|Budget Amount *help
¥4,400,000 (Direct Cost : ¥4,400,000)
Fiscal Year 1994 : ¥4,400,000 (Direct Cost : ¥4,400,000)
1.Study on hepatitis C virus (HCV) in Chiang Mai, Thailand.
(1) Epidemiological analysis : Anti-HCV was detected in 2.4% (12/508) among healthy blood donors. On the other hand, the prevalence was 97% (59/61) and 23% (9/39) among intravenous drug users and opium/heroin smokers, respectively.
(2) Analysis of HCV genome : Anti-HCV-positive sera were subjected to reverse transcription-polymerase chain reaction (RT-PCR) to amplify the NS5b region of the HCV genome. 92% (23/25) and 83% (24/29) of the sera from blood donors and drug addicts, respectively, were positive for amplification. The amplified fragments were sequenced and a subtype was assigned to each isolate based on the sequence. HCV-3a was the most common subtype in blood donors (35%), followed by HCV-1a (13%), -3b (13%) and -1b (9%). 13% of the isolates could not be assigned known subtypes. Among drug addicts, HCV-1a (29%) and -3a (25%) were most commonly found, followed by HCV-1b (17%), -3b (13%) and -6a (4a). Again, 13% of the is
olates could not be assigned known subtypes. These sequence variants could be further grouped into 4 novel subtypes.
(3) Immunological analysis : Sera of patients infected with HCV-3a, -3b, -6a or the novel subtypes did not react with either C14-1 or C14-2 antigens, suggesting that the above HCV subtypes have unique antigenicity different from that of HCV-1a, -1b, -2a and -2b.
2.Study on HCV in Surabaya, Indonesia.
(1) Epidemiological analysis : Prevalence of anti-HCV among blood donors with normal liver function (ALT,<23 IU/L) was 1.3% (6/468). On the other hand, the prevalence was significantly higher (8.5% ; P<0.001) in blood donors who have abnormal liver function (ALT,>23 IU/L).
(2) Analysis of HCV genome : HCV-2a was the most common subtype in blood donors (68%), followed by HCV-1b (16%). A new subtype of HCV (HCV-3g) was found to circulate in this area, though less common than HCV-2a and -1b.
3.Study on HCV in Manila, the Philippines.
(1) Analysis of HCV genome : Anti-HCV-positive sera from blood donors and prisoners were analyzed by RT-PCR for the NS5b region of the HCV genome. 75% of the blood donors'sera (15/20) and 74% of the prisoners' sera (17/23) were positive for amplification. Preliminary results of subtype analysis showed that HCV-1a and -1b were among the most common subtypes, while HCV-3a and -3b being less common. This subtype prevalence is clearly different from those observed in Thailand and Indonesia. More detailed analysis is now in progress. Less