DIAGNOSING DENGUE VIRUS-INFECTION IN ARCHIVED AUTOPSY TISSUES BY MEANS OF THE IN-SITU PCR METHOD - A CASE-REPORT

Background: The pathogenesis of the severe form of dengue virus infect ion, dengue hemorrhagic fever, is still obscure. A major research obje ctive has been to determine which body organs are being damaged by den gue virus in this form of dengue. Research has been difficult because dengue hemorrhagic fever is sporadic and tends to occur in parts of th e world where modern facilities are scarce and fresh or frozen patient materials are not available. However, major hospitals in these areas have accumulated libraries of paraffin-embedded surgical and autopsy t issues over the years. These tissues may have been subjected to less t han optimal fixation and storage. Attempts to localize dengue virus us ing antigen detection in the stored tissue have encountered many diffi culties. Objective: Since viral nucleic acid may be preserved under ci rcumstances which destroy protein antigens, our objective was to detec t dengue viral RNA in situ in histologic sections of tissues from pati ents dying of dengue hemorrhagic fever in Thailand. Study design: Tiss ues from an 11-year-old boy who died at Ramathibodi Hospital, Bangkok, Thailand in November, 1987 with the clinical diagnosis of dengue hemo rrhagic fever were treated by transcribing the dengue viral RNA to DNA followed by amplification using the polymerase chain reaction with su bsequent in situ hybridization in order to visualize the cells infecte d with dengue virus. Results: Viral RNA was detected in hepatocytes in the mid-zonal region of the liver, as well as scattered macrophages i n skin and lymph nodes. Conclusion: Dengue virus infection can be dete cted in paraffin-embedded autopsy tissues which have been stored for f ive years. The same procedure can be used for diagnosing dengue viral infection and for studying the pathogenesis of dengue hemorrhagic feve r.