Acute hearing loss due to scrub typhus: a forgotten complication of a reemerging disease

Epidemiologic changes of a longitudinal surveillance study spanning 51 years of scrub typhus in mainland China

Scrub typhus may be one of the world's most prevalent, neglected and serious, but easily treatable, febrile diseases. It has become a significant potential threat to public health in China. In this study we used national disease surveillance data to analyze the incidence and spatial-temporal distribution of scrub typhus in mainland China during 1952-1989 and 2006-2018. Descriptive epidemiological methods and spatial-temporal epidemiological methods were used to investigate the epidemiological trends and identify high-risk regions of scrub typhus infection. Over the 51-year period, a total of 182,991 cases and 186 deaths were notified. The average annual incidence was 0.13 cases/100,000 population during 1952-1989. The incidence increased sharply from 0.09/100,000 population in 2006 to 1.93/100,000 population in 2018 and then exponentially increased after 2006. The incidence was significantly higher in females than males (χ2 = 426.32, P < 0.001). Farmers had a higher incidence of scrub typhus than non-farmers (χ2 = 684.58, P < 0.001). The majority of cases each year were reported between July and November with peak incidence occurring during October each year. The trend surface analysis showed that the incidence of scrub typhus increased gradually from north to south, and from east and west to the central area. The spatial autocorrelation analysis showed that a spatial positive correlation existed in the prevalence of scrub typhus on a national scale, which had the characteristic of aggregated distribution (I = 0.533, P < 0.05). LISA analysis showed hotspots (High-High) were primarily located in the southern and southwestern provinces of China with the geographical area expanding annually. These findings provide scientific evidence for the surveillance and control of scrub typhus which may contribute to targeted strategies and measures for the government.

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.

Co-effects of global climatic dynamics and local climatic factors on scrub typhus in mainland China based on a nine-year time-frequency analysis

Background

Scrub Typhus (ST) is a rickettsial disease caused by Orientia tsutsugamushi. The number of ST cases has been increasing in China during the past decades, which attracts great concerns of the public health.

Methods

We obtained monthly documented ST cases greater than 54 cases in 434 counties of China during 2012-2020. Spatiotemporal wavelet analysis was conducted to identify the ST clusters with similar pattern of the temporal variation and explore the association between ST variation and El Niño and La Niña events. Wavelet coherency analysis and partial wavelet coherency analysis was employed to further explore the co-effects of global and local climatic factors on ST.

Results

Wavelet cluster analysis detected seven clusters in China, three of which are mainly distributed in Eastern China, while the other four clusters are located in the Southern China. Among the seven clusters, summer and autumn-winter peak of ST are the two main outbreak periods; while stable and fluctuated periodic feature of ST series was found at 12-month and 4-(or 6-) month according to the wavelet power spectra. Similarly, the three-character bands were also found in the associations between ST and El Niño and La Niña events, among which the 12-month period band showed weakest climate-ST association and the other two bands owned stronger association, indicating that the global climate dynamics may have short-term effects on the ST variations. Meanwhile, 12-month period band with strong association was found between the four local climatic factors (precipitation, pressure, relative humidity and temperature) and the ST variations. Further, partial wavelet coherency analysis suggested that global climatic dynamics dominate annual ST variations, while local climatic factors dominate the small periods.

Conclusion

The ST variations are not directly attributable to the change in large-scale climate. The existence of these plausible climatic determinants stimulates the interests for more insights into the epidemiology of ST, which is important for devising prevention and early warning strategies.

An unusual presentation of scrub typhus in a child: a case report

Background

Scrub Typhus (ST) is an acute, febrile zoonotic disease caused by the bacterium Orientia tsutsugamushi which is endemic to the Asia-Pacific region. Infected adults rarely present with sensorineural hearing loss and otalgia. Though few cases of pediatric cases are known to present with otalgia, no pediatric cases of sensorineural deafness complicating ST have been reported to date.

Case presentation

A 5-year-old, previously healthy girl presented with a one-week history of high-grade intermittent fever, Headache and right ear pain with a recent onset of reduced hearing. She had a fever up to 39 °C, cervical lymphadenopathy, bilateral pleural effusion with diffuse infiltrations, and mild hepatosplenomegaly with no evidence of rash. Her initial examination was normal except for mildly enlarged tonsils. Unilateral right ear hearing loss was noted using Weber’s test. Evidence of progressive, mild anemia, and raised inflammatory markers was noted. Diagnosis of scrub typhus was confirmed by positive detection of Orentia tsutsugamushi IgM antibodies on rapid diagnostic test and the presence of chigger mite in the right external auditory canal on repeat examination. She responded dramatically to the empirical treatment of ceftriaxone and doxycycline. On follow-up, she did not have any residual hearing loss and her ear pain had resolved completely.

Conclusion

Acute onset hearing loss or severe otalgia with or without findings should be an important diagnostic clue for suspecting scrub typhus in patients who present with a history of fever especially in endemic areas.

Scrub typhus in pregnancy presenting with permanent hearing loss: A case report

As clinicians, we need to be vigilant about these rare and atypical presentations given the endemic nature of scrub typhus in southern belt of the country. Timely diagnosis and appropriate treatment is the key aspect to prevent further complications.

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.

Neuroinflammation associated with scrub typhus and spotted fever group rickettsioses

Scrub typhus and spotted fever rickettsioses (SFR) are understudied, vector-borne diseases of global significance. Over 1 billion individuals are at risk for scrub typhus alone in an endemic region, spanning across eastern and southern Asia to Northern Australia. While highly treatable, diagnostic challenges make timely antibiotic intervention difficult for these diseases. Delayed therapy may lead to severe outcomes affecting multiple organs, including the central nervous system (CNS), where infection and associated neuroinflammation may be lethal or lead to lasting sequelae. Meningitis and encephalitis are prevalent in both scrub typhus and SFR. Additionally, case reports detailing focal neurological deficits have come to light, with attention to both acute and chronic sequelae of infection. Despite the increasing number of clinical reports outlining neurologic consequences of these diseases, relatively little research has examined underlying mechanisms of neuroinflammation. Animal models of scrub typhus have identified cerebral T-cell infiltration and vascular damage associated with endothelial infection and neuropathogenesis. Differential gene expression analysis of brain tissues during murine scrub typhus have revealed selective increases in CXCR3 ligands, proinflammatory and type-1 cytokines and chemokines, and cytotoxicity molecules, as well as alterations in the complement pathway. In SFR, microglial expansion and macrophage infiltration contribute to neurological disease progression. This narrative Review highlights clinical neurologic features of scrub typhus and SFR and evaluates our current understanding of basic research into neuroinflammation for both diseases in animal models. Further investigation into key mediators of neuropathogenesis may yield prognostic markers and treatment regimens for severe patients.

Case Report: Acute pyelonephritis and hearing loss in scrub typhus

Acute pyelonephritis is a common renal manifestation in patients with diabetes. A 52-year-old diabetic lady presented with loin pain, dysuria, and fever and urinary incontinence that had begun seven and three days prior to presentation respectively. She was treated with escalating spectra of intravenous antibiotics without improvement. Urine and blood cultures were sterile, while radiological investigations were suggestive of pyelonephritis. Mild hepatic dysfunction prompted consideration of scrub typhus and she improved with empirical doxycycline. Scrub IgM was later confirmed to be positive. In conclusion, local prevalence of systemic infections such as rickettsioses should always be considered in diabetics with fever, even if symptoms and signs otherwise suggest typical diabetes-related infections. We, therefore report a case of acute pyelonephritis caused by scrub typhus which has not been previously described in English medical literature.

Bilateral Sensorineural Deafness in a Young Pregnant Female Presenting with a Fever: A Rare Complication of a Reemerging Disease-Spotted Fever Group Rickettsioses

Background

Rickettsial illnesses are a group of arthropod-borne remerging diseases. They are subdivided into three groups as typhus, spotted fever, and scrub typhus group. Complications such as reversible bilateral deafness due to spotted fever rickettsioses are infrequently reported in the literature.

Case Presentation

We present a young pregnant female who developed bilateral sensorineural deafness on the fifth day of an acute febrile illness with a maculopapular rash. Rickettsia conorii IgG (>1/450) became highly positive, and she received oral azithromycin for ten days with complete resolution of fever and rash. The sensorineural deafness slowly improved over several months.

Conclusion

Sensorineural deafness is a rare complication of spotted fever group rickettsioses. Since usage of doxycycline is controversial in pregnancy, azithromycin gave a favourable recovery of fever. Sensorineural deafness took several months to resolve after completion of antibiotics.

Enhancer Associated Long Non-coding RNA Transcription and Gene Regulation in Experimental Models of Rickettsial Infection

Recent discovery that much of the mammalian genome does not encode protein-coding genes (PCGs) has brought widespread attention to long noncoding RNAs (lncRNAs) as a novel layer of biological regulation. Enhancer lnc (elnc) RNAs from the enhancer regions of the genome carry the capacity to regulate PCGs in cis or in trans. Spotted fever rickettsioses represent the consequence of host infection with Gram-negative, obligate intracellular bacteria in the Genus Rickettsia. Despite being implicated in the pathways of infection and inflammation, the roles of lncRNAs in host response to Rickettsia species have remained a mystery. We have profiled the expression of host lncRNAs during infection of susceptible mice with R. conorii as a model closely mimicking the pathogenesis of human spotted fever rickettsioses. RNA sequencing on the lungs of infected hosts yielded reads mapping to 74,964 non-coding RNAs, 206 and 277 of which were determined to be significantly up- and down-regulated, respectively, in comparison to uninfected controls. Following removal of short non-coding RNAs and ambiguous transcripts, remaining transcripts underwent in-depth analysis of mouse lung epigenetic signatures H3K4Me1 and H3K4Me3, active transcript markers (POLR2A, p300, CTCF), and DNaseI hypersensitivity sites to identify two potentially active and highly up-regulated elncRNAs NONMMUT013718 and NONMMUT024103. Using Hi-3C sequencing resource, we further determined that genomic loci of NONMMUT013718 and NONMMUT024103 might interact with and regulate the expression of nearby PCGs, namely Id2 (inhibitor of DNA binding 2) and Apol10b (apolipoprotein 10b), respectively. Heterologous reporter assays confirmed the activity of elncRNAs as the inducers of their predicted PCGs. In the lungs of infected mice, expression of both elncRNAs and their targets was significantly higher than mock-infected controls. Induced expression of NONMMUT013718/Id2 in murine macrophages and NONMMUT024103/Apol10b in endothelial cells was also clearly evident during R. conorii infection in vitro. Finally, shRNA mediated knock-down of NONMMUT013718 and NONMMUT024103 elncRNAs resulted in reduced expression of endogenous Id2 and Apl10b, demonstrating the regulatory roles of these elncRNAs on their target PCGs. Our results provide very first experimental evidence suggesting altered expression of pulmonary lncRNAs and elncRNA-mediated regulation of PCGs involved in immunity and during host interactions with pathogenic rickettsiae.

Intra-aural tick bite causing unilateral facial nerve palsy in 29 cases over 16 years in Kandy, Sri Lanka: is rickettsial aetiology possible?

Background

Over the last two decades intra-aural tick infestation (otoacariasis) has been a common occurrence in the hilly central region in Sri Lanka. Very occasional detection of isolated unilateral facial nerve palsy associated with otoacariasis attributed to toxin damage of the nerve prompted us to study the clinico-epidemiology and aetio-pathology of the problem.

Methods

All cases having isolated unilateral facial nerve palsy associated with otoacariasis presented to, Ear Nose and Throat clinic at General Hospital Kandy, Sri Lanka from 2001 to 2016 were included in the study. The facial palsies were assessed with nerve conduction studies and, harvested ticks were identified.

Results

There were 29 patients with mean age of 46 years (range 22–76 years) with male to female ratio of 1:1.9. First 12 patients without specific treatment took 1–55 months for recovery and 4 had axonal degeneration. Last 5 patients were treated with doxycycline and recovered in 4 weeks. They had strong sero-conversion of immunofluorescence antibodies against spotted fever rickettsioses and the tick harvested from the last patient was PCR positive for rickettsial DNA. Identified ticks belonged to Dermacentor, Amblyomma, Rhipicephalus and Hyalomma species.

Conclusions

On contrary to popular toxin theory, we were able to demonstrate treatable rickettsial aetio-pathology as the cause of otoacariasis associated lower motor facial palsy in Sri Lanka.

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.

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.

Rapid Increase in Scrub Typhus Incidence in Mainland China, 2006-2014

Scrub typhus is a vector-borne disease, which has recently reemerged in China. In this study, we describe the distribution and incidence of scrub typhus cases in China from 2006 to 2014 and quantify differences in scrub typhus cases with respect to sex, age, and occupation. The results of our study indicate that the annual incidence of scrub typhus has increased during the study period. The number of cases peaked in 2014, which was 12.8 times greater than the number of cases reported in 2006. Most (77.97%) of the cases were reported in five provinces (Guangdong, Yunnan, Anhui, Fujian, and Shandong). Our study also demonstrates that the incidence rate of scrub typhus was significantly higher in females compared to males (P < 0.001) and was highest in the 60-69 year age group, and that farmers had a higher incidence rate than nonfarmers (P < 0.001). Different seasonal trends were identified in the number of reported cases between the northern and southern provinces of China. These findings not only demonstrate that China has experienced a large increase in scrub typhus incidence, but also document an expansion in the geographic distribution throughout the country.

Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos: a prospective study

Background

Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe complications. However, scarce data exist for the burden of these pathogens in patients with CNS disease in endemic countries. Laos is representative of vast economically poor rural areas in Asia with little medical information to guide public health policy. We assessed whether these pathogens are important causes of CNS infections in Laos.

Methods

Between Jan 10, 2003, and Nov 25, 2011, we enrolled 1112 consecutive patients of all ages admitted with CNS symptoms or signs requiring a lumbar puncture at Mahosot Hospital, Vientiane, Laos. Microbiological examinations (culture, PCR, and serology) targeted so-called conventional bacterial infections (Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, S suis) and O tsutsugamushi, Rickettsia typhi/Rickettsia spp, and Leptospira spp infections in blood or cerebrospinal fluid (CSF). We analysed and compared causes and clinical and CSF characteristics between patient groups.

Findings

1051 (95%) of 1112 patients who presented had CSF available for analysis, of whom 254 (24%) had a CNS infection attributable to a bacterial or fungal pathogen. 90 (35%) of these 254 infections were caused by O tsutsugamushi, R typhi/Rickettsia spp, or Leptospira spp. These pathogens were significantly more frequent than conventional bacterial infections (90/1051 [9%] vs 42/1051 [4%]; p<0·0001) by use of conservative diagnostic definitions. CNS infections had a high mortality (236/876 [27%]), with 18% (13/71) for R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp combined, and 33% (13/39) for conventional bacterial infections (p=0·076).

Interpretation

Our data suggest that R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp infections are important causes of CNS infections in Laos. Antibiotics, such as tetracyclines, needed for the treatment of murine typhus and scrub typhus, are not routinely advised for empirical treatment of CNS infections. These severely neglected infections represent a potentially large proportion of treatable CNS disease burden across vast endemic areas and need more attention.

Funding

Wellcome Trust UK.

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.

Scrub typhus: audit of an outbreak

OBJECTIVES

To document the epidemiological, clinical and laboratory profile of all children with scrub typhus at a tertiary care centre in Chennai between September 2010 and June 2011.

METHODS

The case records of all children admitted and diagnosed with scrub typhus between September 2010 and June 2011 were analysed to look for salient clinical and laboratory parameters.

RESULTS

During the study period, 52 children were admitted with scrub typhus in the authors' hospital. The presenting complaints included fever in all cases. Other symptoms included swelling of legs (50 %) and vomiting (45 %). 13 % presented with CNS symptoms. The commonest physical findings included eschar (67 %), hepatomegaly (94 %), splenomegaly (73 %) and third spacing (67 %). Salient lab parameters included packed cell volume (PCV) <30 (48 %), leucocytosis (56 %), positive C-reactive protein (CRP) (92 %), hypoalbuminemia (79 %). Common complications included acute kidney injury (10 %) and peripheral gangrene (4 %). There was no mortality in the present case series.

CONCLUSIONS

The clinical profile of children with scrub typhus in a tertiary care centre is reported. Eschar and hepatosplenomegaly with a high CRP value is helpful in diagnosis. All patients responded well to the treatment.

Neuritis and gastrointestinal hemorrhage in scrub typhus patients

A 78-year-old woman with scrub typhus exhibited gastric hemorrhage with multiple gastric ulcers. This is the first report to confirm pathologically the presence of not only vasculitis but also, neuritis. The results suggest the necessity of studies confirming neuritis as the cause of gastric ulcer and bleeding in scrub typhus.

Rickettsial diseases and ectoparasites from military bases in Japan

Ectoparasitic arthropods are often vectors of rickettsiosis. We conducted a survey of ectoparasites on U.S. military facilities throughout Japan with the use of specimens submitted by pest control, public health, and veterinary personnel. Over 1,600 individual ectoparasites were collected. Fifteen species were identified, including several significant vectors of human diseases such as scrub typhus and rickettsial spotted fevers. These ectoparasites included Ctenocephalides felis , Haemaphysalis longicornis, Ixodes persulcatus , Leptotrombidium fuji, Leptotrombidium pallidum, and Rhipicephalus sanguineus . Rickettsial agents were detected by PCR and DNA sequencing. These included Bartonella henselae , Bartonella japonica, a novel Bartonella, Coxiella burnetii , an unnamed Coxiella, Ehrlichia canis , Orientia tsutsugamushi , Rickettsia typhi , and "Rickettsia Rf2125"/"Rickettsia cf1and5".

Neuritis and gastrointestinal hemorrhage in scrub typhus patients

A 78-year-old woman with scrub typhus exhibited gastric hemorrhage with multiple gastric ulcers. This is the first report to confirm pathologically the presence of not only vasculitis but also, neuritis. The results suggest the necessity of studies confirming neuritis as the cause of gastric ulcer and bleeding in scrub typhus.

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.

Transient adrenal insufficiency and post-treatment bradycardia in scrub typhus - a case report

Scrub typhus appears throughout the Asia-Pacific rim. This disease is known for its diverse clinical manifestations and complications. There is no literature on the association of scrub typhus with adrenal insufficiency. Relative bradycardia has been reported in scrub typhus during the febrile phase but not during convalescence. We report the case of a 45- year-old woman with scrub typhus whose blood pressure was persistently low due to acute adrenal insufficiency. Adrenal failure responded to supplementation with steroids. She also developed sinus bradycardia during the afebrile period following treatment.

Dynamics of clinical symptoms in patients with scrub typhus

The clinical manifestations and complications of scrub typhus are variable. Few studies have examined the timeline of clinical symptoms after the appropriate antimicrobial agents have been administered. The most prevalent clinical manifestations are fever and cough, followed by headache, myalgia, eschar, skin rash, and nausea. Systemic symptoms are most severe during the early stages of illness (i.e., the first 5 days), but resolve slowly within 2 weeks. The associated skin rash is most severe during the first 8 days of infection, but it resolves slowly within 21 days.

Scrub typhus meningitis in South India--a retrospective study

Background

Scrub typhus is prevalent in India although definite statistics are not available. There has been only one study on scrub typhus meningitis 20 years ago. Most reports of meningitis/meningoencephalitis in scrub typhus are case reports

Methods

A retrospective study done in Pondicherry to extract cases of scrub typhus admitted to hospital between February 2011 and January 2012. Diagnosis was by a combination of any one of the following in a patient with an acute febrile illness- a positive scrub IgM ELISA, Weil-Felix test, and an eschar. Lumbar puncture was performed in patients with headache, nuchal rigidity, altered sensorium or cranial nerve deficits.

Results

Sixty five cases of scrub typhus were found, and 17 (17/65) had meningitis. There were 33 males and 32 females. Thirteen had an eschar. Median cerebrospinal fluid (CSF) cell count, lymphocyte percentage, CSF protein, CSF glucose/blood glucose, CSF ADA were 54 cells/µL, 98%, 88 mg/dL, 0.622 and 3.5 U/mL respectively. Computed tomography was normal in patients with altered sensorium and cranial nerve deficits. Patients with meningitis had lesser respiratory symptoms and signs and higher urea levels. All patients had received doxycycline except one who additionally received chloramphenicol.

Conclusion

Meningitis in scrub typhus is mild with quick and complete recovery. Clinical features and CSF findings can mimic tuberculous meningitis, except for ADA levels. In the Indian context where both scrub typhus and tuberculosis are endemic, ADA and scrub IgM may be helpful in identifying patients with scrub meningitis and in avoiding prolonged empirical antituberculous therapy in cases of lymphocytic meningitis.

Scrub typhus: surveillance, clinical profile and diagnostic issues in Shandong, China

To elucidate the epidemic status, clinical profile, and current diagnostic issues of scrub typhus in Shandong Province, we analyzed the surveillance data of scrub typhus from 2006 to 2011 and conducted a hospital-based disease survey in 2010. Scrub typhus was clustered in mountainous and coastal areas in Shandong Province, with an epidemic period from September to November. The most common manifestations were fever (100%), eschar or skin ulcer (86.3%), fatigue (71.6%), anorexia (71.6%), and rash (68.6%). Predominant complications included bronchopneumonia, toxic hepatitis, and acute cholecystitis in 21.6%, 3.9%, and 2.9% of the cases, respectively. Severe complications including toxic myocarditis, heart failure, pneumonedema, pleural effusion, and emphysema were first reported in Shandong. Missed and delayed diagnosis of scrub typhus was common in local medical institutions. Alarm should be raised for changes of clinical features and current diagnostic issues of scrub typhus in newly developed endemic areas.

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.

A case series of spotted fever rickettsiosis with neurological manifestations in Sri Lanka

BACKGROUND

Spotted fever group (SFG) rickettsial infections are increasingly detected in Sri Lanka. We describe 17 patients with SFG who developed neurological manifestations.

METHODS

The cases were studied prospectively from 2008 at the Teaching Hospital, Peradeniya. An immunofluorescent antibody assay (IFA) was used to confirm the diagnosis.

RESULTS

All had an IFA IgG titer ranging from 1/64 to 1/4096 and a positive IFA IgM titer against Rickettsia conorii antigen; in 10 (59%) cases the IgG titers were ≥ 1/256 (definitive cases). The median age of the patients was 62 years (range 26-82 years); 10 were male and seven female. The median duration of fever was 12 days (range 4-35 days). Neurological manifestations on admission were drowsiness or confusion in 14 (82%) and a semi-comatose state in three (18%). Rigidity of the limbs occurred in 14 (82%), bradykinesia and resting tremors in 12 (71%), which persisted after defervescence, neck stiffness in seven (42%), weakness of the limbs in five (29%), deafness in two (12%), and stupor in three (18%). Electroencephalograms in three (18%) showed generalized slow waves. Cerebrospinal fluid examination showed a cellular reaction, predominantly lymphocytes, in three cases. Two patients died (fatality rate 12%).

CONCLUSION

We have documented for the first time the neurological features of SFG rickettsioses in the Central Province, Sri Lanka. These were predominantly extrapyramidal features in patients of older age.

Dengue fever-like illnesses: how different are they from each other?

In tropical countries and possibly elsewhere, dengue fever can be confused with other common tropical infections like enteric fever, leptospirosis, typhus fever, malaria, etc. Many of these illnesses can present in significant numbers after rains, and because of similar early presentations, can cause confusion in decision-making. With global warming, these diseases can assume significant proportions even in non-endemic areas. Identifying these illnesses in a non-immune returning traveller is equally challenging. Recognition of these diseases is important to diagnose them and treat them early, in order to avoid potentially fatal complications. This review is an attempt to highlight important clinical and laboratory differences among dengue fever-like illnesses.

The clinical differences between dengue and scrub typhus with acute respiratory failure in southern Taiwan

Background

For both dengue and scrub typhus, acute respiratory failure (ARF) is a serious complication. The present study was carried out in order to investigate the clinical courses and outcomes of adult dengue and scrub typhus patients with ARF, and to identify the clinical differences between adult dengue and scrub typhus patients with ARF.

Methods

We conducted a retrospective study of the serologically confirmed adult dengue or scrub typhus patients admitted between 1998 and 2008 at Kaohsiung Chang Gung Memorial Hospital. A total of 980 dengue and 102 scrub typhus adult patients were included in our study.

Results

Eighteen of the 980 adult dengue patients and 8 of the 102 adult scrub typhus patients had ARF. There were significant differences that existed for eschar (P = 0.001; dengue 0%; scrub 62.5%), cough (P = 0.016; dengue 55.6%; scrub typhus 100%), white blood cell (WBC) count [P = 0.026; dengue 7.40 ± 5.74; scrub typhus 11.84 ± 4.95 (×10³/μL)], platelet count [P = 0.008; dengue 42.2 ± 33.9; scrub typhus 104.1 ± 93.3 (×10⁹/L)], prothrombin time (PT) [P = 0.007; dengue 12.82 ± 1.36; scrub typhus 10.74 ± 0.98 (s)], activated partial thromboplastin time (APTT) [P = 0.002; dengue 50.81 ± 10.08; scrub typhus 37.44 ± 4.06 (s)], blood urea nitrogen (BUN) [P < 0.001; dengue 64.6 ± 43.2; scrub typhus 20.9 ± 9.1 (mg/dL)], creatinine [P < 0.001; dengue 3.77 ± 3.37; scrub typhus 1.05 ± 0.37 (mg/dL)], admission day (A-day) [P = 0.027; dengue 2.9 ± 1.3; scrub typhus 5.4 ± 2.6 (days)], and ventilator duration [P = 0.022; dengue 9.4 ± 14.0; scrub typhus 14.8 ± 10.4 (days)] between both groups.

Conclusions

This study provides relatively rare data regarding the clinical differences between adult dengue and scrub typhus patients with ARF.

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.

Chest radiographic presentation in patients with scrub typhus

We conducted a retrospective study of the adult patients (age ≥18 years) with serologically confirmed scrub typhus admitted between January 1998 and December 2009 at Kaohsiung Chang Gung Memorial Hospital. There were 63 adult scrub typhus patients with chest radiographic examinations. A total of 147 chest radiographs were obtained and reviewed. The most frequent abnormal findings in this study were parenchymal infiltration with bilateral and lower lung predilection. The distribution of abnormal chest radiographs was observed more than 50% during the first week. Furthermore, the progressive change was frequently observed during the first week. There is a significant correlation among laboratory findings, clinical course, and outcome. Chest radiography may be a complementary tool to evaluate the clinical course of scrub typhus and chest radiographic examinations should be taken during the first week after the onset of illness.

Differences in clinical features according to Boryoung and Karp genotypes of Orientia tsutsugamushi

Background

Scrub typhus is an infectious disease caused by Orientia tsutsugamushi. The differences in virulence of O. tsutsugamushi prototypes in humans are still unknown. We investigated whether there are any differences in the clinical features of the Boryoung and Karp genotypes.

Methodology/Principal Findings

Patients infected with O. tsutsugamushi, as Boryoung and Karp clusters, who had visited 6 different hospitals in southwestern Korea were prospectively compared for clinical features, complications, laboratory parameters, and treatment responses. Infected patients in the Boryoung cluster had significantly more generalized weakness, eschars, skin rashes, conjunctival injection, high albumin levels, and greater ESR and fibrinogen levels compared to the Karp cluster. The treatment response to current antibiotics was significantly slower in the Karp cluster as compared to the Boryoung cluster.

Conclusion

The frequency of occurrence of eschars and rashes may depend on the genotype of O. tsutsugamushi.

Evoked response audiometry in scrub typhus: prospective, randomised, case-control study

OBJECTIVE

To investigate the hypothesis of cochlear and retrocochlear damage in scrub typhus, using evoked response audiometry.

STUDY DESIGN

Prospective, randomised, case-control study.

METHODS

The study included 25 patients with scrub typhus and 25 controls with other febrile illnesses not known to cause hearing loss. Controls were age- and sex-matched. All subjects underwent pure tone audiometry and evoked response audiometry before commencing treatment.

RESULTS

Six patients presented with hearing loss, although a total of 23 patients had evidence of symmetrical high frequency loss on pure tone audiometry. Evoked response audiometry found significant prolongation of absolute latencies of wave I, III, V, and wave I-III interpeak latency. Two cases with normal hearing had increased interpeak latencies. These findings constitute level 3b evidence.

CONCLUSION

Findings were suggestive of retrocochlear pathology in two cases with normal hearing. In other patients, high frequency hearing loss may have led to altered evoked response results. Although scrub typhus appears to cause middle ear cochlear and retrocochlear damage, the presence of such damage could not be fully confirmed by evoked response audiometry.

Contribution of rickettsioses in Sri Lankan patients with fever who responded to empirical doxycycline treatment

Twenty-eight febrile Sri Lankan patients with undiagnosed fever for 7 days after hospital admission, who responded to empirical treatment with doxycycline, were retrospectively investigated using microimmunofluorescence assay to verify whether they had rickettsial infection. Eleven (39%) patients were confirmed as having spotted fever group rickettsioses and 10 (36%) as having Orientia tsutsugamushi. Seven were negative for all tests. This suggests that greater use of doxycycline appears justified for patients with undiagnosed fever in settings where rickettsial diseases are endemic or re-emerging with inadequate diagnostic facilities.

Reversible hearing impairment: delayed complication of murine typhus or adverse reaction to azithromycin?

Delayed and reversible hearing loss occurred in a 55-year-old male patient with murine typhus infection. The patient had the initial symptoms of headache, fever and chills, followed by the occurrence of bilateral hearing loss on day 9 from fever onset. Murine typhus was diagnosed with a high IgM titre by indirect immunofluorescence assay. After treatment with azithromycin and prednisolone, the fever and other symptoms subsided gradually and bilateral hearing loss improved 3 weeks later. Though an adverse reaction to azithromycin could not be ruled out, delayed onset of hearing loss was more likely a complication of murine typhus, mainly because the hearing loss did not occur during the azithromycin usage period. Although hearing loss due to murine typhus is rare, clinicians should be alert to the existence of such a delayed complication.

Acute sensorineural hearing loss and severe otalgia due to scrub typhus

BACKGROUND

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi.

CASE PRESENTATIONS

We encountered a patient with sensorineural hearing loss complicating scrub typhus, and three patients with scrub typhus who complained of otalgia, which was sudden onset, severe, paroxysmal, intermittent yet persistent pain lasting for several seconds, appeared within 1 week after the onset of fever and rash. The acute sensorineural hearing loss and otalgia were resolved after antibiotic administration.

CONCLUSION

When patients in endemic areas present with fever and rash and have sensorineural hearing loss or otalgia without otoscopic abnormalities, clinicians should suspect scrub typhus and consider empirical antibiotic therapy.

Scrub typhus in patients with liver cirrhosis: a preliminary study

Scrub typhus is a potentially fatal infectious disease caused by the organism Orientia tsutsugamushi. However, to date, there have been no clearly identified determinants or reports published on the clinical severity of scrub typhus in liver cirrhosis (LC) patients. This study was carried out by retrospectively reviewing medical records accumulated over 7 years at a tertiary hospital. Sixteen patients of 160 had underlying LC, and they were defined as 'cases'; those without underlying LC were defined as 'controls'. The duration of hospital stay (23.0 +/- 24.8 days for cases and 6.8 +/- 7.0 days for controls, p 0.020) and APACHE II scores (14.1 +/- 6.0 for cases and 7.2 +/- 4.6 for controls, p <0.001) were, respectively, significantly longer and significantly higher on admission in the cases than in the controls. Surprisingly, hospital mortality was significantly higher in the cases than in the controls (31.3% and 3.5%, respectively, p 0.001). Among the LC group, the highest Model for End-stage Liver Disease (MELD) score during hospitalization (MELD-Peak) (p 0.024) and the lowest blood sodium concentration during hospitalization (MELD-Na-Lo) (p 0.003) were higher in fatal cases than in the survivors (MELD-Na-to). Physicians should be aware of an adverse relationship between LC and scrub typhus, and patients with LC should be advised to avoid exposure to O. tsutsugamushi, particularly in endemic areas and epidemic seasons.