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Yan S, Lu Q, Tao Q, Lu Y, Gao B, Wang S, Cai X, Ai L, Xiong X, Cao M, Tan W. An immunochromatographic test for serological diagnosis of scrub typhus. J Immunol Methods 2024; 528:113653. [PMID: 38430991 DOI: 10.1016/j.jim.2024.113653] [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: 09/03/2023] [Revised: 01/24/2024] [Accepted: 02/27/2024] [Indexed: 03/05/2024]
Abstract
A fluorescent immunochromatographic test (FM-ICT) was developed for rapid detection of anti-Orientia tsutsugamushi antibodies in serum samples. The FM-ICT was constructed based on the dual-antigen sandwich method. Truncated 56 kDa outer membrane protein of O. tsutsugamushi strain SJ, was expressed in E. coli and mixed with those of Ptan and Gillam strains. A thin line of the protein mixture was precisely sprayed across a nitrocellulose membrane making this the "Test" line. Polyclonal antibodies (pAbs) to O.tsutsugamushi were sprayed in another line across the membrane making this the "Control" line. Fluorescent microspheres conjugated 56 kDa proteins reacting with sample serum will be captured on the "Test" line if the sample contains antibodies to O.tsutsugamushi. Several experimental parameters were optimized. After optimizing the reaction procedure, the results are visible, within 6 min, with the naked eye under ultraviolet light. The limit of detection (LOD) was determined to be 7.63 ng/mL with prepared polyclonal antibodies. No cross-reaction was observed with sera samples from other febrile diseases. In clinical evaluations, the strips showed 94.92% sensitivity (106/112) and 93.75% specificity (56/60). The FM-ICT we developed will provide a new tool for on-site diagnosis of scrub typhus.
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Affiliation(s)
- Shuhao Yan
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Qingyu Lu
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Qingyuan Tao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Yawei Lu
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Bao Gao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Sibo Wang
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Xusheng Cai
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Lele Ai
- Nanjing Bioengineering (Gene) Technology Center for Medicine, Nanjing 210002, PR China
| | - Xiaohui Xiong
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Min Cao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
| | - Weilong Tan
- Nanjing Bioengineering (Gene) Technology Center for Medicine, Nanjing 210002, PR China.
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Looareesuwan P, Aiemjoy K, Charoensakulchai S, Thaipadungpanit J, Wongsantichon J, Tanganuchitcharnchai A, Rungrojn A, Blacksell SD, Matsee W. Diagnostic challenges and antibody kinetics in a paediatric traveller with scrub typhus. J Travel Med 2023; 30:taad143. [PMID: 37952213 PMCID: PMC10755204 DOI: 10.1093/jtm/taad143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
Diagnosing scrub typhus in travellers is challenging due to symptom similarities with other travel-related illnesses and limited early diagnostic tools. We present a distinctive case of scrub typhus in a child traveller, providing a comprehensive account of the case, the diagnostic challenges encountered, laboratory findings and the dynamics of antibodies.
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Affiliation(s)
- Panita Looareesuwan
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Thai Travel Clinic, Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kristen Aiemjoy
- Division of Epidemiology, Department of Public Health Sciences, University of California Davis School of Medicine, Davis, CA, USA
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sakarn Charoensakulchai
- Thai Travel Clinic, Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Janjira Thaipadungpanit
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Ampai Tanganuchitcharnchai
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Artharee Rungrojn
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Stuart D Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Center for Tropical Medicine & Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Wasin Matsee
- Thai Travel Clinic, Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Travel Medicine Research Unit, Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Lamichhane P, Pokhrel KM, Alghalyini B, Zaidi ARZ, Alshehery MZ, Khanal K, Bhattarai M, Yadav A. Epidemiology, clinical characteristics, diagnosis, and complications of scrub typhus infection in Nepal: a systematic review. Ann Med Surg (Lond) 2023; 85:5022-5030. [PMID: 37811079 PMCID: PMC10553080 DOI: 10.1097/ms9.0000000000001259] [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] [Received: 07/22/2023] [Accepted: 08/23/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction Scrub typhus (ST) is a neglected tropical disease of serious concern in Nepal. This systematic review aims to describe the burden of disease, clinical presentation, and complications of ST infection in Nepal. Methods A systematic search of PubMed, EMBASE, Google Scholar, and national databases was conducted for any literature published in English between January 2000 and January 2023. Any type of study design (observational studies, case series, and interventional studies) that reported laboratory-confirmed ST and was conducted in Nepal among patients of all age groups was included. The seroprevalence of ST among acute undifferentiated febrile illness (AUFI) cases, geographical distribution, monthly distribution, clinical presentations, complications, and treatment were assessed by the study. Result A total of 15 studies with 10, 977 participants were included in the review. The seroprevalence of ST among the AUFI cases in Nepal was 19.31%. Young people at or below 20 years of age were mostly affected. The maximum number of cases were reported from Bagmati province (59.46%) and in the month of August (26.33%). Fever, headache, cough, shortness of breath, nausea, and abdominal pain were the clinical characteristics in decreasing order of occurrence. The most common complication was acute kidney injury, followed by respiratory problems, cardiac issues, and neurological manifestations. The case fatality rate of ST in Nepal was 2.56%. Conclusion The authors findings showed a significant burden of ST among AUFI cases in Nepal. Improved surveillance, general public awareness, and early detection post-calamities could help reduce the disease burden and improve patient outcomes.
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Affiliation(s)
| | | | - Baraa Alghalyini
- Department of Family and Community Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Abdul Rehman Zia Zaidi
- Department of Family and Community Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Maied Z. Alshehery
- Department of Palliative Care, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Kapil Khanal
- Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, Nepal
| | - Madhur Bhattarai
- Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, Nepal
| | - Alisha Yadav
- Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, Nepal
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Narayanappa D, Geetha R, Rajani HS. Diagnostic Accuracy of Rapid Antibody Detection Test for Scrub Typhus. Indian Pediatr 2023; 60:546-548. [PMID: 37424119 DOI: 10.1007/s13312-023-2932-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/20/2022] [Accepted: 05/10/2023] [Indexed: 08/24/2023]
Abstract
OBJECTIVE To detect the diagnostic accuracy of rapid antibody detection test using IgM immunochromatography for scrub typhus in children. METHODS This cross-sectional study enrolled children aged 2 months-18 years hospitalized over a period of 18 months with undifferentiated fever of duration five days or more. The blood samples were subjected to serological tests like Weil-Felix, Scrub IgM ELISA, immunofluroscence assay (IFA) and rapid diagnostic test (IgM Immunochromatography). Diagnostic accuracy was measured against IFA as the gold standard. RESULTS A total of 90 children were included in the study, among which 43 children were positive for gold standard test IFA. Rapid diagnostic test showed sensitivity of 88.3%, specificity of 89.3%, positive predictive value of 88.3% and negative predictive value of 89.3%. The sensitivity, specificity, PPV and NPV of Weil-Felix test was 39.5%, 84.2%, 58.6 and 71.1%, respectively and of IgM ELISA was 93%, 89.3%,88.8% and 93.3%, respectively. CONCLUSION IgM immunochromatography had good diagnostic accuracy for scrub typhus in children with acute undifferentiated fever.
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Affiliation(s)
- Doddaiah Narayanappa
- Department of Paediatrics, JSS Medical College, JSS Academy of Higher Education and Research, Mysore, Karnataka
| | - Ravi Geetha
- Department of Paediatrics, JSS Medical College, JSS Academy of Higher Education and Research, Mysore, Karnataka
| | - Hassan Sreenivasamurthy Rajani
- Department of Paediatrics, JSS Medical College, JSS Academy of Higher Education and Research, Mysore, Karnataka. Correspondence to: Dr Rajani HS, Associate Professor, Department of Pediatrics, JSS Hospital, Mahatma Gandhi Road, Mysore 570 004, Karnataka.
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Comparative evaluation of serological tests used for the diagnosis of rickettsial diseases prevalent in the temperate region of North India. Indian J Med Microbiol 2021; 40:294-298. [PMID: 34980488 DOI: 10.1016/j.ijmmb.2021.12.004] [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: 06/10/2021] [Revised: 09/17/2021] [Accepted: 12/11/2021] [Indexed: 11/20/2022]
Abstract
PURPOSE The clinical manifestations of rickettsial diseases mimic other endemic infections with similar presentations thus posing a serious challenge to clinicians for their diagnosis. For the diagnosis of rickettsial disease serological tests like Weil Felix, ELISA and IFA are used. There are limited studies that have evaluated different serological tests for the diagnosis of rickettsial diseases. Therefore, the present study was undertaken to evaluate the ELISA and Weil Felix test for the diagnosis of rickettsial diseases prevalent in this region. METHODS Samples from 281 patients clinically suspected of rickettsial diseases were tested for spotted fever group (SFG), typhus group (TG) and scrub typhus group (STG) by Weil Felix, ELISA and IFA was taken as the gold standard. Baseline titers and cut-off ODs were calculated by taking samples from healthy blood donors. RESULTS The sensitivity, specificity, positive and negative predictive value of Weil Felix test ranged from 30% to 44%, 83.46%-97.86%, 9%-77%, 92-96% respectively. The sensitivity and specificity, positive and negative predictive value of ELISA ranged from 80.77% to 96.15%, 96.33%-98.43%, 70.21%-88.64%, 92.89%-99.60% respectively. Maximum cross-reactions were observed between SFG and STG by the Weil Felix test and between STG and TG by ELISA. CONCLUSIONS ELISA was found to be sensitive and specific for the diagnosis of rickettsial diseases. It is easy to perform, does not require a technical expert for result interpretation and a large number of samples can be processed at a time.
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Paulraj PS, Renu G, Ranganathan K, Leo VJ, Veeramanoharan R. First seroprevalence report of scrub typhus from the tribal belts of the Nilgiris district, Tamil Nadu, India. Indian J Med Res 2021; 153:503-507. [PMID: 34380797 PMCID: PMC8354048 DOI: 10.4103/ijmr.ijmr_1223_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background & objectives Scrub typhus, an acute febrile Rickettsial disease is caused by the bacterial pathogen Orientia tsutsugamushi which is spread by the bite of infected chigger mite vectors belonging to the family Trombiculidae. A study was undertaken to find out the prevalence of scrub typhus among the indigenous population from Nilgiris, Tamil Nadu. Methods This study was conducted among 214 patients with fever of unknown aetiology and a recent history of febrile illness attending the Nilgiris Adivasi Welfare Association medical facilities available at Nilgiris district, Tamil Nadu. Serum samples were tested for scrub typhus IgM enzyme-linked immunosorbent assay. Results Overall, 13 (6.07%) of the 214 samples tested were positive for scrub typhus. This is the first seroprevalence report of scrub typhus from the indigenous people belonging to Irula, Kurumba, Paniyar, and Kota tribes from the Nilgiris district, Tamil Nadu. Interpretation & conclusions Early diagnosis and effective management will protect this indigenous population from this disease. This report would help in creating awareness regarding scrub typhus infection among clinicians and public health authorities in the region and take appropriate measures for treatment and control.
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Affiliation(s)
- Philip Samuel Paulraj
- Department of Health Research, ICMR-Vector Control Rresearch Centre-Field Station, Madurai, Tamil Nadu, India
| | - Govindarajan Renu
- Department of Health Research, ICMR-Vector Control Rresearch Centre-Field Station, Madurai, Tamil Nadu, India
| | | | - Victor Jerald Leo
- Department of Health Research, ICMR-Vector Control Rresearch Centre-Field Station, Madurai, Tamil Nadu, India
| | - Rajamannar Veeramanoharan
- Department of Health Research, ICMR-Vector Control Rresearch Centre-Field Station, Madurai, Tamil Nadu, India
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Tran HTD, Hattendorf J, Do HM, Hoang TT, Hoang HTH, Lam HN, Huynh MK, Vu LTH, Zinsstag J, Paris DH, Schelling E. Ecological and behavioural risk factors of scrub typhus in central Vietnam: a case-control study. Infect Dis Poverty 2021; 10:110. [PMID: 34412700 PMCID: PMC8374119 DOI: 10.1186/s40249-021-00893-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/04/2021] [Indexed: 12/04/2022] Open
Abstract
Background The risk factors for scrub typhus in Vietnam remain unknown. Scrub typhus caused by Orientia tsutsugamushi often presents as an undifferentiated febrile illness and remains under appreciated due to the limited availability of diagnostic tests. This tropical rickettsial illness is increasingly recognized as an important cause of non-malaria acute undifferentiated fever in Asia. This study aimed to investigate behavioural and ecological related risk factors of scrub typhus to prevent this potentially life-threatening disease in Vietnam. Methods We conducted a clinical hospital-based active surveillance study, and a retrospective residence-enrolment date-age-matched case–control study in Khanh Hoa province, Vietnam, from August 2018 to March 2020. Clinical examinations, polymerase chain reaction and enzyme-linked immunosorbent assay IgM tests were applied to define cases and controls. All enrolled participants filled out a questionnaire including demographic socio-economic status, personal behaviors/protective equipment, habitat connections, land use, and possible exposure to the vector. Multivariable conditional logistic regression was used to define the scrub typhus associated risk factors. Results We identified 44 confirmed cases and matched them with 152 controls. Among cases and controls, the largest age group was the 41–50 years old and males accounted for 61.4% and 42.8%, respectively. There were similarities in demographic characteristics between the two groups, with the exception of occupation. Several factors were significantly associated with acquisition of scrub typhus, including sitting/laying directly on household floor [adjusted OR (aOR) = 4.9, 95% CI: 1.6–15.1, P = 0.006], household with poor sanitation/conditions (aOR = 7.9, 95% CI: 1.9–32.9, P = 0.005), workplace environment with risk (aOR = 3.0, 95% CI: 1.2–7.6, P = 0.020), always observing mice around home (aOR = 3.7, 95% CI: 1.4–9.9, P = 0.008), and use of personal protective equipment in the field (aOR = 0.4, 95% CI: 0.1–1.1, P = 0.076). Conclusions Ecological and household hygiene-related factors were more associated with scrub typhus infection, than individual-level exposure activities in the hyper-endemic area. These findings support local education and allow people to protect themselves from scrub typhus, especially in areas with limitations in diagnostic capacity. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s40249-021-00893-6.
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Affiliation(s)
- Hanh Thi Duc Tran
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,Department of Epidemiology, Hanoi University of Public Health, Hanoi, Vietnam. .,University of Basel, Basel, Switzerland.
| | - Jan Hattendorf
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Hung Manh Do
- Department for Infectious Disease Control and Prevention, Nha Trang Pasteur Institute, Nha Trang, Khanh Hoa, Vietnam
| | - Thanh Tien Hoang
- Department for Infectious Disease Control and Prevention, Nha Trang Pasteur Institute, Nha Trang, Khanh Hoa, Vietnam
| | - Hang Thi Hai Hoang
- Department for Infectious Disease Control and Prevention, Nha Trang Pasteur Institute, Nha Trang, Khanh Hoa, Vietnam
| | - Hoa Ngoc Lam
- Institute of Gastroenterology and Hepatology, Hanoi, Vietnam
| | - Mai Kim Huynh
- Department of Microbiology and Immunology, Nha Trang Pasteur Institute, Nha Trang, Khanh Hoa, Vietnam
| | - Lan Thi Hoang Vu
- Department of Epidemiology, Hanoi University of Public Health, Hanoi, Vietnam
| | - Jakob Zinsstag
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Daniel Henry Paris
- Faculty of Medicine, University of Basel, Basel, Switzerland.,Department of Medicine, Swiss Tropical and Public Health Institute, Basel, Switzerland
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Paris DH, Kelly DJ, Fuerst PA, Day NPJ, Richards AL. A Brief History of the Major Rickettsioses in the Asia-Australia-Pacific Region: A Capstone Review for the Special Issue of TMID. Trop Med Infect Dis 2020; 5:tropicalmed5040165. [PMID: 33121158 PMCID: PMC7709643 DOI: 10.3390/tropicalmed5040165] [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: 09/12/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
The rickettsioses of the "Far East" or Asia-Australia-Pacific region include but are not limited to endemic typhus, scrub typhus, and more recently, tick typhus or spotted fever. These diseases embody the diversity of rickettsial disease worldwide and allow us to interconnect the various contributions to this special issue of Tropical Medicine and Infectious Disease. The impact of rickettsial diseases-particularly of scrub typhus-was substantial during the wars and "police actions" of the last 80 years. However, the post-World War II arrival of effective antibiotics reduced their impact, when recognized and adequately treated (chloramphenicol and tetracyclines). Presently, however, scrub typhus appears to be emerging and spreading into regions not previously reported. Better diagnostics, or higher population mobility, change in antimicrobial policies, even global warming, have been proposed as possible culprits of this phenomenon. Further, sporadic reports of possible antibiotic resistance have received the attention of clinicians and epidemiologists, raising interest in developing and testing novel diagnostics to facilitate medical diagnosis. We present a brief history of rickettsial diseases, their relative importance within the region, focusing on the so-called "tsutsugamushi triangle", the past and present impact of these diseases within the region, and indicate how historically, these often-confused diseases were ingeniously distinguished from each another. Moreover, we will discuss the importance of DNA-sequencing efforts for Orientia tsutsugamushi, obtained from patient blood, vector chiggers, and rodent reservoirs, particularly for the dominant 56-kD type-specific antigen gene (tsa56), and whole-genome sequences, which are increasing our knowledge of the diversity of this unique agent. We explore and discuss the potential of sequencing and other effective tools to geographically trace rickettsial disease agents, and develop control strategies to better mitigate the rickettsioses.
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Affiliation(s)
- Daniel H. Paris
- Department of Medicine, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
- Department of Clinical Research, University of Basel, 4051 Basel, Switzerland
- Correspondence: ; Tel.: +41-61-284-8111
| | - Daryl J. Kelly
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA; (D.J.K.); (P.A.F.)
| | - Paul A. Fuerst
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA; (D.J.K.); (P.A.F.)
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Programme, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand;
- Center for Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Old Road, Headington, Oxford OX3 7LJ, UK
| | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA;
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Kala D, Gupta S, Nagraik R, Verma V, Thakur A, Kaushal A. Diagnosis of scrub typhus: recent advancements and challenges. 3 Biotech 2020; 10:396. [PMID: 32834918 PMCID: PMC7431554 DOI: 10.1007/s13205-020-02389-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Scrub typhus is a mite-borne, acute febrile illness caused by the bacterium Orientia tsutsugamushi. It is a re-emerging infectious disease of the tsutsugamushi triangle. Scrub typhus is transmitted through bites of contaminated chiggers (larval stage). Diagnosis of scrub typhus is challenging as its symptoms mimic with other acute febrile illnesses. Several methods are effectual for diagnosis of scrub typhus that includes enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), immunochromatographic test (ICT), Weil-Felix, polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP). Weil-Felix test was initially used for the diagnosis of scrub typhus in underdeveloped countries but not preferred due to a lack of both specificity and sensitivity. Other immuno-based methods like IFA and ELISA are most outrank for detection of scrub typhus due to their higher sensitivity and specificity, but not vigorous to lay bare the infection at early stages and need the convalescent sampling for verification of positive samples. On another deed, PCR based methods becoming acceptable over era due to its dexterity of early-stage diagnosis with higher specificity and sensitivity but lack its applicability in circumstances of scrub typhus due to the variegated genetic makeup of Orientia tsutsugamushi among its serotypes. The present review focused on various detection methods along with their advantages and disadvantages used in the diagnosis of scrub typhus. A comparison between available methods of diagnosis with challenges in the detection of scrub typhus is also summarized.
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Affiliation(s)
- Deepak Kala
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | | | | | | | - Atul Thakur
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | - Ankur Kaushal
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
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Wangrangsimakul T, Greer RC, Chanta C, Nedsuwan S, Blacksell SD, Day NPJ, Paris DH. Clinical Characteristics and Outcome of Children Hospitalized With Scrub Typhus in an Area of Endemicity. J Pediatric Infect Dis Soc 2020; 9:202-209. [PMID: 30864670 PMCID: PMC7192406 DOI: 10.1093/jpids/piz014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/31/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Scrub typhus, caused by Orientia tsutsugamushi, is a major cause of acute febrile illness in children in the rural tropics. METHODS We recruited 60 febrile pediatric patients with a positive scrub typhus rapid diagnostic test result and 40 healthy controls from Chiang Rai Province in northern Thailand. Diagnosis was confirmed by the detection of (1) O. tsutsugamushi-specific DNA in blood or eschar samples with a polymerase chain reaction assay, (2) a fourfold rise in immunoglobulin M (IgM) titer to ≥1:3200 in paired plasma samples with an indirect immunofluorescence assay (IFA), or (3) a single IgM titer of ≥1:3200 in an acute plasma sample with an IFA. Demographic, clinical, and laboratory data were collected, and patients were followed up for 1 year. RESULTS Diagnosis was confirmed in 35 (58%) of 60 patients, and all controls tested negative for scrub typhus. Patients with confirmed scrub typhus had clinical symptoms, including fever (35 of 35 [100%]), eschar (21 of 35 [60%]), cough (21 of 35 [60%]), tachypnea (16 of 35 [46%]), lymphadenopathy (15 of 35 [43%]), and headache (14 of 35 [40%]). Only 4 (11%) of 35 patients received appropriate antibiotic treatment for scrub typhus before admission. The median fever-clearance time was 36 hours (interquartile range, 24-53 hours). Complications observed include hepatitis (9 of 35 [26%]), severe thrombocytopenia (7 of 35 [20%]), pneumonitis (5 of 35 [14%]), circulatory shock (4 of 35 [11%]), and acute respiratory distress syndrome (3 of 35 [9%]). Treatment failure, defined by failure to defervesce within 72 hours of antibiotic treatment initiation, was noted in 8 (23%) of 35 patients, and 1 (3%) of the 35 patients died. No evidence of relapse or reinfection was found. CONCLUSION Pediatric scrub typhus in northern Thailand is often severe and potentially fatal with delays in treatment a likely contributing factor. Additional studies to investigate the bacterial, pharmacologic, and immunologic factors related to treatment outcome along with measures to improve public awareness should be prioritized.
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Affiliation(s)
- Tri Wangrangsimakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Rachel C Greer
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Chulapong Chanta
- Department of Pediatrics, Chiang Rai Prachanukroh Hospital, Thailand
| | - Supalert Nedsuwan
- Department of Family Medicine, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand
| | - Stuart D Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Daniel H Paris
- Department of Medicine, Swiss Tropical and Public Health Institute and Faculty of Medicine, University of Basel, Switzerland
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Li W, Huang L, Zhang W. Scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia: a case report and review of the literature. J Med Case Rep 2019; 13:358. [PMID: 31810465 PMCID: PMC6898947 DOI: 10.1186/s13256-019-2299-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 10/18/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Scrub typhus is an acute infectious zoonotic disease caused by Orientia tsutsugamushi. Multi-organ dysfunction secondary to scrub typhus is hard to diagnose and has a high mortality rate. Only one case of scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia has been reported thus far. In this study, we report a second case of scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia, and we summarize its diagnosis and treatment. CASE PRESENTATION A 43-year-old Han Chinese woman, a sanitation worker, was admitted to our hospital after 7 days of a skin infection and 5 days of a sore throat with fever and dizziness. A physical examination revealed the presence of an eschar on the right side of her neck. She had a history of insect bites during her sanitation work. A diagnostic evaluation identified scrub typhus as the primary illness, which was associated with multi-organ dysfunction syndrome and immune thrombocytopenia. She recovered completely after 15 days of treatment and extensive symptomatic supportive care. CONCLUSION We report a second case of tsutsugamushi disease with multi-organ dysfunction syndrome and immune thrombocytopenia, which resolved after treatment and extensive care.
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Affiliation(s)
- Weijia Li
- Department of Intensive Care Unit, Peking University Shenzhen Hospital, Shenzhen, 518036, People's Republic of China
| | - Lei Huang
- Department of Intensive Care Unit, Peking University Shenzhen Hospital, Shenzhen, 518036, People's Republic of China.
| | - Weixing Zhang
- Department of Intensive Care Unit, Peking University Shenzhen Hospital, Shenzhen, 518036, People's Republic of China.
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Elangovan D, Perumalla S, Rose W, Verghese VP, Mammen J, Gowri MS, Jude Prakash JA. Assessment of two immunoassays for detection of IgM antibodies to scrub typhus using a serum panel. Indian J Med Microbiol 2019; 37:584-586. [PMID: 32436884 DOI: 10.4103/ijmm.ijmm_20_130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Laboratory tests are necessary for diagnosis of scrub typhus (ST) especially in the absence of the distinctive eschar. Performance of an ELISA and ICT (immunochromatography) to detect IgM antibodies to scrub typhus was assessed using a panel of 346 sera chosen from healthy individuals, those with scrub typhus and scrub-typhus like illness. A sensitivity of 98.7% for ST IgM ICT and 97.4% for ST IgM ELISA was observed while specificity was 96.3% for ICT and 95.9% for ELISA. As excellent concordance (98.8%) was noted between the two assays, IgM ICT can be used for rapid diagnosis of scrub typhus. Abbreviations: ST IgM ELISA: Scrub typhus IgM ELISA; ST IgM ICT: Scrub Typhus IgM Immunochromatography, Rapid diagnostic test: RDT.
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Affiliation(s)
- Divyaa Elangovan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Susmitha Perumalla
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Winsley Rose
- Department of Child Health-III, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Joy Mammen
- Department of Clinical Pathology, Christian Medical College, Vellore, Tamil Nadu, India
| | - M S Gowri
- Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India
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Kingston HW, Hossain M, Leopold S, Anantatat T, Tanganuchitcharnchai A, Sinha I, Plewes K, Maude RJ, Chowdhury MAH, Paul S, Uddin RAME, Siddiqui MAN, Zahed AS, Abu Sayeed A, Rahman MH, Barua A, Uddin MJ, Sattar MA, Dondorp AM, Blacksell SD, Day NPJ, Ghose A, Hossain A, Paris DH. Rickettsial Illnesses as Important Causes of Febrile Illness in Chittagong, Bangladesh. Emerg Infect Dis 2019; 24. [PMID: 29553921 PMCID: PMC5875266 DOI: 10.3201/eid2404.170190] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Scrub and murine typhus are common, treatable causes of undifferentiated febrile illnesses in hospitalized patients. We conducted a yearlong prospective study of febrile patients admitted to a tertiary referral hospital in Chittagong, Bangladesh, to assess the proportion of patients with rickettsial illnesses and identify the causative pathogens, strain genotypes, and associated seasonality patterns. We diagnosed scrub typhus in 16.8% (70/416) and murine typhus in 5.8% (24/416) of patients; 2 patients had infections attributable to undifferentiated Rickettsia spp. and 2 had DNA sequence–confirmed R. felis infection. Orientia tsutsugamushi genotypes included Karp, Gilliam, Kato, and TA763-like strains, with a prominence of Karp-like strains. Scrub typhus admissions peaked in a biphasic pattern before and after the rainy season, whereas murine typhus more frequently occurred before the rainy season. Death occurred in 4% (18/416) of cases; case-fatality rates were 4% each for scrub typhus (3/70) and murine typhus (1/28). Overall, 23.1% (96/416) of patients had evidence of treatable rickettsial illnesses, providing important evidence toward optimizing empirical treatment strategies.
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Poor Sensitivity of a Rapid Kit for Diagnosing Scrub typhus: Need for Continuous Monitoring and Regular Quality Check Type of Article: Brief Communication. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2018. [DOI: 10.22207/jpam.12.3.64] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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15
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Blacksell SD, Kingston HWF, Tanganuchitcharnchai A, Phanichkrivalkosil M, Hossain M, Hossain A, Ghose A, Leopold SJ, Dondorp AM, Day NPJ, Paris DH. Diagnostic Accuracy of the InBios Scrub Typhus Detect™ ELISA for the Detection of IgM Antibodies in Chittagong, Bangladesh. Trop Med Infect Dis 2018; 3:tropicalmed3030095. [PMID: 30274491 PMCID: PMC6160969 DOI: 10.3390/tropicalmed3030095] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/20/2018] [Accepted: 08/27/2018] [Indexed: 11/16/2022] Open
Abstract
Here we estimated the accuracy of the InBios Scrub Typhus Detect™ immunoglobulin M (IgM) ELISA to determine the optimal optical density (OD) cut-off values for the diagnosis of scrub typhus. Patients with undifferentiated febrile illness from Chittagong, Bangladesh, provided samples for reference testing using (i) qPCR using the Orientia spp. 47-kDa htra gene, (ii) IFA ≥1:3200 on admission, (iii) immunofluorescence assay (IFA) ≥1:3200 on admission or 4-fold rise to ≥3200, and (iv) combination of PCR and IFA positivity. For sero-epidemiological purposes (ELISA vs. IFA ≥1:3200 on admission or 4-fold rise to ≥3200), the OD cut-off for admission samples was ≥1.25, resulting in a sensitivity (Sn) of 91.5 (95% confidence interval (95% CI: 96.8–82.5) and a specificity (Sp) of 92.4 (95% CI: 95.0–89.0), while for convalescent samples the OD cut-off was ≥1.50 with Sn of 66.0 (95% CI: 78.5–51.7) and Sp of 96.0 (95% CI: 98.3–92.3). Comparisons against comparator reference tests (ELISA vs. all tests including PCR) indicated the most appropriate cut-off OD to be within the range of 0.75–1.25. For admission samples, the best Sn/Sp compromise was at 1.25 OD (Sn 91.5%, Sp 92.4%) and for convalescent samples at 0.75 OD (Sn 69.8%, Sp 89.5%). A relatively high (stringent) diagnostic cut-off value provides increased diagnostic accuracy with high sensitivity and specificity in the majority of cases, while lowering the cut-off runs the risk of false positivity. This study underlines the need for regional assessment of new diagnostic tests according to the level of endemicity of the disease given the high levels of residual or cross-reacting antibodies in the general population.
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Affiliation(s)
- Stuart D Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, UK.
| | - Hugh W F Kingston
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
| | - Ampai Tanganuchitcharnchai
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
| | - Meghna Phanichkrivalkosil
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
| | | | - Amir Hossain
- Chittagong Medical College Hospital, Chittagong, Bangladesh.
| | - Aniruddha Ghose
- Chittagong Medical College Hospital, Chittagong, Bangladesh.
| | - Stije J Leopold
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, UK.
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, UK.
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, UK.
| | - Daniel H Paris
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, UK.
- Department of Medicine, Swiss Tropical and Public Health Institute, 4056 Basel, Switzerland.
- Faculty of Medicine, University of Basel, 4003 Basel, Switzerland.
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16
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Varghese GM, Rajagopal VM, Trowbridge P, Purushothaman D, Martin SJ. Kinetics of IgM and IgG antibodies after scrub typhus infection and the clinical implications. Int J Infect Dis 2018; 71:53-55. [PMID: 29653201 PMCID: PMC5985369 DOI: 10.1016/j.ijid.2018.03.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 03/23/2018] [Accepted: 03/30/2018] [Indexed: 11/18/2022] Open
Abstract
The kinetics of IgM and IgG post scrub typhus infection remain elusive. Scrub typhus patients were followed up to study antibody kinetics. IgM remained above the threshold for 12 months. IgG reached a peak at 10 months and remained above the threshold for 36 months. Paired IgM samples are required for accurate diagnosis.
Objectives The serological detection of IgM antibodies is the most widely used test to diagnose scrub typhus infection. However, the kinetics of IgM and IgG antibodies post-infection remain elusive, which could contribute to false positivity. The objective of this study was to document the nature of the evolution of these antibody titres after infection. Methods Adult patients previously confirmed to have scrub typhus by IgM ELISA, positive PCR, or both, were included in this cross-sectional study. The levels of IgM and IgG antibodies in serum samples were tested using an ELISA and the distribution curve was plotted. Results Two hundred and three patients were included in this study. Post-infection serum sampling was done between 1 month and 46 months after documented infection. IgM levels declined gradually but remained elevated above the diagnostic cut-off for up to 12 months post-infection. However, IgG levels continued to rise reaching a peak at 10 months, followed by a gradual decline over several months. In the majority of cases, the IgG levels remained above the cut-off threshold for more than 36 months. Conclusions Clinicians need to be cautious in using a single serum sample for the detection of IgM to diagnose scrub typhus, as it remains elevated for up to 12 months after the infection, whereas the serum IgG level could be used as an indicator of past infection.
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Affiliation(s)
- George M Varghese
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India.
| | | | - Paul Trowbridge
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
| | - Divya Purushothaman
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
| | - Sherry Joseph Martin
- Department of Infectious Diseases, Christian Medical College, Vellore 632004, Tamil Nadu, India
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17
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Saraswati K, Day NPJ, Mukaka M, Blacksell SD. Scrub typhus point-of-care testing: A systematic review and meta-analysis. PLoS Negl Trop Dis 2018; 12:e0006330. [PMID: 29579046 PMCID: PMC5892940 DOI: 10.1371/journal.pntd.0006330] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 04/10/2018] [Accepted: 02/21/2018] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Diagnosing scrub typhus clinically is difficult, hence laboratory tests play a very important role in diagnosis. As performing sophisticated laboratory tests in resource-limited settings is not feasible, accurate point-of-care testing (POCT) for scrub typhus diagnosis would be invaluable for patient diagnosis and management. Here we summarise the existing evidence on the accuracy of scrub typhus POCTs to inform clinical practitioners in resource-limited settings of their diagnostic value. METHODOLOGY/PRINCIPAL FINDINGS Studies on POCTs which can be feasibly deployed in primary health care or outpatient settings were included. Thirty-one studies were identified through PubMed and manual searches of reference lists. The quality of the studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). About half (n = 14/31) of the included studies were of moderate quality. Meta-analysis showed the pooled sensitivity and specificity of commercially available immunochromatographic tests (ICTs) were 66.0% (95% CI 0.37-0.86) and 92.0% (95% CI 0.83-0.97), respectively. There was a significant and high degree of heterogeneity between the studies (I2 value = 97.48%, 95% CI 96.71-98.24 for sensitivity and I2 value = 98.17%, 95% CI 97.67-98.67 for specificity). Significant heterogeneity was observed for total number of samples between studies (p = 0.01), study design (whether using case-control design or not, p = 0.01), blinding during index test interpretation (p = 0.02), and QUADAS-2 score (p = 0.01). CONCLUSIONS/SIGNIFICANCE There was significant heterogeneity between the scrub typhus POCT diagnostic accuracy studies examined. Overall, the commercially available scrub typhus ICTs demonstrated better performance when 'ruling in' the diagnosis. There is a need for standardised methods and reporting of diagnostic accuracy to decrease between-study heterogeneity and increase comparability among study results, as well as development of an affordable and accurate antigen-based POCT to tackle the inherent weaknesses associated with serological testing.
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Affiliation(s)
- Kartika Saraswati
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, United Kingdom
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, United Kingdom
| | - Mavuto Mukaka
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, United Kingdom
| | - Stuart D. Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, United Kingdom
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18
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Pote K, Narang R, Deshmukh P. Diagnostic Performance of Serological Tests to Detect Antibodies Against Acute Scrub Typhus Infection in Central India. Indian J Med Microbiol 2018; 36:108-112. [DOI: 10.4103/ijmm.ijmm_17_405] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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19
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Xu G, Walker DH, Jupiter D, Melby PC, Arcari CM. A review of the global epidemiology of scrub typhus. PLoS Negl Trop Dis 2017; 11:e0006062. [PMID: 29099844 PMCID: PMC5687757 DOI: 10.1371/journal.pntd.0006062] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/15/2017] [Accepted: 10/21/2017] [Indexed: 12/18/2022] Open
Abstract
Scrub typhus is a serious public health problem in the Asia-Pacific area. It threatens one billion people globally, and causes illness in one million people each year. Caused by Orientia tsutsugamushi, scrub typhus can result in severe multiorgan failure with a case fatality rate up to 70% without appropriate treatment. The antigenic heterogeneity of O. tsutsugamushi precludes generic immunity and allows reinfection. As a neglected disease, there is still a large gap in our knowledge of the disease, as evidenced by the sporadic epidemiologic data and other related public health information regarding scrub typhus in its endemic areas. Our objective is to provide a systematic analysis of current epidemiology, prevention and control of scrub typhus in its long-standing endemic areas and recently recognized foci of infection.
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Affiliation(s)
- Guang Xu
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - David H. Walker
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Daniel Jupiter
- Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Peter C. Melby
- Department of Internal Medicine, Division of Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Christine M. Arcari
- Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, Texas, United States of America
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State of the art of diagnosis of rickettsial diseases: the use of blood specimens for diagnosis of scrub typhus, spotted fever group rickettsiosis, and murine typhus. Curr Opin Infect Dis 2017; 29:433-9. [PMID: 27429138 PMCID: PMC5029442 DOI: 10.1097/qco.0000000000000298] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE OF REVIEW With improved malaria control, acute undifferentiated febrile illness studies in tropical regions reveal a startling proportion of rickettsial illnesses, especially scrub typhus, murine typhus, and spotted fever group rickettsioses. Laboratory diagnosis of these infections evolved little over the past 40 years, but combinations of technologies like PCR and loop-mediated isothermal amplification, with refined rapid diagnostic tests and/or ELISA, are promising for guidance for early antirickettsial treatment. RECENT FINDINGS The long-term reliance on serological tests - useful only late in rickettsial infections - has led to underdiagnosis, inappropriate therapies, and undocumented morbidity and mortality. Recent approaches integrate nucleic acid amplification and recombinant protein-based serological tests for diagnosing scrub typhus. Optimized using Bayesian latent class analyses, this strategy increases diagnostic confidence and enables early accurate diagnosis and treatment - a model to follow for lagging progress in murine typhus and spotted fever. SUMMARY A laboratory diagnostic paradigm shift in rickettsial infections is evolving, with replacement of indirect immunofluorescence assay by the more objective ELISA coupled with nucleic acid amplification assays to expand the diagnostic window toward early infection intervals. This approach supports targeted antirickettsial therapy, reduces morbidity and mortality, and provides a robust evidence base for further development of diagnostics and vaccines.
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Abstract
Scrub typhus is an acute febrile illness in the “tsutsugamushi triangle”, transmitted by chiggers that can be treated effectively if detected early. Laboratory testing, including molecular and serological assays, is needed for confirming the diagnosis, especially in the absence of the pathognomonic eschar. In this review, factors that play a role in disease occurrence and clinical clues for diagnosis, in addition to risk factors contributing to disease severity, including mortality, are discussed in detail. Moreover, issues related to diagnostic assays, treatment, and mixed infections are also enumerated and described.
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Kalal BS, Shivalli S. Comment on "Serological Evidence of Scrub Typhus among Cases of PUO in the Kashmir Valley- A Hospital Based Study". J Clin Diagn Res 2017; 11:DL01-DL02. [PMID: 28764167 DOI: 10.7860/jcdr/2017/25345.10038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/04/2017] [Indexed: 11/24/2022]
Affiliation(s)
- Bhuvanesh Sukhlal Kalal
- Senior Research Fellow (CSIR), Department of Biochemistry, Yenepoya Medical College, Yenepoya University, Mangalore, Karnataka, India and Yenepoya Research Centre, Yenepoya University, Mangalore, India
| | - Siddharudha Shivalli
- Associate Professor, Community Medicine, Yenepoya University, Mangalore, India and Regional Technical Advisor South-East Asia, TEPHINET, Task Force for Global Health, Inc., USA
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Chao CC, Zhang Z, Belinskaya T, Thipmontree W, Tantibhedyangkul W, Silpasakorn S, Wongsawat E, Suputtamongkol Y, Ching WM. An ELISA assay using a combination of recombinant proteins from multiple strains of Orientia tsutsugamushi offers an accurate diagnosis for scrub typhus. BMC Infect Dis 2017; 17:413. [PMID: 28601091 PMCID: PMC5466769 DOI: 10.1186/s12879-017-2512-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 06/01/2017] [Indexed: 12/02/2022] Open
Abstract
Background Scrub typhus (ST) is a disease caused by an obligate intracellular bacterium, Orientia tsutsugamushi, an organism that requires a BSL3 laboratory for propagation. The disease is hallmarked by an eschar at the site of the chigger bite, followed by the development of fever, malaise, myalgia, anorexia, and papulomacular rash. Indirect immunofluorescent assay (IFA) is the gold standard for scrub typhus diagnosis, however, the subjectivity of the assay, the need for a specialized laboratory and instruments has limited the wide use of the test in resource limited areas. Methods A recombinant-protein based enzyme linked immunosorbent assay (ELISA) using the most abundant and immunodominant protein for the detection of Orientia specific antibodies in serum has been developed. The performance of the assay was evaluated using prospectively collected acute sera from 248 randomly selected patients in Thailand. The ELISA assay was evaluated using two different cutoff values. Results The receiver operating characteristic (ROC) curve generated cutoff values gave slightly better consistency with diagnosis of ST than those cutoff values established by averaging ELISA optical density of known negatives at 99% confidence interval. Both cutoff values provided similar statistical parameters when compared with the diagnosis of ST, indicating the validity of both calculations to derive cutoff values. These results suggest that both IgG and IgM ELISA performed well to accurately diagnose scrub typhus cases in endemic areas using only acute serum samples. Conclusions We have successfully developed an ELISA assay for the detection of Orientia-specific antibodies in serum that could provide effective screening of acute sera under clinical setup and it is also a useful assay to estimate seroprevalence in various endemic areas. Electronic supplementary material The online version of this article (doi:10.1186/s12879-017-2512-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chien-Chung Chao
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA. .,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
| | - Zhiwen Zhang
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA.,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Tatyana Belinskaya
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA.,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Wilawan Thipmontree
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.,Department of Medicine, Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima, Thailand
| | - Wiwit Tantibhedyangkul
- Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Saowaluk Silpasakorn
- Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Ekkarat Wongsawat
- Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Yupin Suputtamongkol
- Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Wei-Mei Ching
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, USA.,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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Li T, Huang M, Xiao H, Zhang G, Ding J, Wu P, Zhang H, Sheng J, Chen C. Selection and characterization of specific nanobody against bovine virus diarrhea virus (BVDV) E2 protein. PLoS One 2017; 12:e0178469. [PMID: 28582444 PMCID: PMC5459339 DOI: 10.1371/journal.pone.0178469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 05/13/2017] [Indexed: 01/15/2023] Open
Abstract
Bovine viral diarrhea-mucosal disease (BVD-MD) is caused by bovine viral diarrhea virus (BVDV), and results in abortion, stillbirth, and fetal malformation in cows. Here, we constructed the phage display vector pCANTAB 5E-VHH and then transformed it into Escherichia coli TG1-competent cells, to construct an initial anti-BVDV nanobody gene library. We obtained a BVDV-E2 antigen epitope bait protein by prokaryotic expression using the nucleotide sequence of the E2 gene of the BVDV-NADL strain published in GenBank. Phage display was used to screen the anti-BVDV nanobody gene library. We successfully constructed a high quality phage display nanobody library, with an initial library capacity of 4.32×105. After the rescue of helper phage, the titer of the phage display nanobody library was 1.3×1011. The BVDV-E2 protein was then expressed in Escherichia coli (DE3), and a 49.5 kDa band was observed with SDS-PAGE analysis that was consistent with the expected nanobody size. Thus, we were able to isolate one nanobody that exhibits high affinity and specificity against BVDV using phage display techniques. This isolated nanobody was then used in Enzyme Linked Immunosorbent Assay and qRT-PCR, and ELISA analyses of BVDV infection of MDBK cells indicated that the nanobodies exhibited good antiviral effect.
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Affiliation(s)
- Tiansen Li
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Meiling Huang
- Shihezi University Library, Shihezi University, Shihezi, Xinjiang, China
| | - Hongran Xiao
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Guoqi Zhang
- College of Life Science, Shihezi University, Shihezi, Xinjiang, China
| | - Jinhua Ding
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Peng Wu
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Jinliang Sheng
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Chuangfu Chen
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
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Trowbridge P, P D, Premkumar PS, Varghese GM. Prevalence and risk factors for scrub typhus in South India. Trop Med Int Health 2017; 22:576-582. [PMID: 28173608 DOI: 10.1111/tmi.12853] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To determine the prevalence and risk factors of scrub typhus in Tamil Nadu, South India. METHODS We performed a clustered seroprevalence study of the areas around Vellore. All participants completed a risk factor survey, with seropositive and seronegative participants acting as cases and controls, respectively, in a risk factor analysis. After univariate analysis, variables found to be significant underwent multivariate analysis. RESULTS Of 721 people participating in this study, 31.8% tested seropositive. By univariate analysis, after accounting for clustering, having a house that was clustered with other houses, having a fewer rooms in a house, having fewer people living in a household, defecating outside, female sex, age >60 years, shorter height, lower weight, smaller body mass index and smaller mid-upper arm circumference were found to be significantly associated with seropositivity. After multivariate regression modelling, living in a house clustered with other houses, female sex and age >60 years were significantly associated with scrub typhus exposure. CONCLUSIONS Overall, scrub typhus is much more common than previously thought. Previously described individual environmental and habitual risk factors seem to have less importance in South India, perhaps because of the overall scrub typhus-conducive nature of the environment in this region.
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Affiliation(s)
- Paul Trowbridge
- Spectrum Health Center for Integrative Medicine, Grand Rapids, MI, USA.,Tufts Medical Center/Tufts University, Boston, MA, USA
| | - Divya P
- Christian Medical College, Vellore, India
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Anitharaj V, Stephen S, Pradeep J, Park S, Kim SH, Kim YJ, Kim EY, Kim YW. Serological Diagnosis of Acute Scrub Typhus in Southern India: Evaluation of InBios Scrub Typhus Detect IgM Rapid Test and Comparison with other Serological Tests. J Clin Diagn Res 2016; 10:DC07-DC10. [PMID: 28050364 DOI: 10.7860/jcdr/2016/24051.8861] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 10/10/2016] [Indexed: 01/30/2023]
Abstract
INTRODUCTION Scrub Typhus (ST) is being reported from different parts of India in the recent past. However, the diagnosis and confirmation of ST cases require specific serological and molecular diagnostic tests. Both rapid and conventional ELISA tests need to be properly evaluated. AIM Evaluation of a new ST IgM Immunochromatography (ICT) test kit (InBios Scrub Typhus Detect IgM Rapid Test) and compare it with another rapid kit, conventional ELISA kit and Weil-Felix (WF) test. MATERIALS AND METHODS This prospective study was carried out in Mahatma Gandhi Medical College and Research Institute, Puducherry, during November 2015 to June 2016. Clinically suspected 220 ST patients were examined by a new kit, InBios Scrub Typhus Detect IgM Rapid Test, taking the conventional InBios Scrub Typhus Detect IgM ELISA as reference. Additional comparison was made with ImmuneMed Scrub Typhus Rapid, and WF test (single OXK titers ≥1:320). Statistical analysis was performed (Chi-square, Spearman's correlation and Kappa) using IBM SPSS Statistics 17 for Windows (SPSS Inc; Chicago, USA). RESULTS Percentage Sensitivity, Specificity, Positive Predictive and Negative Predictive Values for InBios, ImmuneMed and WF were 99.25, 93.02, 95.68, 98.77; 94.87, 94.19, 96.21, 92.05 and 50.38, 95.51, 94.29, 56.67 respectively. A total of 134 patients were positive in reference standard InBios IgM ELISA. CONCLUSION This new rapid ST IgM kit validated for the first time in India, showed good sensitivity and specificity. As a Point-of-Care (PoC) test, the kit would be helpful in both urban and remote rural parts of India.
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Affiliation(s)
- Velmurugan Anitharaj
- Ph.D. Scholar, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India
| | - Selvaraj Stephen
- Professor, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India
| | - Jothimani Pradeep
- Ph.D. Scholar, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India
| | - Sungman Park
- Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea
| | - Seung-Han Kim
- Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea
| | - Young Jin Kim
- Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea
| | - Eun-Ye Kim
- Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea
| | - Yoon-Won Kim
- Teaching Faculty, Department of Microbiology, Hallym University College of Medicine , Chuncheon, Gangwon do, South Korea
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27
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Abstract
The obligate intracellular bacterium Orientia tsutsugamushi is responsible for more than one million cases of scrub typhus annually throughout the Asia-Pacific region. Human infection occurs via the bite of the larval form (chigger) of several species of trombiculid mites. While in some patients the result of infection is a mild, febrile illness, others experience severe complications, which may even be fatal. This review discusses the genome and biology of the causative agent, the changing epidemiology of scrub typhus, the challenges of its diagnosis, and current treatment recommendations.
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Affiliation(s)
- Sunil Thomas
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania USA
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28
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Kalal BS, Puranik P, Nagaraj S, Rego S, Shet A. Scrub typhus and spotted fever among hospitalised children in South India: Clinical profile and serological epidemiology. Indian J Med Microbiol 2016; 34:293-8. [DOI: 10.4103/0255-0857.188315] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Watthanaworawit W, Kolakowska E, Hanboonkunupakarn B, Ling C, McGready R. Scrub typhus infection in pregnancy: the dilemma of diagnosis and treatment in a resource-limited setting. Clin Case Rep 2016; 4:584-8. [PMID: 27398202 PMCID: PMC4891484 DOI: 10.1002/ccr3.572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 03/13/2016] [Accepted: 04/19/2016] [Indexed: 01/30/2023] Open
Abstract
To save the life of both mother and fetus, the risks and benefits of the few antibiotics considered effective in the treatment of severe scrub typhus require consideration. In this case, chloramphenicol treatment averted maternal but not fetal mortality. Evidence‐based guidelines appropriate for resource‐limited endemic areas are required.
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Affiliation(s)
- Wanitda Watthanaworawit
- Shoklo Malaria Research Unit Mahidol-Oxford Tropical Medicine Research Unit Faculty of Tropical Medicine Mahidol University Mae Sot Thailand
| | - Edyta Kolakowska
- Shoklo Malaria Research Unit Mahidol-Oxford Tropical Medicine Research Unit Faculty of Tropical Medicine Mahidol University Mae Sot Thailand
| | - Borimas Hanboonkunupakarn
- Mahidol-Oxford Tropical Medicine Research Unit Faculty of Tropical Medicine Mahidol University Bangkok Thailand
| | - Clare Ling
- Shoklo Malaria Research Unit Mahidol-Oxford Tropical Medicine Research Unit Faculty of Tropical Medicine Mahidol University Mae Sot Thailand
| | - Rose McGready
- Shoklo Malaria Research Unit Mahidol-Oxford Tropical Medicine Research Unit Faculty of Tropical Medicine Mahidol University Mae Sot Thailand; Centre for Tropical Medicine Nuffield Department of Medicine University of Oxford Oxford UK
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Lubell Y, Althaus T, Blacksell SD, Paris DH, Mayxay M, Pan-Ngum W, White LJ, Day NPJ, Newton PN. Modelling the Impact and Cost-Effectiveness of Biomarker Tests as Compared with Pathogen-Specific Diagnostics in the Management of Undifferentiated Fever in Remote Tropical Settings. PLoS One 2016; 11:e0152420. [PMID: 27027303 PMCID: PMC4814092 DOI: 10.1371/journal.pone.0152420] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/14/2016] [Indexed: 01/21/2023] Open
Abstract
Background Malaria accounts for a small fraction of febrile cases in increasingly large areas of the malaria endemic world. Point-of-care tests to improve the management of non-malarial fevers appropriate for primary care are few, consisting of either diagnostic tests for specific pathogens or testing for biomarkers of host response that indicate whether antibiotics might be required. The impact and cost-effectiveness of these approaches are relatively unexplored and methods to do so are not well-developed. Methods We model the ability of dengue and scrub typhus rapid tests to inform antibiotic treatment, as compared with testing for elevated C-Reactive Protein (CRP), a biomarker of host-inflammation. Using data on causes of fever in rural Laos, we estimate the proportion of outpatients that would be correctly classified as requiring an antibiotic and the likely cost-effectiveness of the approaches. Results Use of either pathogen-specific test slightly increased the proportion of patients correctly classified as requiring antibiotics. CRP testing was consistently superior to the pathogen-specific tests, despite heterogeneity in causes of fever. All testing strategies are likely to result in higher average costs, but only the scrub typhus and CRP tests are likely to be cost-effective when considering direct health benefits, with median cost per disability adjusted life year averted of approximately $48 USD and $94 USD, respectively. Conclusions Testing for viral infections is unlikely to be cost-effective when considering only direct health benefits to patients. Testing for prevalent bacterial pathogens can be cost-effective, having the benefit of informing not only whether treatment is required, but also as to the most appropriate antibiotic; this advantage, however, varies widely in response to heterogeneity in causes of fever. Testing for biomarkers of host inflammation is likely to be consistently cost-effective despite high heterogeneity, and can also offer substantial reductions in over-use of antimicrobials in viral infections.
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Affiliation(s)
- Yoel Lubell
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Thomas Althaus
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stuart D. Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel H. Paris
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos
- Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Laos
| | - Wirichada Pan-Ngum
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Lisa J. White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul N. Newton
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos
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