mNGS helped diagnose scrub typhus-associated HLH in children: a report of two cases.

Background: Scrub typhus, caused by the Orientia tsutsugamushi (Ot), is a widespread vector-borne disease transmitted by chigger mites. Hemophagocytic lymphohistiocytosis (HLH) is considered to be one of the potentially severe complications. The diagnosis of scrub typhus-associated HLH may be overlooked due to the non-specific clinical characteristics and the absence of pathognomonic eschar. Case presentation: We obtained clinical data from two patients in the South of Sichuan, China. The first case involved a 6-year-old girl who exhibited an unexplained fever and was initially diagnosed with sepsis, HLH, and pulmonary infection. The other patient presented a more severe condition characterized by multiple organ dysfunction and was initially diagnosed with septic shock, sepsis, HLH, acute kidney injury (AKI), and pulmonary infection. At first, a specific examination for scrub typhus was not performed due to the absence of a characteristic eschar. Conventional peripheral blood cultures yielded negative results in both patients, and neither of them responded to routine antibiotics. Fortunately, the causative pathogen Orientia tsutsugamushi (Ot) was detected in the plasma samples of both patients using metagenomics next-generation sequencing (mNGS) and further confirmed by polymerase chain reaction. Subsequently, they both were treated with doxycycline and recovered quickly. Conclusion: The unbiased mNGS provided a clinically actionable diagnosis for an uncommon pathogen-associated infectious disease that had previously evaded conventional diagnostic approaches.

Diagnostic markers of acute encephalitis syndrome and COVID-associated multisystem inflammatory syndrome in children from Southern India.

Acute encephalitis syndrome (AES) in children poses a significant public health challenge in India. This study aims to explore the utility of host inflammatory mediators and neurofilament (NfL) levels in distinguishing etiologies, assessing disease severity, and predicting outcomes in AES. We assessed 12 mediators in serum (n = 58) and 11 in cerebrospinal fluid (CSF) (n = 42) from 62 children with AES due to scrub typhus, viral etiologies, and COVID-associated multisystem inflammatory syndrome (MIS-C) in Southern India. Additionally, NfL levels in serum (n = 20) and CSF (n = 18) were examined. Clinical data, including Glasgow coma scale (GCS) and Liverpool outcome scores, were recorded. Examining serum and CSF markers in the three AES etiology groups revealed notable distinctions, with scrub typhus differing significantly from viral and MIS-C causes. Viral causes had elevated serum CCL11 and CCL2 compared with scrub typhus, while MIS-C cases showed higher HGF levels than scrub typhus. However, CSF analysis showed a distinct pattern with the scrub typhus group exhibiting elevated levels of IL-1RA, IL-1ß, and TNF compared with MIS-C, and lower CCL2 levels compared with the viral group. Modeling the characteristic features, we identified that age ≥3 years with serum CCL11 < 180 pg/mL effectively distinguished scrub typhus from other AES causes. Elevated serum CCL11, HGF, and IL-6:IL-10 ratio were associated with poor outcomes (p = 0.038, 0.005, 0.02). Positive CSF and serum NfL correlation, and negative GCS and serum NfL correlation were observed. Median NfL levels were higher in children with abnormal admission GCS and poor outcomes. Measuring immune mediators and brain injury markers in AES provides valuable diagnostic insights, with the potential to facilitate rapid diagnosis and prognosis. The correlation between CSF and serum NfL, along with distinctive serum cytokine profiles across various etiologies, indicates the adequacy of blood samples alone for assessment and monitoring. The association of elevated levels of CCL11, HGF, and an increased IL-6:IL-10 ratio with adverse outcomes suggests promising avenues for therapeutic exploration, warranting further investigation.

Guillain-Barre syndrome following scrub typhus: a case report and literature review.

BACKGROUND: Scrub typhus is an acute infectious disease caused by Orientia tsutsugamushi. Guillain-Barre syndrome (GBS) is an autoimmune-mediated peripheral neuropathy with a frequent history of prodromal infections, but GBS associated with scrub typhus is very rare. CASE PRESENTATION: We report a 51-year-old male patient who developed dysarthria and peripheral facial paralysis following the cure of scfrub typhus. CSF examination and electrophysiological findings suggested a diagnosis of GBS. After treatment with intravenous immunoglobulin, the patient's neurological condition improved rapidly. CONCLUSIONS: Scrub typhus infection is likely to be a potential predisposing factor in GBS, while scrub typhus-associated GBS has a favorable prognosis.

Association of scrub typhus with the risk of venous thromboembolism and long-term mortality: a population-based cohort study.

BACKGROUND: The existing literature lacks studies examining the epidemiological link between scrub typhus and deep vein thrombosis (DVT) or pulmonary embolism (PE), and the long-term outcomes. The objective of this study is to explore the potential association between scrub typhus and the subsequent risk of venous thromboembolism, and long-term mortality. METHOD: This nationwide cohort study identified 10,121 patients who were newly diagnosed with scrub typhus. Patients with a prior DVT or PE diagnosis before the scrub typhus infection were excluded. A comparison cohort of 101,210 patients was established from the general population using a propensity score matching technique. The cumulative survival HRs for the two cohorts were calculated by the Cox proportional hazards model. RESULT: After adjusting for sex, age, and comorbidities, the scrub typhus group had an adjusted HR (95% CI) of 1.02 (0.80-1.30) for DVT, 1.11 (0.63-1.93) for PE, and 1.16 (1.08-1.25) for mortality compared to the control group. The post hoc subgroup analysis revealed that individuals younger than 55 years with a prior scrub typhus infection had a significantly higher risk of DVT (HR: 1.59; 95% CI: 1.12-2.25) and long-term mortality (HR: 1.75; 95% CI, 1.54-1.99). CONCLUSION: The scrub typhus patients showed a 16% higher risk of long-term mortality. For those in scrub typhus cohort below 55 years of age, the risk of developing DVT was 1.59 times higher, and the risk of mortality was 1.75 times higher. Age acted as an effect modifier influencing the relationship between scrub typhus and risk of new-onset DVT and death.

Digital Gangrene Associated with Scrub Typhus: A Case Series.

Rickettsial diseases cover a broad spectrum of illnesses. Scrub typhus is present worldwide, and Orientia tsutsugamushi is the causative agent of this chigger mite-borne infectious illness. Infections exhibit a range of severity, from mild illness to the more severe manifestation of multiorgan failure. We report three cases of scrub fever (55-year-old female, 63-year-old female, and 29-year-old male), all cases developed focal or pan-digital gangrene. All cases were successfully treated by administering doxycycline and additional supportive measures. Digital gangrene is uncommon in scrub typhus. Clinical suspension for early diagnosis and appropriate treatment may avoid further complications.

Acute ischemic stroke in Tsutsugamushi: understanding the underlying mechanisms and risk factors.

BACKGROUND: Tsutsugamushi (scrub typhus) is an acute infectious febrile disease common in the Asia-Pacific region. Common symptoms of tsutsugamushi include lymphadenopathy, fever, and myalgia, and it rarely causes acute ischemic stroke (AIS). However, we hypothesized that tsutsugamushi infection could trigger AIS. METHOD: We retrospectively examined patients diagnosed with AIS within 2 weeks of tsutsugamushi diagnosis at three hospitals over a 15-year period. We categorized patients who developed AIS while being treated for tsutsugamushi as the case group and those (of similar age and sex) who did not develop AIS as the control group. The case and control groups consisted of 22 and 66 participants, respectively. When a scattered pattern was observed or lesions were found in two or more vascular territories on diffusion-weighted imaging, the pattern was defined as embolic. Other patterns were defined as nonembolic. RESULTS: Among the 19 patients, excluding three with transient ischemic stroke, 15 (78.9%) showed an embolic pattern. Although fever was common in the control group, it was less common in the case group. A higher D-dimer level at the time of hospitalization was associated with the development of AIS in patients with tsutsugamushi. CONCLUSIONS: AIS in patients with tsutsugamushi showed an embolic rather than a non-embolic pattern on brain magnetic resonance imaging. It was more likely to occur in patients with risk factors for stroke. Tsutsugamushi patients with AIS were likely to have no fever or high D-dimer levels. We hypothesized that D-dimers play an important role in the pathophysiology, where tsutsugamushi infection increases the likelihood of AIS.

Spontaneous splenic rupture associated with scrub typhus: a case report.

BACKGROUND: Scrub typhus, an acute febrile disease with mild to severe, life-threatening manifestations, potentially presents with a variety of complications, including pneumonia, acute respiratory distress syndrome, cardiac arrhythmias (such as atrial fibrillation), myocarditis, shock, peptic ulcer, gastrointestinal bleeding, meningitis, encephalitis, and renal failure. Of the various complications associated with scrub typhus, splenic rupture has rarely been reported, and its mechanisms are unknown. This study reports a case of scrub typhus-related spontaneous splenic rupture and identifies possible mechanisms through the gross and histopathologic findings. CASE PRESENTATION: A 78-year-old man presented to our emergency room with a 5-day history of fever and skin rash. On physical examination, eschar was observed on the left upper abdominal quadrant. The abdomen was not tender, and there was no history of trauma. The Orientia tsutsugamushi antibody titer using the indirect immunofluorescent antibody test was 1:640. On Day 6 of hospitalization, he complained of sudden-onset left upper abdominal quadrant pain and showed mental changes. His vital signs were a blood pressure of 70/40 mmHg, a heart rate pf 140 beats per min, and a respiratory rate of 20 breaths per min, with a temperature of 36.8 °C. There were no signs of gastrointestinal bleeding, such as hematemesis, melena, or hematochezia. Grey Turner's sign was suspected during an abdominal examination. Portable ultrasonography showed retroperitoneal bleeding, so an emergency exploratory laparotomy was performed, leading to a diagnosis of hemoperitoneum due to splenic rupture and a splenectomy. The patient had been taking oral doxycycline (100 mg twice daily) for 6 days; after surgery, this was discontinued, and intravenous azithromycin (500 mg daily) was administered. No arrhythmia associated with azithromycin was observed. However, renal failure with hemodialysis, persistent hyperbilirubinemia, and multiorgan failure occurred. The patient did not recover and died on the fifty-sixth day of hospitalization. CONCLUSIONS: Clinicians should consider the possibility of splenic rupture in patients with scrub typhus who display sudden-onset abdominal pain and unstable vital signs. In addition, splenic capsular rupture and extra-capsular hemorrhage are thought to be caused by splenomegaly and capsular distention resulting from red blood cell congestion in the red pulp destroying the splenic sinus.

Clinical and laboratory findings in scrub typhus associated Guillain-Barré syndrome in South Korea.

BACKGROUND AND AIMS: Scrub typhus is an endemic disease in the fall season that occurs in a limited number of places known as the Tsutsugamushi Triangle. Peripheral neuropathy is a common complication of scrub typhus. Herein, we encountered several patients with ascending paralysis after scrub typhus infection, who were diagnosed with Guillain-Barré syndrome (GBS). We aimed to investigate the clinical and laboratory characteristics of patients who developed GBS after scrub typhus. METHODS: Patients were retrospectively recruited from six nationwide tertiary centers in South Korea from January 2017 to December 2021. Patients who had been clinically diagnosed with GBS and confirmed to have scrub typhus via laboratory examination and/or the presence of an eschar before the onset of acute limb paralysis were included. The GBS-associated clinical and electrophysiological characteristics, outcomes, and scrub typhus-associated features were collected. RESULTS: Of the seven enrolled patients, six were female and one was male. The median time from scrub typhus infection to the onset of limb weakness was 6 (range: 2-14) days. All patients had eschar on their bodies. Four patients (57.1%) were admitted to the intensive care unit and received artificial ventilation for respiratory distress. At 6 months, the median GBS disability score was 2 (range, 1-4) points. INTERPRETATION: Patients with scrub typhus-associated GBS have a severe clinical presentation and require intensive treatment with additional immunotherapies. Therefore, GBS should be included in the differential diagnosis when peripheral neuropathies develop during scrub typhus treatment. Notably, scrub typhus is associated to GBS.

Case report of scrub typhus with bilateral acute sensorineural hearing loss and cerebral salt-wasting disease.

Scrub typhus is a re-emerging and endemic disease in the Asia Pacific region caused by Orientia tsutsugamushi. We present a 65-year-old male from Sri Lanka who presented with fever, bilateral acute sensorineural hearing loss, and confusion. On examination, he was dehydrated. Significant orthostatic hypotension and an eschar were noted. Investigations revealed hyponatraemia with elevated urine sodium, reduced serum osmolality, and normal urine osmolality suggestive of cerebral salt wasting. After initial hydration with 0.9% NaCl, hyponatraemia was corrected with 3% NaCl. Oral doxycycline was prescribed, and he showed dramatic clinical improvement. A diagnosis of typhus must be considered in a patient presenting with a febrile illness and acute hearing loss. Cerebral salt-wasting disease should be considered in a patient with typhus who develops hyponatraemia with dehydration. Furthermore, acute sensorineural hearing loss in both ears is an important manifestation of the disease.

Identification of novel variants for complicating cardiac disease in the scrub typhus infection using whole genome sequencing.

BACKGROUND/AIMS: Scrub typhus infection has been known to complicate cardiovascular diseases mainly attributing to high mortality. Genetic susceptibility loci for complicating cardiac diseases such as atrial fibrillation, heart failure, and ischemic heart disease identified by genomic study have been limited in scrub typhus infection. Therefore, we investigated the genetic novel variants predicting complicating cardiac diseases in patients with confirmed scrub typhus infection using whole genome sequencing. METHODS: We performed a prospective study for eight consecutive patients with scrub typhus infection. During follow-up, six cases were clinically diagnosed with complicating cardiac diseases and two controls without complicating cardiac diseases. The whole genomes of the all patients were sequenced, and the individual sequence variants were compared between accordcase and control patients. Variant genotypes were compared and identified as a single nucleotide polymorphism (SNP) of the different genotype distributions between six cases and two controls. RESULTS: The GG genotype in SNP (rs4977397) of solute carrier 24 family member 2 (SLC24A2) gene and non-TT genotype in SNP (rs2676750) of adenosine deaminase, RNA specific, B2 (ADARB2) gene were distinctively found in the case patients with complicated cardiac disease, compared with control patents in the scrub typhus infection. CONCLUSION: We suggest that the SNPs of SLC24A2 and ADARB2 might be genetic surrogate markers for complicating cardiac diseases in the scrub typhus infection. Our study show that early detection based on individual sequence variants might be feasible to predict complicating cardiac diseases in patients with scrub typhus infection, if further studies with more participants confirm these findings.

Molecular characterization of Orientia tsutsugamushi causing fatal scrub typhus in a young male affected by so-called "mystery fever" in North India.

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi. Although the presence of eschar is considered pathognomic, diagnosis of scrub typhus is challenging due to overlapping presentation. The diagnosis is based on the serological and molecular assay. Here, we describe a case of a young male patient who was diagnosed with scrub typhus and developed complications in the course of the disease. We also performed molecular characterization of the strain which revealed a close relatedness to Karp-like Linh.DT strains were previously reported from Vietnam.

Clinical Characteristics and Diagnostic Prediction of Severe Fever with Thrombocytopenia Syndrome and Rickettsiosis in the Co-Endemic Wakayama Prefecture, Japan.

Background and Objectives: The Wakayama prefecture is endemic for two types of tick-borne rickettsioses: Japanese spotted fever (JFS) and scrub typhus (ST). Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne hemorrhagic viral disease with a high mortality rate and is often difficult to differentiate from such rickettsioses. SFTS cases have recently increased in Wakayama prefecture. For early diagnosis, this study aimed to evaluate the clinical characterization of such tick-borne infections in the co-endemic area. Materials and Methods: The study included 64 febrile patients diagnosed with tick-borne infection in Wakayama prefecture between January 2013 and May 2022. Medical records of 19 patients with SFTS and 45 with rickettsiosis (JSF, n = 26; ST, n = 19) were retrospectively examined. The receiver operating curve (ROC) and area under the curve (AUC) were calculated to evaluate potential factors for differentiating SFTS from rickettsiosis. Results: Adults aged ≥70 years were most vulnerable to tick-borne infections (median, 75.5 years; interquartile range, 68.5-84 years). SFTS and rickettsiosis occurred mostly between summer and autumn. However, no significant between-group differences were found in age, sex, and comorbidities; 17 (89%) patients with SFTS, but none of those with rickettsiosis, experienced gastrointestinal symptoms such as vomiting, abdominal pain, and diarrhea. Meanwhile, 43 (96%) patients with rickettsiosis, but none of those with SFTS, developed a skin rash. The AUCs of white blood cells (0.97) and C-reactive protein (CRP) levels (0.98) were very high. Furthermore, the differential diagnosis of SFTS was significantly associated with the presence of gastrointestinal symptoms (AUC 0.95), the absence of a skin rash (AUC 0.98), leukopenia <3.7 × 109/L (AUC 0.95), and low CRP levels < 1.66 mg/dL (AUC 0.98) (p < 0.001 for each factor). Conclusions: Clinical characteristics and standard laboratory parameters can verify the early diagnosis of SFTS in areas where tick-borne infections are endemic.

Clinical treatment of patients with scrub typhus-induced liver injury and intracranial infection.

Scrub typhus is an infectious disease caused by Orientia tsutsugamushi, a bacterium within the family Rickettsiaceae. The clinical symptoms are usually acute and are characterized by fever, eschar formation or ulceration, local or generalized lymphadenopathy, and rash. Because of the extensive damage to small blood vessels throughout the body, scrub typhus can involve multiple systems and organs, causing damage to the respiratory, digestive, and nervous systems and inducing kidney and liver dysfunction. Death can occur in severe cases. We herein report two cases of scrub typhus with liver damage and intracranial infection. Among patients with scrub typhus, the risk of death is significantly higher in those who develop liver injury and intracranial infection. However, there are few reports on the treatment of patients with liver injury and intracranial infection caused by scrub typhus, and relevant treatment experience is thus lacking. Our clinical case report helps to fill the knowledge gap in this area.

A CARE-compliant article: A case report of unusual eschar and extensive soft tissue necrosis in Tsutsugamushi disease.

RATIONALE: Tsutsugamushi disease is a common infectious disease in the Northern Hemisphere. A patient infected with tsutsugamushi disease will show a characteristic clinical course with eschar formation, which is mostly small and self-limited in nature without causing major problems. We report a rare case of unusually extensive necrosis started from a small eschar. PATIENT CONCERNS: In this report, a 65-year-old female patient with a history of diabetes mellitus present an 8 × 6 cm-sized huge eschar and extensive soft tissue necrosis aggravated from a small eschar. Also, there were 3 other small eschars in the scalp and left flank area. In early July, she was farming in a field in Hongseong-gun, South Korea. She had been treated at another hospital for 2 weeks. However, the eschar became bigger and worse. DIAGNOSES: After admission, escharectomy was performed and extensive soft tissue necrosis was identified. Orientia tsutsugamushi antibody tests were positive from blood test. Providencia rettgeri and Enterococcus faecalis were detected in a tissue bacterial culture test. INTERVENTION: While using oral azithromycin and intravenous imipenem/cilastatin, the necrosis of the thigh was excised and covered by lateral femoral circumflex artery based myocutaneous Keystone flap. OUTCOMES: The remaining small eschars recovered spontaneously, the large eschars that had caused necrosis were successfully treated, and all other clinical symptoms improved without complications. LESSONS: For unusual eschar of an unknown cause, especially in patients with uncontrolled diabetes or immunocompromised, the possibility of Tsutsugamushi should be considered. Careful physical examination and proper management should be performed as soon as possible.

Orientia tsutsugamushi detected by microbiome diagnostics.

Scrub typhus is caused by the mite-borne bacterium Orientia tsutsugamushi. Imported cases have been suspected in Denmark but no diagnostic method has yet been available to confirm the diagnosis. This is a case report of a 38-year-old male admitted to hospital with high fever, severe malaise and headache after returning from Malaysia. Scrub typhus was suspected and the patient recovered after one week of doxycycline treatment. The pathogen was identified by use of microbiome 16S/18S rRNA next-generation sequencing on ethylenediamine tetraacetic acid (EDTA) blood, which in the future may serve an important role in the investigation of travel-associated infections.

Scrub typus fulminating as liver failure: A rare report.

Scrub typhus is almost an endemic tropical mite-borne, zoonotic illness often cognate with the bacterium Orientia tsutsugamushi. After a typical incubation period of a fortnight, non-specific symptoms including fever, headache, and a specific skin 'eschar' is customary. If untreated after a symptomatic week, scrub typus may precipitate end-organ involvements spiraling into vivid complications. Nevertheless, crub typhus tends to display mild transaminitis, frank liver failure is hardly common in clinical practice. An instance of scrub typus triggering fulminant hepatic failure (FHF) in a middle-aged female is being reported here.