Scrub typhus: a frequently overlooked cause of acute renal failure

Japanese Spotted Fever and Irreversible Renal Dysfunction during Immunosuppressive Therapy after a Living-Donor Kidney Transplant

Ten years ago, a 56-year-old woman with a history of IgA nephropathy who received a living-donor kidney transplant across ABO barriers was managed with immunosuppressive drugs. The kidney transplant donor was her father who had poor kidney function. The patient’s renal function was stable for 10 years. The patient visited our department with a complaint of skin rash, occurring 2 days after an onset of fever. Although a skin rash is atypical for Japanese spotted fever (JSF), we suspected JSF and started treatment with minocycline because we found a scar suggestive of an eschar. Furthermore, the blood test results were similar to those associated with JSF, and the patient lived in a JSF-endemic area. The patient’s symptoms improved after 1 week. She was diagnosed with JSF by serological tests against Rickettsia japonica. JSF usually does not cause any complications after recovery. However, the patient’s renal function did not completely recover. JSF can cause an atypical rash in patients taking excessive immunosuppressive drugs. Early treatment is required for patients with suspected JSF to prevent complications of renal dysfunction after receiving a living-donor kidney transplant.

Urinary Exosomal microRNA-21 as a Marker for Scrub Typhus-Associated Acute Kidney Injury

Background: Urinary microRNA (miRNA)-21 is a biomarker for acute kidney injury (AKI). We conducted this study to determine if a urinary exosomal analysis for this biomarker could serve as a novel diagnostic approach for detecting kidney disease. Materials and Methods: We investigated the clinical significance of urinary exosomal miRNA-21 levels for AKI in scrub typhus patients. We collected 138 urine samples from scrub typhus patients at the time of admission. Urinary exosomal miRNA-21 was assessed in 25 age- and sex-matched scrub typhus patients with and without AKI. Results: The total leukocyte count was higher in AKI patients than in non-AKI patients (10.40 × 10³/mL vs. 6.40 × 10³/mL, p < 0.01). Urinary exosomal miRNA-21 levels were higher in the AKI group than in the non-AKI group (20.1 ± 1.2 vs. 17.8 ± 1.8 ΔCt value of miRNA-21, p < 0.01). Additionally, the miRNA-21 levels correlated directly with the total leukocyte counts and inversely with the estimated glomerular filtration rate. A receiver operating characteristic curve analysis demonstrated good discriminative power for the diagnosis of scrub typhus-associated AKI, with an area under the curve value of 0.907. Conclusion: Urinary exosomal miRNA-21 could be a surrogate marker for scrub typhus-associated AKI diagnosis.

Scrub typhus: a reemerging infection

PURPOSE OF REVIEW

Scrub typhus, caused by Orientia tsutsugamushi, is a widely neglected disease which is gaining global momentum because of its resurgence patterns. The disease is now being reported in newer regions as well as areas previously endemic areas. In this review, we aim to comprehensively review the data available to assist physicians in making an accurate diagnosis and appropriate management of the disease.

RECENT FINDINGS

Several diagnostic tests have been developed for confirming scrub typhus. However, there is lack of clarity on which tests are most appropriate in a given clinical scenario. A recent study has demonstrated that in early disease (<7 days) when serological tests remain negative, the quantitative polymerase chain reaction is the most sensitive test. Among the serological tests, both IgM enzyme-linked immunosorbent assay as well as rapid diagnostic tests revealed excellent sensitivities and specificities.

SUMMARY

With the reemergence of scrub typhus, a high degree of clinical suspicion is required to appropriately diagnose this disease which presents as an acute febrile illness. It can progress to develop various complications leading to multi-organ dysfunction syndrome. Mild illness responds well to antibiotic treatment with doxycycline and azithromycin. Further studies are required to determine the most optimal therapy in severe scrub typhus infections and superiority of one drug over the other.

Scrub typhus - A case series from the state of Sikkim, India

Scrub typhus is one of the leading causes of acute febrile illness in India. It is associated with rash and often an eschar, which responds dramatically to antibiotics. In some cases, it results in serious illness leading to multiple organ involvement and finally death. The various clinical manifestations of scrub typhus arise mainly due to systemic vasculitis, caused by direct effects of organism as well as exaggerated immune response. The disease course is often complicated, leading to mortality in the absence of treatment. Here, in this case series, we describe three cases depicting the typical manifestations which a patient of scrub typhus can present with highlighting the fact that high index of clinical suspicion is of utmost importance for this deadly disease.

Scrub typhus infection, not a benign disease: an experience from a tertiary care center in Northern India

Introduction

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. It is characterised by fever, rash, myalgia and diffuse lymphadenopathy. Most common complications are sepsis, shock, acute respiratory distress syndrome (ARDS), hepatitis, pre renal azotemia and multi organ dysfunction syndrome (MODS). Mortality rates range from 7–30% in untreated cases. Scrub typhus is endemic to a part of the world known as ‘the tsutsugamushi triangle’. River banks, grassy areas generally harbour scrub typhus infection; however, recently there has been an increase in prevalence of infection from dry regions like Haryana.

Objective

To assess the clinical spectrum and complications of scrub typhus infection at a tertiary care centre in North India.

Material and methods

An observational study was conducted on patients >14 years old with acute febrile illness >7 days duration, admitted indoor from emergency department, from July to November 2017. Suspected cases were tested for specific IgM antibodies against Orientia tsutsugamushi by ELISA.

Results

Among the 230 patients, screened for scrub typhus infection, 39 (16.95%) came out to be positive. Most common patient complaints were fever followed by cough and breathlessness, myalgia, nausea, vomiting and behavioral abnormality. 15% of patients required inotropic support initially and 48% had oxygen saturation of less than 90% at the time of presentation. Pleural effusion and crepitations were present in 41% of patients. Most common biochemical alterations were: abnormal liver function tests (95%), followed by thrombocytopenia, anemia, abnormal renal function tests, and hyponatremia. 12 patients (30.7%) were shifted to intensive care unit, 8 of which (20.5%) needed invasive mechanical ventilation and 4 patients (10.3%) underwent hemodialysis. Various complications were noted in 89.7% of cases, the most common being ARDS followed by sepsis, acute kidney injury (AKI) and meningitis. The mortality rate in this study was 18%.

Conclusions

This study emphasizes that scrub typhus infection is on a rampant resurgence and it is associated with significant complications. High degree of suspicion as well as development of effective measures to treat, control and prevent is critical to lower the disease burden.

Predictors of Severity in Pediatric Scrub Typhus

OBJECTIVE

To identify the factors that can predict the severity of scrub typhus in children.

METHODS

This prospective study was conducted at a tertiary care teaching hospital between November 2014 to October 2016. All children <12y of age admitted with fever for more than 7d and positive IgM ELISA for scrub typhus were included in the study. These children were followed during the hospital course and their laboratory results, response to treatment and complications were documented. Cases of 'severe scrub typhus' were identified based on criteria from published adult and pediatric studies.

RESULTS

Out of 930 children with fever for more than 7d, IgM ELISA for scrub typhus was positive in 230 children. Ninety one (40.6%) cases fulfilled the criteria of 'severe scrub typhus' in children. Out of 45 factors, 27 potential factors were studied. The multivariate analysis identified 5 factors, breathlessness (OR: 6.85, 95%CI: 2.69 to 9.87), altered sensorium (OR: 11.48, 95% CI 3.43 to 10.19), leucocytosis (OR: 3.38, 95% CI 1.12 to 10.16), hypoalbuminemia (OR: 10.78, 95% CI 2.66 to 48.76), and hyponatremia (OR: 10.08, 95% CI 2.11 to 23.42) to be significantly associated with the 'severe scrub typhus' cases.

CONCLUSIONS

Breathlessness, altered sensorium, leucocytosis, hypoalbuminemia, and hyponatremia predict severity in childhood scrub typhus. Presence of these factors should alert the treating physician regarding the need for intensive monitoring, treatment or referral.

A Case of Scrub Typhus complicated with a Splenic Infarction

We present a patient with scrub typhus complicated with a splenic infarction. A 40-year-old man visited the emergency medical center complaining of fever for the previous week. He had no past medical history, but reported engaging in outdoor activities. Examination revealed a maculopapular rash on his trunk and an eschar on his epigastrium. Abdominal computed tomography was performed to examine the cause of the tenderness on the left upper quadrant of his abdomen, which revealed a splenic infarct. The patient was diagnosed with scrub typhus based on the results of blood polymerase chain reaction testing, and genetic sequencing confirmed the presence of Orientia tsutsugamushi Boryong. His symptoms improved following doxycycline treatment.

Clinical significance of NGAL and KIM-1 for acute kidney injury in patients with scrub typhus

Background

The aim of this study is to investigate the clinical significance of neutrophil gelatinase–associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) for acute kidney injury (AKI) in patients with scrub typhus.

Methods

From 2014 to 2015, 145 patients were diagnosed with scrub typhus. Of these, we enrolled 138 patients who were followed up until renal recovery or for at least 3 months. We measured serum and urine NGAL and KIM-1 levels and evaluated prognostic factors affecting scrub typhus–associated AKI.

Results

Of the 138 patients, 25 had scrub typhus–associated AKI. The incidence of AKI was 18.1%; of which 11.6%, 4.3%, and 2.2% were classified as risk, injury, and failure, respectively, according to RIFLE criteria. Compared with patients in the non-AKI group, patients in the AKI group were older and showed higher total leukocyte counts and hypoalbuminemia or one or more comorbidities such as hypertension (72% vs 33%, p<0.01), diabetes (40% vs 14%, p<0.01), or chronic kidney disease (32% vs 1%, p<0.01). In addition, serum NGAL values (404± 269 vs 116± 78 ng/mL, P<0.001), KIM-1 values (0.80± 0.52 vs 0.33± 0.68 ng/mL, P<0.001), urine NGAL/creatinine values (371± 672 vs 27± 39 ng/mg, P<0.001) and urine KIM-1/creatinine values (4.04± 2.43 vs 2.38± 1.89 ng/mg, P<0.001) were higher in the AKI group than in the non-AKI group. By multivariate logistic regression, serum NGAL and the presence of chronic kidney disease were significant predictors of AKI.

Conclusion

Serum NGAL might be an additive predictor for scrub typhus–associated AKI.

Incidence, risk factors and clinical outcomes of acute kidney injury associated with scrub typhus: a retrospective study of 510 consecutive patients in South Korea (2001-2013)

OBJECTIVES

Renal involvement in scrub typhus ranges from simple urinary abnormalities to acute kidney injury (AKI) leading to death. This study evaluated the incidence, predictors and prognosis of AKI associated with scrub typhus according to the RIFLE (risk, injury, failure, loss, end-stage kidney disease) criteria.

METHODS

We retrospectively evaluated the medical records of patients diagnosed with scrub typhus from January 2001 to November 2013 in Gyeongsang National University Hospital.

RESULTS

During the study period, 510 patients were diagnosed with scrub typhus and the incidence of AKI was 35.9%. There were 132 (25.9%) patients at risk, 37 (7.3%) with injury and 14 (2.7%) with failure. In comparison with the non-AKI group, the AKI group was older (73.9 vs 63.4 years, p<0.001) and had more comorbidities such as hypertension, diabetes mellitus and chronic kidney disease (CKD). AKI frequently occurs in hypertensive patients taking angiotensin receptor blockers or ACE inhibitors (p=0.002), and in patients with diabetes with higher glycated haemoglobin levels (p=0.033). Haematuria and proteinuria were more frequent in the AKI group. There was no relationship between the severity of proteinuria and occurrence of AKI. Intensive care unit admission and death were more frequent in the AKI group. The renal function of most patients with AKI recovered without sequelae, except for 1 patient who had underlying CKD. Multivariate analysis showed that age, presence of CKD, serum albumin level and time to hospital presentation after symptom onset were independent predictors of AKI in patients with scrub typhus.

CONCLUSIONS

Our current results suggest that the presence of underlying CKD, older age, lower serum albumin level and time to hospital presentation after symptom onset were important risk factors to determine occurrence of AKI. Whether earlier diagnosis and treatment in patients with the above risk factors reduce the incidence and severity of AKI deserves to be investigated.

Acute kidney injury due to tropical infectious diseases and animal venoms: a tale of 2 continents

South and Southeast Asia and Latin American together comprise 46 countries and are home to approximately 40% of the world population. The sociopolitical and economic heterogeneity, tropical climate, and malady transitions characteristic of the region strongly influence disease behavior and health care delivery. Acute kidney injury epidemiology mirrors these inequalities. In addition to hospital-acquired acute kidney injury in tertiary care centers, these countries face a large preventable burden of community-acquired acute kidney injury secondary to tropical infectious diseases or animal venoms, affecting previously healthy young individuals. This article reviews the epidemiology, clinical picture, prevention, risk factors, and pathophysiology of acute kidney injury associated with tropical diseases (malaria, dengue, leptospirosis, scrub typhus, and yellow fever) and animal venom (snakes, bees, caterpillars, spiders, and scorpions) in tropical regions of Asia and Latin America, and discusses the potential future challenges due to emerging issues.

Tropical Diseases Nephropathy - An Underemphasized Comorbidity

The tropical areas are a home to a number of diseases because of the hot & humid climate, and lack of health care facilities. Tropical Nephropathies are a major health problem and a matter of great concern. The main causes of kidney injury in tropics are due to bacterial, viral or parasitic infections like malaria, dengue, leptospirosis, scrub typhus, acute gastroenteritis, tuberculosis, leprosy and toxic envenomations like snake bite. Renal injury associated with tropical infections has a wide spectrum of presentations ranging from acute kidney injury to chronic kidney disease. Renal involvement in infectious diseases by one or other mechanism is a definite cause of increased morbidity and mortality. Proper understanding of these diseases, early diagnosis, patient education and improved health care facilities will lead to a better outcome and improved survival. This article reviews the various tropical infections causing kidney injury including pathophysiology and line of management.

Spontaneous Splenic Rupture Caused by Scrub Typhus

Spontaneous rupture of the spleen is rarely described as a complication of scrub typhus infection. We report a previously healthy 74-year-old Thai female farmer who presented in Nakhon Ratchasima, Thailand, with a history of fever and malaise for 5 days, followed by abdominal pain for 1 day. An exploratory laparotomy was performed due to peritonitis. Operative findings revealed a ruptured spleen and hemoperitoneum. A splenectomy was performed afterward. Scrub typhus was confirmed by a 4-fold increase of IgM titer using an indirect immunofluorescence antibody assay and a positive result from the polymerase chain reaction targeting the 47- and 56-kDa genes in Orientia tsutsugamushi She responded well to intravenous chloramphenicol and defervesced within 24 hours without any complication.

Scrub Typhus and Its Causative Agent, Orientia tsutsugamushi

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.

IL-33-Dependent Endothelial Activation Contributes to Apoptosis and Renal Injury in Orientia tsutsugamushi-Infected Mice

Endothelial cells (EC) are the main target for Orientia tsutsugamushi infection and EC dysfunction is a hallmark of severe scrub typhus in patients. However, the molecular basis of EC dysfunction and its impact on infection outcome are poorly understood. We found that C57BL/6 mice that received a lethal dose of O. tsutsugamushi Karp strain had a significant increase in the expression of IL-33 and its receptor ST2L in the kidneys and liver, but a rapid reduction of IL-33 in the lungs. We also found exacerbated EC stress and activation in the kidneys of infected mice, as evidenced by elevated angiopoietin (Ang) 2/Ang1 ratio, increased endothelin 1 (ET-1) and endothelial nitric oxide synthase (eNOS) expression. Such responses were significantly attenuated in the IL-33-/- mice. Importantly, IL-33-/- mice also had markedly attenuated disease due to reduced EC stress and cellular apoptosis. To confirm the biological role of IL-33, we challenged wild-type (WT) mice with a sub-lethal dose of O. tsutsugamushi and gave mice recombinant IL-33 (rIL-33) every 2 days for 10 days. Exogenous IL-33 significantly increased disease severity and lethality, which correlated with increased EC stress and activation, increased CXCL1 and CXCL2 chemokines, but decreased anti-apoptotic gene BCL-2 in the kidneys. To further examine the role of EC stress, we infected human umbilical vein endothelial cells (HUVEC) in vitro. We found an infection dose-dependent increase in the expression of IL-33, ST2L soluble ST2 (sST2), and the Ang2/Ang1 ratio at 24 and 48 hours post-infection. This study indicates a pathogenic role of alarmin IL-33 in a murine model of scrub typhus and highlights infection-triggered EC damage and IL-33-mediated pathological changes during the course of Orientia infection.

Possibility of scrub typhus in fever of unknown origin (FUO) cases: an experience from Rajasthan

PURPOSE

Fever of unknown origin (FUO) has multiple causes. Scrub typhus is less known cause of FUO in India. The present study reports a recent epidemic of scrub typhus amongst cases of FUO from different areas of Rajasthan, India. There was high mortality in undiagnosed cases of FUO which lead to the diagnosis of scrub typhus.

OBJECTIVE

To study the possibility of scrub typhus as a causative factor in FUO cases by qualitative detection of IgM antibodies with ELISA.

MATERIALS AND METHODS

From September 2012 to December 2012, 271 serum samples of FUO cases were analysed for IgM antibodies to Orientia tsutsugamushi along with dengue, malaria, typhoid, tuberculosis and brucellosis.

RESULTS

Scrub typhus IgM antibodies by ELISA were detected in 133 (49.1%) patients. Scrub typhus positivity was significantly higher among female in comparison to males (P<0.05). Maximum positivity of scrub typhus was found in females of 46-60 years age group. The laboratory parameters were abnormal in most of the patients as evident by thrombocytopenia (63%), deranged liver functions (56%) and renal functions (25%).

CONCLUSION

The present study emphasises the importance of scrub typhus among cases of FUO especially after rainy season and during early cooler months. The study also highlights the significance of ELISA method for rapid and early reporting and ruling out scrub typhus in FUO cases.

Hematogenously disseminated Orientia tsutsugamushi-infected murine model of scrub typhus [corrected]

Orientia tsutsugamushi, the etiologic agent of scrub typhus, is a mite-borne rickettsia transmitted by the parasitic larval stage of trombiculid mites. Approximately one-third of the world's population is at risk of infection with Orientia tsutsugamushi, emphasizing its importance in global health. In order to study scrub typhus, Orientia tsutsugamushi Karp strain has been used extensively in mouse studies with various inoculation strategies and little success in inducing disease progression similar to that of human scrub typhus. The objective of this project was to develop a disease model with pathology and target cells similar to those of severe human scrub typhus. This study reports an intravenous infection model of scrub typhus in C57BL/6 mice. This mouse strain was susceptible to intravenous challenge, and lethal infection occurred after intravenous inoculation of 1.25×10⁶ focus (FFU) forming units. Signs of illness in lethally infected mice appeared on day 6 with death occurring ∼6 days later. Immunohistochemical staining for Orientia antigens demonstrated extensive endothelial infection, most notably in the lungs and brain. Histopathological analysis revealed cerebral perivascular, lymphohistiocytic infiltrates, focal hemorrhages, meningoencephalitis, and interstitial pneumonia. Disseminated infection of endothelial cells with Orientia in C57BL/6 mice resulted in pathology resembling that of human scrub typhus. The use of this model will allow detailed characterization of the mechanisms of immunity to and pathogenesis of O. tsutsugamushi infection.

Scrub typhus is a disease found in Southeast Asia that infects over 1 million people each year. This disease is caused by the intracellular pathogen Orientia tsutsugamushi transmitted by the bite of chigger mites. Scrub typhus is characterized by pulmonary disease and in severe cases, multiorgan system failure. The current research model utilizes an intraperitoneal route of inoculation of mice to study the host response to Orientia infection. Infection via this route results in severe peritonitis that does not occur in human scrub typhus. The development of animal models that accurately portray human disease is an important step toward understanding and managing disease. In this manuscript we describe a new mouse model that results in scrub typhus-like pathology following intravenous inoculation of mice. This model presents dose-dependent mortality with scrub typhus-like pathology that parallels human disease. Utilization of this model will provide a valuable research tool for characterizing the immune response and pathogenesis induced by O. tsutsugamushi allowing development of better treatment and an effective vaccine.

Scrub typhus is an under-recognized cause of acute febrile illness with acute kidney injury in India

BACKGROUND

Infection-related acute kidney injury (AKI) is an important preventable cause of morbidity and mortality in the tropical region. The prevalence and outcome of kidney involvement, especially AKI, in scrub typhus is not known. We investigated all patients with undiagnosed fever and multisystem involvement for scrub typhus and present the pattern of renal involvement seen.

METHODS

From September 2011 to November 2012, blood samples of all the patients with unexplained acute febrile illness and/or varying organ involvement were evaluated for evidence of scrub typhus. A confirmed case of scrub typhus was defined as one with detectable Orientia tsutsugamushi deoxyribonucleic acid (DNA) in patient's blood sample by nested polymerase chain reaction (PCR) targeting the gene encoding 56-kDa antigen and without any alternative etiological diagnosis. Renal involvement was defined by demonstration of abnormal urinalysis and/or reduced glomerular filtration rate. AKI was defined as per Kidney Disease: Improving Global Outcomes (KDIGO) definition.

RESULTS

Out of 201 patients tested during this period, 49 were positive by nested PCR for scrub typhus. Mean age of study population was 34.1±14.4 (range 11-65) years. Majority were males and a seasonal trend was evident with most cases following the rainy season. Overall, renal abnormalities were seen in 82% patients, 53% of patients had AKI (stage 1, 2 and 3 in 10%, 8% and 35%, respectively). The urinalysis was abnormal in 61%, with dipstick positive albuminuria (55%) and microscopic hematuria (16%) being most common. Acute respiratory distress syndrome (ARDS) and shock were seen in 57% and 16% of patients, respectively. Hyperbilirubinemia was associated with AKI (p = 0.013). A total of 8 patients (including three with dialysis dependent AKI) expired whereas rest all made uneventful recovery. Jaundice, oliguria, ARDS and AKI were associated with mortality. However, after multivariate analysis, only oliguric AKI remained a significant predictor of mortality (p = 0.002).

CONCLUSIONS

Scrub typhus was diagnosed in 24% of patients presenting with unexplained febrile illness according to a strict case definition not previously used in this region. Renal abnormalities were seen in almost 82% of all patients with evidence of AKI in 53%. Our finding is contrary to current perception that scrub typhus rarely causes renal dysfunction. We suggest that all patients with unexplained febrile illness be investigated for scrub typhus and AKI looked for in scrub typhus patients.

Clinical risk-scoring algorithm to forecast scrub typhus severity

Background

The study explored clinical risk characteristics that may be used to forecast scrub typhus severity under routine clinical practices.

Methods

Retrospective data were collected from patients registered at two university-affiliated tertiary care hospitals in the north of Thailand, from 2004 to 2010. Key information was retrieved from in-patient records, out patient cards, laboratory reports and registers. Patients were classified into three severity groups: nonsevere, severe (those with at least one organ involvement), and deceased. Prognostic characteristics for scrub typhus severity were analyzed by a multivariable ordinal continuation ratio regression.

Results

A total of 526 patients were classified into nonsevere (n = 357), severe (n = 100), and deceased (n = 69). The significant multivariable prognostic characteristics for scrub typhus severity were increased body temperature (odds ratio [OR] = 0.58, 95% confidence interval [CI] = 0.45–0.74, P < 0.001), increased pulse rate (OR = 1.03, 95% CI = 1.01–1.05, P < 0.001), presence of crepitation (OR = 3.25, 95% CI = 1.52–6.96, P = 0.001), increased percentage of lymphocytes (OR = 0.97, 95% CI = 0.95–0.98, P = 0.001), increased aspartate aminotransferase (every 10 IU/L) (OR = 1.04, 95% CI = 1.02–1.06, P < 0.001), increased serum albumin (OR = 0.47, 95% CI = 0.27–0.80, P = 0.001), increased serum creatinine (OR = 1.83, 95% CI = 1.50–2.24, P < 0.001), and increased levels of positive urine albumin (OR = 1.43, 95% CI = 1.17–1.75, P < 0.001).

Conclusion

Patients suspicious of scrub typhus with low body temperature, rapid pulse rate, presence of crepitation, low percentage of lymphocyte, low serum albumin, elevated aspartate aminotransferase, elevated serum creatinine, and positive urine albumin should be monitored closely for severity progression.

Clinical risk-scoring algorithm to forecast scrub typhus severity

Purpose

To develop a simple risk-scoring system to forecast scrub typhus severity.

Patients and methods

Seven years’ retrospective data of patients diagnosed with scrub typhus from two university-affiliated hospitals in the north of Thailand were analyzed. Patients were categorized into three severity groups: nonsevere, severe, and dead. Predictors for severity were analyzed under multivariable ordinal continuation ratio logistic regression. Significant coefficients were transformed into item score and summed to total scores.

Results

Predictors of scrub typhus severity were age >15 years, (odds ratio [OR] =4.09), pulse rate >100/minute (OR 3.19), crepitation (OR 2.97), serum aspartate aminotransferase >160 IU/L (OR 2.89), serum albumin ≤3.0 g/dL (OR 4.69), and serum creatinine >1.4 mg/dL (OR 8.19). The scores which ranged from 0 to 16, classified patients into three risk levels: non-severe (score ≤5, n=278, 52.8%), severe (score 6–9, n=143, 27.2%), and fatal (score ≥10, n=105, 20.0%). Exact severity classification was obtained in 68.3% of cases. Underestimations of 5.9% and overestimations of 25.8% were clinically acceptable.

Conclusion

The derived scrub typhus severity score classified patients into their severity levels with high levels of prediction, with clinically acceptable under- and overestimations. This classification may assist clinicians in patient prognostication, investigation, and management. The scoring algorithm should be validated by independent data before adoption into routine clinical practice.

Clinical characteristics of acute kidney injury in patients with scrub typhus--RIFLE criteria validation

There are limited data available on the validity of the RIFLE classification for AKI in patients with scrub typhus. We investigated the incidence and clinical characteristics of scrub typhus associated AKI using the RIFLE criteria. From 2010 to 2012, 238 patients were diagnosed with scrub typhus. Of these, we included 223 patients who were followed up until renal recovery or for at least three months. We evaluated the incidence, clinical characteristics, and severity of AKI based on the RIFLE classification. Of the 223 patients, 47 (21%) had scrub typhus-associated AKI. The incidence of AKI was 21.1%; of which, 10.7%, 9.4% and 1% were classified as Risk, Injury and Failure, respectively. In comparison with patients in the non-AKI group, the patients in the AKI group were older (70 ± 9 vs 61 ± 14 year, P = 0.01) and had one or more comorbidities such as hypertension, diabetes, and chronic kidney disease (77% vs 22%, p = 0.01). In the AKI group, forty-four patients had AKI prior to admission, and three patients experienced AKI during their hospitalization. By multivariate logistic regression analysis, age and comorbidity were significant predictors of AKI. All patients recovered baseline renal function without renal replacement therapy following antibiotics therapy and supportive care. The incidence of AKI in patient with scrub typhus is 21%. Age and co-morbidity are significant predictors of AKI in scrub typhus. In cases of scrub typhus-associated AKI, anti-rickettsia agent and supportive care are very important.

A case of scrub typhus requiring maintenance hemodialysis

Renal failure caused by scrub typhus is known to be reversible. In most cases, renal function is almost fully restored after appropriate antibiotic treatment. A 71-year-old man was diagnosed with scrub typhus complicated by renal failure. A renal biopsy revealed histopathologic findings consistent with acute tubulointerstitial nephritis. Renal function did not improve 18 months after discharge and the patient required continuous hemodialysis. Although severe renal failure requiring dialysis is a rare complication of scrub typhus, we describe a case of scrub typhus requiring maintenance hemodialysis. To the best of our knowledge, this is the first such report.

A case of Tsutsugamushi disease presenting with nephrotic syndrome

Nephrotic syndrome associated with Tsutsugamushi disease has not been previously reported. We are describing a case of Tsutsugamuchi disease presenting with nephrotic syndrome. A 72-year-old woman presented with fever and generalized edema. Laboratory studies revealed a leukocytosis, hypoalbuminemia, and hypercholesterolemia. Her urine protein excretion was 5.4 g/day. The anti-Tsutsugamushi antibody test was strongly positive (1:2,560). A renal biopsy was performed, and pathologic findings revealed membranous glomerulonephritis. The patient's clinical symptoms improved markedly after treatment with doxycycline.

Scrub typhus associated acute kidney injury--a study from a tertiary care hospital from western Himalayan State of India

OBJECTIVE

To report the clinical profile of acute kidney injury (AKI) associated with scrub typhus.

METHODS

Retrospective study of hospitalized patients of acute febrile illness who were diagnosed scrub typhus and had AKI.

RESULTS

174 (35%) patients (75.9% female), mean age (41.4 ± 15.9 years) were studied. The laboratory abnormalities were: anemia (63.2%), leukocytosis (44.3%), thrombocytopenia (61.5%), hyponatremia (35.6%), hypernatremia (2.9%), and hypokalemia (12.1%), hyperkalemia (11.5%), hypoalbuminemia (56.9%), hepatic dysfunction (70%) and metabolic acidosis (28.7%). The complications of hypotension (5.7%), septic shock (3.4%), pneumonia (10.9%), acute respiratory distress syndrome (ARDS) (11.5%), meningoencephalitis (6.9%), encephalopathy (5.2%), gastrointestinal bleed (1.3%), myocarditis (3.4%), disseminated intravascular coagulation (2.9%) and multi organ failure (MOF) (10.3%) developed during course of hospitalization in these patients. Twenty-five (14.4%) patients required intensive care support (ICU) support and seven (4%) patients were dialyzed. 146 (83.9%) patients survived. Twenty-eight (16.1%) patients died. There was a significant difference in the age, various hematological & biochemical abnormalities, complications and need for ICU support in the non-survival group as compared the survival group.

CONCLUSION

This study shows that AKI in scrub typhus is common and a severe disease. Age, a shorter hospital stay, severities of leukocytosis, thrombocytopenia, azotemia, hypoalbuminemia, hepatic dysfunction and the complications of ARDS, encephalopathy, MOF and need for ICU support are the factors associated with mortality.

A case of scrub typhus complicated by acute calculous cholecystitis

We report a case of acute calculous cholecystitis through scrub typhus. A 69-year-old woman presented with a history of general myalgia, fever, and right abdominal pain. She referred to our hospital for surgical treatment of clinically suspected acute cholecystitis. Physicians concluded the cause of cholecystitis as gall bladder (GB) stone and proper antibiotics treatment of scrub typhus was started later. The patient developed acute respiratory distress syndrome and multi organ failure through scrub typhus. Five days after admission, the patient was treated with proper antibiotics and discharged on the 13th day after starting doxycycline treatment without any sequelae. In areas endemic for tsutsugamushi disease, even though a patient with GB stone presents with symptoms of acute cholecystitis, careful history and physical examination are required to reveal the existence of eschars or skin eruptions.

Characteristics of pediatric scrub typhus during an outbreak in the North Eastern region of India: peculiarities in clinical presentation, laboratory findings and complications

OBJECTIVE

To identify and report a recent outbreak of scrub typhus cases recorded from October 2009 to January 2010 in the state of Meghalaya, India.

METHODS

The case sheets of all the children were retrieved and reviewed retrospectively. Twenty four (24) patients, who were both clinically and serologically confirmed as scrub typhus cases were included in the study.

RESULTS

Fever for more than 1 wk duration was the most common manifestation (100%) followed by splenomegaly (45.8%), eschar (41.7%), cough (37.5%), hepatomegaly (33.3%), headache and body ache (25%), pain abdomen (25%), vomiting (20.8%), altered sensorium (16.6%), seizures (12.5%) lymphadenopathy (12.5%), and loose stools (8.3%). Meningoencephalitis was the most common complication (29.2%) followed by pneumonia (16.3%) and subconjunctival hemorrhage (8.3%).Cortical blindness, septic shock, peritonitis, myocarditis with CCF, pancytopenia, acute renal failure, coagulopathy, prolonged oxygen dependency and urinary tract infection (UTI) were found in one of each case. Hyponatremia (66.7%), elevated liver enzymes without significant rise of bilirubin (58.3%), hypoalbuminemia (52.2%) and thrombocytopenia (26%) were the other significant laboratory findings. Patients were treated with chloramphenicol, doxycycline and azithromycin. There was no mortality.

CONCLUSIONS

This is the first outbreak report from the north eastern region of India with varied clinical presentations, laboratory investigations and complications. Weil Felix test still remains fruitful for diagnosing this disease in a resource limited set up.

Acute kidney injury in the tropics

Acute kidney injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. AKI in the tropics is strikingly different from that in the developed world in terms of etiology and presentation. In addition, there is a stark contrast between well-developed and poor areas in the tropics. The true epidemiological picture of AKI in the tropics is not well understood due to the late presentation of patients to tertiary centers. Infections remain the major culprit in most cases of AKI, with high mortality rates in the tropics. Human immunodeficiency virus-related AKI, related to nephrotoxicity due to antiretroviral therapy, is on the rise. Acute tubular necrosis and thrombotic microangiopathy are the most common mechanisms of AKI. A notable problem in the tropics is the scarcity of resources in health centers to support patients who require critical care due to AKI. This article reviews the unique and contrasting nature of AKI in the tropics and describes its management in each situation.

Delay in tetracycline treatment increases the risk of complications in Tsutsugamushi disease: data from the Japanese Diagnosis Procedure Combination database

OBJECTIVE

Tsutsugamushi disease (scrub typhus) is caused by Orientia tsutsugamushi, and has been endemic in Asia and Western Pacific islands. Though sporadic case reports have described the clinical consequences of this vector-borne disease, data on the actual incidence of complications or mortality are scarce. It also remains unclear how a delay in effective treatments affects the occurrence of complications associated with this Rickettsial disease.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database in Japan, we identified patients with Tsutsugamushi disease between July 1 and December 31 in 2007 and 2008. We examined location of hospitals, patient's age, sex, comorbidities, complications, inhospital deaths, date of admission, date of starting therapy with tetracyclines. A logistic regression was conducted to analyze the association between delay in effective treatments and the occurrence of complications.

RESULTS

A total of 210 cases were identified. Overall, 29 (13.8%) had at least one complication and two deaths were identified. Age was a significant risk factor for complications [odds ratio (OR), 1.48; 95% confidence interval (CI), 1.08-2.03; p=0.014, for a 10-year age increase]. Patients with ≥2 days delay in treatment with tetracyclines had a significantly higher risk of complications compared to those with no delay (OR, 2.71; 95% CI, 1.03-7.12; p=0.044).

CONCLUSION

Tsutsugamushi disease remains a threat to public health. Our study clearly indicates the importance of early diagnosis and immediate tetracycline treatment to prevent severe complications in Tsutsugamushi disease.

Comparison of conventional, nested, and real-time quantitative PCR for diagnosis of scrub typhus

Orientia tsutsugamushi is the causative agent of scrub typhus. For the diagnosis of scrub typhus, we investigated the performances of conventional PCR (C-PCR), nested PCR (N-PCR), and real-time quantitative PCR (Q-PCR) targeting the O. tsutsugamushi-specific 47-kDa gene. To compare the detection sensitivities of the three techniques, we used two template systems that used plasmid DNA (plasmid detection sensitivity), including a partial region of the 47-kDa gene, and genomic DNA (genomic detection sensitivity) from a buffy coat sample of a single patient. The plasmid detection sensitivities of C-PCR, N-PCR, and Q-PCR were 5 × 10(4) copies/μl, 5 copies/μl, and 50 copies/μl, respectively. The results of C-PCR, N-PCR, and Q-PCR performed with undiluted genomic DNA were negative, positive, and positive, respectively. The genomic detection sensitivities of N-PCR and Q-PCR were 64-fold and 16-fold (crossing point [Cp], 37.7; 426 copies/μl), respectively. For relative quantification of O. tsutsugamushi bacteria per volume of whole blood, we performed real-time DNA PCR analysis of the human GAPDH gene, along with the O. tsutsugamushi 47-kDa gene. At a 16-fold dilution, the copy number and genomic equivalent (GE) of GAPDH were 1.1 × 10(5) copies/μl (Cp, 22.64) and 5.5 × 10(4) GEs/μl, respectively. Therefore, the relative concentration of O. tsutsugamushi at a 16-fold dilution was 0.0078 organism/one white blood cell (WBC) and 117 organisms/μl of whole blood, because the WBC count of the patient was 1.5 × 10(4) cells/μl of whole blood. The sensitivities of C-PCR, N-PCR, and Q-PCR performed with blood samples taken from patients within 4 weeks of onset of fever were 7.3% (95% confidence interval [CI], 1.6 to 19.9), 85.4% (95% CI, 70.8 to 94.4), and 82.9% (95% CI, 67.9 to 92.8), respectively. All evaluated assays were 100% specific for O. tsutsugamushi. In conclusion, given its combined sensitivity, specificity, and speed, Q-PCR is the preferred assay for the diagnosis of scrub typhus.

Scrub typhus in Southern India: are we doing enough?

Scrub typhus is a potentially fatal infectious disease caused by Orientia tsutsugamushi. We report on a retrospective analysis of clinical manifestations, lab investigations and outcome of patients admitted to our hospital from January 2009 to December 2009 with scrub typhus. The Weil-Felix test was the serological method used to diagnose scrub typhus. A total of 29 patients were diagnosed with scrub typhus and the majority of them presented with fever (100%), headache (51%), myalgia (51%) and gastrointestinal symptoms (44%) as predominant features. Six patients (20%) presented with altered sensorium and signs of meningial irritation. There is an emergence of rickettsial infection in southern India, posing diagnostic difficulty and delay in treatment. Early diagnosis and treatment are important as it prevents serious complications associated with the disease.

Clinical and laboratory findings associated with severe scrub typhus

BACKGROUND

Scrub typhus is a mite-borne bacterial infection of humans caused by Orientia tsutsugamushi that causes a generalized vasculitis that may involve the tissues of any organ system. The aim of this study was to identify factors associated to severe complications from scrub typhus.

METHODS

We conducted this prospective, case-control study on scrub typhus patients who presented to the Department of Internal Medicine at Chosun University Hospital between September, 2004 and December, 2006. Cases were 89 scrub typhus patients with severe complications and controls were 119 scrub typhus patients without severe complications.

RESULTS

There were significant differences in the absence of eschar, white blood cell (WBC) counts, hemoglobin, albumin, serum creatinine, fibrinogen, C-reactive protein (CRP), and active partial thromboplastin time (aPTT) between the two groups. Multivariate analysis demonstrated that only the following four factors were significantly associated with the severe complications of scrub typhus: (1) age >or= 60 years (odd ratio [OR] = 3.13, P = 0.002, confidence interval [CI] = 1.53-6.41), (2) the absence of eschar (OR = 6.62, P = 0.03, CI = 1.22-35.8, (3) WBC counts > 10, 000/mm3 (OR = 3.6, P = 0.001, CI = 1.65-7.89), and (4) albumin <or= 3.0 g/dL (OR = 5.01, P = 0.004, CI = 1.69-14.86).

CONCLUSIONS

Our results suggest that clinicians should be aware of the potential for complications, when scrub typhus patients are older (>or= 60 years), presents without eschar, or laboratory findings such as WBC counts > 10, 000/mm3, and serum albumin level <or= 3.0 g/dL. Close observation and intensive care for scrub typhus patients with the potential for complications may prevent serious complications with subsequent reduction in its mortality rate.

Scrub typhus: an unrecognized threat in South India - clinical profile and predictors of mortality

Scrub typhus is an important cause of acute undifferentiated febrile illnesses in the Indian subcontinent. Delay in diagnosis and in the initiation of appropriate treatment can result in severe complications such as acute respiratory distress syndrome (ARDS), septic shock and multisystem organ failure culminating in death. We conducted a prospective, observational study to delineate the clinical profile and predictors of mortality in scrub typhus in adults admitted to the medical wards of a tertiary care, referral hospital in South India over a one-year period. The case fatality rate in this study was 12.2%. Metabolic acidosis (odds ratio [OR] 6.1), ARDS (OR 3.6), altered sensorium (OR 3.6) and shock (OR 3.1) were independent predictors of mortality. It appears that scrub typhus has four possible overlapping clinical presentations: mild disease; respiratory predominant disease; central nervous system predominant disease (meningoencephalitis); or sepsis syndrome. Given the telltale presence of an eschar (evident in 45.5%), the characteristic clinical profile and the dramatic therapeutic response to a cheap, yet effective, drug such as doxycycline, medical practitioners in the region should have ample opportunity to reach an early diagnosis and initiate treatment which could, potentially, reduce the mortality and morbidity associated with scrub typhus.

Massive small bowel bleeding caused by scrub typhus in Korea

A 79-year-old man was diagnosed with scrub typhus based on fever, eschar, skin rash and a markedly elevated serum tsutsugamushi antibody and doxycycline was started. Five days later, hematochezia developed and multiple small bowel ulcerations with hemorrhage were seen on colonoscopy. Despite intensive therapy, the massive hematochezia worsened and the distal small bowel was resected. Multiple ulcerated lesions were identified pathologically as vasculitis caused by scrub typhus. This is the first reported case of pathologically proven small bowel involvement in scrub typhus infection.

Association of high Orientia tsutsugamushi DNA loads with disease of greater severity in adults with scrub typhus

Orientia tsutsugamushi, the cause of scrub typhus, is a major pathogen in the Asia-Pacific region. The severity of infection ranges from mild features to multiorgan failure and death. The aim of this prospective study was to define the O. tsutsugamushi loads in the blood samples of patients with scrub typhus on the day of hospital admission and to determine whether this was associated with disease severity. Quantitation was performed using a real-time PCR assay targeting the 16S rRNA gene of O. tsutsugamushi. A total of 155 patients with a confirmed diagnosis of scrub typhus had a median (interquartile range [IQR], range) O. tsutsugamushi DNA load in blood of 13 (0 to 334, 0 to 310,253) copies/ml. This included 74 patients who had undetectable bacterial loads. An analysis of bacterial load versus clinical features for all 155 patents demonstrated that duration of illness (P < 0.001), presence of eschar (P = 0.004), and concentrations of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase (P < 0.001 for all three) were positively correlated with bacterial load. Patients who died had a significantly higher bacterial load than those who survived (mean [standard deviation] values: 17,154 [12.7] versus 281 [5.2] copies/ml; P < 0.001). This study has demonstrated a relationship between bacterial load and disease severity in adults with scrub typhus.

Acute renal failure due to acute tubular necrosis caused by direct invasion of Orientia tsutsugamushi

We describe a scrub typhus patient with acute renal failure for whom a diagnosis was made based on serology as well as immunohistochemical (IHC) staining and an electron microscopic examination (EM) of a renal biopsy specimen. For our case, we demonstrated by IHC staining and EM that renal failure was caused by acute tubular necrosis due to a direct invasion of Orientia tsutsugamushi.

Scrub typhus: clinical, pathologic, and imaging findings

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. The main pathologic change is focal or disseminated vasculitis caused by the destruction of endothelial cells and the perivascular infiltration of leukocytes. The diagnosis of scrub typhus is based on the patient's history of exposure, clinical features, and results of serologic testing. Regional and generalized lymphadenopathy is common. The pulmonary manifestations of scrub typhus include interstitial pneumonia, interstitial edema, and hemorrhage caused by vasculitis. Abdominal manifestations include splenomegaly, periportal edema, gallbladder wall thickening, and lymphadenopathy. Although the severity of scrub typhus varies considerably, involvement of the central nervous system is seen in almost all patients and can result in meningoencephalitis. A high degree of clinical suspicion and familiarity with the various radiologic manifestations of scrub typhus allow early diagnosis and timely initiation of appropriate therapy, and thereby may help reduce patient morbidity.

Scrub typhus serologic testing with the indirect immunofluorescence method as a diagnostic gold standard: a lack of consensus leads to a lot of confusion

A review was performed to determine the evidence base for scrub typhus indirect immunofluorescence assay (IFA) methodologies and the criteria for positive results. This review included a total of 109 publications, which comprised 123 eligible studies for analysis (14 publications included 2 substudies). There was considerable underreporting of the IFA methodology and seropositivity criteria used, with most studies using a defined cutoff titer rather than an increase in the titer in paired samples. The choice of positivity cutoff titer varied by country and purpose of the IFA test. This variation limits the comparability of seroprevalence rates between studies and, more seriously, raises questions about the appropriateness of the cutoffs for positive IFA results chosen for diagnosis of acute scrub typhus infection. We suggest that the diagnosis of scrub typhus using IFA should be based on a > or =4-fold increase in the titer in paired serum samples and should only be based on a single sample titer when there is an adequate local evidence base.

Fatal septicemic melioidosis in a young military person possibly co-infected with Leptospira interrogans and Orientia tsutsugamushi

Concurrent melioidosis, leptospirosis, and scrub typhus after rural activities is rarely reported. A 19-year-old previously healthy man had fever onset after 2 weeks of military training. Pneumonia became evident on the fifth day of fever under intravenous penicillin and oral minocycline therapy. Acute respiratory failure developed the next day with shock and acute renal and liver function deterioration, which resulted in death. Blood cultures on the third and fifth days grew Burkholderia pseudomallei. Serology revealed leptospirosis and scrub typhus. The emergence of melioidosis in Taiwan and this death without antibiotic treatment for melioidosis alert us that B. pseudomallei should be included as a possible pathogen of pneumonia and sepsis, especially after rural activities.

Acute scrub typhus in Northern Thailand: EKG changes

The electrocardiographic (EKG) manifestations of scrub typhus were prospectively evaluated in 29 adult patients who acquired Orientia tsutsugamushi infection in Chiang Rai, Northern Thailand. EKGs were normal in 22 of the 29 patients (76%); minor non-specific changes were found in the other 7 patients; ie ST segment/T wave changes (10%), U waves (7%), and premature ventricular contractions (4%). These results suggest that EKG changes in scrub typhus acquired in areas of diminished antibiotic susceptibility are similar to those observed in O. tsutsugamushi infection acquired elsewhere.