Dabo
- School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Ilesh V Jani
- Instituto Nacional de Saúde (INS), Maputo Province, Mozambique
| | | | - Abdramane Bassiahi Soura
- Institut Supérieur des Sciences de la Population, Université Joseph Ki-Zerbo de Ouagadougou, Ouagadougou, Burkina Faso
| | - Octavie Lunguya
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
- Department of Medical Biology, University Teaching Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - A Duncan Steele
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
- University of Antananarivo, Antananarivo, Madagascar
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
- Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany
- Correspondence: Florian Marks, Tel +82-2-881-1133, Email
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14
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Vikas S, Duggal N. An observational study to compare the diagnostic accuracy of rapid antigen test and rapid antibody tests in various periods of enteric fever. Trop Doct 2022; 52:311-314. [DOI: 10.1177/00494755221074538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A cross-sectional observational study was done on 180 fever patients to assess the diagnostic accuracy of rapid serological tests in early detection (<5 days of fever) of S. typhi and S. paratyphi in comparison to blood culture and Widal test Blood culture was positive in 58 (32.22%) cases. The diagnostic accuracy (<5 days of fever) of rapid antigen test, rapid antibody test, and Widal test was 45.56%, 42.22%, and 41.11% (p = 0.675) while sensitivity was 68.97%, 48.28%, and 46.55%, respectively. In conclusion, rapid antigen test holds moderately higher sensitivity in the first five days of fever as compared to rapid antibody and Widal tests. It is recommended that the antigen detection tests should be used for screening enteric fever in the first week of presentation.
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Affiliation(s)
- Saini Vikas
- University College Of Medical Sciences And Guru Teg Bahadur Hospital, Delhi, India
| | - Nandini Duggal
- Atal Bihari Vajpayee Institute of Medical Sciences (ABVIMS) and Dr RML Hospital, New Delhi, India
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15
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William V, Rusmawatiningtyas D, Makrufardi F, Kumara IF. Sepsis and disseminated intravascular coagulation are rare complications of typhoid fever: A case report. Ann Med Surg (Lond) 2022; 73:103226. [PMID: 35079365 PMCID: PMC8767294 DOI: 10.1016/j.amsu.2021.103226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION and importance: Typhoid fever is an infection caused by Salmonella typhi. The common complications are intestinal perforation and typhoid encephalopathy. Cases of typhoid fever with sepsis and/or disseminated intravascular coagulation (DIC) are rarely reported, even though typhoid fever is endemic in Indonesia. CASE PRESENTATION A 4-year-old male referral case from a district hospital was experiencing fever, decrease of consciousness and massive bleeding from his gastrointestinal tract and nose. Investigation revealed results from the IgM typhoid test using Tubex®TF, with the score of +8. PELOD 2 score was 10, and PSOFA was 5. DIC score was 7. Based on these findings, the patient was diagnosed with typhoid fever, with DIC and sepsis being the complication of the typhoid fever. CLINICAL DISCUSSION DIC is mostly a subclinical event, and severe bleeding complications found in typhoid fever are uncommon, although DIC scores which indicate an imbalance of coagulation and fibrinolysis are markedly elevated in patients with typhoid. DIC can be a part of multi-organ dysfunction due to sepsis syndrome. Acute infection can also result in systemic activation of coagulation. CONCLUSION Sepsis and DIC are rare complications of typhoid fever. Typhoid fever can be presented with profound bleeding manifestation other than gastrointestinal bleeding, since it is a common symptom of typhoid fever. Further research should be conducted to postulate association between typhoid fever and DIC.
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16
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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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17
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Vasconcelos A, Sousa S, Bandeira N, Alves M, Papoila AL, Pereira F, Machado MC. Antenatal screenings and maternal diagnosis among pregnant women in Sao Tome & Principe-Missed opportunities to improve neonatal health: A hospital-based study. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0001444. [PMID: 36962895 PMCID: PMC10021443 DOI: 10.1371/journal.pgph.0001444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 11/30/2022] [Indexed: 12/30/2022]
Abstract
Newborn mortality and adverse birth outcomes (ABOs) in Sao Tome & Príncipe (STP) are overwhelmingly high, and access to quality-antenatal care (ANC) is one of the strategies to tackle it. This study aimed to fill the gaps in ANC screenings with a focus on how to improve neonatal outcomes. We conducted a retrospective hospital-based study in which ANC pregnancy cards were reviewed. Screenings were described and compared according to the total number of ANC contacts: 1-3 (inadequate), 4-7 (adequate), and ≥8 (complete). The collected data were entered into QuickTapSurvey and exported to SPSS version 25 for analysis. Statistical significance was considered at a p-value ≤0.05. A total of 511 ANC pregnancy cards were reviewed. Mothers' mean age was 26.6 (SD = 7.1), 51.7% had a first trimester early booking, 14.9% (76) had 1-3 ANC contacts, 46.4% (237) had 4-7 and 38.7% (198) ≥8. Screening absence was found in 24%-41%, lack of money was registered in 36%. Pregnant women had no screening performed for HIV in 4.5%, syphilis in 8.8%, HBV 39.3%, malaria 25.8%, hemoglobin 24.5%, blood glucose 45.4%, urine 29.7%, stool exams 27.8% and 41.1% had no ultrasound. Screening completion for blood group, HIV, malaria, urine, hemoglobin, and coproparasitological exam were found to have a statistically significant difference (p<0.001) for the complete ANC group when compared to other groups. Antenatal problems identified were: 1) bacteriuria (43.2%); 2) maternal anemia (37%); 3) intestinal parasitic infections (59.2%); 4) sickle cell solubility test positive (13%); and 5) a RhD-negative phenotype (5.8%). Missed-ANC treatments were up to 50%. This study reveals a coverage-quality gap in STP since no pregnant woman is left without ANC contact, although most still miss evidence-based screenings with an impact on neonatal outcomes. Strategies such as implementing a total free ANC screening package in STP would enhance maternal diagnosis and prompt treatments.
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Affiliation(s)
- Alexandra Vasconcelos
- Unidade de Clínica Tropical-Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa, Lisboa, Portugal
| | | | - Nelson Bandeira
- Hospital Dr. Ayres de Menezes, São Tomé, Sao Tome and Principe
| | - Marta Alves
- CEAUL, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Ana Luísa Papoila
- CEAUL, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Filomena Pereira
- Unidade de Clínica Tropical-Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa, Lisboa, Portugal
| | - Maria Céu Machado
- Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisboa, Portugal
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18
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Frempong SN, King N, Sagoo GS. The cost-effectiveness of using rapid diagnostic tests for the diagnosis of typhoid fever in patients with suspected typhoid fever: a systematic review. Expert Rev Pharmacoecon Outcomes Res 2021; 22:391-397. [PMID: 34842022 DOI: 10.1080/14737167.2022.2012453] [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: 10/19/2022]
Abstract
INTRODUCTION Despite the availability of several commercial rapid diagnostic tests (RDTs) developed to detect typhoid fever, the cost-effectiveness in resource-limited settings is unclear. This review aimed to explore the literature on typhoid economic evaluations in order to assess the cost-effectiveness of using typhoid RDTs in resource-limited settings. AREAS COVERED A systematic review was conducted focusing on the identification of economic evaluations of typhoid RDTs to diagnose patients with suspected typhoid fever. Two studies were identified and included for narrative synthesis. Whilst highlighting a gap in the published literature, this review shows the use of typhoid RDTs to potentially be cost-effective in resource-limited settings. Factors that appeared as significant in determining cost-effectiveness related to test characteristics (such as sensitivity, specificity, and cost) and the prevalence of typhoid fever and should factor into any future evaluations. EXPERT OPINION Concerted effort is needed in resource-limited settings with regard to medical device regulation to ensure that clinically effective and cost-effective typhoid RDTs are widely available and introduced into clinical practice. Typhoid modeling (with respect to typhoid testing and treatment strategies) represents an understudied area and further work is needed.
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Affiliation(s)
- Samuel N Frempong
- Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, United Kingdom (UK).,National Institute for Health Research (NIHR) Leeds in Vitro Diagnostics Co-operative, Leeds, United Kingdom (UK)
| | - Natalie King
- Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, United Kingdom (UK)
| | - Gurdeep S Sagoo
- Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, United Kingdom (UK).,National Institute for Health Research (NIHR) Leeds in Vitro Diagnostics Co-operative, Leeds, United Kingdom (UK)
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19
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Hefele L, Black AP, Van Tan T, Tri Minh N, Duc Hoang N, Virachith S, Muller CP, Hübschen JM, Russell P, Bartholdson Scott J, Ngoc Minh CN, Thieu Nga TV, Baker S. An age-stratified serosurvey against purified Salmonella enterica serovar Typhi antigens in the Lao People´s Democratic Republic. PLoS Negl Trop Dis 2021; 15:e0010017. [PMID: 34898620 PMCID: PMC8700045 DOI: 10.1371/journal.pntd.0010017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 12/23/2021] [Accepted: 11/22/2021] [Indexed: 11/18/2022] Open
Abstract
The epidemiology of typhoid fever in Lao People`s Democratic Republic is poorly defined. Estimating the burden of typhoid fever in endemic countries is complex due to the cost and limitations of population-based surveillance; serological approaches may be a more cost-effective alternative. ELISAs were performed on 937 serum samples (317 children and 620 adults) from across Lao PDR to measure IgG antibody titers against Vi polysaccharide and the experimental protein antigens, CdtB and HlyE. We measured the significance of the differences between antibody titers in adults and children and fitted models to assess the relationship between age and antibody titers. The median IgG titres of both anti-HylE and CdtB were significantly higher in children compared to adults (anti-HylE; 351.7 ELISA Units (EU) vs 198.1 EU, respectively; p<0.0001 and anti-CdtB; 52.6 vs 12.9 EU; p<0.0001). Conversely, the median anti-Vi IgG titer was significantly higher in adults than children (11.3 vs 3.0 U/ml; p<0.0001). A non-linear trend line fitted to the anti-CdtB and anti-HlyE IgG data identified a peak in antibody concentration in children <5 years of age. We identified elevated titers of anti-HlyE and anti-CdtB IgG in the serum of children residing in Lao PDR in comparison to adults. These antigens are associated with seroconversion after typhoid fever and may be a superior measure of disease burden than anti-Vi IgG. This approach is scalable and may be developed to assess the burden of typhoid fever in countries where the disease may be endemic, and evidence is required for the introduction of typhoid vaccines. Typhoid fever is a serious bloodstream infection caused by the bacterium Salmonella Typhi. Estimating the burden of typhoid fever is complex due to the limitations, cost, and scalability of current diagnostic surveillance methods. The detection of specific antibody responses against the organism may be a more sustainable manner of measuring exposure and disease burden in endemic location. We measured antibody (IgG) in 937 serum samples (317 children and 620 adults) from across the Lao People`s Democratic Republic against a polysaccharide (Vi) and two experimental protein antigens, CdtB and HlyE, that may more appropriate markers of disease exposure. We measured the significance of the differences between antibody titers in adults and children and fitted models to assess the relationship between age and antibody titers. The median IgG titres against HylE and CdtB were significantly higher in children than adults. Conversely, the median IgG titres against Vi was significantly higher in adults than children. We identified a significant association between a peak in IgG titres against CdtB and HlyE in children aged under 5 years. These data are indicative of high level of typhoid fever exposure in children under 5 years of age in Lao PDR and we surmise that IgG titres against HylE and CdtB may be a superior measure of typhoid disease burden than IgG titres against Vi. Our approach is scalable and can be further validated to assess the burden of typhoid fever in countries where the disease may be endemic, and evidence is required for the introduction of typhoid vaccines.
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Affiliation(s)
- Lisa Hefele
- Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Grand-Duchy of Luxembourg
- Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
| | - Antony P. Black
- Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
| | - Trinh Van Tan
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nguyen Tri Minh
- University of Natural Sciences, Ho Chi Minh City Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Nguyen Duc Hoang
- University of Natural Sciences, Ho Chi Minh City Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Siriphone Virachith
- Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao People’s Democratic Republic
| | - Claude P. Muller
- Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Grand-Duchy of Luxembourg
| | - Judith M. Hübschen
- Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Grand-Duchy of Luxembourg
| | - Paula Russell
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Josefin Bartholdson Scott
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Chau Nguyen Ngoc Minh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran Vu Thieu Nga
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- * E-mail:
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20
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Srinivasan M, Sindhu KN, Ramanujam K, Ramasamy RK, Subramaniam S, Ganesan SK, Vajja S, David AS, Lankala P, Rose W, Moses PD, Grassly NC, Kang G, John J. Factors Predicting Blood Culture Positivity in Children With Enteric Fever. J Infect Dis 2021; 224:S484-S493. [PMID: 35238358 PMCID: PMC8892536 DOI: 10.1093/infdis/jiab357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Blood culture, despite low sensitivity, is the gold standard for enteric fever diagnosis. Understanding predictors of blood culture positivity may help design strategies to optimize enteric fever diagnosis. METHODS A cohort of 6760 children aged 0.5-15 years was followed for 3 years for enteric fever with blood cultures in an automated system, for fevers >3 days. Factors affecting test positivity in fevers and participant-level predictors for culture refusals were analyzed using regression models. RESULTS Overall, 6097 suspected typhoid/paratyphoid fever (STF) episodes were reported, of which 5703 (93.5%) STFs had sampling for blood cultures, with 394 (6.5%) refusals. Salmonella enterica serovar Typhi/Paratyphi positivity was culture-confirmed in 3.8% (218/5703) of STF episodes. Older children (odds ratio [OR], 1.96 [95% CI, 1.39-2.77]), larger blood volume inoculated (OR, 2.82 [95% CI, 1.71-4.66]), higher temperatures during fever (OR, 3.77 [95% CI, 2.89-4.91]), and fevers diagnosed as suspected typhoid or acute undifferentiated fever (OR, 6.06 [95% CI, 3.11-11.78]) had a higher probability of culture positivity. Antibiotics before culture did not decrease culture positivity. Blood culture refusals were higher for children from wealthier households or with milder illness. CONCLUSIONS Performing blood cultures in older children with fever, especially those fevers with toxic presentation and increasing blood volume for inoculation are strategies to improve enteric fever detection in surveillance settings.
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Affiliation(s)
- Manikandan Srinivasan
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | | | - Karthikeyan Ramanujam
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Ranjith Kumar Ramasamy
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Sathyapriya Subramaniam
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Santhosh Kumar Ganesan
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Swathi Vajja
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Anita Shirley David
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Pramitha Lankala
- Department of Community Health, Christian Medical College, Vellore, India
| | - Winsley Rose
- Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Prabhakar D Moses
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Nicholas C Grassly
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Wellcome Trust Research Laboratory, Christian Medical College, Vellore, India
| | - Jacob John
- Department of Community Health, Christian Medical College, Vellore, India,Correspondence: Jacob John, MD, PhD, Department of Community Health, Christian Medical College, Vellore, Tamil Nadu 632 004, India ()
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21
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Waqas S. An alarm bell: increase in MDR and XDR enteric fever over ten years. J R Coll Physicians Edinb 2021; 51:310-317. [PMID: 34528634 DOI: 10.4997/jrcpe.2021.330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Sarmad Waqas
- St Vincent's University Hospital, Elm Park, Dublin 4, Republic of Ireland,
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22
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Performance of Immunodiagnostic Tests for Typhoid Fever: A Systematic Review and Meta-Analysis. Pathogens 2021; 10:pathogens10091184. [PMID: 34578216 PMCID: PMC8467574 DOI: 10.3390/pathogens10091184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 12/23/2022] Open
Abstract
Typhoid fever, also known as typhoid, is a life-threatening bacterial infection that remains a global health concern. The infection is associated with a significant morbidity and mortality rate, resulting in an urgent need for specific and rapid detection tests to aid prevention and management of the disease. The present review aims to assess the specificity and sensitivity of the available literature on the immunodiagnostics of typhoid fever. A literature search was conducted using three databases (PubMed, ProQuest and Scopus) and manual searches through the references of identified full texts to retrieve relevant literature published between 1 January 2011 and 31 December 2020. Of the 577 studies identified in our search, 12 were included in further analysis. Lipopolysaccharides (LPS) and hemolysin E (HlyE) were the most frequently studied antigens. The specimens examined in these studies included serum and saliva. Using blood culture as the gold standard, anti-LPS IgA gave the highest sensitivity of 96% (95% CI: 93–99) and specificity of 96% (95% CI: 93–99) for distinguishing between typhoid cases and healthy controls, whereas the combination of anti-LPS and anti-flagellin total IgGAM gave the highest sensitivity of 93% (95% CI: 86–99) and specificity of 95% (95% CI: 89–100) for distinguishing typhoid cases and other febrile infections. A comparably high sensitivity of 92% (95% CI: 86–98) and specificity of 89% (95% CI: 78–100) were shown in testing based on detection of the combination of anti-LPS (IgA and IgM) and anti-HlyE IgG as well as a slightly lower sensitivity of 91% (95% CI: 74–100) in the case of anti-50kDa IgA. Anti-50kDa IgM had the lowest sensitivity of 36% (95% CI: 6–65) against both healthy and febrile controls. The development of a rapid diagnostic test targeting antibodies against lipopolysaccharides combined with flagellin appeared to be a suitable approach for the rapid detection test of typhoid fever. Saliva is added benefit for rapid typhoid diagnosis since it is less invasive. As a result, further studies could be done to develop additional approaches for adopting such samples.
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23
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Carey ME, MacWright WR, Im J, Meiring JE, Gibani MM, Park SE, Longley A, Jeon HJ, Hemlock C, Yu AT, Soura A, Aiemjoy K, Owusu-Dabo E, Terferi M, Islam S, Lunguya O, Jacobs J, Gordon M, Dolecek C, Baker S, Pitzer VE, Yousafzai MT, Tonks S, Clemens JD, Date K, Qadri F, Heyderman RS, Saha SK, Basnyat B, Okeke IN, Qamar FN, Voysey M, Luby S, Kang G, Andrews J, Pollard AJ, John J, Garrett D, Marks F. The Surveillance for Enteric Fever in Asia Project (SEAP), Severe Typhoid Fever Surveillance in Africa (SETA), Surveillance of Enteric Fever in India (SEFI), and Strategic Typhoid Alliance Across Africa and Asia (STRATAA) Population-based Enteric Fever Studies: A Review of Methodological Similarities and Differences. Clin Infect Dis 2021; 71:S102-S110. [PMID: 32725221 PMCID: PMC7388711 DOI: 10.1093/cid/ciaa367] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Building on previous multicountry surveillance studies of typhoid and others salmonelloses such as the Diseases of the Most Impoverished program and the Typhoid Surveillance in Africa Project, several ongoing blood culture surveillance studies are generating important data about incidence, severity, transmission, and clinical features of invasive Salmonella infections in sub-Saharan Africa and South Asia. These studies are also characterizing drug resistance patterns in their respective study sites. Each study answers a different set of research questions and employs slightly different methodologies, and the geographies under surveillance differ in size, population density, physician practices, access to healthcare facilities, and access to microbiologically safe water and improved sanitation. These differences in part reflect the heterogeneity of the epidemiology of invasive salmonellosis globally, and thus enable generation of data that are useful to policymakers in decision-making for the introduction of typhoid conjugate vaccines (TCVs). Moreover, each study is evaluating the large-scale deployment of TCVs, and may ultimately be used to assess post-introduction vaccine impact. The data generated by these studies will also be used to refine global disease burden estimates. It is important to ensure that lessons learned from these studies not only inform vaccination policy, but also are incorporated into sustainable, low-cost, integrated vaccine-preventable disease surveillance systems.
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Affiliation(s)
- Megan E Carey
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - Justin Im
- International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - James E Meiring
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom.,Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Malick M Gibani
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Infectious Diseases, Imperial College London, London, United Kingdom
| | - Se Eun Park
- International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - Ashley Longley
- Global Immunization Division, Centers for Disease Control Foundation, Atlanta, Georgia, USA
| | - Hyon Jin Jeon
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
| | - Caitlin Hemlock
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA
| | - Alexander T Yu
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Abdramane Soura
- Institut Supérieur des Sciences de la Population, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Kristen Aiemjoy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Ellis Owusu-Dabo
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Sahidul Islam
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Octavie Lunguya
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Melita Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - Christiane Dolecek
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Stephen Baker
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
| | | | - Susan Tonks
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - John D Clemens
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.,Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California, USA
| | - Kashmira Date
- Global Immunization Division, Centers for Disease Control Foundation, Atlanta, Georgia, USA
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Robert S Heyderman
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Samir K Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Buddha Basnyat
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Iruka N Okeke
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Idaban, Nigeria
| | - Farah N Qamar
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Merryn Voysey
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - Stephen Luby
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | | | - Jason Andrews
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California, USA
| | - Andrew J Pollard
- Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
| | - Jacob John
- Christian Medical College, Vellore, India
| | - Denise Garrett
- Sabin Vaccine Institute, Washington, District of Columbia, USA
| | - Florian Marks
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,International Vaccine Institute, SNU Research Park, Seoul, Republic of Korea
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24
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Steele AD, Carey ME, Kumar S, MacLennan CA, Ma LF, Diaz Z, Zaidi AKM. Typhoid Conjugate Vaccines and Enteric Fever Control: Where to Next? Clin Infect Dis 2021; 71:S185-S190. [PMID: 32725223 PMCID: PMC7388705 DOI: 10.1093/cid/ciaa343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
After the unprecedented success and acceleration of the global agenda towards typhoid fever control with a strong World Health Organization recommendation and the approval of funding from Gavi, the Vaccine Alliance (Gavi), for the use of a new typhoid conjugate vaccine (TCV), we should turn our minds to the challenges that remain ahead. Despite the evidence showing the safety and clinical efficacy of TCV in endemic populations in developing countries, we should remain vigilant and explore hurdles for the full public health impact of TCV, including vaccine supply for the potential global demand, immunization strategies to optimize the effectiveness and long-term protection provided by the vaccines, potential use of TCV in outbreak settings, and scenarios for addressing chronic carriers. Finally, challenges face endemic countries with poor surveillance systems concerning awareness of the need for TCV and the extent of the issue across their populations, and how to target immunization strategies appropriately.
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Affiliation(s)
- A Duncan Steele
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Megan E Carey
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Supriya Kumar
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Calman A MacLennan
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Lyou-Fu Ma
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Zoey Diaz
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Anita K M Zaidi
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
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25
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Pokharel S, White LJ, Aguas R, Celhay O, Pellé KG, Dittrich S. Algorithm in the Diagnosis of Febrile Illness Using Pathogen-specific Rapid Diagnostic Tests. Clin Infect Dis 2021; 70:2262-2269. [PMID: 31313805 PMCID: PMC7245147 DOI: 10.1093/cid/ciz665] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/16/2019] [Indexed: 11/21/2022] Open
Abstract
Background In the absence of proper guidelines and algorithms, available rapid diagnostic tests (RDTs) for common acute undifferentiated febrile illnesses are often used inappropriately. Methods Using prevalence data of 5 common febrile illnesses from India and Cambodia, and performance characteristics (sensitivity and specificity) of relevant pathogen-specific RDTs, we used a mathematical model to predict the probability of correct identification of each disease when diagnostic testing occurs either simultaneously or sequentially in various algorithms. We developed a web-based application of the model so as to visualize and compare output diagnostic algorithms when different disease prevalence and test performance characteristics are introduced. Results Diagnostic algorithms with appropriate sequential testing predicted correct identification of etiology in 74% and 89% of patients in India and Cambodia, respectively, compared with 46% and 49% with simultaneous testing. The optimally performing sequential diagnostic algorithms differed in India and Cambodia due to varying disease prevalence. Conclusions Simultaneous testing is not appropriate for the diagnosis of acute undifferentiated febrile illnesses with presently available tests, which should deter the unsupervised use of multiplex diagnostic tests. The implementation of adaptive algorithms can predict better diagnosis and add value to the available RDTs. The web application of the model can serve as a tool to identify the optimal diagnostic algorithm in different epidemiological settings, while taking into account the local epidemiological variables and accuracy of available tests.
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Affiliation(s)
- Sunil Pokharel
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Lisa J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Ricardo Aguas
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Olivier Celhay
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Karell G Pellé
- Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Sabine Dittrich
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom.,Foundation for Innovative New Diagnostics, Geneva, Switzerland
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26
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Ndako JA, Olisa JA, Ifeanyichukwu IC, Ojo SKS, Okolie CE. Evaluation of diagnostic assay of patients with enteric fever by the box-plot distribution method. New Microbes New Infect 2020; 38:100795. [PMID: 33299564 PMCID: PMC7704413 DOI: 10.1016/j.nmni.2020.100795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/14/2020] [Indexed: 11/02/2022] Open
Abstract
Enteric fever is an invasive bacterial infection mostly caused by Salmonella enterica serovar Typhi, which is a common agent of enteric fever. This illness has been a major public health issue, as it affects a large number of individuals globally. The box-plot analytic method is involved in exploratory data analysis using statistical techniques to identify patterns that may be hidden in a group of numbers used to visually summarize and compare groups of data. We evaluted the effect of enteric fever on various haematologic parameters using the box-plot distribution model. Samples were obtained from 400 volunteer patients as well as healthy subjects (controls). Assay for typhoid fever was carried out using obtained serum samples to detect specific O and H antigens. Antibody titres of 1:80 and higher for anti-TO and 1:160 and higher for anti-TH antibodies were taken as cutoff values to indicate recent infection of typhoid fever. The haematologic parameters were evaluated using an automated haematology analyser. A statistically significant decrease was observed in packed cell volume, white blood cell count, erythrocyte sedimentation rate and haemoglobin concentration, while a statistically insignificant difference was observed in the neutrophils, lymphocytes and monocytes seen in the box-plot distribution analysis. Typhoid fever causes significant haematologic changes which could be helpful in diagnosis. The box-and-whisker plots compared the distributions of the haematologic parameters, spread and overall ranges. Awareness of these parameters could be useful in providing accurate diagnosis and therapy, particularly in underresourced endemic regions in developing countries.
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Affiliation(s)
- J A Ndako
- Department of Microbiology, Landmark University, Nigeria
| | - J A Olisa
- Department of Medical Services, Nigeria
| | - I C Ifeanyichukwu
- Department of Medical Laboratory Services, Landmark University Medical Center, Omu-Aran, Nigeria
| | - S K S Ojo
- Department of Microbiology, Federal University, Oye-Ekiti, Nigeria
| | - C E Okolie
- Department of Microbiology, Landmark University, Nigeria
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27
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Carey ME, Diaz ZI, Broadstock M, Bailey R, Bentsi-Enchill AD, Larson HJ. Toward Control? The Prospects and Challenges of Typhoid Conjugate Vaccine Introduction. Clin Infect Dis 2020; 69:S408-S411. [PMID: 31612940 PMCID: PMC6792119 DOI: 10.1093/cid/ciz483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
With a newly World Health Organization (WHO)-prequalified typhoid conjugate vaccine (TCV), Gavi funding for eligible countries, and a WHO policy recommendation for TCV use, now is the time for countries to introduce TCVs as part of an integrated typhoid control program, particularly in light of the increasing burden of antimicrobial resistance. Continued vaccine development efforts will lead to secure supply of low-cost vaccines, and ongoing vaccine studies will provide critical vaccine performance data and inform optimal deployment strategies, in both routine use and in outbreak settings. TCV programs should include thoughtful communication planning and community engagement to counter vaccine hesitancy.
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Affiliation(s)
- Megan E Carey
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Zoey I Diaz
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | | | - Roderick Bailey
- Wellcome Centre for Ethics and Humanities, University of Oxford, United Kingdom
| | - Adwoa D Bentsi-Enchill
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Heidi J Larson
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, United Kingdom.,Department of Health Metrics and Evaluation, University of Washington, Seattle
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28
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Mahendradas P, Kawali A, Luthra S, Srinivasan S, Curi AL, Maheswari S, Ksiaa I, Khairallah M. Post-fever retinitis - Newer concepts. Indian J Ophthalmol 2020; 68:1775-1786. [PMID: 32823394 PMCID: PMC7690479 DOI: 10.4103/ijo.ijo_1352_20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/09/2020] [Accepted: 07/20/2020] [Indexed: 12/18/2022] Open
Abstract
Post-fever retinitis (PFR) is an infectious or para-infectious uveitic entity caused by bacterial or viral agents and seen mainly in tropical countries. Systemic symptoms such as joint pain, skin rash are common during the febrile stage. On the basis of only clinical presentation, it is difficult to pin-point the exact etiology for PFR. Serological investigations, polymerase chain reaction, and knowledge of concurrent epidemics in the community may help to identify the etiological organism. Bacterial causes of PFR such as rickettsia and typhoid are treated with systemic antibiotics, with or without systemic steroid therapy, whereas PFR of viral causes such as chikungunya, dengue, West Nile virus, and Zika virus have no specific treatment and are managed with steroids. Nevertheless, many authors have advocated mere observation and the uveitis resolved with its natural course of the disease. In this article, we have discussed the clinical features, pathogenesis, investigations, and management of PFR.
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Affiliation(s)
- Padmamalini Mahendradas
- Department of Uveitis and Ocular Immunology, Narayana Nethralaya, Bengaluru, Karnataka, India
| | - Ankush Kawali
- Department of Uveitis and Ocular Immunology, Narayana Nethralaya, Bengaluru, Karnataka, India
| | | | - Sanjay Srinivasan
- Department of Uveitis and Ocular Immunology, Narayana Nethralaya, Bengaluru, Karnataka, India
| | - Andre L Curi
- National Institute of Infectious Diseases-INI-FIOCRUZ, Rio de Janeiro – Brazil
| | | | - Imen Ksiaa
- Department of Ophthalmology, FattoumaBourguiba University Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Moncef Khairallah
- Department of Ophthalmology, FattoumaBourguiba University Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
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29
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Soble A, Patel Z, Sosler S, Hampton L, Johnson H. Gavi Support for Typhoid Conjugate Vaccines: Moving From Global Investments to Country Introduction. Clin Infect Dis 2020; 71:S160-S164. [PMID: 32725236 PMCID: PMC7388709 DOI: 10.1093/cid/ciaa342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 03/27/2020] [Indexed: 11/17/2022] Open
Abstract
Nine years elapsed between Gavi’s investment decision to support typhoid conjugate vaccines (TCVs) in 2008 and Gavi support becoming available for countries to introduce TCV. The protracted path toward Gavi support for TCV highlights the challenges of vaccine development for lower-income countries and the importance of Gavi engagement as early as possible in product development processes to support the alignment of manufacturing, global policy, and program implementation. Early engagement would provide inputs to inform strategic vaccine investment decisions that transition more efficiently toward country implementation. Several countries have been approved for Gavi support to introduce TCV in 2019–2020. The paucity of generalizable typhoid epidemiological data in early introducing countries has reinforced the need for continued evidence generation regarding typhoid epidemiology and TCV impact. This has led to the development of guidance and tools to support country decision making for TCV introduction based on enhanced understanding of local typhoid burden and risk.
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Affiliation(s)
- Adam Soble
- Gavi, the Vaccine Alliance, Geneva, Switzerland
| | | | | | - Lee Hampton
- Gavi, the Vaccine Alliance, Geneva, Switzerland
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30
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Alhaj-Qasem DM, Al-Hatamleh MAI, Irekeola AA, Khalid MF, Mohamud R, Ismail A, Mustafa FH. Laboratory Diagnosis of Paratyphoid Fever: Opportunity of Surface Plasmon Resonance. Diagnostics (Basel) 2020; 10:diagnostics10070438. [PMID: 32605310 PMCID: PMC7400347 DOI: 10.3390/diagnostics10070438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/18/2020] [Accepted: 06/25/2020] [Indexed: 12/19/2022] Open
Abstract
Paratyphoid fever is caused by the bacterium Salmonellaenterica serovar Paratyphi (A, B and C), and contributes significantly to global disease burden. One of the major challenges in the diagnosis of paratyphoid fever is the lack of a proper gold standard. Given the absence of a licensed vaccine against S. Paratyphi, this diagnostic gap leads to inappropriate antibiotics use, thus, enhancing antimicrobial resistance. In addition, the symptoms of paratyphoid overlap with other infections, including the closely related typhoid fever. Since the development and utilization of a standard, sensitive, and accurate diagnostic method is essential in controlling any disease, this review discusses a new promising approach to aid the diagnosis of paratyphoid fever. This advocated approach is based on the use of surface plasmon resonance (SPR) biosensor and DNA probes to detect specific nucleic acid sequences of S. Paratyphi. We believe that this SPR-based genoassay can be a potent alternative to the current conventional diagnostic methods, and could become a rapid diagnostic tool for paratyphoid fever.
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Affiliation(s)
| | - Mohammad A. I. Al-Hatamleh
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia; (M.A.I.A.-H.); (R.M.)
| | - Ahmad Adebayo Irekeola
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia;
- Microbiology Unit, Department of Biological Sciences, College of Natural and Applied Sciences, Summit University Offa, Offa PMB 4412, Kwara State, Nigeria
| | - Muhammad Fazli Khalid
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia; (M.F.K.); (A.I.)
| | - Rohimah Mohamud
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia; (M.A.I.A.-H.); (R.M.)
- Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia
| | - Aziah Ismail
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia; (M.F.K.); (A.I.)
| | - Fatin Hamimi Mustafa
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia; (M.F.K.); (A.I.)
- Correspondence: ; Tel.: +60-9767-2432
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31
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Islam MT, Im J, Ahmmed F, Kim DR, Khan AI, Zaman K, Ali M, Marks F, Qadri F, Kim JH, Clemens JD. Use of Typhoid Vi-Polysaccharide Vaccine as a Vaccine Probe to Delineate Clinical Criteria for Typhoid Fever. Am J Trop Med Hyg 2020; 103:665-671. [PMID: 32588803 PMCID: PMC7410438 DOI: 10.4269/ajtmh.19-0968] [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: 11/23/2022] Open
Abstract
Blood cultures (BCs) detect an estimated 50% of typhoid fever cases. There is need for validated clinical criteria to define cases that are BC negative, both to help direct empiric antibiotic treatment and to better evaluate the magnitude of protection conferred by typhoid vaccines. To derive and validate a clinical rule for defining BC-negative typhoid fever, we assessed, in a cluster-randomized effectiveness trial of Vi-polysaccharide (ViPS) typhoid vaccine in Kolkata, India, 14,797 episodes of fever lasting at least 3 days during 4 years of comprehensive, BC-based surveillance of 70,865 persons. A recursive partitioning algorithm was used to develop a decision rule to predict BC-proven typhoid cases with a diagnostic specificity of 97–98%. To validate this rule as a definition for BC-negative typhoid fever, we assessed whether the rule defined culture-negative syndromes prevented by ViPS vaccine. In a training subset of individuals, we identified the following two rules: rule 1: patients aged < 15 years with prolonged fever accompanied by a measured body temperature ≥ 100°F, headache, and nausea; rule 2: patients aged ≥ 15 years with prolonged fever accompanied by nausea and palpable liver but without constipation. The adjusted protective efficacy of ViPS against clinical typhoid defined by these rules in persons aged ≥ 2 years in a separate validation subset was 33% (95% CI: 4–53%). We have defined and validated a clinical rule for predicting BC-negative typhoid fever using a novel vaccine probe approach. If validated in other settings, this rule may be useful to guide clinical care and to enhance typhoid vaccine evaluations.
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Affiliation(s)
- Md Taufiqul Islam
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Justin Im
- International Vaccine Institute, Seoul, Republic of Korea
| | - Faisal Ahmmed
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Deok Ryun Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - Ashraful Islam Khan
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Khalequ Zaman
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Florian Marks
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,International Vaccine Institute, Seoul, Republic of Korea
| | - Firdausi Qadri
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Jerome H Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - John D Clemens
- Korea University College of Medicine, Seoul, South Korea.,UCLA Fielding School of Public Health, Los Angeles, California.,International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
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32
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Pouzol S, Tanmoy AM, Ahmed D, Khanam F, Brooks WA, Bhuyan GS, Fabre L, Bryant JE, Gustin MP, Vanhems P, Carman B, Weill FX, Qadri F, Saha S, Endtz H. Clinical Evaluation of a Multiplex PCR for the Detection of Salmonella enterica Serovars Typhi and Paratyphi A from Blood Specimens in a High-Endemic Setting. Am J Trop Med Hyg 2020; 101:513-520. [PMID: 31287048 PMCID: PMC6726943 DOI: 10.4269/ajtmh.18-0992] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Enteric fever is a major public health concern in endemic areas, particularly in infrastructure-limited countries where Salmonella Paratyphi A has emerged in increasing proportion of cases. We aimed to evaluate a method to detect Salmonella Typhi (S. Typhi) and Salmonella Paratyphi A (S. Paratyphi A) in febrile patients in Bangladesh. We conducted a prospective study enrolling patients with fever > 38°C admitted to two large urban hospitals and two outpatient clinics located in Dhaka, Bangladesh. We developed and evaluated a method combining short culture with a new molecular assay to simultaneously detect and differentiate S. Typhi and S. Paratyphi A from other Salmonella directly from 2 to 4 mL of whole blood in febrile patients (n = 680). A total of 680 cases were enrolled from the four participating sites. An increase in the detection rate (+38.8%) in S. Typhi and S. Paratyphi A was observed with a multiplex polymerase chain reaction (PCR) assay, and absence of non-typhoidal Salmonella detection was reported. All 45 healthy controls were culture and PCR negative, generating an estimated 92.9% of specificity on clinical samples. When clinical performance was assessed in the absence of blood volume prioritization for testing, a latent class model estimates clinical performance ≥ 95% in sensitivity and specificity with likelihood ratio (LR) LR+ > 10 and LR− < 0.1 for the multiplex PCR assay. The alternative method to blood culture we developed may be useful alone or in combination with culture or serological tests for epidemiological studies in high disease burden settings and should be considered as secondary endpoint test for future vaccine trials.
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Affiliation(s)
- Stephane Pouzol
- Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Arif Mohammad Tanmoy
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.,Child Health Research Foundation (CHRF), Dhaka, Bangladesh
| | - Dilruba Ahmed
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Farhana Khanam
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - W Abdullah Brooks
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Golam Sarower Bhuyan
- Institute for Developing Science and Health Initiatives (ideSHi), Dhaka, Bangladesh
| | - Laetitia Fabre
- Unité des Bactéries Pathogènes Entériques, Institut Pasteur, Paris, France
| | - Juliet E Bryant
- Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Marie-Paule Gustin
- Department of Public Health, Institute of Pharmacy, University of Lyon 1, Lyon, France.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Philippe Vanhems
- Service d'Hygiène, Epidémiologie et Prévention, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Bill Carman
- Fast Track Diagnostics, Esch sur alzette, Esch-sur-Alzette, Luxembourg
| | | | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Samir Saha
- Child Health Research Foundation (CHRF), Dhaka, Bangladesh
| | - Hubert Endtz
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
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Frempong SN, Sutton AJ, Davenport C, Barton P. Early Economic Evaluation to Identify the Necessary Test Characteristics of a New Typhoid Test to be Cost Effective in Ghana. PHARMACOECONOMICS - OPEN 2020; 4:143-157. [PMID: 31377968 PMCID: PMC7018929 DOI: 10.1007/s41669-019-0159-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND In Ghana, there are issues with the diagnosis of typhoid fever; these include delays in diagnosis, concerns about the accuracy of current tests, and lack of availability. These issues highlight the need for the development of a rapid, accurate, and easily accessible diagnostic test. The aim of this study was to conduct an early economic analysis of a hypothetical rapid test for typhoid fever diagnosis in Ghana and identify the necessary characteristics of the test for it to be cost effective in Ghana. METHODS An early cost-utility analysis was conducted using a decision tree parameterized with secondary data sources, with reasonable assumptions made for unknown parameters. The patient population considered is individuals presenting with symptoms suggestive of typhoid fever at a healthcare facility in Ghana; a time horizon of 180 days and the Ghanaian national health service perspective were adopted for the analysis. Extensive sensitivity analysis was undertaken, including headroom analysis. RESULTS The results here show that for a hypothetical test to perform better than the existing test (Widal) in terms of QALYs gained and cost effectiveness, it is necessary for it to have a high specificity (at least 70%) and should not be priced more than US$4. The overall value of conducting research to reduce uncertainty (over 5 years) is US$3287. CONCLUSION The analysis shows the potential for the hypothetical test to replace the Widal test and the market potential of developing a new test in the Ghanaian setting.
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Affiliation(s)
- Samuel N Frempong
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Andrew J Sutton
- Institute of Health Economics, 1200 10405 Jasper Avenue, Edmonton, AB, T5J 3N4, Canada.
| | - Clare Davenport
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Pelham Barton
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
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Carey ME, Diaz ZI, Zaidi AKM, Steele AD. A Global Agenda for Typhoid Control-A Perspective from the Bill & Melinda Gates Foundation. Clin Infect Dis 2020; 68:S42-S45. [PMID: 30766999 PMCID: PMC6376097 DOI: 10.1093/cid/ciy928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recognizing that enteric fever disproportionately affects the poorest and the most vulnerable communities that have limited access to improved sanitation, safe water sources, and optimal medical care, the Bill & Melinda Gates Foundation has funded efforts to augment global understanding of the disease since the foundation’s inception. At the turn of the century, early efforts focused on characterizing the burden of disease in Asia and evaluating use of the available Vi-polysaccharide vaccines through the Diseases of the Most Impoverished projects at the International Vaccine Institute (IVI). More recent efforts have centered on supporting development of typhoid conjugate vaccines and expanding disease surveillance efforts into Africa, as well as generating a greater understanding of the clinical severity and sequelae of enteric fever in Africa, Asia, and India. The Typhoid Vaccine Accelerator Consortium is playing a critical role in coordinating these and other global efforts for the control of typhoid fever. Here, we outline the scope of support and strategic view of the foundation and describe how, by working through strong partnerships, we can realize a radical reduction of the significance of enteric fever as a global public health problem in the next 10 to 15 years.
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Affiliation(s)
- Megan E Carey
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Zoey I Diaz
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Anita K M Zaidi
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - A Duncan Steele
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
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Clinico-Bacteriological Profile of Typhoid Fever in a Private Sector Hospital in New Delhi. Indian Pediatr 2019. [DOI: 10.1007/s13312-019-1686-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Bundalian R, Valenzuela M, Tiongco RE. Achieving accurate laboratory diagnosis of typhoid fever: a review and meta-analysis of TUBEX® TF clinical performance. Pathog Glob Health 2019; 113:297-308. [PMID: 31778097 DOI: 10.1080/20477724.2019.1695081] [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: 10/25/2022] Open
Abstract
This review discusses currently available serological diagnostic methods for typhoid fever with a focus on the clinical utility of TUBEX® TF as an alternative to the Widal or Typhidot test. A literature search was conducted in PubMed for related publications written in English. A qualitative analysis was done to determine various serological tests used for typhoid fever diagnosis with emphasis on TUBEX® TF in comparison to the Widal of Typhidot test. Further, a meta-analysis was performed to obtain a pooled estimate of diagnostic accuracy (sensitivity and specificity) using different analysis models. A total of sixteen studies was included in the qualitative analysis. Further screening of these studies yielded ten studies that were used for the meta-analysis. The sensitivity/specificity range of different commonly used serological tests in typhoid patients is between 55-100%/58-100% for TUBEX® TF, 54-67%/54-95% for Typhidot, and 32-95%/4-98% for the Widal test. As for the pooled meta-analysis estimates, the TUBEX® TF showed superior results when differentiating individuals with febrile illness of unknown origin from those with typhoid fever. Overall, the results of this review and meta-analysis suggest that the TUBEX® TF is more advantageous to use as a serological test for typhoid fever diagnosis due its accuracy and simplicity. However, further studies are still needed to validate our results.
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Affiliation(s)
- Reynaldo Bundalian
- Center for Research and Development, Angeles University Foundation, Angeles City, Philippines
| | - Madonna Valenzuela
- Public Health Program, Graduate School, Angeles University Foundation, Angeles City, Philippines
| | - Raphael Enrique Tiongco
- Department of Medical Technology, College of Allied Medical Professions, Angeles University Foundation, Angeles City, Philippines
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Mather RG, Hopkins H, Parry CM, Dittrich S. Redefining typhoid diagnosis: what would an improved test need to look like? BMJ Glob Health 2019; 4:e001831. [PMID: 31749999 PMCID: PMC6830052 DOI: 10.1136/bmjgh-2019-001831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Typhoid fever is one of the most common bacterial causes of acute febrile illness in the developing world, with an estimated 10.9 million new cases and 116.8 thousand deaths in 2017. Typhoid point-of-care (POC) diagnostic tests are widely used but have poor sensitivity and specificity, resulting in antibiotic overuse that has led to the emergence and spread of multidrug-resistant strains. With recent advances in typhoid surveillance and detection, this is the ideal time to produce a target product profile (TPP) that guides product development and ensure that a next-generation test meets the needs of users in the resource-limited settings where typhoid is endemic. METHODS A structured literature review was conducted to develop a draft TPP for a next-generation typhoid diagnostic test with minimal and optimal desired characteristics for 36 test parameters. The TPP was refined using feedback collected from a Delphi survey of key stakeholders in clinical medicine, microbiology, diagnostics and public and global health. RESULTS A next-generation typhoid diagnostic test should improve patient management through the diagnosis and treatment of infection with acute Salmonella enterica serovars Typhi or Paratyphi with a sensitivity ≥90% and specificity ≥95%. The test would ideally be used at the lowest level of the healthcare system in settings without a reliable power or water supply and provide results in <15 min at a cost of CONCLUSION This report outlines the first comprehensive TPP for typhoid fever and is intended to guide the development of a next-generation typhoid diagnostic test. An accurate POC test will reduce the morbidity and mortality of typhoid fever through rapid diagnosis and treatment and will have the greatest impact in reducing antimicrobial resistance if it is combined with diagnostics for other causes of acute febrile illness in a treatment algorithm.
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Affiliation(s)
- Richard G Mather
- Malaria and Fever Program, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Heidi Hopkins
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Christopher M Parry
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Sabine Dittrich
- Malaria and Fever Program, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Blohmke CJ, Muller J, Gibani MM, Dobinson H, Shrestha S, Perinparajah S, Jin C, Hughes H, Blackwell L, Dongol S, Karkey A, Schreiber F, Pickard D, Basnyat B, Dougan G, Baker S, Pollard AJ, Darton TC. Diagnostic host gene signature for distinguishing enteric fever from other febrile diseases. EMBO Mol Med 2019; 11:e10431. [PMID: 31468702 PMCID: PMC6783646 DOI: 10.15252/emmm.201910431] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 07/30/2019] [Accepted: 08/09/2019] [Indexed: 12/19/2022] Open
Abstract
Misdiagnosis of enteric fever is a major global health problem, resulting in patient mismanagement, antimicrobial misuse and inaccurate disease burden estimates. Applying a machine learning algorithm to host gene expression profiles, we identified a diagnostic signature, which could distinguish culture-confirmed enteric fever cases from other febrile illnesses (area under receiver operating characteristic curve > 95%). Applying this signature to a culture-negative suspected enteric fever cohort in Nepal identified a further 12.6% as likely true cases. Our analysis highlights the power of data-driven approaches to identify host response patterns for the diagnosis of febrile illnesses. Expression signatures were validated using qPCR, highlighting their utility as PCR-based diagnostics for use in endemic settings.
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Affiliation(s)
- Christoph J Blohmke
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | | | - Malick M Gibani
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Hazel Dobinson
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Sonu Shrestha
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Soumya Perinparajah
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Celina Jin
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Harri Hughes
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Luke Blackwell
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Sabina Dongol
- Patan Academy of Healthy SciencesOxford University Clinical Research UnitKathmanduNepal
| | - Abhilasha Karkey
- Patan Academy of Healthy SciencesOxford University Clinical Research UnitKathmanduNepal
| | | | - Derek Pickard
- Infection Genomics ProgramThe Wellcome Trust Sanger InstituteHinxtonUK
| | - Buddha Basnyat
- Patan Academy of Healthy SciencesOxford University Clinical Research UnitKathmanduNepal
| | - Gordon Dougan
- Infection Genomics ProgramThe Wellcome Trust Sanger InstituteHinxtonUK
| | - Stephen Baker
- The Hospital for Tropical DiseasesWellcome Trust Major Overseas ProgrammeOxford University Clinical Research UnitHo Chi Minh CityVietnam
| | - Andrew J Pollard
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
| | - Thomas C Darton
- Department of PaediatricsCentre for Clinical Vaccinology and Tropical MedicineOxford Vaccine GroupOxfordUK
- Oxford National Institute of Health Research Biomedical CentreUniversity of OxfordOxfordUK
- The Hospital for Tropical DiseasesWellcome Trust Major Overseas ProgrammeOxford University Clinical Research UnitHo Chi Minh CityVietnam
- Department of Infection, Immunity and Cardiovascular DiseaseUniversity of SheffieldSheffieldUK
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Msefula CL, Olgemoeller F, Jambo N, Segula D, Van Tan T, Nyirenda TS, Nedi W, Kennedy N, Graham M, Henrion MYR, Baker S, Feasey N, Gordon M, Heyderman RS. Ascertaining the burden of invasive Salmonella disease in hospitalised febrile children aged under four years in Blantyre, Malawi. PLoS Negl Trop Dis 2019; 13:e0007539. [PMID: 31314752 PMCID: PMC6663031 DOI: 10.1371/journal.pntd.0007539] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/29/2019] [Accepted: 06/10/2019] [Indexed: 11/19/2022] Open
Abstract
Typhoid fever is endemic across sub-Saharan Africa. However, estimates of the burden of typhoid are undermined by insufficient blood volumes and lack of sensitivity of blood culture. Here, we aimed to address this limitation by exploiting pre-enrichment culture followed by PCR, alongside routine blood culture to improve typhoid case detection. We carried out a prospective diagnostic cohort study and enrolled children (aged 0-4 years) with non-specific febrile disease admitted to a tertiary hospital in Blantyre, Malawi from August 2014 to July 2016. Blood was collected for culture (BC) and real-time PCR after a pre-enrichment culture in tryptone soy broth and ox-bile. DNA was subjected to PCR for invA (Pan-Salmonella), staG (S. Typhi), and fliC (S. Typhimurium) genes. A positive PCR was defined as invA plus either staG or fliC (CT<29). IgM and IgG ELISA against four S. Typhi antigens was also performed. In total, 643 children (median age 1.3 years) with nonspecific febrile disease were enrolled; 31 (4.8%) were BC positive for Salmonella (n = 13 S. Typhi, n = 16 S. Typhimurium, and n = 2 S. Enteritidis). Pre-enrichment culture of blood followed by PCR identified a further 8 S. Typhi and 15 S. Typhimurium positive children. IgM and IgG titres to the S. Typhi antigen STY1498 (haemolysin) were significantly higher in children that were PCR positive but blood culture negative compared to febrile children with all other non-typhoid illnesses. The addition of pre-enrichment culture and PCR increased the case ascertainment of invasive Salmonella disease in children by 62-94%. These data support recent burden estimates that highlight the insensitivity of blood cultures and support the targeting of pre-school children for typhoid vaccine prevention in Africa. Blood culture with real-time PCR following pre-enrichment should be used to further refine estimates of vaccine effectiveness in typhoid vaccine trials.
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Affiliation(s)
- Chisomo L. Msefula
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- * E-mail:
| | - Franziska Olgemoeller
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Paediatrics, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Ndaru Jambo
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- University of Liverpool, Liverpool, United Kingdom
| | - Dalitso Segula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Internal Medicine, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Trinh Van Tan
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tonney S. Nyirenda
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Wilfred Nedi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Neil Kennedy
- Department of Paediatrics, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
- Centre for Medical Education, Queens University, Belfast, United Kingdom
| | - Matthew Graham
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Marc Y. R. Henrion
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen Baker
- The Department of Medicine, The University of Cambridge, Cambridge, United Kingdom
| | - Nicholas Feasey
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Melita Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- University of Liverpool, Liverpool, United Kingdom
| | - Robert S. Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Division of Infection & Immunity, University College London, London, England, United Kingdom
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Sharma T, Sharma C, Sankhyan A, Bedi SP, Bhatnagar S, Khanna N, Gautam V, Sethi S, Vrati S, Tiwari A. Serodiagnostic evaluation of recombinant CdtB of S. Typhi as a potential candidate for acute typhoid. Immunol Res 2019; 66:503-512. [PMID: 29931558 DOI: 10.1007/s12026-018-9009-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Typhoid fever caused by human restricted Salmonella typhi presents a considerable health burden on developing South-Asian nations like India. The suboptimal sensitivity and specificity associated with culture-based isolation of etiological agent and the extensively used surface antigen-based serological assays often lead to misdiagnosis and inappropriate antimicrobial treatment. The increasing reports of the emergence of resistant strains and undefined disease burden signify the critical need for an inexpensive, reliable, easy-to-use, and highly sensitive diagnostic test for typhoid fever. Utilizing S. typhi-specific and immunogenic antigens in sero-diagnostic assays could lead to precise diagnosis of acute typhoid and prompt treatment. In this study, we report cloning, expression, and purification of recombinant Cytolethal distending toxin subunit B (CdtB) of S. typhi, which is reported to be highly specific, immunogenic, and expressed only upon S. typhi infection. We further evaluated the purified recombinant CdtB for its diagnostic potential in an IgM-based indirect ELISA format using 33 human samples. Twenty-one serum samples from blood culture confirmed cases (n = 21) of typhoid and 12 samples from healthy controls (n = 12) were tested. The assay showed sensitivity of 100% and specificity of 83.3% respectively with positive and negative predictive values of 91.3 and 100% respectively. Efficient detection of specific IgM antibodies indicates that CdtB could be highly valuable in sero-diagnosis of acute typhoid and rapid screening of clinical samples.
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Affiliation(s)
- Tarang Sharma
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Chandresh Sharma
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Anurag Sankhyan
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India.,Central Research Institute, Kasauli, Himachal Pradesh, India
| | - Sanjiv Pal Bedi
- Department of Experimental Medicine & Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shinjini Bhatnagar
- Paediatric Biology Centre, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Navin Khanna
- International Centre for Genetic Engineering & Biotechnology, New Delhi, India
| | - Vikas Gautam
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sunil Sethi
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sudhanshu Vrati
- Regional Centre for Biotechnology, Faridabad, Haryana, India
| | - Ashutosh Tiwari
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India. .,Department of Experimental Medicine & Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
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Silvestre R, Torrado E. Metabolomic-Based Methods in Diagnosis and Monitoring Infection Progression. EXPERIENTIA SUPPLEMENTUM (2012) 2019; 109:283-315. [PMID: 30535603 PMCID: PMC7124096 DOI: 10.1007/978-3-319-74932-7_7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A robust biomarker screening and validation is crucial for overcoming the current limits in the clinical management of infectious diseases. In this chapter, a general workflow for metabolomics is summarized. Subsequently, an overview of the major contributions of this omics science to the field of biomarkers of infectious diseases is discussed. Different approaches using a variety of analytical platforms can be distinguished to unveil the key metabolites for the diagnosis, prognosis, response to treatment and susceptibility for infectious diseases. To allow the implementation of such biomarkers into the clinics, the performance of large-scale studies employing solid validation criteria becomes essential. Focusing on the etiological agents and after an extensive review of the field, we present a comprehensive revision of the main metabolic biomarkers of viral, bacterial, fungal, and parasitic diseases. Finally, we discussed several articles which show the strongest validation criteria. Following these research avenues, precious clinical resources will be revealed, allowing for reduced misdiagnosis, more efficient therapies, and affordable costs, ultimately leading to a better patient management.
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Affiliation(s)
- Ricardo Silvestre
- Life and Health Sciences Research Institute, University of Minho, Braga, Portugal
| | - Egídio Torrado
- Life and Health Sciences Research Institute, University of Minho, Braga, Portugal
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Shrivastava V, Ahmad S, Mittal G, Gupta V, Shirazi N, Kalra V. Evaluation of haematological and volume, conductivity and scatter parameters of leucocytes for aetiological diagnosis of undifferentiated fevers. Trans R Soc Trop Med Hyg 2019; 111:546-554. [PMID: 29509943 DOI: 10.1093/trstmh/try012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/31/2018] [Indexed: 11/14/2022] Open
Abstract
Background In this follow-up study, we aimed to establish the cut-off values of the volume, conductivity and scatter (VCS) parameters of leucocytes that significantly differ in dengue fever, malaria, scrub typhus and enteric fever, as described in our pilot study. Methods A prospective observational case-control study was undertaken on patients with an established diagnosis of acute malaria (n=476), dengue fever (n=927), scrub typhus (n=425), bacterial sepsis (n=1598) or enteric fever (n=885) and the haematological and VCS data obtained by the Coulter LH 750 analyser were compared with controls. Results Malaria significantly altered the platelet count and plateletcrit. The cut-offs for the monocyte volume, lymphocyte volume, neutrophil volume, neutrophil volume distribution width, lymphocyte volume distribution width, monocyte volume distribution width and neutrophil conductivity distribution width had 90% negative predictive values (NPVs) for malaria. Except for the proportion of monocytes, lymphocyte scatter distribution width and platelet distribution width, a >70% positive (PPV) and negative predictive value (NPV) for dengue was noted in all the haematological and VCS parameters analysed. While the cut-offs determined in scrub typhus had a good (>80%) PPV and NPV, a significant difference was seen in neutrophil, monocyte and lymphocyte conductivities, but with low sensitivity, specificity, PPV and NPV in enteric fever. Conclusions Aetiology-specific changes occur both in numbers as well as in VCS properties in acute fevers. Formulae and/or algorithms need to be utilized to realize the full potential of the VCS technology.
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Affiliation(s)
- Vikas Shrivastava
- Department of Pathology, Himalayan Institute of Medical Sciences, Dehradun, India
| | - Sohaib Ahmad
- Department of Medicine, Himalayan Institute of Medical Sciences, Dehradun, India
| | - Garima Mittal
- Department of Microbiology, Himalayan Institute of Medical Sciences, Dehradun, India
| | - Vibha Gupta
- Department of Pathology, Himalayan Institute of Medical Sciences, Dehradun, India
| | - Nadia Shirazi
- Department of Pathology, Himalayan Institute of Medical Sciences, Dehradun, India
| | - Varun Kalra
- Department of Medicine, Himalayan Institute of Medical Sciences, Dehradun, India
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Gal-Mor O. Persistent Infection and Long-Term Carriage of Typhoidal and Nontyphoidal Salmonellae. Clin Microbiol Rev 2019; 32:e00088-18. [PMID: 30487167 PMCID: PMC6302356 DOI: 10.1128/cmr.00088-18] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The ability of pathogenic bacteria to affect higher organisms and cause disease is one of the most dramatic properties of microorganisms. Some pathogens can establish transient colonization only, but others are capable of infecting their host for many years or even for a lifetime. Long-term infection is called persistence, and this phenotype is fundamental for the biology of important human pathogens, including Helicobacter pylori, Mycobacterium tuberculosis, and Salmonella enterica Both typhoidal and nontyphoidal serovars of the species Salmonella enterica can cause persistent infection in humans; however, as these two Salmonella groups cause clinically distinct diseases, the characteristics of their persistent infections in humans differ significantly. Here, following a general summary of Salmonella pathogenicity, host specificity, epidemiology, and laboratory diagnosis, I review the current knowledge about Salmonella persistence and discuss the relevant epidemiology of persistence (including carrier rate, duration of shedding, and host and pathogen risk factors), the host response to Salmonella persistence, Salmonella genes involved in this lifestyle, as well as genetic and phenotypic changes acquired during prolonged infection within the host. Additionally, I highlight differences between the persistence of typhoidal and nontyphoidal Salmonella strains in humans and summarize the current gaps and limitations in our understanding, diagnosis, and curing of persistent Salmonella infections.
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Affiliation(s)
- Ohad Gal-Mor
- Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Saito MK, Parry CM, Yeung S. Modelling the cost-effectiveness of a rapid diagnostic test (IgMFA) for uncomplicated typhoid fever in Cambodia. PLoS Negl Trop Dis 2018; 12:e0006961. [PMID: 30452445 PMCID: PMC6277117 DOI: 10.1371/journal.pntd.0006961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 12/03/2018] [Accepted: 10/31/2018] [Indexed: 11/18/2022] Open
Abstract
Typhoid fever is a common cause of fever in Cambodian children but diagnosis and treatment are usually presumptive owing to the lack of quick and accurate tests at an initial consultation. This study aimed to evaluate the cost-effectiveness of using a rapid diagnostic test (RDT) for typhoid fever diagnosis, an immunoglobulin M lateral flow assay (IgMFA), in a remote health centre setting in Cambodia from a healthcare provider perspective. A cost-effectiveness analysis (CEA) with decision analytic modelling was conducted. We constructed a decision tree model comparing the IgMFA versus clinical diagnosis in a hypothetical cohort with 1000 children in each arm. The costs included direct medical costs only. The eligibility was children (≤14 years old) with fever. Time horizon was day seven from the initial consultation. The number of treatment success in typhoid fever cases was the primary health outcome. The number of correctly diagnosed typhoid fever cases (true-positives) was the intermediate health outcome. We obtained the incremental cost effectiveness ratio (ICER), expressed as the difference in costs divided by the difference in the number of treatment success between the two arms. Sensitivity analyses were conducted. The IgMFA detected 5.87 more true-positives than the clinical diagnosis (38.45 versus 32.59) per 1000 children and there were 3.61 more treatment successes (46.78 versus 43.17). The incremental cost of the IgMFA was estimated at $5700; therefore, the ICER to have one additional treatment success was estimated to be $1579. The key drivers for the ICER were the relative sensitivity of IgMFA versus clinical diagnosis, the cost of IgMFA, and the prevalence of typhoid fever or multi-drug resistant strains. The IgMFA was more costly but more effective than the clinical diagnosis in the base-case analysis. An IgMFA could be more cost-effective than the base-case if the sensitivity of IgMFA was higher or cost lower. Decision makers may use a willingness-to-pay threshold that considers the additional cost of hospitalisation for treatment failures.
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Affiliation(s)
- Mari Kajiwara Saito
- Department of Non-Communicable Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Christopher M. Parry
- Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Shunmay Yeung
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Clinical Research, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, United Kingdom
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45
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Radhakrishnan A, Als D, Mintz ED, Crump JA, Stanaway J, Breiman RF, Bhutta ZA. Introductory Article on Global Burden and Epidemiology of Typhoid Fever. Am J Trop Med Hyg 2018; 99:4-9. [PMID: 30047370 PMCID: PMC6128367 DOI: 10.4269/ajtmh.18-0032] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This article is the introduction to a 12-paper supplement on global trends in typhoid fever. The Tackling Typhoid (T2) project was initiated in 2015 to synthesize the existing body of literature on typhoidal salmonellae and study national and regional typhoid fever trends. In addition to a global systematic review, eight case studies were undertaken to examine typhoid and paratyphoid fever trends in endemic countries alongside changes in relevant contextual factors. Incidence variations exist both within and between regions with large subnational differences as well, suggesting that public health changes impacting typhoid and paratyphoid fevers in one setting may not have similar impacts in another. This supplement also brings to light the lack of national typhoid fever surveillance systems, inconsistencies in diagnostics, and the lack of typhoid fever associated morbidity and mortality data in many countries, making it difficult to accurately quantify and track burden of disease. To better understand typhoid fever there is a need for more high-quality data from resource-poor settings. The implementation of typhoid surveillance systems alongside the transition to blood-culture confirmation of cases, where possible, would aid in the improvement of data quality in low-income settings. The following supplement includes the results of our global systematic review, eight-country case study articles, a qualitative article informed by semistructured interviews, and a conclusion article on potential ways forward for typhoid control.
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Affiliation(s)
| | - Daina Als
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Canada
| | - Eric D Mintz
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Jefferey Stanaway
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - Zulfiqar A Bhutta
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Canada.,Center of Excellence in Women and Child Health, The Aga Khan University, Karachi, Pakistan.,Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
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Ajibola O, Mshelia MB, Gulumbe BH, Eze AA. Typhoid Fever Diagnosis in Endemic Countries: A Clog in the Wheel of Progress? MEDICINA (KAUNAS, LITHUANIA) 2018; 54:E23. [PMID: 30344254 PMCID: PMC6037256 DOI: 10.3390/medicina54020023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/17/2018] [Accepted: 04/19/2018] [Indexed: 12/27/2022]
Abstract
Typhoid fever causes significant morbidity and mortality in developing countries, with inaccurate estimates in some countries affected, especially those situated in Sub-Saharan Africa. Disease burden assessment is limited by lack of a high degree of sensitivity and specificity by many current rapid diagnostic tests. Some of the new technologies, such as PCR and proteomics, may also be useful but are difficult for low-resource settings to apply as point-of-care diagnostics. Weak laboratory surveillance systems may also contribute to the spread of multidrug resistant Salmonella serovar Typhi across endemic areas. In addition, most typhoid-endemic countries employ serological tests that have low sensitivity and specificity making diagnosis unreliable. Here we review currently available typhoid fever diagnostics, and advances in serodiagnosis of S. Typhi.
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Affiliation(s)
- Olumide Ajibola
- Department of Microbiology, Faculty of Science, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo, Kebbi State, Nigeria.
| | - Mari B Mshelia
- Department of Microbiology, Faculty of Science, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo, Kebbi State, Nigeria.
| | - Bashar H Gulumbe
- Department of Microbiology, Faculty of Science, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo, Kebbi State, Nigeria.
| | - Anthonius A Eze
- Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu 400241, Nigeria.
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Semret M, Ndao M, Jacobs J, Yansouni CP. Point-of-care and point-of-'can': leveraging reference-laboratory capacity for integrated diagnosis of fever syndromes in the tropics. Clin Microbiol Infect 2018; 24:836-844. [PMID: 29649602 DOI: 10.1016/j.cmi.2018.03.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 01/07/2023]
Abstract
BACKGROUND There is an urgent need for integrated diagnosis of febrile syndromes able to account for multiple pathogens and to inform decisions for clinical care and public health. AIMS To reflect on the evolving roles of laboratory-based testing for non-malarial febrile illnesses (NMFIs) in low-resource settings, and to consider how advances in diagnostics, in connectivity and transport, and in implementation of quality systems may substantially enhance the capacity of reference laboratories to bridge the current gap between remote passive surveillance and clinically meaningful integrated fever diagnosis. SOURCES Iterative search of PubMed databases, organizational reports, and expert consultation. CONTENT Implementation of new technologies-such as very broad molecular panels for surveillance and mass spectrometry-may considerably diminish capability gaps in reference laboratories in low-resource settings. Although the need for clinical bacteriology diagnostics is now recognized, the lack of new simple and rapid phenotypic tests for antimicrobial resistance remains a key deficiency. Several initiatives to strengthen diagnostic preparedness for infectious disease outbreaks have highlighted the need for functional tiered laboratory networks. Recently, dramatic headway in connectivity-such as combining automated readers with the image processing and data transmission capabilities of smartphones-now allows for more complex testing and interfacing with distant laboratory information systems while reducing workload and errors. Together with connectivity to transmit and receive results, new approaches to specimen collection and transport-such as the validation of rectal swabs and the use of aerial drones to transport specimens to distant laboratories-now make remote testing feasible. The above innovations also open up the possibility of implementing quality systems through community-level diagnostic stewardship. Finally, strengthened laboratory networks actively support the feasibility of implementing quality-assured point-of-care testing where it is needed. IMPLICATIONS Recent advances offer the present-day possibility of innovations to re-invent the relationship between distant reference laboratories and end-users for integrated diagnosis of NMFIs.
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Affiliation(s)
- M Semret
- J.D. MacLean Centre for Tropical Diseases, McGill University Health Centre, Montreal, Canada
| | - M Ndao
- National Reference Centre for Parasitology, Montreal, Canada
| | - J Jacobs
- Institute of Tropical Medicine, Antwerp, Belgium; KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
| | - C P Yansouni
- J.D. MacLean Centre for Tropical Diseases, McGill University Health Centre, Montreal, Canada.
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Kaur A, Kapil A, Elangovan R, Jha S, Kalyanasundaram D. Highly-sensitive detection of Salmonella typhi in clinical blood samples by magnetic nanoparticle-based enrichment and in-situ measurement of isothermal amplification of nucleic acids. PLoS One 2018; 13:e0194817. [PMID: 29590194 PMCID: PMC5874042 DOI: 10.1371/journal.pone.0194817] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/10/2018] [Indexed: 12/31/2022] Open
Abstract
Enteric fever continues to be a major cause of mortality and morbidity globally, particularly in poor resource settings. Lack of rapid diagnostic assays is a major driving factor for the empirical treatment of enteric fever. In this work, a rapid and sensitive method ‘Miod’ ‘has been developed. Miod includes a magnetic nanoparticle-based enrichment of target bacterial cells, followed by cell lysis and loop-mediated isothermal amplification (LAMP) of nucleic acids for signal augmentation along with concurrent measurement of signal via an in–situ optical detection system. To identify positive/negative enteric fever infections in clinical blood samples, the samples were processed using Miod at time = 0 hours and time = 4 hours post-incubation in blood culture media. Primers specific for the STY2879 gene were used to amplify the nucleic acids isolated from S. typhi cells. A limit of detection of 5 CFU/mL was achieved. No cross-reactivity of the primers were observed against 106 CFU/mL of common pathogenic bacterial species found in blood such as E. coli, P. aeruginosa, S. aureus, A. baumanni, E. faecalis, S. Paratyphi A and K. pneumonia. Miod was tested on 28 human clinical blood samples. The detection of both pre-and post-four-hours incubation confirmed the presence of viable S. typhi cells and allowed clinical correlation of infection. The positive and negative samples were successfully detected in less than 6 hours with 100% sensitivity and specificity.
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Affiliation(s)
- Avinash Kaur
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India
| | - Arti Kapil
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Ravikrishnan Elangovan
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India
| | - Sandeep Jha
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India
- Department of Biomedical Engineering, All India Institute of Medical Sciences, New Delhi, India
| | - Dinesh Kalyanasundaram
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India
- Department of Biomedical Engineering, All India Institute of Medical Sciences, New Delhi, India
- * E-mail: ,
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Thompson CN, Karkey A, Dongol S, Arjyal A, Wolbers M, Darton T, Farrar JJ, Thwaites GE, Dolecek C, Basnyat B, Baker S. Treatment Response in Enteric Fever in an Era of Increasing Antimicrobial Resistance: An Individual Patient Data Analysis of 2092 Participants Enrolled into 4 Randomized, Controlled Trials in Nepal. Clin Infect Dis 2018; 64:1522-1531. [PMID: 28329181 PMCID: PMC5434338 DOI: 10.1093/cid/cix185] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/25/2017] [Indexed: 12/16/2022] Open
Abstract
Background. Enteric fever, caused by Salmonella Typhi and Salmonella Paratyphi A, is the leading cause of bacterial febrile disease in South Asia. Methods. Individual data from 2092 patients with enteric fever randomized into 4 trials in Kathmandu, Nepal, were pooled. All trials compared gatifloxacin with 1 of the following comparator drugs: cefixime, chloramphenicol, ofloxacin, or ceftriaxone. Treatment outcomes were evaluated according to antimicrobial if S. Typhi/Paratyphi were isolated from blood. We additionally investigated the impact of changing bacterial antimicrobial susceptibility on outcome. Results. Overall, 855 (41%) patients had either S. Typhi (n = 581, 28%) or S. Paratyphi A (n = 274, 13%) cultured from blood. There were 139 (6.6%) treatment failures with 1 death. Except for the last trial with ceftriaxone, the fluoroquinolone gatifloxacin was associated with equivalent or better fever clearance times and lower treatment failure rates in comparison to all other antimicrobials. However, we additionally found that the minimum inhibitory concentrations (MICs) against fluoroquinolones have risen significantly since 2005 and were associated with increasing fever clearance times. Notably, all organisms were susceptible to ceftriaxone throughout the study period (2005-2014), and the MICs against azithromycin declined, confirming the utility of these alternative drugs for enteric fever treatment. Conclusion. The World Health Organization and local government health ministries in South Asia still recommend fluoroquinolones for enteric fever. This policy should change based on the evidence provided here. Rapid diagnostics are urgently required given the large numbers of suspected enteric fever patients with a negative culture.
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Affiliation(s)
- Corinne N Thompson
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Abhilasha Karkey
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Lalitpur, and
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Lalitpur, and
| | - Amit Arjyal
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Lalitpur, and
| | - Marcel Wolbers
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Thomas Darton
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Jeremy J Farrar
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Guy E Thwaites
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Christiane Dolecek
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ; and
| | - Buddha Basnyat
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Lalitpur, and
- Global Antibiotic Resistance Partnership, Nepal
| | - Stephen Baker
- Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
- Department of Medicine, University of Cambridge, United Kingdom
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50
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Kavai SM, Kangogo M, Muigai AWT, Kariuki S. Analysis of Trends in Resistance to Fluoroquinolones and Extended Spectrum Beta-Lactams among <i>Salmonella</i> Typhi Isolates Obtained from Patients at Four Outpatient Clinics in Nairobi County, Kenya. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/aim.2018.87038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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