Case report of scrub typhus complicated by hypokalemia and multiple organ dysfunction syndrome

ABSTRACT CONTEXT: Scrub typhus, caused by Orientia tsutsugamushi, has a wide range of clinical manifestations, including meningoencephalitis, acute renal failure, pneumonitis, myocarditis, and septic shock. However, there are no documented cases of scrub typhus with hypokalemia. In this report, we present a case of scrub typhus with hypokalemia and multiple organ failure syndrome, highlighting the importance of electrolyte imbalance in patients with scrub typhus. CASE REPORT: A 59-year-old woman presented to the emergency department with abdominal pain that had been present for 1 day. On admission, the physical examination and laboratory test results indicated that the patient had renal, liver, and circulatory failure, and hypokalemia. She developed meningitis and disseminated intravascular coagulation during hospitalization. She recovered with appropriate management, and was discharged on day 17. CONCLUSION: This report highlights the potential for atypical presentations of scrub typhus, including a previously undocumented association with hypokalemia. Although the contribution of hypokalemia to the patient's clinical course remains uncertain, this case underscores the importance of considering electrolyte imbalance in the management of patients with scrub typhus. Further research is warranted to better understand the relationship between scrub typhus and electrolyte imbalance.

Determination of a cut-off value for the serological diagnosis of scrub typhus by detecting anti-Orientia tsutsugamushi immunoglobulin M

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.

Research progress on the epidemiology of tsutsugamushi disease of summer type in China / 预防医学

@#Tsutsugamushi disease, also known as scrub typhus, is a zoonosis caused by Orientia tsutsugamushi, with rats as the main sources of infection and chigger mites as the only medium of transmission, and has no effective vaccines. Tsutsugamushi disease can be divided into summer, autumn and winter types according to seasons in China, while the summer type is characterized by strong virulence, typical and severe symptoms, high rates of misdiagnosis and mortality. The summer type of tsutsugamushi disease is distributed in the south of 31°N in China, with the epidemic time from June to August, and the cases are predominantly females, farmers and people at ages of over 40 years. Affected by natural environment, social and economic factors, the epidemic areas and the number of cases of summer type of tsutsugamushi disease are increasing continuously. Based on publications pertaining to the epidemiology of summer type of tsutsugamushi disease in China from 1960 to 2023, this review summarizes the mechanism of transmission, epidemiological characteristics and influencing factors, so as to provide the basis for prevention and control of summer type of tsutsugamushi disease in China.

Early diagnostic value of mNGS for 15 cases with critical rickettsial disease in Hainan / 中华检验医学杂志

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.

Clinical characteristics and severe risk factors of tsutsugamushi disease / 中国热带医学

@#Abstract: Objective To investigate the clinical features and risk factors for severe tsutsugamushi disease, so as to provide reference for diagnosis and differentiation of severe tsutsugamushi disease as soon as possible. Methods The clinical data of 178 cases of inpatients with tsutsugamushi disease admitted to the Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 2016 to September 2021 were collected and analyzed according to their gender, age, underlying diseases, clinical characteristics at admission, laboratory examination results within 24 hours of admission and epidemiological history. The patients were divided into the severe group and the non-severe group according to the diagnostic criteria. The data of clinical characteristics, laboratory examination and prognosis of the two groups were compared. Multivariate logistic regression analysis was performed on the variables with statistical significance and the receiver operating characteristic curve (ROC) was drawn. Results A total of 178 patients were included in this study, with 37 in the severe group and 141 in the non-severe group. Compared with the non-severe group, the age of the severe group was older, the underlying diseases were more, the incidence of dyspnea and the levels of white blood cell, total bilirubin, aspartate aminotransferase, lactate dehydrogenase, cystatin C, uric acid and serum creatinine were significantly increased, the levels of platelet and albumin were significantly decreased (all P<0.05). The dyspnea [odds ratio (OR value)=8.93, 95% confidence interval (CI): 1.200-66.424; P=0.032], total bilirubin (OR=1.091, 95%CI: 1.028-1.159; P=0.004) and serum creatinine (OR=1.052, 95%CI: 1.004-1.102; P=0.033) were independent risk factors for severe tsutsugamushi disease. The area under ROC curve of total bilirubin and serum creatinine were 0.777 and 0.764, respectively (both P<0.01), indicating high predictive value for severe tsutsugamushi disease. The optimal cut-off value for total bilirubin was 23.01 µmol/L, with a sensitivity of 54.10% and a specificity of 90.60%; the optimal cut-off value for creatinine was 126.45 µmol/L, with a sensitivity of 43.20% and a specificity of 100.00%. The case fatality rate of severe tsutsugamushi disease was 2.70%. Conclusions The patients with severe tsutsugamushi disease are older, and have more underlying diseases. Dyspnea, increased total bilirubin and elevated serum creatinine are independent risk factors for severe tsutsugamushi disease, which can help in the early identification of severe tsutsugamushi disease early.

Vector and rodent surveillance for Orientia tsutsugamushi in north India

Background & objectives: Scrub typhus or chigger borne typhus, caused by Orientia tsutsugamushi is an emerging vector-borne disease as large numbers of cases have been reported in various tropical countries. It is transmitted to humans through bites of infected chiggers (larval mites). The knowledge about the vector, its distribution, density and habitat are important so as to understand the epidemiology of scrub typhus in a given area. To control rickettsial infections, regular rodent-vector surveillance should be planned in areas where the disease transmission is occurring and it will also help to strengthen the existing entomological data related to the vector of scrub typhus in northern India. Methods: In the present study, rodent-vector surveillance was planned for one whole year, covering both mite active and non-active seasons (October 2019–December 2020) in selected areas of Chandigarh and Punjab in north India. Rodent tissues and mites were also examined for the presence of O. tsutsugamushi by nested PCR for 56 kDa gene and real-time PCR for 47 kDa outer membrane protein gene. 18S gene PCR was performed for molecular identification of mites. Results: In the surveillance, three types of ectoparasite, viz. mites, fleas and ticks were obtained in rodents. All mites found were of Laelapidae family. None of the pooled rodent tissue samples as well as mite samples were found positive for O. tsutsugamushi by nested PCR for rickettsial DNA. Interpretation & conclusion: In the present study, we did not get any evidence of carriage of O. tsutsugamushi in either mites or rodents collected and sampled in selected regions in Chandigarh and Punjab. We need to strengthen the entomological surveillance over a broader region and increase the frequency of trapping rodents to increase clarity on vector-reservoir dynamics in this geographical region.

Emerging trends of scrub typhus disease in southern Rajasthan, India: A neglected public health problem

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

Molecular epidemiology of Orientia tsutsugamushi from outbreak regions, Madhya Pradesh, central India

Scrub typhus is a seriously neglected life threatening disease in Asia and the islands of the Pacific and Indian oceans. The causative agent is Orientia tsutsugamushi, an obligate intra-cytosolic bacterium transmitted to vertebrate animals such as human or rodent by larval trombiculid mites (chiggers). Here, we conducted an outbreak investigation in Madhya Pradesh state in central India after sudden upsurge in scrub typhus cases and mortality in humans. Sixty-five live traps were placed for capturing the rodents. The captured rodent species were identified and the samples were subjected to nested PCR targeting 56kDa TSA gene. Analysis revealed for the first-time predominant circulation of Karp genotype in this region. The vector species involved in transmission is Leptotrobidium deliense. In conclusion, we reported the circulation of Karp strain in outbreak regions of Madhya Pradesh and suggest that public health monitoring and surveillance needs to be improved. Studies on antigenic diversity, association of strains with clinical spectrum and pathogenicity in the local setup will be essential for development of region-specific diagnostics and vaccines.

Scrub Typhus and Myocarditis: A Rare Complication

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.

Scrub Typhus with Multiple Cranial Nerve Palsy: A Rare Case Presentation

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

A case of tsutsugamushi disease complicated by multiple organ dysfunction syndrome treated by extracorporeal membrane oxygenation / 中华危重病急救医学

Tsutsugamushi disease is an acute infectious disease caused by Rickettsia. Occasionally it has been reported in Macau, China. Critical cases are rare. Because the clinical manifestations of tsutsugamushi disease are non-specific and diverse, if not diagnosed and treated in time, the disease may progress to multiple organ dysfunction syndrome (MODS), severe acute respiratory distress syndrome (ARDS), and even death. A patient with tsutsugamushi disease complicated by MODS was admitted to the intensive care unit (ICU) of Kiang Wu Hospital in Macau, China on September 30, 2021. Combined with the history of outdoor activities (exposure to chigger mite larvae), clinical symptoms and signs (characteristic eschar of tsutsugamushi disease was found on the abdominal skin), related laboratory examinations (Weil-Felix test: negative). Diagnosis of tsutsugamushi disease with MODS. After admission, the patient was treated by anti-infection, correction of coagulation dysfunction, tracheal intubation and mechanical ventilation, noradrenalin to maintain blood pressure, continuous renal replacement therapy (CRRT), but the condition didn't improve significantly. We initiated veno-venous ECMO (VV-ECMO), which was initially setted blood flow to 5 L/min (70 mL·kg -1·min -1), rotate speed to 3 500 rpm, fractional concentration of inspired oxygen (FiO 2) to 1.00. Heparin was used as anticoagulant and activated coagulation time (ACT) was kept between 180 and 200 seconds. Meanwhile the speed of fluid removal in CRRT was adjusted. After 9 hours of ECMO support, the oxygenation improved, the blood flow of ECMO was reduced to about 4 L/min (58 mL·kg -1·min -1), rotate speed to 3 000 rpm. The patient's condition improved after 4 days of ECMO treatment and her ECMO flow rate and FiO 2 could be decreased gradually. On hospital day 5, ECMO was removed. Eight days on mechanical ventilation, the patient was successfully weaned and extubated. On day 11 of hospitalization, weaned the CRRT and turned to intermittent hemodialysis. The patient was transferred out of ICU due to her stable condition on the 12th day hospitalization. After that, her spontaneous urine output increased gradually. The functions of various organs returned to normal. After 36 days of hospitalization, she recovered and was discharged.

Predictive value of the C-reactive protein/albumin ratio in tsutsugamushi disease complicated with organ function damage / 中华急诊医学杂志

Objective:To explore the predictive value of the serum C-reactive protein (CRP)/albumin (ALB) ratio (CAR) for organ damage in tsutsugamushi disease.Methods:The clinical data of 166 patients with tsutsugamushi disease admitted to the First Affiliated Hospital of Wenzhou Medical University from January 1, 2010 to December 31, 2020 were retrospectively analyzed. The patients were divided into the organ damage group (72 cases) and non-organ damage group (94 cases) according to the organ damage criteria. The general data and laboratory test results of the two groups of patients were compared. The significant indicators of univariate analysis were analyzed by multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to analyze the predictive value of CAR for organ damage in patients with tsutsugamushi disease.Results:There were no significant differences in age, sex, days of fever, and admission body temperature between the organ damage group and non-organ damage group ( P>0.05). However, the body mass index, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ), sequential organ failure assessment (SOFA), length of hospital stay, hospitalization expense, percentage of neutrophils (NEUT), lymphocyte count, procalcitonin, CRP, and CAR in the organ damage group were significantly higher than those in the non-organ damage group ( P<0.05), and ALB was significantly lower than that in the non-organ damage group ( P<0.05). Multivariate logistic regression analysis showed that APACHEⅡ( P=0.039), NEUT ( P=0.003), and CAR ( P=0.011) were independent risk factors for tsutsugamushi disease complicated by organ damage. The ROC curve showed that the AUCs of APACHEⅡ, NEUT, and CAR were 0.655, 0.716, and 0.727, respectively. When the cut-off value of CAR was 2.86, the sensitivity was 55.6%, and the specificity was 79.8%. Conclusions:Elevated CAR is an independent risk factor for tsutsugamushi disease complicated with organ damage and can be used as an important indicator to evaluate the presence or absence of organ damage in patients with tsutsugamushi disease.

Clinical characteristics of 38 cases of tsutsugamushi disease in Zaozhuang City, Shandong Province / 中华地方病学杂志

Objective:To understand the epidemiological and clinical characteristics of patients with tsutsugamushi disease in Zaozhuang City, Shandong Province, and to provide a basis for formulating effective diagnosis and treatment plan of tsutsugamushi disease. Methods:Retrospective analysis was carried out to collect clinical data of 38 patients with tsutsugamushi disease admitted to Zaozhuang Municipal Hospital of Shandong Province from 2018 to 2020. The epidemiological characteristics, clinical manifestations, laboratory examination results and drug treatment of patients with tsutsugamushi disease were analyzed. Results:Among the 38 patients with tsutsugamushi disease, 15 were males and 23 were females, aged (58.58 ± 14.47) years old; the occupation distribution was mainly farmers, accounting for 92.11% (35/38); the onset time was concentrated in October and November, accounting for 100.00% (38/38); the regional distribution was mainly in Yicheng District, accounting for 34.21% (13/38); 38 patients had a history of grassland/forest contact. All patients had fever, and other main symptoms were eschar (97.37%, 37/38), headache (68.42%, 26/38), fatigue (42.11%, 16/38), and whole body aches (36.84%, 14/38), etc. The results of laboratory examination mainly showed that C-reactive protein increased (89.47%, 34/38), procalcitonin increased (81.58%, 31/38), abnormal liver function (78.95%, 30/38), D-dimer increased (71.05%, 27/38), eosinophils decreased (60.53%, 23/38), and erythrocyte sedimentation rate increased (57.89%, 22/38). All 38 patients were cured after treated with doxycycline or azithromycin. Conclusions:The high incidence time of tsutsugamushi disease in Zaozhuang City is autumn. The clinical symptoms are mainly fever, eschar and headache. Doxycycline and azithromycin are the first choices for treatment of the disease.

Epidemiology and clinical characteristics of scrub typhus based on 680 unexplained fever patients in Hainan / 中国热带医学

@#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.

Circulatory and hepatic failure at admission predicts mortality of severe scrub typhus patients: A prospective cohort study

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.

Scrub typhus mimicking the clinical course of infectious mononucleosis: a case report / Journal of Rural Medicine

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.

Comparison of diagnostic performance between serological tests (Scrub IgM-ELISA) and Scrub-PCR for scrub typhus fever in an Indian tertiary care teaching hospital

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.

Evidence of natural infection of Orientia tsutsugamushi in vectors and animal hosts � Risk of scrub typhus transmission to humans in Puducherry, South India

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.

A single-centre experience of scrub typhus in a tertiary care centre - a re-emerging infection

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.

Assessment of Predictors for Severity in Scrub Typhus-A Case-Control Study

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.