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Background: Scrub typhus is an emerging but neglected infectious diseases that generally results in acute febrile illness, with spectrum of diseases ranging from mild illness to multiorgan dysfunction. Hence we planned this study to know the demographic, clinical and biochemical profile of scrub typhus patients in hilly state of Uttarakhand. Methods: This was a prospective observational study conducted from June 2020 to November 2020 in the Department of Internal Medicine, in a tertiary care institution located in state of Uttarakhand, India. All scrub typhus patients were evaluated by detailed history, examination and laboratory tests. Results: Among 60 cases, the mean age of patients was 38.3�.43 years, with majority of patients (70.2%) being young adults between the age 18?40 years. Majority of patients were females (60.0%) with (M:F-1:1.3). 53.3% patients reported from rural and 46.7% patients from urban area. Fever (100%), cough and breathlessness (40.0%), nausea and vomiting (20%), abdominal pain and diarrhoea (16.7%), headache (16.7%) and altered sensorium (8.3%) were the predominant clinical features. Hepatic dysfunction (51; 85.0%) and respiratory dysfunction (25; 41.6%) were the commonest findings followed by renal dysfunction (13; 21.7%). Conclusions: Scrub typhus is often misdiagnosed or diagnosed late due to its wide clinical spectrum overlapping with clinical presentation of other commonly prevalent tropical diseases. An increasing awareness of this disease coupled with prompt management will go a long way in reducing both morbidity and mortality in this disease.
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Scrub typhus is a type of natural focal disease caused by a bacteria called Orientia tsutsugamushi and mainly en-demic in East and Southeast Asia.The most common clinical symptoms of scrub typhus include fever,eschar,ulcer,lymph node enlargement and rash,which are not typical on early stage and could easily lead to misdiagnosis and missed diagnosis.By reviewing relevant guidelines and references at home and abroad,combining clinical diagnosis and treatment experiences in Chi-na,the experts from Biodiagnostic Technology Branch of China Medical Biotechnology Association and Chinese Society of Mi-crobiology Committee on Zoonotic Pathogens formed this consensus on the clinical diagnosis and treatment of scrub typhus.
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Background & objectives: The diagnosis of scrub typhus (ST) is usually done using enzyme-linked immunosorbent assay (ELISA) due to its ease of performance and reading objectivity. The cut-off value for ELISA needs to be calculated for each geographical location as it depends on zonal endemicity of the disease. This study was, therefore, undertaken to calculate the pan-India cut-off for anti-Orientia tsutsugamushi (OT) immunoglobulin M (IgM) by ELISA. Methods: Samples from cases (cases of ST) and controls (voluntary, consenting, healthy adults) were collected by a network of 29 laboratories across India and tested for anti-OT IgM by immunofluorescence assay (IFA), the considered gold standard test. These samples were retested by ELISA for anti-OT IgM and their optical densities (ODs) were used for cut-off estimation by receiver operating characteristic (ROC) curve. Results: Anti-OT IgM ELISA ODs from 273 controls and 136 cases were used for the cut-off estimation. The ODs of the anti-OT IgM ELISA on healthy individuals and those of confirmed ST cases ranged from 0.1 to 0.75 and 0.5 to 4.718, respectively. ROC curve-based cut-off for ELISA was calculated as 0.554 at a sensitivity of 95.2 per cent and specificity of 95.1 per cent. A value of >1 was noted to have a specificity of 100 per cent in diagnosing ST. Interpretation & conclusions: The cut-off calculated for India was similar to the previous cut-off that was used until now.
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Scrub typhus, an acute febrile infectious disease prevalent in the “Tsutsugamushi triangle”, is a mite-born rickettsial zoonosis, caused by Orientia tsutsugamushi. Although the clinical presentation is protean, it rarely causes abducens nerve palsy. We report a 13-year-old previously healthy Indian boy who presented with a recent onset right abducens nerve palsy, headache and fever but without the classic dermatological manifestation (“eschar”) of the disease. After exclusion of common infectious and other causes, he was finally diagnosed with scrub typhus associated with an abducens nerve palsy, which responded to doxycycline therapy.
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Background: Scrub typhus presents as an acute, febrile, exanthematous illness. Due to its non-specific and varied clinical presentation, this is underdiagnosed. Low index of suspicion among clinicians, and lack of diagnostic facilities also keeps it undiagnosed. This study was carried out to know the seroprevalence of scrub typhus in a tertiary care centre with pyrexia of unknown origin (PUO) and to compare a rapid test with IgM enzyme-linked immunosorbent assay (ELISA) for the diagnosis of scrub typhus. Methods: This cross-sectional analytical study was conducted for a period of 1 year. The study population comprised mainly 320 patients attending outdoor and indoor patients admitted to a tertiary care hospital with fever and related symptoms. The serum samples were tested for IgM ELISA, and rapid card test. Results: The mean age group of the study population was 35–60 years, of which 30 cases were positive. The major predisposing factors for scrub typhus infection were crops and animals around houses. The sensitivity and specificity of both, card test and IgM ELISA were 100%. Conclusions: In this study, 9.3% of febrile patients were positive for scrub typhus. Dengue, malaria and typhoid were the common coinfections found in scrub typhus, positive patients. Early identification of cases and treatment at the earliest will prevent complications.
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Objective:To explore the clinical utility of metagenomic next-generation sequencing (mNGS) for patients with critically ill atypical rickettsial infections in the early diagnosis and therapy.Methods:From Jan 2020 to Aug 2022, clinical features, blood biochemical results, imaging data and mNGS results in patients with unexplained critical illnesses were collected and analyzed retrospectively. Fisher's exact test was used to compare the positive rate of mNGS and weil felix reaction.Results:All 15 patients with rickettsial disease had fever, 12 cases had headache, but only 3 had a typical rash or scab of diagnostic significance, 6 had septic shock and all had multi-organ dysfunction; blood mNGS tests were positive in 15 cases, of which 10 had Orientia tsutsugamushi detected in their blood and the remaining five had Rickettsia moschata detected in their blood. The positive rate of mNGS was significantly higher than that of the weil felix reaction (15/15 vs 0, P<0.001). All patients were given doxycycline and other treatments after diagnosis, of which 14 improved and were discharged, and one died 1 week after discharge due to critical condition and abandonment of treatment. Conclusion:mNGS can improve the detection rate of atypical rickettsiae in patients with negative routine test results, which can provide valuable reference basis for early diagnosis and early anti-infection treatment of patients with critical rickettsial disease.
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The clinical data of 67 patients with tsutsugamushi disease diagnosed and treated in Department of General Medicine, Yuxi People′s Hospital of Yunnan Province from January 2020 to December 2022 were retrospectively analyzed. Among them, 43 were males and 24 were females and most of patients were from rural areas ( n=56, 83.58%); there were 14 severe cases and 53 non-severe cases, the age of patients ranged from 41 to 65 years,and the average age of severe cases was older than that of non-severe cases. Most of patients were encountered in July to October ( n=59, 88.1%). All patients presented eschar or ulcer, which were occurred in limbs ( n=27, 40.4%), body folds ( n=22, 32.8%) or trunk ( n=18, 26.8%). The incidence of systemic rash and chills in severe group was higher than that in non-severe group ( P<0.05).The levels of Hb, platelet, ALB, uric acid and TBil in severe cases were lower than those in non-severe cases (all P<0.05), while the levels of CRP, PTC, ALT, AST, Scr, Urea nitrogen, CKMB, LDH, and APTT were higher than those in non-severe cases (all P<0.05). The curative effect of anti-rickettsia therapy in non-severe group was better than that in severe group ( χ 2=5.16, P<0.05). It is suggested that general practitioners should pay attention to tsutsugamushi disease, and early diagnosis and treatment can achieve good therapeutic effect.
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Scrub typhus is the oldest known vector-borne zoonotic infectious disease in the world which is life-threatening for all age groups as it presents acute febrile illness along with multi-organ involvements and spread with the biting of infectious ‘Trombiculid mite’ (chigger mite). The pathogen of this disease is an obligatory coccobacillus gram-negative rickettsial bacteria Orientia tsutsugamushi. Scrub typhus disease was previously confined geographically only to the Asia Pacific region (tsutsugamushi triangle), but in recent years it has crossed its limit and has spread in other countries beyond the tsutsugamushi triangle and has become more hazardous for the community. The objective of this study is to explore the scrub typhus disease outbreak trends with existing information in southern Rajasthan state, India. This study concluded that scrub typhus disease is being re-emerged again and again in various Indian geographical regions with new species of vectors. The disease has been raised in tremendous amounts in Rajasthan within the last five years especially in the hilly zone and has led to major public health problems with other zoonotic diseases
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Scrub typhus, also called bush typhus, is a zoonotic disease a Gram-negative bacterium. Its presentation may range from nonspecific febrile illness to severe disease, with cardiovascular, renal, hepatic and neurological involvement. Myocarditis is one of the rare complications of scrub typhus. Hence, we are reporting a case of a 50-year-old male, farmer by occupation, presenting to us in multiorgan dysfunction syndrome who developed myocarditis during second week of his illness.
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Scrub typhus, a rickettsial disease endemic in several parts of India, usually presents with acute symptoms. It is caused by small intracellular Gram-negative bacteria belonging to the Rickettsiaceae family. Optic neuritis and lateral rectus palsy may be associated with a range of autoimmune disorders, infectious diseases and raised intracranial tension. In this case, we report optic neuritis and lateral rectus palsy induced by Orientia tsutsugamushi. We report a case of a 23-year-old woman presenting with complaints of high-grade fever, vomiting and generalized swelling since 5 days. During this febrile period, on 4/10/2021, she complained of difficulty in vision and double vision. She was found to be positive for scrub typhus on 5/10/2021. Optic neuritis was diagnosed on the basis of ophthalmologic examination and magnetic resonance imaging (MRI) brain. Investigation was done to rule out autoimmune disorders (vasculitis and connective tissue diseases). Rickettsial optic neuritis was confirmed by detection of specific antibodies in serum and the negativity of other serologic tests. Fever, eschar, history of tick exposure and supportive diagnostic tests usually lead to the diagnosis. This case aims to raise awareness among the healthcare providers for this type of association. Scrub typhus should be included in the differential diagnosis when a patient presents with fever with or without eschar and isolated or multiple cranial nerve palsy
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@#Abstract: Objective To analyze the epidemiological characteristics of scrub typhus in 680 patients with unexplained fever in Hainan Island and provide guidance for local scrub typhus prevention and control. Methods Blood samples from patients with clinically diagnosed unexplained fever in the First Affiliated Hospital of Hainan Medical University, Second Affiliated Hospital of Hainan Medical University, Haikou Municipal People's Hospital and Central South University Xiangya Medical College Affiliated Hospital, People's Hospital of Qiongzhong Li Miao Autonomous County were collected between 2018 and 2021, then samples were tested for Orientia tsutsugamushi specific IgM, IgG antibodies and Orientia tsutsugamushi 56kD-specific antigen genes using colloidal gold immunochromatography and PCR methods. The clinical and epidemiological information of the samples were also collected. Epidemiological analysis was carried out on the obtained sample information and test results. Results A total of 680 samples from patients with clinically unknown fever were collected. The positive rates of scrub typhus IgM antibody, IgG antibody, PCR were 23.97% (163/680), 36.62% (249/680), 20.88% (142/680), respectively, and eschar or rash was observed in 12.06% (82/680) of all patients. According to the diagnostic criteria, 223 patients were finally diagnosed with scrub typhus. Among them, there were 111 males (49.78%) and 109 females (48.88%); the average age was (53.14±15.12) years old, and the 40-<60 years old was the main incidence group (98 cases, accounting for 43.95%). The ethnicity of the patient with scrub typhus was mainly Han ethnicity (136 cases, accounting for 60.99%). Farmers were the main morbidity group (93 cases, 41.70%). The patient with scrub typhus distributed throughout the island except for Sanya and Wuzhishan, with Haikou and Qiongzhong show the highest number of cases. The number of cases in autumn was the highest (114 cases, 51.12%). The clinical manifestations of infected patients were mainly non-specific symptoms and signs, 36.77% of patients developed skin-specific ulcers or eschars, which were mainly distributed in the shoulder and neck, armpits, elbow fossa, chest and abdomen, back, buttocks, groin, scrotum and other joints and skin folds of the upper and lower limbs. Conclusions Hainan Island is the foci of scrub typhus and the epidemic time has obvious seasonality. Its prevention should focus on rural areas in autumn, and its clinical features are mainly high fever and eschar or ulceration.
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Objective: Scrub typhus is a relatively common life-threating disease; its symptoms are non-specific and similar to those of other viral infections. Therefore, scrub typhus might be underdiagnosed.Patient: Herein, we report a patient with scrub typhus whose clinical course mimicked that of infectious mononucleosis. A 63-year-old male patient with hypertension presented to our hospital complaining of symptoms including prolonged fever, pharyngeal discomfort, and a mild headache. He showed the appearance of a rash after amoxicillin administration. At the same time, he did not show a crusted rash on his body surface.Results: After a comprehensive examination, Epstein-Barr virus and cytomegalovirus infections were ruled out. We suspected that this patient suffered from scrub typhus on the basis of his usual lifestyle. Finally, polymerase chain reaction analysis showed a positive result for deoxyribonucleic acid of Orientia tsutsugamushi in his blood sample. Fortunately, he recovered naturally with only supportive treatment during his hospitalization.Conclusion: We should observe and monitor patients with infectious mononucleosis-like symptoms and emphasize the importance of a clinical interview.
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Objective: To study the spectrum and outcome of severe scrub typhus in adult patients and to predict the hospital mortality by organ failure on admission. Methods: This was a prospective observational cohort study conducted between July 2017 and October 2020 at the medical emergency centre of PGIMER, Chandigarh, India. One hundred and twenty-six patients aged =13 years were diagnosed with scrub typhus. Severe disease was defined as the presence of organ failure based on the Sequential Organ Failure Assessment (SOFA) score on admission. Results: About two-thirds of the patients were from geographic regions outside the endemic sub-Himalayan belt. Fever (99.21%) and dyspnea (79.36%) were the most frequent complaints. Respiratory failure (81.75%) was the most common organ failure, followed by hepatic (52.38%), coagulative (47.62%), circulatory (33.33%), renal (21.43%), and cerebral dysfunction (13.49%). The median (Q1, Q3) SOFA score was 8 (6, 9), and 48.41% of the patients had a quick-SOFA score =2. Organ supports with invasive ventilation (40.48%), vasopressors (36.51%), and renal replacement therapy (7.14%) were frequently required. The in-hospital mortality was 11.90% and was independently predicted by circulatory and hepatic failures on multivariate logistic regression (OR 11.12, 95% CI 1.73-71.31 and OR 8.49, 95% CI 1.18-61.41, respectively). Conclusions: Most patients had pulmonary dysfunction; circulatory or hepatic failure on admission strongly predicts death.
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Scrub typhus is a mite borne transmittable disease caused by the obligate intracellular bacterium known as Orientiatsutsugamushi. Although it presents with nonspecific clinical manifestation, early diagnosis and treatment oftenprevents it’s complication. Here in this study, we used two different diagnostic tools Scrub-polymerase chainreaction (PCR) and serologic Scrub IgM antibody based enzyme-linked immunosorbent assay (IgM ELISA) test.Out of 154 cases, total of 101 cases were found Scrub IgM-ELISA positive. Both serology and Scrub-PCR wasdone in total 96 cases. Out of 96 cases, 41.6% (n−40) were Scrub-PCR positive and 58.3% (n−56) cases werePCR negative. Eighty percent cases become serology positive (IgM ELISA) those who presented after 7 days butbefore 14 days of illness and least (54%) when presented before 1 week of illness. Twenty cases were found to beIgM positive but PCR negative. The mean duration of illness among those 20 patients who were IgM positive butPCR negative was found to 12.55 days. Only four cases were PCR positive but IgM negative. The mean durationof illness was 6.2 days among those four patients so that the antibody conversion was not detectable at that phase.Therefore, the combination of molecular and serological tests needs to be used, so that it can cover the entireduration of illness for early and accurate diagnosis so as to prevent the complications.
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Background: Scrub typhus infection is endemic in India and reported to be the major cause for acute encephalitis syndrome (AES) in humans. Periodic occurrence of scrub typhus cases and presence of pathogen in rodents were also reported in areas with human cases of scrub typhus in Puducherry. Objectives: This study was carried out to screen Orientia tsutsugamushi in rodent/shrew reservoirs and vectors in villages of Puducherry with no reports of human scrub typhus cases. Methods: This study was conducted during October 2017 to January 2018 in ten randomly selected villages in Puducherry. Rodents/shrews in the peridomestic area were trapped using Sherman traps. Screening of O. tsutsugamushi in rodents/shrews and mite vectors was done by polymerase chain reaction (PCR). Weil-Felix test was done to screen antibodies against O. tsutsugamushi in rodent serum samples. Results: Among the 54 rodents trapped, Suncus murinus was the major small animal and Leptotrombidium deliense was the major mite species retrieved. PCR screening revealed pathogen positivity in 8 rodent blood and 3 pooled mite samples. Phylogenetic analysis has shown that Kato was the circulating serotype of O. tsutsugamushi. None of the rodent serum samples was tested positive for antibodies against O. tsutsugamushi by Weil-Felix test. Conclusions: The presence of pathogen in both vectors and reservoir animal hosts imposes a risk for scrub typhus transmission to the inhabitants; hence, initiation of vector control measures before the start of winter is recommended in the study area. It is also recommended to screen scrub typhus in patients with undifferentiated acute febrile illness and AES.
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Background: Scrub typhus is a documented disease in Himachal Pradesh, but there have been few clinico-epidemiological studies in this area. The present study is done with IgM ELISA as a diagnostic test which has higher sensitivity and specificity as most of the previous studies had used Weil Felix test as a diagnostic test. Methodology: This was a prospective observational study. All the patients more than 18 years of age with positive IgM ELISA for scrub typhus with/without eschar were included. The clinical profile was observed. IgM scrub typhus was done by ELISA. Results: Total of 39 patients were observed between July 2016 to Dec 2016. Maximum patients were observed in August, September, and October. Fever with Headache was the most common presenting complaint. Eschar was present in 10 % patients. Complications were seen in 76.92 %. The mortality rate was 0 %. Conclusion: The varied presentations and high rate of complications require a high index of suspicion for Scrub Typhus. The general physicians should be sensitized for the early diagnosis and treatment to reduce morbidity and mortality.
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Objective: Scrub typhus is a rickettsial febrile condition caused by bacteria called Orientia tsusugamushi. It spreads to people through bites of infected larval mites. The objective of this study was to predict the severity of scrub typhus. Methods: A case-control study was done at Kasturba Medical College Hospital (2012-2015) retrospectively on patients admitted with scrub typhus. Patient demographics, lab parameters, investigations and treatment courses were noted. Subjects were divided into two groups, non-severe and severe group. Patient clinical details and laboratory parameters were compared in both the groups. The lab parameters associated with the severity of disease and mortality were also analyzed. A total of 210 patients out of which 140 controls (non-severe group) and 70 were cases (severe group). Results: The overall mortality due to scrub typhus infection was 14.3%. Eschar was present in 21.4% of the patients. Among the cases, the common symptoms were cough, chest pain, abdominal pain and distension, pedal edema and facial puffiness. Lymphadenopathy was observed with non-severe cases of scrub typhus and was statistically significant whereas, icterus, maculopapular rash, and hepatomegaly were associated with severe scrub typhus infection. Hemoglobin, platelet count and serum albumin were considerably lower in patients who died, whereas AST, aPTT, serum urea and creatinine were higher in them. Conclusion: Lower levels of hemoglobin, platelet count, serum albumin and higher levels of total leucocyte count, hepatic transaminases and serum creatinine correlated with severity. Doctors need to be watchful for such lab parameters and act quickly.
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Scrub typhus has re-emerged as an important cause of acute febrile illness in India. There is a dearth of information on strain diversity of Orientia tsutsugamushi from Karnataka, India, hence the present study sought to address this issue. One hundred clinically suspected cases of scrub typhus/rickettsiosis (as per the DHR-ICMR guidelines) were included. Nested-polymerase chain reaction (PCR) for 56-kDa gene and phylogenetic analysis was performed. PCR was positive in 22 cases and phylogenetic analysis showed the presence of different strains, with predominance of clustering (57%) with Gilliam-type for the first time in Karnataka. Knowledge of genetic diversity has implications in development of diagnostics and vaccine.
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OBJECTIVES: Chigger mites are vectors for scrub typhus. This study evaluated the annual fluctuations in chigger mite populations and Orientia tsutsugamushi infections in South Korea.METHODS: During 2006 and 2007, chigger mites were collected monthly from wild rodents in 4 scrub typhus endemic regions of South Korea. The chigger mites were classified based on morphological characteristics, and analyzed using nested PCR for the detection of Orientia tsutsugamushi.RESULTS: During the surveillance period, the overall trapping rate for wild rodents was 10.8%. In total, 17,457 chigger mites (representing 5 genera and 15 species) were collected, and the average chigger index (representing the number of chigger mites per rodent), was 31.7. The monthly chigger index was consistently high (> 30) in Spring (March to April) and Autumn (October to November). The mite species included Leptotrombidium pallidum (43.5%), L. orientale (18.9%), L. scutellare (18.1%), L. palpale (10.6%), and L. zetum (3.6%). L. scutellare and L. palpale populations, were relatively higher in Autumn. Monthly O. tsutsugamushi infection rates in wild rodents (average: 4.8%) and chigger mites (average: 0.7%) peaked in Spring and Autumn.CONCLUSION: The findings demonstrated a bimodal pattern of the incidence of O. tsutsugamushi infections. Higher infection rates were observed in both wild rodents and chigger mites, in Spring and Autumn. However, this did not reflect the unimodal incidence of scrub typhus in Autumn. Further studies are needed to identify factors, such as human behavior and harvesting in Autumn that may explain this discordance.
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Humans , Globus Pallidus , Incidence , Korea , Mites , Orientia tsutsugamushi , Polymerase Chain Reaction , Rodentia , Scrub Typhus , TrombiculidaeABSTRACT
Objective: To predict B cell and T cell epitopes of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins. Methods: The sequences of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins which were derived from Orientia tsutsugamushi were analyzed by SOPMA, DNAstar, Bcepred, ABCpred, NetMHC, NetMHCⅡ and IEDB. The 58-kDa tertiary structure model was built by MODELLER9.17. Results: The 22-kDa B-cell epitopes were located at positions 194-200, 20-26 and 143-154, whereas the T-cell epitopes were located at positions 154-174, 95-107, 17-25 and 57-65. The 47-kDa protein B-cell epitopes were at positions 413-434, 150-161 and 283-322, whereas the T-cell epitopes were located at positions 129-147, 259-267, 412-420 and 80-88. The 56-kDa protein B-cell epitopes were at positions 167-173, 410-419 and 101-108, whereas the T-cell epitopes were located at positions 88-104, 429-439, 232-240 and 194-202. The 58-kDa protein B-cell epitopes were at positions 312-317, 540-548 and 35-55, whereas the T-cell epitopes were located at positions 415-434, 66-84 and 214-230. Conclusions: We identified candidate epitopes of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins from Orientia tsutsugamushi. In the case of 58-kDa, the dominant antigen is displayed on tertiary structure by homology modeling. Our findings will help target additional recombinant antigens with strong specificity, high sensitivity, and stable expression and will aid in their isolation and purification.