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Abstract
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.
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Abstract
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.
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Affiliation(s)
- Ashwani K Sood
- Department of Pediatrics and Adolescent Medicine, Indira Gandhi Medical College, Shimla, India.
| | - Amit Sachdeva
- Department of Community Medicine, Indira Gandhi Medical College, Shimla, India
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Rajapakse S, Weeratunga P, Sivayoganathan S, Fernando SD. Clinical manifestations of scrub typhus. Trans R Soc Trop Med Hyg 2018; 111:43-54. [PMID: 28449088 DOI: 10.1093/trstmh/trx017] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 04/11/2017] [Indexed: 01/10/2023] Open
Abstract
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.
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Affiliation(s)
- Senaka Rajapakse
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
| | - Praveen Weeratunga
- University Medical Unit, National Hospital, Regent Street, Colombo 08, Sri Lanka
| | - Sriharan Sivayoganathan
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
| | - Sumadhya Deepika Fernando
- Department of Parasitology, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 08, Sri Lanka
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Jung LY, Jeon M, Choi SH, Hwang JH, Lee CS, Rhee KS. Relative Bradycardia in Scrub Typhus. Am J Trop Med Hyg 2017; 97:1316-1318. [PMID: 29016300 DOI: 10.4269/ajtmh.17-0259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
To investigate the relationship between heart rate and temperature, we examined 493 febrile patients with documented disease. These patients were diagnosed serologically and analyzed retrospectively: 337 (68.4%) responded to fever with increased heart rate < 10 beats/minute/°C (relative bradycardia [RB]), and 156 patients had a heart rate response ≥ 10 beats/minute/°C (general heart rate increase [GHRI]). The RB group had a higher median resting heart rate and lower heart rate at maximum temperature than the GHRI group. Despite differences in heart rate response, no significant differences were seen in clinical outcomes (acute kidney injury, systemic inflammatory response syndrome (SIRS), and death). We concluded that most patients with scrub typhus presented with RB. In scrub typhus infection, RB can be included as one of the clinical features for differential diagnosis from other infectious diseases.
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Affiliation(s)
- Lae Young Jung
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Mir Jeon
- Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Seung Hee Choi
- Industrial Design, Chonbuk National University, Jeonju, Republic of Korea
| | - Joo-Hee Hwang
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Chang-Seop Lee
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Kyoung-Suk Rhee
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
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Jung LY, Yoon JY, Song SK, Lee CS. Persistent Sick Sinus Syndrome in Scrub Typhus. Am J Trop Med Hyg 2017; 96:1005-1006. [PMID: 28500798 PMCID: PMC5417185 DOI: 10.4269/ajtmh.16-0909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Lae-Young Jung
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Ji-Young Yoon
- Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Soo-Kyeong Song
- Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
| | - Chang-Seop Lee
- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea.,Department of Internal Medicine, Chonbuk National University, Jeonju, Republic of Korea
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Peter JV, Sudarsan TI, Prakash JAJ, Varghese GM. Severe scrub typhus infection: Clinical features, diagnostic challenges and management. World J Crit Care Med 2015; 4:244-250. [PMID: 26261776 PMCID: PMC4524821 DOI: 10.5492/wjccm.v4.i3.244] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/27/2015] [Accepted: 04/09/2015] [Indexed: 02/06/2023] Open
Abstract
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%.
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Iqbal N, Titus S, Basheer A, George S, George S, Mookkappan S, Nair S, Alexander T, Ramdas A, Periyasamy S, Anitha P, Kanungo R. Polyarthritis and massive small bowel bleed: An unusual combination in scrub typhus. Australas Med J 2015; 8:89-95. [PMID: 25870659 PMCID: PMC4385814 DOI: 10.4066/amj.2015.2299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Scrub typhus is an acute febrile illness caused by the intracellular parasite Orientia tsutsugamushi. Although most cases present with mild symptoms and signs and recover spontaneously, some cases can be severe with multi-organ dysfunction and a protracted course, which may be fatal if left untreated. Apart from fever and constitutional symptoms, atypical presentations allow this disease to mimic several common conditions. We report a case of scrub typhus in an 18-year-old male who presented with severe polyarthritis involving all large joints and a massive lower gastrointestinal bleed from ulcers in the terminal ileum, secondary to vasculitis in the small bowel. This combination of pathologies has not previously been reported in cases of scrub typhus. The patient improved following surgical intervention and specific anti-rickettsial therapy with azithromycin.
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Affiliation(s)
- Nayyar Iqbal
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Solomon Titus
- Department of General Surgery, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Aneesh Basheer
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Sanjoy George
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Sanjoy George
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Sudhagar Mookkappan
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Shashikala Nair
- Department of Microbiology, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Thomas Alexander
- Department of Gastroenterology, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Anita Ramdas
- Department of Pathology, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Sivakumar Periyasamy
- Department of General Medicine, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Patricia Anitha
- Department of Microbiology, Pondicherry Institute of Medical Sciences, Pondicherry, India
| | - Reba Kanungo
- Department of Microbiology, Pondicherry Institute of Medical Sciences, Pondicherry, India
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