We report a case of acute hepatitis A that developed following an occurrence of dengue fever during a stay in India. The patient was a 52-year-old Japanese man who visited Delhi, India, from September 29 to October 20, 2010. During that stay, he developed a high fever and rash, with thrombocytopenia and slight liver dysfunction (platelet count 7.0×10＾4/μl, AST 94 IU/ml, ALT 63 IU/ml), then was diagnosed with dengue fever on October 14. Soon after returning to Japan, the patient was well, with anti-HA IgM, hepatitis B surface antigen, and anti-hepatitis C all negative, though liver dysfunction transiently worsened. The DENV genome-sequence was not amplified, while IgM and IgG antibodies were detected. In mid-December 2010, one month after returning from India, he noted fatigue and appetite loss. When the patient came to us on January 12, 2011, jaundice was apparent. A laboratory examination revealed highly elevated aminotransferase levels (AST 4002 IU/ml ALT 4715 IU/ml) and positivity for anti-HA IgM, and we made a diagnosis of acute hepatitis A. The clinical course of acute hepatitis A showed smooth improvement without adverse symptoms. By the end of March 2012, the total bilirubin and aminotrasferase levels were completely normalized. We recommend that non-immune individuals be pre-immunized with HA-vaccine and be fully aware of potential health risks at their intended destinations before traveling to endemic countries
