• Health policy
• One health
• Structural violence of policies
• Zoonoses

• control program
• diagnosis
• disease management
• implementation research
• protocol
• public health
• scrub typhus

• Scrub Typhus/diagnosis
• Humans
• India
• Early Diagnosis
• Orientia tsutsugamushi/isolation & purification
• Public Health

• Indian Council of Medical Research

• Orientia tsutsugamushi
• Northeast India
• clinical presentations
• co-infections
• diagnosis
• entomology
• genetic diversity
• scrub typhus

• Animals
• Humans
• Scrub Typhus/diagnosis
• Scrub Typhus/epidemiology
• Scrub Typhus/microbiology
• Orientia tsutsugamushi
• Trombiculidae/microbiology
• Disease Reservoirs
• India/epidemiology

• ecology
• microbiology
• climate sciences
• environmental sciences
• risk factors

• Humans
• Aged
• Scrub Typhus/epidemiology
• India/epidemiology
• Retrospective Studies
• Prospective Studies
• Risk Factors
• Orientia tsutsugamushi

• Animals
• Humans
• India/epidemiology
• Prevalence
• Rickettsia/isolation & purification
• Rickettsia/immunology
• Rickettsia Infections/epidemiology
• Rickettsia Infections/diagnosis
• Scrub Typhus/epidemiology
• Scrub Typhus/diagnosis
• Ticks/microbiology

• Kashmir Valley
• Rickettsial
• Weil Felix
• seroprevalence

• Female
• Humans
• Seroepidemiologic Studies
• India/epidemiology
• Rickettsia Infections/epidemiology
• Scrub Typhus/epidemiology
• Scrub Typhus/diagnosis
• Rickettsia

• prediction
• random forest model
• risk factors
• scrub typhus

• 202102080035 Science and Technology Plan Grant of Guangzhou
• 2021-2023-12 Key Project of Medicine Discipline of Guangzhou
• 202102100001 Basic Research Project of Key Laboratory of Guangzhou

• ELISA
• IgG
• IgM
• Odisha
• scrub typhus

• IgM ELISA
• In-house PCR
• O.tsutsugamushi
• Scrub typhus

• Genotype
• Humans
• Immunoglobulin M
• Orientia
• Orientia tsutsugamushi
• Phylogeny
• Polymerase Chain Reaction
• Prospective Studies
• Scrub Typhus/diagnosis
• Scrub Typhus/epidemiology
• Scrub Typhus/microbiology

Background and objective

Scrub typhus (ST) is a rickettsial infection caused by Orientia tsutsugamushi, which is transmitted by the bite of the larval stage (chiggers) of trombiculid mites. Although it presents as an acute undifferentiated febrile illness (AUFI), its course can be complicated with acute respiratory distress syndrome, acute kidney injury (AKI), myocarditis, meningoencephalitis, hepatitis, multi-organ dysfunction syndrome (MODS), and ultimately death. This study aimed to evaluate the epidemiological features, clinical profile, laboratory features, and clinical outcomes of cases of scrub typhus and identify the predictors of disease severity.

Methods and materials

This study is a retrospective observational study that included confirmed cases of scrub typhus admitted in the medical wards and critical care unit (CCU) of Tata Main Hospital (TMH) from January 1, 2019, to December 31, 2021. The case records of patients were analyzed for demographic characteristics, clinical features, treatment, and outcomes, which included length of stay (LOS), complications, and mortality. The required odds ratio (OR) was calculated, univariate and binary regression analyses were done, and a p-value of <0.05 was considered statistically significant.

Results

Of the 42 confirmed cases, 38.1% were males and 61.9% were females. The average age of male patients was 12.6 ± 11.2 years, while that of females was 22 ± 19.3 years. Of the patients, 64.3% were in the age group of 1-20 years. The clinical manifestations in descending order were fever (71.2%), skin rash (19.1%), cough (16.7%), vomiting (28.6%), altered sensorium (23.8%), abdominal pain (23.8%), loose stools (14.3%), seizures (14.3%), anasarca (9.7%), breathlessness (9.7%), and melena (7.1%). Eschar was noted in 38.1% of patients. Swelling of the body (6.7%) and lymphadenopathy (10%) were seen exclusively in children. The common laboratory abnormalities observed were leukocytosis in 34.3% of cases; thrombocytopenia in 68.8% of cases, of which 25% of patients had platelets < 50,000/mm³; and transaminitis in 87.5% of cases. The ratio of AST/ALT of more than one was seen in 89.3% of patients, while it was less than one in 10.7% of patients. The average C-reactive protein (CRP) level was 10.9 ± 6.3 mg/dL. The complications noted were acute respiratory distress syndrome (ARDS) (16.7%), meningoencephalitis (21.4%), septic shock (14.3%), capillary leak syndrome (26.2%), thrombocytopenia (68.8%), transaminitis (87.5%), myocarditis (4.8%), disseminated intravascular coagulation (2.4%), and hypocalcemia (11.9%). The average length of stay (LOS) was 8.1 ± 4.2 days. Twenty-four (57.2%) patients required transfer to the critical care unit (CCU) for managing various complications. There was no mortality in this series, giving rise to the case fatality ratio (CFR) of 0.

Conclusion

Scrub typhus is a reemerging cause of acute febrile illness. The highest number of cases were found during the post-monsoon period and in those with rural backgrounds. It presents with varying clinical manifestations with or without eschar. Hence, a high degree of suspicion along with a thorough clinical examination is needed to diagnose this condition. The disease responds dramatically to doxycycline. One must be aware of its complications and atypical presentations, as a timely diagnosis can reduce the morbidity and mortality associated with this disease.

• children
• complications
• mortality
• orientia tsutsugamushi
• rickettsia
• scrub typhus

• Adolescent
• Adult
• Child
• Cross-Sectional Studies
• Enzyme-Linked Immunosorbent Assay
• Female
• Fever/epidemiology
• Fluorescent Antibody Technique
• Humans
• India/epidemiology
• Logistic Models
• Male
• Middle Aged
• Multivesicular Bodies
• Orientia tsutsugamushi/genetics
• Orientia tsutsugamushi/isolation & purification
• Polymerase Chain Reaction
• Scrub Typhus/epidemiology
• Young Adult

• Acute encephalitis syndrome
• Orientia tsutsugamushi
• community-based
• scrub typhus
• seroincidence
• seroprevalence
• serosurvey

• Acute Febrile Encephalopathy/epidemiology
• Animals
• Epidemics
• Female
• India/epidemiology
• Male
• Orientia
• Orientia tsutsugamushi
• Scrub Typhus/epidemiology
• Seroepidemiologic Studies

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

• Acute kidney injury
• atrial fibrillation
• scrub typhus

Scrub typhus is a mite-borne acute febrile illness caused by Orientia. tsutsugamushi, a zoonotic bacterial infection common in the region known as the tsutsugamushi triangle. This study aims to determine the seroprevalence, seasonal variation, and risk factors of scrub typhus among the acute febrile illness patients attending different hospitals of central Nepal. Blood samples were collected from hospitalized patients of acute febrile illness suspected of scrub typhus infection attending different hospitals of central Nepal from April 2017 to March 2018. The IgM antibody to Orientia tsutsugamushi was detected by using the Scrub Typhus Detect™ Kit. Among the total cases (1585), 358 (22.58%) were positive for IgM Antibodies. Multivariate analysis identified several risks factors to be significantly associated with the scrub typhus infection, including gender (female) (odds ratio [OR] = 1.976, p ≤ 0.001, confidence interval [CI] = 1.417–2.756), rural residential location (odds ratio [OR] = 0.431, p = 0.001, confidence interval [CI] = 0.260–0.715), house near grassland (odds ratio [OR] = 3.288, p ≤ 0.001, confidence interval [CI] = 1.935–5.587), and working in the field (odds ratio [OR] = 9.764, p = 0.004, confidence interval [CI] = 2.059–46.315). The study findings indicate scrub typhus infection to be a significant health problem in Nepal. The proper diagnosis of infection cases, timely institution of therapy, public awareness, and vector control are important measures to be taken for the prevention and management of scrub typhus.

• ELISA
• Nepal
• Orientia tsutsugamushi
• scrub typhus

• Acute encephalitis syndrome
• Acute undifferentiated febrile illness
• Leptotrombidium
• Orientia tsutsugamushi
• Scrub typhus

India is a tropical country with a high burden of febrile zoonotic/infectious illnesses, scrub typhus being such a cause with multiple epidemics reported from different regions of the country.

This study was plotted to document the clinical and diagnostic manifestations, treatment, and outcomes of scrub typhus in the sub-Himalayan region of India and to compare the results with other Indian and Asian studies.

This was a retrospective observational study involving collection of data for 54 IgM ELISA-confirmed in-patient cases of scrub typhus at a tertiary care institute in Uttarakhand, India, from their case records.

The majority of patients were from rural background. Housewives constituted 28 (51.85%) patients. The most common symptoms were due to involvement of gastrointestinal tract in the form of abdominal pain in 39 (72.22%) and vomiting in 29 (53.7%) patients. Central nervous system involvement in the form of altered sensorium in 14 (25.9%) patients and pulmonary involvement as cough in 28 (51.85%) patients was observed. An eschar was found in 7 (12.96%) patients and upper eyelid edema in 40 (74.07%) patients. The most common laboratory abnormality documented was elevation of liver transaminases (aspartate aminotransferase > alanine aminotransferase), 40 (74.07%), and blood urea levels, 47 (87.03%). There was no difference in the clinical presentation, severity, or mortality in pregnant females when compared with nonpregnant females. One (1.45% mortality) died in our study.

Scrub typhus is an important cause of acute febrile illness with variable, often nonspecific and multisystem involvement. Early recognition and antibiotic administration are the key to reduce complications and mortality, especially for a primary care physician.

• Communicable diseases
• Orientia tsutsugamushi
• rickettsia
• scrub typhus
• zoonoses

• ERD/NERD ratio
• Eschar
• Eschar-related rickettsial disease (ERD)
• Non-eschar rickettsial disease (NERD)
• Rickettsioses

• Adult
• Animals
• Arthropod Vectors
• Boutonneuse Fever/diagnosis
• Diagnosis, Differential
• Female
• Fever/diagnosis
• Humans
• Male
• Middle Aged
• Necrosis/etiology
• Rickettsia
• Rickettsia Infections/diagnosis
• Rickettsia Infections/pathology
• Scrub Typhus/diagnosis
• Skin/pathology
• Spotted Fever Group Rickettsiosis/diagnosis
• Travel-Related Illness

• Orientia
• Orientia tsutsugamushi
• chiggers
• mites
• rickettsia
• scrub typhus

• A1230 Military Infectious Diseases Research Program

Scrub typhus is a re-emerging mite-borne rickettsiosis, which continues to be underdiagnosed, with lethal consequences. The present study was conducted to determine the seasonality, clinical presentation and predictors of mortality in patients with scrub typhus at a tertiary care teaching hospital in northern India.

Scrub typhus was suspected in patients attending the hospital as per the standard case definition and serological evidence was obtained by performing an IgM ELISA.

A total of 284 patients with scrub typhus from urban and rural areas were seen, predominantly from July to November. The most common clinical presentation was a bilateral community-acquired pneumonia (CAP), which resembled pneumonia due to atypical pathogens and often progressed to acute respiratory distress syndrome (ARDS). An acute undifferentiated febrile illness (AUFI) or a febrile illness associated with altered sensorium, aseptic meningitis, shock, abdominal pain, gastrointestinal bleeding or jaundice was also seen. Eschars were seen in 17 per cent of patients, and thrombocytopenia, transaminitis and azotaemia were frequent. There were 24 deaths (8.5%) caused predominantly by ARDS and multi-organ dysfunction. The mortality in patients with ARDS was high (37%). ARDS [odds ratio (OR)=38.29, 95% confidence interval (CI): 9.93, 147.71] and acute kidney injury (OR=8.30, 95% CI: 2.21, 31.21) were the major predictors of death.

The present findings indicate that scrub typhus may be considered a cause of CAP, ARDS, AUFI or a febrile illness with multisystem involvement, in Uttarakhand and Uttar Pradesh, especially from July to November. Empiric therapy of CAP may include doxycycline or azithromycin to ensure coverage of underlying unsuspected scrub typhus.

• Asia/epidemiology
• Humans
• Neglected Diseases/epidemiology
• Neglected Diseases/microbiology
• Neglected Diseases/prevention & control
• Orientia tsutsugamushi/isolation & purification
• Scrub Typhus/epidemiology
• Scrub Typhus/microbiology
• Scrub Typhus/parasitology
• Scrub Typhus/prevention & control

Scrub typhus is a vector-borne zoonotic infection caused by Orientia tsutsugamushi. Local epidemiology of the circulating serotypes of scrub typhus is not available from most parts of India. We conducted this study for the diagnosis of scrub typhus using IgM ELISA and to detect O. tsutsugamushi serotypes circulating in southern Andhra Pradesh, India.

Samples were collected from patients clinically suspected to have scrub typhus and were subjected to IgM ELISA to measure IgM antibodies against O. tsutsugamushi. Nested polymerase chain reaction (PCR) was performed targeting strain-specific regions in ELISA-positive samples.

Of a total of 663 samples, 258 (38.91%) were found to be positive by IgM ELISA. Serotypes could be detected in 230 (34.69%) samples only. Only two serotypes, Karp and Kawasaki, were found in the serum samples, with the former being predominant. The dual infection of Karp and Kawasaki serotypes was found in seven patients. Other serotypes such as Gilliam, Kuroki and Kato were not detected in the samples.

The nested PCR products proved useful in presumptively identifying the endemic O. tsutsugamushi serotypes. The present study could be significant in understanding scrub typhus epidemiology in this region.

• Hospital
• India
• Longitudinal
• Mortality
• Multiple Organ Dysfunction Syndrome (MODS)
• Scrub typhus

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.

• orientia
• scrub typhus
• trombiculid mite
• 56-kda antigen
• serotypes
• intracellular
• diagnosis
• eschar
• epidemiology
• treatment

• IgM ELISA
• Indirect immunofluorescence test
• Orentia tsutsugamushi
• Rickettsia
• Weil Felix Test

• Children
• India
• Rural
• Scrub typhus

• IgM ELISA
• Orientia tsutsugamushi
• Weil-Felix test

Clarifying local antigenic diversity is critical for development of region-specific vaccines and diagnostics.

Scrub typhus, an acute febrile illness that is widespread in the Asia-Pacific region, is caused by the bacterium Orientia tsutsugamushi, which displays high levels of antigenic variation. We conducted an investigation to identify the circulating genotypes of O. tsutsugamushi in 3 scrub typhus–endemic geographic regions of India: South India, Northern India, and Northeast India. Eschar samples collected during September 2010–August 2012 from patients with scrub typhus were subjected to 56-kDa type-specific PCR and sequencing to identify their genotypes. Kato-like strains predominated (61.5%), especially in the South and Northeast, followed by Karp-like strains (27.7%) and Gilliam and Ikeda strains (2.3% each). Neimeng-65 genotype strains were also observed in the Northeast. Clarifying the genotypic diversity of O. tsutsugamushi in India enhances knowledge of the regional diversity among circulating strains and provides potential resources for future region-specific diagnostic studies and vaccine development.

• Adult
• DNA, Bacterial/genetics
• Female
• Genetic Variation
• Genotype
• Humans
• India/epidemiology
• Male
• Middle Aged
• Molecular Epidemiology
• Molecular Sequence Data
• Molecular Typing
• Orientia tsutsugamushi/genetics
• Phylogeny
• Phylogeography
• Scrub Typhus/epidemiology
• Scrub Typhus/microbiology
• Sequence Analysis, DNA

• T32 AI007438 NIAID NIH HHS
• T32 AI055412 NIAID NIH HHS

Scrub typhus infection is an important cause of acute undifferentiated fever in South East Asia. The clinical picture is characterized by sudden onset fever with chills and non-specific symptoms that include headache, myalgia, sweating and vomiting. The presence of an eschar, in about half the patients with proven scrub typhus infection and usually seen in the axilla, groin or inguinal region, is characteristic of scrub typhus. Common laboratory findings are elevated liver transaminases, thrombocytopenia and leukocytosis. About a third of patients admitted to hospital with scrub typhus infection have evidence of organ dysfunction that may include respiratory failure, circulatory shock, mild renal or hepatic dysfunction, central nervous system involvement or hematological abnormalities. Since the symptoms and signs are non-specific and resemble other tropical infections like malaria, enteric fever, dengue or leptospirosis, appropriate laboratory tests are necessary to confirm diagnosis. Serological assays are the mainstay of diagnosis as they are easy to perform; the reference test is the indirect immunofluorescence assay (IFA) for the detection of IgM antibodies. However in clinical practice, the enzyme-linked immuno-sorbent assay is done due to the ease of performing this test and a good sensitivity and sensitivity when compared with the IFA. Paired samples, obtained at least two weeks apart, demonstrating a ≥ 4 fold rise in titre, is necessary for confirmation of serologic diagnosis. The mainstay of treatment is the tetracycline group of antibiotics or chloramphenicol although macrolides are used alternatively. In mild cases, recovery is complete. In severe cases with multi-organ failure, mortality may be as high as 24%.

• Rickettsia
• Diagnosis
• Management
• Outcome
• Multi-organ failure

Scrub typhus is rampant in northern, eastern, and southern India. Central nervous system involvement in the form of meningitis or meningoencephalitis is common in scrub typhus. As specific laboratory methods remain inadequate or inaccessible in developing countries, prompt diagnosis is often difficult.

The aim of this study was to characterize neurological complications in scrub typhus from northeastern region of India.

We did a prospective study of scrub meningoencephalitis at North Eastern Indira Gandhi Regional Institute of Medical Sciences among patients admitted to hospital between October 2009 and November 2011. The diagnosis was made based on the clinical pictures, presence of an eschar, and a positive Weil–Felix test (WFT) with a titer of >1:160 and if required a positive scrub IgM enzyme-linked immunosorbent assay. Lumbar puncture was performed in patients with headache, nuchal rigidity, altered sensorium or cranial nerve deficits, and magnetic resonance imaging (MRI) brain performed if needed.

Twenty-three patients of scrub typhus meningitis that were serologically confirmed were included in the study. There were 13 males and 10 females. Fever ≥1 week was the most common manifestation (39.1%). Interestingly, none had an eschar. Median cerebrospinal fluid (CSF) cell count, lymphocyte percentage, CSF protein, CSF glucose/blood glucose, CSF ADA were 17 cells/μL, 90%, 86 mg/dL, 0.6605 and 3.6 U/mL, respectively. All patients were treated with doxycycline. There was no mortality in our study.

Absence of Eschar does not rule out scrub typhus. Clinical features and CSF findings can mimic tuberculous meningitis so misdiagnosis may lead to unwarranted prolonged empirical antituberculous therapy in cases of lymphocytic meningoencephalitis. Delay in treatment can be potentially fatal. WFT still serves as a useful and affordable diagnostic tool for this disease in resource-poor countries.

• Eschar
• Meningoencephalitis
• Orientia tsutsugamushi
• Scrub Typhus
• Weil–Felix Test

• scrub typhus
• meteorological variables
• risk factor
• correlation
• early warning

• Animals
• Arthropod Vectors/microbiology
• China/epidemiology
• Humans
• Incidence
• Risk Factors
• Scrub Typhus/epidemiology
• Scrub Typhus/microbiology
• Trombiculidae/microbiology
• Weather

• Orientia tsutsugamushi
• outbreaks
• scrub typhus

The world of microbes on our planet is vast and diverse. This includes the normal bacterial flora present on the skin and mucous membranes of humans. The human microbiome project (HMP) was launched by NIH in 2007 as a part of a road map for medical research. The HMP serves as a template for researchers who are studying more than 1,000 microbial genomes with a focus on their role in health and disease. The study samples have been derived from five human body regions that are known to be inhabited by microbial flora. These include the gastrointestinal tract, female urogenital tract, mouth, nose, and skin. The techniques being used include finger printing, sequencing, dynamic range, and comparison of multiple samples. It is now well accepted that there are more microbial cells than human cells in the human body. Just the gastrointestinal tract harbors more than tenfold microbial cells than the number of human cells in the entire body. The understanding of the relationship between microbes and humans is at best rudimentary at this point in time. Similarly, the relationship between humans and microbes in the environment and environmental surfaces is poorly understood except for a few pathogenic microbes.