Spectrum of cardiac manifestations and its relationship to outcomes in patients admitted with scrub typhus infection

The first case report of acute myocardial infarction in young adult caused by scrub typhus

RATIONALE

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi, a gram-negative intracellular bacterium and endemic in Asia-Pacific area. Acute myocardial infarction after Oricntia tsutsugamushi infection was rarely reported, and young adult was not reported.

PATIENT CONERNS

A 33-year-old man came to the emergency complained with chest tightness and fever for 4 days.

DIAGONOSES

After Weil-Felix agglutination test (titer 1:160) twice, scrub typhus was diagnosed.

INTERVENTIONS

After treating with a hormonotherapy, antibiotic and ventilator-assisted ventilation, his chest tightness was mild lessened with normal breath and body temperature. However, an emergent coronary angiography performed unnormal, then a percutaneous coronary intervention was realized with the implantation of a stent.

OUTCOMES

After the surgeon, his chest tightness was totally released, and he was discharged.

LESSONS

Our case was the first report of young adult acute myocardial infarction after O tsutsugamushi infection and we tried to figure out the potential mechanism and how to deal with.

Multifaceted realities of scrub typhus: a case series from southern India

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi, a Gram-negative bacillus, commonly occurring in the Asia-Pacific region. It is transmitted to humans by the bite of an infected Leptotrombidium mite and the bacterium causes endothelial dysfunction resulting in widespread vasculitis and the possible development of thrombocytopenia, meningitis, acute respiratory distress syndrome, and infrequently, myocarditis. Early diagnosis and prompt treatment are crucial in managing scrub typhus. Here, we present four cases of scrub typhus with a comprehensive literature review. This study highlights the significance of considering scrub typhus as a possible diagnosis in patients of all ages from endemic regions who exhibit symptoms such as fever, thrombocytopenia, or transaminitis, even in the absence of typical clinical features. Two cases exhibited the characteristic lesion of eschar at the site of mite feeding. One case involved a middle-aged woman who was diagnosed with typhus-induced myocarditis with left ventricular dysfunction. Another case involved a 23-day-old neonate with poor feeding and seizures, who was diagnosed with late-onset sepsis with meningitis. Scrub typhus was confirmed in all cases using a positive qualitative IgM ELISA. However, it is preferred to use paired (ELISA before and after antibiotic therapy) or quantitative titers for confirmation. Healthcare providers must consider the patient's exposure history and clinical presentation to diagnose and treat scrub typhus promptly.

A Study of the Profile of Scrub Typhus in a Tertiary Care Hospital in Jharkhand: An Underestimated Problem

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.

Scrub typhus: a reemerging infection

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Scrub Typhus and Other Rickettsial Infections

Scrub typhus and other rickettsial infections contribute to 25 - 50% of acute undifferentiated febrile illnesses in endemic regions. Delayed recognition and therapy increase the morbidity and mortality. The constellation of fever with eschar or rash and multisystem involvement should facilitate the diagnosis and initiation of appropriate therapy. The pathological hallmark of rickettsial infections is endothelial infection and inflammation causing vasculitis. Endothelial inflammation results in microvascular dysfunction and increased vascular permeability. Immune and endothelial activation may worsen microvascular dysfunction, predisposing to multi-organ failure. Serology is the mainstay of diagnosis, although false negatives occur early in the disease. Point-of-care rapid diagnostic tests and molecular techniques, such as quantitative polymerase chain reaction (qPCR), can hasten diagnostic processes. Intravenous doxycycline with a loading dose is the most widely used antibiotic in critically ill patients, with azithromycin as a suitable alternative. Early appropriate treatment and organ support can decrease the duration of illness and be life-saving. How to cite this article: Gunasekaran K, Bal D, Varghese GM, et al. Scrub Typhus and Other Rickettsial Infections. Indian J Crit Care Med 2021;25(Suppl 2):S138-S143.

Rickettsioses in Children - A Review

Rickettsial diseases, caused by a variety of obligate intracellular, Gram-negative bacteria from the genera Rickettsia, Orientia, Ehrlichia, Neorickettsia, Neoehrlichia, and Anaplasma are considered some of the most covert emerging and re-emerging diseases. Scrub typhus, murine flea-borne typhus and Indian tick typhus are commonly being reported and during the last decade. Scrub typhus (ST) has emerged as a serious public health problem in India. Rickettsial infections are generally incapacitating and difficult to diagnose; untreated cases have case fatality rates as high as 30-45% with multiple organ dysfunction, if the specific treatment is delayed. Early clinical suspicion, timely diagnosis followed by institution of specific antimicrobial therapy shortens the course of the disease, lowers the risk of complications and reduces morbidity and mortality due to rickettsial diseases. Still there is large gap in our knowledge of Rickettsioses and the vast variability and non-specific presentation of these have often made it difficult to diagnose clinically. The present review describes the epidemiology, clinical manifestations, diagnostic modalities and treatment of Scrub typhus which is a vastly underdiagnosed entity and clinicians should suspect and test for the disease more often.

Scrub typhus in patients with acute febrile illness: a 5-year study from India

BACKGROUND

Scrub typhus was once thought to be a disease of rural origin and was confined to specific pockets in South Asia. Early diagnosis and treatment is extremely important as it is associated with high mortality if left untreated.

AIM

To delineate the clinical and molecular epidemiology of scrub typhus in patients presenting with acute febrile illness from various parts of India.

METHODS

During the study period of 5 years (October 2013 to October 2018), a total of 1742 patients with acute febrile illness <15 days were enrolled after taking informed consent. Patients were diagnosed using IgM Enzyme-linked immunosorbent assay (ELISA) based on the pre-determined region specific cut offs. Patients with positive IgM ELISA were also subjected to IgM Immunofluorescence assay and nested polymerase chain reaction (PCR) assay. The demographic and relevant clinical details of the patients were documented and analyzed.

RESULTS

A total of 210 (12.1%) patients were diagnosed with scrub typhus. Of these, nested PCR was positive in only 85 patients. Sequencing and phylogenetic analysis showed that the predominant circulating genotypes were Gilliam and Karp. On multivariate analysis, acute respiratory distress syndrome, myocarditis, encephalitis/encephalopathy, jaundice and splenomegaly were significantly more common in those patients who were diagnosed with scrub typhus. A total of 14 patients diagnosed with scrub typhus succumbed to the illness.

CONCLUSION

Patients with fever, headache, pulmonary manifestations, CNS manifestations, myocarditis, transaminitis or thrombocytopenia presenting in the monsoon and post-monsoon season should be evaluated for scrub typhus irrespective of the geographical location in India.