Detection of Hantaan and Seoul viruses by reverse transcriptase-polymerasechain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) in renal syndrome patients with hemorrhagic fever

Background: Hemorrhagic fever with renal syndrome (HFRS), also called Korea n hemorrhagic fever (KHF), is the most common cause of acute renal failure in the Far East. Two serotypes of hantavirus, Hantaan and Seoul viruses are known pathogens for HFRS in Korea. Purpose: To elucidate the diagnostic ap plicability for the serotype diagnosis in HFRS patients, we used nested rev erse transcriptase-PCR and restriction fragment length polymorphism (nRT-PC R/RFLP) to screen 2 prototype viruses, 11 virus isolates from HFRS patients , and 69 specimens obtained from 31 HFRS patients. Methods: The nRT-PCR was performed using primers specific for the G1 segments of the Hantaan (HF3 1 140-1163, HB14 1363-1342) and Seoul (SF2 809-832, SB3 1200-1177) viruses. T he initial PCR products were then further amplified using nested primers fo r the Hantaan (HF4 1141-1164, HB13 1360-1339) and Seoul (SF7 863-884, SB1 1 165-1142) viruses. Amplified segments were then digested with restriction e nzymes specific for either Hantaan (Cla I) or Seoul (Sac I) virus sequences . Results: In all cultured viruses, the serotypes identified by nRT-PCR/RFL P were consistent with those of PRNT. nRT-PCR/RFLP results indicated the pr esence of Hantaan virus in 10 patients and of Seoul virus in 15 patients. I n 3 patients, both Hantaan- and Seoul-specific amplified bands were visuali zed in serially collected samples, and in 4 patients no amplicon was detect ed. Among 69 specimens, 55 were positive; these positive specimens were obt ained between days 3 and days 33 of illness. The positive rate was not affe cted by the clinical phase, day of illness, or severity of HFRS. Conclusion s: nRT-PCR/RFLP is a rapid and convenient method for serotype diagnosis in most HFRS patients. It could also allow detection of genetic variation of h antavirus within the same serotype.