Scrub typhus encephalomyelitis with prominent focal neurologic signs

Scrub Typhus Presenting as Bilateral Sixth Nerve Palsy

Scrub typhus, a tropical rickettsial infection, can have various neurological manifestations. Here, we present the case of an otherwise healthy 19-year-old female who presented to the emergency department with fever, headache, and diplopia. On examination, she was found to have bilateral sixth nerve palsy and bilateral papilledema. Initial unenhanced CT of the brain and CT venogram were unremarkable. The cerebrospinal fluid study was normal. Later, bloodwork revealed high titers of Orientia tsutsugamushi antibody. A thorough physical examination revealed no evidence of any eschar. She was treated with doxycycline and had significant clinical improvement with partial recovery of bilateral lateral rectus function. We want to highlight the importance of maintaining a high index of suspicion for atypical neurological presentations of scrub typhus.

Scrub Typhus Meningoencephalitis: An Overlooked Entity

Scrub typhus is common in rural parts of Nepal, but its diagnosis remains difficult due to a lack of clinical suspicion and poor diagnostic resources. The absence of common clinical features further complicates this problem. Acute kidney injury (AKI), myocarditis, rhabdomyolysis, hepatitis, acute respiratory distress syndrome, and meningoencephalitis are complications of the disease associated with high mortality. Overlap findings can be noted in scrub typhus meningoencephalitis and other tropical infections. This makes diagnosing the disease more challenging, especially in areas where the burden of infectious diseases is high. We report three cases of scrub typhus meningoencephalitis. All three patients were treated successfully with doxycycline. Because patients with scrub typhus have an excellent response to treatment, delay in treatment and rate of complications can be prevented with high clinical suspicion of the condition.

Scrub Typhus Meningoencephalitis: Review of Literature and Unique Diagnostic & Management Challenges in Resource-Limited Settings

Scrub typhus is a zoonotic febrile illness caused by Orientia tsutsugamushi and transmitted by Leptotrombidium larvae. Scrub typhus often presents with nonspecific clinical features, and ranges in severity from mild illness to multiorgan failure and fatality. The disease is primarily found in the Asia-Pacific rim, including India, Pakistan, Thailand, Malaysia, Korea, and China. Due to frequent limitations in healthcare resources in many of these countries, the diagnosis and management of scrub typhus meningoencephalitis pose unique challenges. This review focuses on the epidemiology, clinical features, diagnostic testing, and management modalities in such resource-limited settings. Exercising a high index of clinical suspicion and timely diagnostic tests and management strategies are vital to prevent life-threatening complications of this treatable illness.

Neurological Manifestations of Scrub Typhus

PURPOSE OF REVIEW

The occurrence of cases of scrub typhus is on the rise in South Asian and Southeast Asian countries. The present review discusses neurological complications following scrub typhus to appraise clinicians practicing in endemic regions about considering this treatable disease in the differential diagnosis of acute febrile illnesses, especially when accompanied with clinical neurological features.

RECENT FINDINGS

While the association of aseptic meningitis, encephalitis, and meningoencephalitis with scrub typhus is well known, more recently described neurological syndromes associated with scrub typhus include acute disseminated encephalomyelitis, various cranial nerve palsies, cerebellitis, cerebrovascular diseases including cerebral venous sinus thrombosis, transverse myelitis, longitudinally extensive transverse myelitis, Guillain-Barré syndrome, opsoclonus-myoclonus syndrome, parkinsonism, and many more. Early diagnosis is key to successful treatment. While diagnostic confirmation is generally made by the detection of IgM antibody by either ELISA or indirect fluorescent antibody tests, conventional PCR using 56 kDa gene (cPCR) and loop-mediated isothermal amplification assay (LAMP assay), as well as a newly introduced metagenomic next-generation sequencing (mNGS), are currently available for detection of Orientia tsutsugamushi infection in clinically suspected cases. Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. The cutaneous hallmark of the disease is the "eschar." Scrub typhus results in multisystem involvement. Neurological compromise is present in about 20% of scrub typhus patients and affects both the central nervous system and the peripheral nervous system. The postulated underlying mechanisms include direct invasion of the organism, a vasculitis-like process, or an immune-mediated injury. Diagnosis of scrub typhus is confirmed by detection of O. tsutsugamushi IgM antibody in serum. Awareness among clinicians regarding the varied presentations of this disease is very important in order to reduce morbidity and mortality. Co-infection with dengue and/or chickungunya viruses may occur in endemic regions. The history of an acute febrile illness preceding the neurological illness is crucial. A very careful search for the eschar is essential; however, the absence of the skin lesion cannot exclude the diagnosis of scrub typhus. Neurological manifestations mostly respond to doxycycline therapy.

Clinical profile and management of sixth nerve palsy in pediatric patients (0-15 years) in Southern India - A hospital-based study

PURPOSE

This study was done to evaluate the clinical profile in pediatric patients (0-16 years) presenting with acute onset esotropia due to sixth nerve palsy and its management options in a tertiary care set up of Southern India.

METHODS

A total of 12 patients presenting to our OPD with acute onset esotropia due to sixth nerve palsies were included in this retrospective study. All patients were observed for 6 months and managed with prism and/or patching while waiting for spontaneous resolution and later managed surgically. Neuroimaging was done in all cases.

RESULTS

The mean deviation of esotropia at presentation was 30.17 ± 5.7 Prism Diopter (range 12-50 Prism Diopter 95% CI, SD 10.11). Mean age of the patients during presentation was 8.6 ± 2.4 years (range: 1-15 years, SD 4.27). Among the common causes of sixth nerve palsy in our study population were trauma and idiopathic intracranial hypertension followed by tumor and miscellaneous causes. Only three patients underwent surgical correction of residual deviation after a waiting period of 6 months for self-resolution. Spontaneous resolution was observed in 41.6% patients, and surgical correction (unilateral resection-recession) was done in 25% of the patients with good surgical outcome.

CONCLUSION

At 1-year follow up, the motor outcome was satisfactory except for one patient who had diffuse pontine glioma and had worsening neurological symptoms on follow-up.

The epidemiology, diagnosis and management of scrub typhus disease in China

Thirty-nine years ago, scrub typhus (ST), a disease, was not among the China's notifiable diseases. However, ST has reemerged to become a growing public health issue in the southwest part of China. The major factors contributing to an increased incidence and prevalence of this disease include rapid globalization, urbanization, expansion of humans into previously uninhabited areas, and climate change. The clinical manifestation of ST also consists of high fever, headache, weakness, myalgia, rash, and an eschar. In severe cases, complications (e.g. multi-organ failure, jaundice, acute renal failure, pneumonitis, myocarditis, and even death) can occur. The diagnosis of ST is mainly based on serological identification by indirect immunofluorescence assay and other molecular methods. Furthermore, several groups of antibiotics (e.g. tetracycline, chloramphenicol, macrolides, and rifampicin) are currently effective in treating this disease. This fact suggests the need for robust early diagnostic techniques, increased surveillance, and prompt treatment, and develop future vaccine.

Neurological facets of scrub typhus: A comprehensive narrative review

Scrub typhus is one of the most frequent causes of acute febrile illness in South and South-east Asian countries. Neurological features accompany 20% of scrub typhus infections, and may affect the central or peripheral nervous system, and sometime, may even occur in combination. Of late, its recognition among clinicians has increased with widening detection of its cutaneous hallmark, called eschar. Multiple mechanisms underlie neurological involvement, including direct invasion (meningitis, encephalitis), vasculitis (myositis) or immune-mediated mechanisms (opsoclonus, myoclonus, optic neuritis, Guillain–Barre syndrome). Despite an immunological basis for several neurological manifestations, response to doxycycline is remarkable, although immune therapy may be necessary for severe involvement. Scientific literature on scrub typhus neurology chiefly emanates from case reports, case series and small studies, and a comprehensive review is warranted to aid clinicians in recognising neurological involvement. This review aims at enriching this gap, and summarises clinical features, laboratory findings, and treatment options for various neurological facets of scrub typhus.

Acute transverse myelitis following scrub typhus: A case report and review of the literature

Context: Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi. The disease can usually involve the lungs, heart, liver, spleen and brain through hematogenous dissemination. However, very rarely, acute transverse myelitis in the spinal cord develops from scrub typhus. We present a case of acute transverse myelitis following scrub typhus with a review of the literature. Findings: A 66-year-old male visited a hospital for general myalgia, mild headache, and fever in October. He was noted to have thick, black papule skin on his abdomen, which was highly suggestive of scrub typhus. To confirm the diagnosis, O. tsutsugamushi antibody titers were examined and detected highly in serum by an indirect fluorescence antibody assay. Doxycycline, the standard treatment for scrub typhus, was administered. However, after seven days of treatment, he rapidly developed weakness in the right leg, paresthesia in both lower limbs, and voiding difficulty. Spinal magnetic resonance imaging (MRI) revealed lesions with high signal intensity involving the spinal cord at the thoracolumbar junction. Paraparesis gradually improved following steroid pulse therapy for five days. At one-year follow-up, he could walk without cane. Conclusions:Orientia tsutsugamushi causes scrub typhus, which can affect not only the brain, but also the spinal cord. Although acute transverse myelitis develops rarely from scrub typhus, this should be considered as differential diagnosis in patients of fever with neurological deficit in endemic areas.

Chronic encephalopathy and locked-in state due to scrub typhus related CNS vasculitis

BACKGROUND

Scrub Typhus, prevalent in Asia-Pacific region, often has neurological manifestations in the setting of acute febrile illness, as acute encephalitis syndrome.

CASE REPORT

A 20-year-old female, from western Rajasthan, India presented with calf pain followed by nausea, vomiting, dizziness, and sequentially progressive weakness of limbs, anarthria and loss of bladder control over 10 days. MRI Brain showed T2-weighted and FLAIR hyperintense lesions in corpus callosum, subcortical and periventricular white matter, basal ganglia, thalamus, brainstem and cerebellum producing starry sky appearance with diffusion restriction. Serum IgM for Scrub typhus was positive and patient progressively improved over 3 weeks with doxycycline.

CONCLUSIONS

This report highlights an unusual presentation of scrub typhus with subacute onset and static course, quadriparesis and locked-in state for 2 months, suspected based on red flags on neuroimaging and reversal of deficits with appropriate treatment.

Prolonged coma in a scrub typhus patient

Central nervous system symptoms occur in more than 80% of patients with scrub typhus infection; however, the entity of central nervous system involvement is still not fully understood. We present the case of a patient with fulminant scrub typhus with multiple organ failure, including prolonged deep coma, and detail the sequential neurological symptoms, signs, laboratory data, and neuroradiological findings.

Clinical manifestations of scrub typhus

The mite-borne rickettsial zoonosis scrub typhus is widely prevalent in parts of Southeast and Far East Asia, and northern Australia. The disease is an acute febrile illness, associated with rash and often an eschar, which responds dramatically to treatment with antibiotics. In some cases it results in a serious illness leading to multiple organ involvement and death. The disease manifestations are thought to result from a systemic vasculitis, caused by both direct effects of the organisms as well as an exaggerated immune response, although little is understood about its pathogenesis. A wide spectrum of clinical manifestations, affecting nearly every organ system, have been described with scrub typhus. Some of these manifestations are serious and life threatening. In this systematic review, we summarise the typical and atypical manifestations of scrub typhus reported in the literature. Awareness of these unusual manifestations will hopefully guide clinicians towards diagnosing the condition early, and initiating early appropriate antibiotics and other supportive measures.

A review of the global epidemiology of scrub typhus

Scrub typhus is a serious public health problem in the Asia-Pacific area. It threatens one billion people globally, and causes illness in one million people each year. Caused by Orientia tsutsugamushi, scrub typhus can result in severe multiorgan failure with a case fatality rate up to 70% without appropriate treatment. The antigenic heterogeneity of O. tsutsugamushi precludes generic immunity and allows reinfection. As a neglected disease, there is still a large gap in our knowledge of the disease, as evidenced by the sporadic epidemiologic data and other related public health information regarding scrub typhus in its endemic areas. Our objective is to provide a systematic analysis of current epidemiology, prevention and control of scrub typhus in its long-standing endemic areas and recently recognized foci of infection.

Successfully Managed Acute Transverse Myelitis Related to Scrub Typhus and Serial Image Findings

Central nervous system involvement manifesting as meningitis or meningoencephalitis is a known complication of scrub typhus, but very few spinal cord lesions such as acute transverse myelitis (ATM) have been reported in association with this disease. Scrub typhus patients with a spinal lesion present with neurologic symptoms including dysuria, motor, and sensory weakness. Herein, we describe a rare case of ATM associated with scrub typhus. Clinical characteristics, cerebrospinal fluid cytology, Orientia tsutsugamushi serum antibody titer, and serial magnetic resonance imaging scans resulted in a diagnosis of ATM associated with scrub typhus.

An Unusual Presentation of Scrub Typhus

Presentation of scrub typhus associated with brachial neuritis is extremely rare with only a few cases reported so far. Here, we report a case of a 45-year-old female who presented with fever and right shoulder pain. Laboratory parameters showed leucocytosis with ELISA and PCR for scrub typhus positive. Electromyography (EMG) and Nerve Conduction Velocity (NCV) study was suggestive of brachial neuritis. She was given doxycycline therapy for 10 days following which her shoulder pain resolved.

CNS Manifestations in Orientia tsutsugamushi Disease (Scrub Typhus) in North India

OBJECTIVE

To present the clinical, lab profile and outcome of a series of six children who had features of meningoencephalitis (median age of 10.5 y) diagnosed as confirmed scrub typhus (ST) by using a lgM ELISA commercial kit (InBiOS International Inc. USA).

METHODS

This was a prospective observational study conducted at a tertiary care hospital, over a period of 7 mo through April 2014. All the patients with undifferentiated febrile illness (aged 1-18 y) with fever of 5-21 d duration were evaluated. After thorough physical examination they were subjected to blood investigations such as complete blood count (CBC), blood culture, hepatic and kidney function tests, serum electrolytes, cerebrospinal fluid (CSF) analysis and IgM ELISA for scrub typhus, coagulogram and chest radiograph, wherever indicated.

RESULTS

During this period, of the total 81 confirmed cases based on a positive scrub IgM ELISA and/or eschar, 6 (7.4 %), had neurological involvement in the form of presence of neck stiffness, altered sensorium and/or seizures and the CSF findings were suggestive of meningoencephalitis and all had evidence of multiple organ dysfunction syndrome (MODS) needing intensive care. The CECT could be performed in four patients only showing evidence of effacement of sulci and evidence of brain edema.

CONCLUSIONS

This communication highlights that variable central nervous system (CNS) involvement is not uncommon in patients with scrub typhus with high mortality. CSF and neuro-radiology findings are nonspecific as these are also observed in patients with aseptic meningitis or encephalitis. Early suspection and institution of appropriate therapy without delay will lead to substantial reduction in the morbidity and mortality.

Ophthalmoplegia Due to Scrub Typhus

Scrub typhus is an acute febrile infectious disease caused by Orientia tsutsugamushi. The illness is usually characterized by fever, rash, and lymphadenopathy, but severe cases progress to pulmonary and neurological involvement. We report a 69-year-old man who developed ptosis and ophthalmoplegia with a focal nodular lesion in the anterior cavernous sinus detected with magnetic resonance imaging. Found to have scrub typhus, the ptosis and ophthalmoplegia resolved after treatment with doxycycline.

Neurological manifestations of scrub typhus in adults

In order to study the neurological manifestations in adult patients suffering from scrub typhus, 323 patients aged over 18 years, admitted with a positive diagnosis, were screened for neurological dysfunction; 37 patients with symptoms and/or signs suggestive of neurological dysfunction were included in the study. Of these, 31 (84%) patients had altered sensorium, four (11%) had cerebellitis, one (2%) patient had acute transverse myelitis and one (2%) had bilateral papilloedema without focal neurological deficit. Of the 31 patients with altered sensorium, 15 (40%) had meningoencephalitis, three (8%) had seizures, two (5%) had cerebral haemorrhages, one (2%) had a presentation likened to neuroleptic malignant syndrome (NMS) and one (2%) had a 6th nerve palsy with inflammation of the right cavernous sinus. Cerebrospinal fluid (CSF) analysis was abnormal in 23 patients (raised lymphocytes in 68%, raised protein in 80%). All patients improved with anti-rickettsial therapy.

Scrub Typhus Presenting with Bilateral Lateral Rectus Palsy in A Female

Scrub typhus, a rickettsial disease is endemic in several parts of India usually presenting with acute symptoms. Fever, maculopapular rash, eschar, history of tick exposure and supportive diagnostic tests usually leads to diagnosis. Scrub typhus should be included in the differential diagnosis in occasions when a patient presents with fever with or without eschar and isolated cranial nerve palsy. Here we are reporting a case of Scrub typhus who presented with fever and altered sensorium of short duration, eschar formation and bilateral lateral rectus palsy. Patient was treated with doxycycline with complete reversal of neurodeficit.

Scrub typhus mimicking Parkinson's disease

Background

Scrub typhus is a re-emerging infection in Sri Lanka. It often poses a diagnostic challenge and tends to present as a febrile illness of uncertain origin. Undiagnosed illness may progress to serious multi-systemic complications. Here we report a case of scrub typhus presenting with features of Parkinsonism.

Case presentation

A 62-year-old previously healthy Sri Lankan native male from the Western province of Sri Lanka presented with high fever with malaise, myalgia and arthralgia for 17 days. On the 5th day of illness he developed intermittent resting tremor in his right arm and leg associated with stiffness, difficulty in carrying out normal work and difficulty in smiling. He denied similar previous episodes. There were no other associated neurological manifestations. Clinical examination revealed a high amplitude low frequency resting tremor in his right hand, a mask-like face and increased muscle tone limited to the right side with normal reflexes. The rest of the system examination was normal except for an eschar over the abdomen. His investigations revealed lymphocytic leukocytosis, high erythrocyte sedimentation rate and immunofluorescence assay-IgM and IgG against Orientia tsutsugamushi Karp antigen were positive with rising titers. With oral doxycycline and azithromycin his fever settled within 48 h and a complete recovery of Parkinson’s features was observed within 2 weeks.

Conclusion

Doctors practicing in endemic regions should be familiar with delayed clinical manifestations of scrub typhus and should carefully look for an eschar in order to avoid delay in the diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1428-x) contains supplementary material, which is available to authorized users.

Neurological manifestations of scrub typhus

OBJECTIVE

To evaluate the neurological manifestations of scrub typhus and correlate their clinical, EEG and MRI findings.

METHODS

A cross-sectional study over 2 years included patients with scrub typhus diagnosed by solid phase immunochromatographic assay or Weil-Felix test. A detailed clinical evaluation including Glasgow Coma Scale (GCS) was documented. Blood counts, chemistry, ECG, chest radiograph, cerebrospinal fluid (CSF), EEG and cranial MRI were performed. Outcome on discharge and at 1 month were categorised into good and poor based on modified Rankin Scale.

RESULTS

Thirty-seven patients with ages ranging between 3 and 71 years were included; 51% of whom were females. All patients had fever and myalgia. Thirty-one (84%) patients had impaired consciousness, and six were deeply comatose (GCS score ≤8). Eight patients presented with status epilepticus. MRI revealed meningeal enhancement in only 1/25 (4%) patient and EEG showed generalised slowing in 6/28 (21.4%). Among 31 patients with altered sensorium, CSF studies were conducted on 28. Nineteen patients had meningoencephalitis and 9 encephalopathy, but no significant differences were observed in clinical, laboratory, EEG and MRI findings. All patients responded within 48 h to doxycycline and had good recovery at 1 month. Patients with low GCS score had significantly more focal neurological deficit (r=0.5; p=0.002), longer hospital stay (r=-0.4; p=0.03) and more disability on discharge (r=-0.4; p=0.01).

CONCLUSIONS

Meningoencephalitis/encephalopathy may be seen in two-third of patients with scrub typhus. Scrub typhus should be included in the differential diagnosis of febrile encephalopathy.

Role of advanced MRI brain sequences in diagnosing neurological complications of scrub typhus

Scrub typhus is a rare disease affecting many organs and causing vasculitis by affecting the endothelium of blood vessels. Review of literature shows that there are only a few case reports describing the neuroradiological manifestations of scrub typhus. This case report describes how newer and advanced MRI sequences are able to diagnose neurological complications of scrub typhus, such as hemorrhages, meningoencephalitis, infarctions, cranial nerve involvement, thrombosis, and hypoperfusion, that are not picked up on routine magnetic resonance imaging (MRI) sequences.

Profile of organ dysfunction and predictors of mortality in severe scrub typhus infection requiring intensive care admission

Background and Aims:

Scrub typhus, a zoonotic rickettsial infection, is an important reason for intensive care unit (ICU) admission in the Indian subcontinent. We describe the clinical profile, organ dysfunction, and predictors of mortality of severe scrub typhus infection.

Materials and Methods:

Retrospective study of patients admitted with scrub typhus infection to a tertiary care university affiliated teaching hospital in India during a 21-month period.

Results:

The cohort (n = 116) aged 40.0 ± 15.2 years (mean ± SD), presented 8.5 ± 4.4 days after symptom onset. Common symptoms included fever (100%), breathlessness (68.5%), and altered mental status (25.5%). Forty-seven (41.6%) patients had an eschar. Admission APACHE-II score was 19.6 ± 8.2. Ninety-one (85.2%) patients had dysfunction of 3 or more organ systems. Respiratory (96.6%) and hematological (86.2%) dysfunction were frequent. Mechanical ventilation was required in 102 (87.9%) patients, of whom 14 (12.1%) were solely managed with non-invasive ventilation. Thirteen patients (11.2%) required dialysis. Duration of hospital stay was 10.7 ± 9.7 days. Actual hospital mortality (24.1%) was less than predicted APACHE-II mortality (36%; 95% Confidence interval 32-41). APACHE-II score and duration of fever were independently associated with mortality on logistic regression analysis.

Conclusions:

In this cohort of severe scrub typhus infection with multi-organ dysfunction, survival was good despite high severity of illness scores. APACHE-II score and duration of fever independently predicted mortality.

Pure cerebellitis due to scrub typhus: a unique case report

We report the case of a 24-year old Indian man who presented with: high fever; drowsiness; an eschar and gross cerebellar dysfunction with horizontal gaze nystagmus; ataxic speech; and truncal ataxia. Scrub typhus was diagnosed by serological tests. This is the first case of a pure cerebellar involvement as the only manifestation of scrub typhus in the published literature.

First case of scrub typhus with meningoencephalitis from Kerala: An emerging infectious threat

Scrub typhus is a rickettsial disease caused by Orientia tsutsugamushi, one of the most common infectious diseases in the Asia-Pacific region. It has been reported from northern, eastern, and southern India, and its presence has been documented in at least 11 Indian states. However, scrub typhus meningoencephalitis has not been well documented in Kerala. We report two cases of scrub typhus meningoencephalitis from northern Kerala. The diagnosis was made based on the clinical pictures, presence of eschar, and a positive Weil–Felix test with a titer of > 1:320. The first patient succumbed to illness due to respiratory failure and the second patient improved well.

Scrub typhus-associated severe hemophagocytic lymphohistiocytosis with encephalomyelitis leading to permanent sequelae: a case report and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disorder. There have been a few reports on HLH secondary to scrub typhus in adults. Here, we describe the case of a 9-year-old Korean girl who presented with the typical findings of HLH. Despite adequate antirickettsial and HLH treatment, the neurological impairment worsened and remained. This is the first case report of severe neurological impairment resulting from the very rare association of HLH with scrub typhus. Therefore, in endemic areas, a high index of suspicion for scrub typhus is warranted in patients presenting with HLH.

Scrub typhus associated with transient parkinsonism and myoclonus

Parkinsonism with myoclonus is rarely associated with infectious disease in adults. We present a 55-year-old man experiencing acute onset bilateral limb tremor, rigidity, and myoclonus with small-stepped gait, and skin rash involving the trunk and limbs, after a fever. Serum was positive for anti-Orientia tsutsugamushi immunoglobulin M antibody. Brain MRI revealed no abnormalities. The fever improved with oral doxycycline, and the parkinsonism and myoclonus improved with amantadine and clonazepam. This is a rare case of parkinsonism with myolonus associated with scrub typhus infection.

Scrub typhus: pathophysiology, clinical manifestations and prognosis

Scrub typhus is a zoonosis caused by the pathogen Orientia tsutsugamushi (O. tsutsugamushi). The disease has significant prevalence in eastern and Southeast Asia. Usually presenting as an acute febrile illness, the diagnosis is often missed because of similarities with other tropical febrile infections. Many unusual manifestations are present, and these are described in this review, together with an outline of current knowledge of pathophysiology. Awareness of these unusual clinical manifestations will help the clinician to arrive at an early diagnosis, resulting in early administration of appropriate antibiotics. Prognostic indicators for severe disease have not yet been clearly established.

Bilateral simultaneous facial palsy following scrub typhus meningitis: a case report and literature review

Scrub typhus is widely distributed across the Asia-Pacific region, Taiwan included. The clinical manifestations and complications of scrub typhus vary and the illness ranges in severity from mild to fatal. The etiology of facial nerve palsy varies and infectious agents have been associated with this condition. Rickettsiae species have, however, rarely been reported as the causative agents. We report the case of a 49-year-old man who had fever, malaise, headache, oligouria and tea-colored urine. Bilateral pneumonitis, acute renal failure, acalculous cholecystitis and aseptic meningitis were diagnosed after a series of examinations. The patient recovered after doxycycline treatment but he developed bilateral facial palsy during the convalescent phase, which improved after the administration of a steroid. The diagnosis of infection with Orientia tsutsugamushi was confirmed by the Taiwan Center of Disease Control and the tests for Leptospira, Rickettsia typhi and Coxiella burnetii were all negative. This case indicates that scrub typhus needs to be included in the differential diagnoses of cases of bilateral and simultaneous facial nerve palsy, particularly in areas where the disease is endemic.

Isolated abducens nerve palsy in a patient with scrub typhus

Abducens nerve palsies associated with infectious diseases are infrequent. Scrub typhus is an acute, febrile, infectious illness caused by Orientia tsutsugamushi (formerly Rickettsia tsutsugamushi), an obligate-intracellular gram-negative bacterium. The organism has been reported to be capable of entering the nervous system, causing meningitis and focal neurologic abnormalities. We report a case of isolated abducens nerve palsy associated with a scrub typhus infection.

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.

Polyneuropathy and cerebral infarction complicating scrub typhus

We describe a 64-year-old man with scrub typhus who presented with both polyneuropathy and cerebral infarction. A eurological examination revealed a confused mental state, stiff neck, hearing impairment, symmetric weakness, sensory loss, and ataxia. Electrophysiologic studies showed demyelinating sensorimotor polyneuropathy and sensorineural hearing loss. Brain magnetic resonance imaging showed multiple infarctions. Brain involvement or polyneuropathy associated with scrub typhus has been rarely reported, and the pathogenic mechanism underlying the multiple neurological complications remains to be elucidated.

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.