Objective: Determine the frequency of abnormalities of liver function test in children with scrub typhus and its relation with severity of disease.
Material and Method: Fifty-four children diagnosed with scrub typhus at Chiang Rai Regional Hospital from January 2004 to December 2005 were studied. The diagnosis of scrub typhus in the present study was based on a single indirect immunofluorescent antibody (IFA) titer against O tsutsugamushi of > 1:400 or a four fold or greater rise in IFA titer to at least 1:200. Liver function tests (LFT) were done on the first few days of admission in all patients. Abnormalities of LFT were focused on serum AST, ALT, albumin and total bilirubin level. All of the patients were divided into two groups based on the presence or absence of complications.
Results: Fifty-two patients (96.3%) had abnormal LFT. Evaluation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were detected in 52 (96.3%) and 36 (66.7%) cases, respectively. Hypoalbuminemia and hyperbilirubinemia were detected in 23 (42.6%) and 4 (7.4%) cases, respectively. The higher level of AST, ALT, and lower level of serum albumin correlated significantly with the severity of scrub typhus in children.
Conclusion: Hepatic dysfunction is common in children with scrub typhus. Elevation of AST level may be used as a screening test for diagnosis of scrub typhus in areas where rapid diagnostic test is not commercially available. Increased AST, ALT, and hypoalbuminemia related with severity of disease.

Keywords: Hepatic dysfunction, Liver function test, Pediatric scrub typhus