DOI: 10.1148/rg.271065074
RadioGraphics 2007;27:161-172
© RSNA, 2007
Scrub Typhus: Clinical, Pathologic, and Imaging Findings1
Yeon Joo Jeong, MD,
Suk Kim, MD,
Yeh Dae Wook, MD,
Jun Woo Lee, MD,
Kun-Il Kim, MD and
Sun Hee Lee, MD
1 From the Department of Diagnostic Radiology (Y.J.J., S.K., Y.D.W., J.W.L., K.I.K.) and Division of Infectious Medicine, Department of Medicine (S.H.L.), Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Pusan National University, 1-10 Ami-Dong, Seo-gu, Pusan 602-739, Republic of Korea. Presented as an education exhibit at the 2005 RSNA Annual Meeting. Received April 21, 2006; revision requested May 17 and received July 5; accepted July 10. All authors have no financial relationships to disclose.
Address correspondence to S.K. (e-mail: kimsuk{at}medigate.net).
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Abstract
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Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. The main pathologic change is focal or disseminated vasculitis caused by the destruction of endothelial cells and the perivascular infiltration of leukocytes. The diagnosis of scrub typhus is based on the patient’s history of exposure, clinical features, and results of serologic testing. Regional and generalized lymphadenopathy is common. The pulmonary manifestations of scrub typhus include interstitial pneumonia, interstitial edema, and hemorrhage caused by vasculitis. Abdominal manifestations include splenomegaly, periportal edema, gallbladder wall thickening, and lymphadenopathy. Although the severity of scrub typhus varies considerably, involvement of the central nervous system is seen in almost all patients and can result in meningoencephalitis. A high degree of clinical suspicion and familiarity with the various radiologic manifestations of scrub typhus allow early diagnosis and timely initiation of appropriate therapy, and thereby may help reduce patient morbidity.
© RSNA, 2007
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Introduction
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Scrub typhus, also known as tsutsugamushi disease, is an acute febrile illness caused by infection with Orientia tsutsugamushi and characterized by focal or disseminated vasculitis and perivasculitis, which may involve the lungs, heart, liver, spleen, and central nervous system (1–3). Scrub typhus is a public health problem in Asia, where about 1 million new cases are identified annually and 1 billion people may be at risk for this disease (4). In addition, reports of infection are becoming increasingly common in travelers returning from Asia to their home countries (5,6).
The symptoms are usually mild and the clinical course self-limited, with spontaneous recovery after a few days; however, some cases are more severe and protracted, and the disease may be fatal (1). The diagnosis of scrub typhus is based on the patient’s history of exposure, the clinical features, and the results of serologic testing (1,4, 7,8). The radiologic findings of scrub typhus are varied and nonspecific (9). Nevertheless, an awareness of the related findings at imaging, especially at computed tomography (CT), may facilitate accurate diagnosis.
The article provides a review of the epidemiologic, clinical, pathologic, and imaging features of scrub typhus. In particular, the authors report their findings at contrast material–enhanced whole-body CT in patients with scrub typhus.
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Epidemiologic and Clinical Features
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Scrub typhus occurs over a wide area of eastern Asia and the western Pacific region (1) (Fig 1). O tsutsugamushi, the causative agent of scrub typhus, is an obligate intracellular bacterium (10). The name tsutsugamushi is derived from the two Japanese words tsutsuga (something small and dangerous) and mushi (creature) (8). The organism was formerly called Rickettsia tsutsugamushi, but after differences from Rickettsia species were identified in its genetic makeup and cell wall structures, it was reclassified as O tsutsugamushi (11).
The disease in humans results after the introduction of O tsutsugamushi through the skin by the bite of a larval-stage (chigger) trombiculid mite (1,8). It occurs in persons who engage in occupational or recreational behavior that brings them into contact with mite-infested habitats such as brush and grass (8). These mites have a four-stage life cycle (egg, larva, nymph, and adult) (8) (Fig 2). The larva feeds only once on a vertebrate. After a blood meal, the chigger detaches and matures into a nymph and subsequently into an adult. Both the nymph and the adult are free-living in the soil. Normally, the chiggers feed on small mammals or ground-feeding birds. Humans accidentally enter the natural cycle of infection. Person-to-person transmission of infection has not been reported (8). Periods of epidemics are influenced by the activities of the infected mite. Therefore, they may be influenced by temperature and humidity (4). Transmission occurs throughout the year in tropical areas. However, in more temperate zones this is not the case (4). In Korea, transmission is seasonal, and the peak occurs during October and November (12).
After an incubation period that ranges from 6 to 21 days (usually, 10–12 days), the onset of disease is characterized by fever, headache, myalgia, cough, and gastrointestinal symptoms (1). The severity of the symptoms varies widely, depending on the susceptibility of the host, the virulence of the bacterial strain, or both (1).
The classic case description includes an eschar at the site of chigger feeding, regional lymphadenopathy, and a maculopapular rash (1,4,8). Five to 8 days after the onset of fever, a macular or maculopapular rash may appear on the trunk, and later it may extend to the arms and the legs. There is usually tenderness from lymphadenopathy in the region of the bite wound or eschar. An eschar at the wound site is the single most useful diagnostic clue (Fig 3) (4). An eschar usually occurs at sites where skin surfaces meet or clothes bind, such as the axilla, groin, neck, waist, and inguinal area. An eschar is usually found on Caucasian and East Asian patients but is seen less frequently on South Asians, especially those who are dark skinned (13–15). The eschar begins as a small papule that enlarges, undergoes central necrosis, and eventually acquires a blackened crust with an erythematous halo that resembles a cigarette burn (4). The skin surrounding the ulcer is moderately red (2). Generalized lymphadenopathy and splenomegaly are common at physical examination (1,8). In a small proportion of patients, tremors, delirium, nervousness, or nuchal rigidity may develop in the 2nd week of illness (1,16). In patients with a history of exposure in a geographic area where the disease is endemic and with findings of an eschar, rash, and generalized or regional lymphadenopathy, scrub typhus should be considered in the differential diagnosis, along with infections such as rickettsialpox, Mediterranean spotted fever, dengue, leptospirosis, and murine typhus (1,8).
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Figure 3a. Eschar from the bite of a Leptotrombidium mite. (a) Photograph shows an epidermal ulcer covered by a black crust surrounded by an erythematous halo. (b) High-power photomicrograph (original magnification, x400; hematoxylin-eosin stain) shows dermal vasculitis with perivascular infiltrates that consist mostly of lymphocytes and macrophages.
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Figure 3b. Eschar from the bite of a Leptotrombidium mite. (a) Photograph shows an epidermal ulcer covered by a black crust surrounded by an erythematous halo. (b) High-power photomicrograph (original magnification, x400; hematoxylin-eosin stain) shows dermal vasculitis with perivascular infiltrates that consist mostly of lymphocytes and macrophages.
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Routine laboratory studies are of no diagnostic value. However, elevated levels of hepatic enzymes such as aspartate and alanine aminotransferases or the biliary canalicular marker alkaline phosphatase are frequently observed in patients with scrub typhus (16).
A diagnosis can be made in the presence of a significant increase in the serum antibody titer measured either with the Weil-Felix agglutination test or with indirect immunofluorescence (1,4,7, 8). At indirect immunofluorescence, the criterion for a positive result is either one demonstration of a titer of 1:400 or greater or a fourfold increase to a titer of 1:200 or greater. A disadvantage of relying on the serologic test results for diagnosis is the fact that low antibody titers are common in the first 4–5 days of illness. Serologic surveys of population groups in geographic areas in which the disease is endemic have shown a prevalence of antibody to O tsutsugamushi of up to 77% (17–19). However, Kawamura et al (19) reported that most serologically positive individuals had an in-apparent infection of avirulent O tsutsugamushi. The immunoperoxidase test or the polymerase chain reaction also has been used effectively to diagnose acute infection with O tsutsugamushi (1).
Tetracycline and chloramphenicol are both effective oral or intravenous agents against scrub typhus, and fever dissipates within 24 hours after treatment with one of these drugs in most patients (1). No vaccine against scrub typhus is yet available. Therefore, prevention is based mainly on avoiding the arthropod bite (1).
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Pathologic and Imaging Findings
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Pulmonary Involvement
Pulmonary involvement is a well-documented complication of scrub typhus infection. In autopsy series, interstitial pneumonia has been found in almost all patients with scrub typhus (2). The basic pathologic process in pulmonary involvement of scrub typhus is interstitial pneumonia with or without vasculitis (9). At microscopy, blood vessels in specimens from the interlobular septa and alveolar walls appear congested and surrounded by a mononuclear cellular infiltrate. In addition, the nonvascular tissues of the interlobular septa and alveolar walls show edema and infiltration by mononuclear cells (2).
The reported incidence of chest radiographic abnormalities in patients with scrub typhus varies from 59% to 72% (9,20). Bilateral diffuse areas of reticulonodular opacity, hilar lymph node enlargement, and septal lines are the most common findings (9,20) (Figs 4, 5). Airspace consolidation is relatively uncommon and generally appears in the lower zone of both lungs (9,20).
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Figure 4. Chest radiographic findings of scrub typhus. Initial radiograph in a 75-year-old woman shows septal lines, ground-glass opacity, peribronchial cuffing (arrows), redistribution of pulmonary vasculature, and an increased cardiothoracic ratio, as well as bilateral pleural effusion. Follow-up radiograph (not shown), obtained 4 days after treatment, revealed a decrease in the extent of parenchymal opacity.
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Figure 5. Chest radiographic findings of scrub typhus. Initial radiograph in a 66-year-old man shows multiple foci of reticular and patchy opacity in both lungs. Follow-up radiograph (not shown), obtained 5 months after treatment, showed resolution of the parenchymal lesions.
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Unilateral or bilateral hilar enlargement and pleural effusion are common radiographic features, found in 25%–27% and 12%–43% of patients, respectively (9,20).
High-resolution CT also depicts bilateral abnormalities, predominantly in the lower zone of the lung. Common findings include interlobular septal thickening, axial interstitial thickening, ground-glass opacity, and centrilobular nodules (9,20) (Figs 6–8). Consolidation and large nodules are less common findings (9,20). CT findings of scrub typhus may reflect cellular infiltration, edema, and hemorrhage caused by vasculitis or may be due to interstitial edema secondary to cardiac involvement (9).
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Figure 6a. Scrub typhus in a 68-year-old man with previously diagnosed usual interstitial pneumonia. (a) Initial chest radiograph shows patchy opacity (arrow) in the upper lobe of the right lung and areas of reticular and ground-glass opacity near the base in both lungs, findings suggestive of usual interstitial pneumonia. (b) Axial thin-section (1.0-mm collimation) CT image obtained with lung window settings shows a focal area of ground-glass opacity in the upper lobe of the right lung. Follow-up thin-section CT images obtained 2 weeks later and 17 months later (not shown) revealed resolution of the parenchymal opacity in the right upper lobe.
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Figure 6b. Scrub typhus in a 68-year-old man with previously diagnosed usual interstitial pneumonia. (a) Initial chest radiograph shows patchy opacity (arrow) in the upper lobe of the right lung and areas of reticular and ground-glass opacity near the base in both lungs, findings suggestive of usual interstitial pneumonia. (b) Axial thin-section (1.0-mm collimation) CT image obtained with lung window settings shows a focal area of ground-glass opacity in the upper lobe of the right lung. Follow-up thin-section CT images obtained 2 weeks later and 17 months later (not shown) revealed resolution of the parenchymal opacity in the right upper lobe.
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Figure 8a. Scrub typhus in a 67-year-old woman. Axial thin-section (1.0-mm collimation) CT scans of the left (a) and right (b) lungs show centrilobular nodules (arrows in b) and interlobular septal thickening in the lower zone of both lungs.
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Figure 8b. Scrub typhus in a 67-year-old woman. Axial thin-section (1.0-mm collimation) CT scans of the left (a) and right (b) lungs show centrilobular nodules (arrows in b) and interlobular septal thickening in the lower zone of both lungs.
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Cardiomegaly and increased pulmonary vascular diameter are suggestive of cardiac involvement (9).
Between August 2000 and November 2005, 106 patients with scrub typhus were admitted to our institution. Of these 106 patients, 11 (eight women and three men; mean age, 67 years; age range, 49–78 years) were evaluated with contrast-enhanced chest CT performed with a four–detector row multidetector CT scanner (LightSpeed Plus; GE Healthcare, Milwaukee, Wis). The CT findings in these patients are listed in Table 1.
In concordance with previous reports, ground-glass opacity and interlobular septal thickening were common findings at thin-section CT in our patient series, whereas centrilobular nodules and axial interstitial thickening were less common (Table 1). Pleural effusion was observed in six (55%) of 11 patients. Contrast-enhanced chest CT images in most cases depicted mediastinal and axillary lymphadenopathy, which was defined as the presence of one or more lymph nodes with a short-axis diameter of more than 10 mm. Mediastinal lymphadenopathy occurred in 10 (91%) of 11 patients, and axillary lymphadenopathy occurred in eight (73%) of 11 patients (Fig 9). Hilar lymphadenopathy also was common (five [45%] of 11). The lymph nodes were typically large and did not have necrotic centers. These findings correspond well with those in previous autopsy series (2). To the best of our knowledge, contrast-enhanced chest CT findings of scrub typhus have not been described in the literature. Further studies will be needed to confirm these initial observations in a larger study group of patients.
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Figure 9a. Scrub typhus in a 76-year-old woman. Axial contrast-enhanced CT images obtained with mediastinal window settings (a at a higher level than b) show enlarged bilateral hilar, mediastinal (arrows in a), and axillary (arrowheads in a) lymph nodes, as well as bilateral pleural effusion.
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Figure 9b. Scrub typhus in a 76-year-old woman. Axial contrast-enhanced CT images obtained with mediastinal window settings (a at a higher level than b) show enlarged bilateral hilar, mediastinal (arrows in a), and axillary (arrowheads in a) lymph nodes, as well as bilateral pleural effusion.
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Acute respiratory distress syndrome may develop in scrub typhus (Fig 10). This is a rarely reported but serious complication (21). Older age, thrombocytopenia, and the presence of early pneumonitis (defined as evidence of infiltrates on chest radiographs at least 2 days before the development of respiratory distress) have been suggested as risk factors for the development of acute respiratory distress syndrome (21). With appropriate antibiotic therapy, patients usually recover without serious sequelae. The major cause of mortality is a delay in diagnosis (21).
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Figure 10a. Acute respiratory distress syndrome in a 47-year-old woman with scrub typhus. (a) Initial anteroposterior chest radiograph shows diffuse ground-glass opacity in the right lung and the lower zone of the left lung and a small amount of pleural effusion in both lungs. (b) Follow-up anteroposterior chest radiograph obtained 6 days later shows extensive airspace consolidation in both lungs, a feature suggestive of acute respiratory distress syndrome.
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Figure 10b. Acute respiratory distress syndrome in a 47-year-old woman with scrub typhus. (a) Initial anteroposterior chest radiograph shows diffuse ground-glass opacity in the right lung and the lower zone of the left lung and a small amount of pleural effusion in both lungs. (b) Follow-up anteroposterior chest radiograph obtained 6 days later shows extensive airspace consolidation in both lungs, a feature suggestive of acute respiratory distress syndrome.
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Cardiac Involvement
Myocardial lesions were observed in 80% of patients in one autopsy series (3). Cellular infiltration frequently has been observed in the endocardium and pericardium (2,3). Vasculitis and perivasculitis in the myocardium induce cellular infiltration along with hemorrhage and edema of interstitial tissues. Cardiomegaly, which may be due to myocardial or pericardial involvement in the infection (22–24), is usually reversible (9) (Fig 11).
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Figure 11. Scrub typhus in a 47-year-old woman. Initial anteroposterior chest radiograph shows an increased cardiothoracic ratio. Follow-up chest radiography, performed 15 days after treatment, demonstrated a decrease in the size of the heart.
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Abdominopelvic Involvement
Abdominal involvement is not uncommon in patients with scrub typhus. However, to our knowledge, abdominopelvic CT findings of scrub typhus have not been described in the literature.
We retrospectively reviewed the CT images of 19 patients (12 women and seven men; mean age, 62 years; age range, 35–77 years) who underwent abdominal or abdominopelvic CT within 1 week after the manifestation of symptoms. We gave particular attention to the presence of abnormalities in the spleen, liver, lymph nodes, gallbladder, and gastrointestinal tract. Table 2 provides a summary of the abdominopelvic CT findings that were seen in patients with scrub typhus. In our series, splenomegaly was commonly demonstrated at CT, whereas splenic infarct and ascites were less common (Table 2).
Reported pathologic findings in the liver at autopsy have included hepatic congestion, periportal inflammation, and peripheral necrosis (2,3). Hepatic congestion is thought to be caused by heart failure due to myocarditis, periportal inflammation, or both (3).
Periportal areas of low attenuation, which may be associated with myocarditis and periportal lymphedema, were found in nine (47%) of our 19 patients with scrub typhus who underwent CT (Fig 12).
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Figure 12a. Scrub typhus in a 58-year-old man with abdominal pain and fever. Serial contrast-enhanced abdominal CT images depict periportal areas of low attenuation (arrows in a) in the liver, pericholecystic edema, and enlarged lymph nodes in the portocaval and para-aortic regions (arrowheads in b).
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Figure 12b. Scrub typhus in a 58-year-old man with abdominal pain and fever. Serial contrast-enhanced abdominal CT images depict periportal areas of low attenuation (arrows in a) in the liver, pericholecystic edema, and enlarged lymph nodes in the portocaval and para-aortic regions (arrowheads in b).
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Contrast-enhanced CT images obtained in nine (47%) of those 19 patients showed mild inhomogeneous parenchymal enhancement of the liver (Fig 13). It has been reported that early inhomogeneous enhancement is seen on dynamic CT images in the presence of various hepatic diseases, such as liver cirrhosis, Budd-Chiari syndrome, hepatic congestion, acute cholangitis, acute cholecystitis, and abscess (25–34). The inhomogeneous parenchymal enhancement of the liver at dynamic contrast-enhanced CT in patients with scrub typhus is similar to the pattern noted in those other hepatic diseases. The hepatic congestion and periportal inflammation that frequently occur in scrub typhus may cause relative obstruction of the hepatic vein outflow as well as compression of the portal vein with dilatation of the peribiliary plexus (35). Because of these hemodynamic changes, hepatic arterial flow may be increased and inhomogeneous early phase enhancement therefore may occur (35).
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Figure 13a. Scrub typhus in a 50-year-old man. Arterial phase dynamic CT images (a at a higher level than b) show mild inhomogeneous enhancement of the hepatic parenchyma as well as splenomegaly.
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Figure 13b. Scrub typhus in a 50-year-old man. Arterial phase dynamic CT images (a at a higher level than b) show mild inhomogeneous enhancement of the hepatic parenchyma as well as splenomegaly.
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Gallbladder wall thickening in patients with scrub typhus may be due to acute vasculitis with perivasculitis similar to that seen in the liver and other organs. Gallbladder wall thickening of more than 3 mm was observed in nine (47%) of 19 patients with scrub typhus at contrast-enhanced CT and ultrasonography (US) (Fig 14). Gallbladder wall thickening that is secondary to scrub typhus may cause confusion during radiologic assessment of the gallbladder for acute cholecystitis. Thickening of the gallbladder wall without tense gallbladder distention is a feature that helps distinguish subserosal edema from acute cholecystitis (36).
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Figure 14a. Scrub typhus in a 52-year-old man. (a) Longitudinal US image shows gallbladder wall thickening and gallbladder distention. (b) Transverse US image, obtained at follow-up 2 weeks after appropriate treatment, shows decreased gallbladder wall thickening.
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Figure 14b. Scrub typhus in a 52-year-old man. (a) Longitudinal US image shows gallbladder wall thickening and gallbladder distention. (b) Transverse US image, obtained at follow-up 2 weeks after appropriate treatment, shows decreased gallbladder wall thickening.
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Acute inflammation of the spleen with marked acute splenic congestion and enlargement was observed in 96% of patients with scrub typhus in one autopsy series (2). Splenic infarction also was observed occasionally (2). Splenomegaly was judged present if the long-axis diameter of the spleen exceeded 10 cm (37). In our patient series, splenomegaly (splenic length of 11.3 cm ± 1.74 [mean ± standard deviation]) was seen in 15 (79%) of 19 infected patients (Fig 15). A splenic infarct was found in three (16%) of 19 patients at CT (Fig 16).
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Figure 15a. Scrub typhus in a 68-year-old man. (a) Initial contrast-enhanced abdominal CT image depicts splenomegaly. (b) Follow-up contrast-enhanced abdominal CT image demonstrates a decrease in the size of the spleen.
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Figure 15b. Scrub typhus in a 68-year-old man. (a) Initial contrast-enhanced abdominal CT image depicts splenomegaly. (b) Follow-up contrast-enhanced abdominal CT image demonstrates a decrease in the size of the spleen.
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Figure 16a. Scrub typhus in a 78-year-old woman. (a) Contrast-enhanced abdominal CT image demonstrates a wedge-shaped hypoattenuated lesion (arrow) in the spleen, a finding indicative of a splenic infarct. Periportal areas of low attenuation (arrowheads) also are visible throughout the hepatic parenchyma. (b) Contrast-enhanced abdominal CT image, obtained at a level 2 cm inferior to a, depicts gallbladder wall thickening (arrowhead), a tiny gallstone, and enlarged lymph nodes (arrows) in the aortocaval and para-aortic regions.
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Figure 16b. Scrub typhus in a 78-year-old woman. (a) Contrast-enhanced abdominal CT image demonstrates a wedge-shaped hypoattenuated lesion (arrow) in the spleen, a finding indicative of a splenic infarct. Periportal areas of low attenuation (arrowheads) also are visible throughout the hepatic parenchyma. (b) Contrast-enhanced abdominal CT image, obtained at a level 2 cm inferior to a, depicts gallbladder wall thickening (arrowhead), a tiny gallstone, and enlarged lymph nodes (arrows) in the aortocaval and para-aortic regions.
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Abdominopelvic lymph nodes with a short-axis diameter of more than 10 mm were seen in nine (47%) of 19 infected patients, in para-aortic, porta hepatic, and inguinal areas and in the splenic hilum (Figs 12, 16).
Scrub typhus also may involve other abdominopelvic organs, including the gastrointestinal tract (Fig 17) and kidneys. It may cause gastrointestinal hemorrhage (2,3,38) and acute renal failure (39). Imaging studies have a limited role in the detection of these lesions and in the management of affected patients.
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Figure 17a. Scrub typhus in a 73-year-old man. (a, b) Serial contrast-enhanced abdominal CT images (a obtained at a higher level than b) demonstrate mild splenomegaly, bilateral pleural effusion, gallbladder wall thickening, and a small amount of ascites (arrow in b). (c) Fiberoptic gastroscopic image shows superficial mucosal hemorrhages and multiple ulcers.
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Figure 17b. Scrub typhus in a 73-year-old man. (a, b) Serial contrast-enhanced abdominal CT images (a obtained at a higher level than b) demonstrate mild splenomegaly, bilateral pleural effusion, gallbladder wall thickening, and a small amount of ascites (arrow in b). (c) Fiberoptic gastroscopic image shows superficial mucosal hemorrhages and multiple ulcers.
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Figure 17c. Scrub typhus in a 73-year-old man. (a, b) Serial contrast-enhanced abdominal CT images (a obtained at a higher level than b) demonstrate mild splenomegaly, bilateral pleural effusion, gallbladder wall thickening, and a small amount of ascites (arrow in b). (c) Fiberoptic gastroscopic image shows superficial mucosal hemorrhages and multiple ulcers.
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Central Nervous System Involvement
Autopsy studies have revealed involvement of the central nervous system in almost all affected patients. Although its severity varied considerably, central nervous system involvement usually resulted in meningoencephalitis (2,3). Pathologic findings of central nervous system involvement in scrub typhus include diffuse or focal mononuclear cellular infiltration of the leptomeninges, typhus nodules (clusters of microglial cells), and brain hemorrhage (2,3).
Although central nervous system involvement is common in scrub typhus (40,41), only one case report of typhus encephalomyelitis diagnosed at brain MR imaging has been published in the English-language literature, to our knowledge. In this case, the T2-weighted images depicted areas of signal hyperintensity in the dorsolateral pontomedullary region, bilaterally in the cerebellar peduncles, and in the cervical spinal cord (42).
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Conclusions
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Scrub typhus is distributed over a wide area of eastern Asia and the western Pacific region and infects an estimated 1 million individuals annually. The possible presence of scrub typhus infection in a patient with fever and respiratory distress should be considered, particularly if an eschar is seen or if the patient has a history of environmental exposure in a geographic area in which scrub typhus is endemic. Serious complications are not uncommon and may be fatal; they include pneumonia, myocarditis, meningoencephalitis, acute renal failure, and gastrointestinal bleeding. Early diagnosis is important because there is usually an excellent response to treatment, and timely antimicrobial therapy may help prevent complications. Although the radiologic findings of scrub typhus are nonspecific, an awareness of the related findings at imaging, especially at CT, may facilitate accurate diagnosis.
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Acknowledgments
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We gratefully acknowledge Sung Mee Kim for providing the map and graphic illustration.
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References
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Abstract
Introduction
