Infections with hepatitis G virus (HGV), a recently characterized member of the hepatitis viruses, had been reported worlwide. The current study details the molecular epidemiology of HGV infection in the Philippines.
A prospective study 1,088 blood samples from volunteer blood donors (healthy adults, n=516), chronic liver disease patients (n=138), hemodialysis patients (n=207) and multiply-transfused patients (n=227) was conducted to determine the prevalence of HGV infection, its co-infection rates with other known parenterally transmitted viruses hepatitis B C (HBV HCV), and the HGV genotype present in the Philippines.
HGV-RNA was detected in the serum of these patients using the reverse transcriptase polymerase chain reaction (RT-PCR). RT-PCR was performed with random hexamer primers and a set of PCR primers from the 5' UTR of the HGV genome. The identity of the PCR products was determined by hybridization using an ELISA-based method with a specific HGV capture probe. HGV-RNA+ serum samples were further tested to detect HCV-RNA and HBsAg using the Amplicor RT-PCR and Hexagon ICT, respectively.
HGV-RNA was found in 1.16%, 7.97%, 3.38% and 6.17% of volunteer blood donors (healthy adults liver disease patients, hemodialysis patients and multiply transfused patients, respectively. HCV-RNA was present among the HGV-RNA+ samples as follows: in 16.67% of HGV-RNA+ samples from the volunteer blood donor group, 54.54% among chronic liver disease patients, 14.29% of hemodialysis patients, and 7.15% of multiply transfused patients. HBsAg prevalence among HGV-RNA+ subjects was 16.67%, 45.45%, 7.14% respectively of the volunteer blood donors, chronic liver disease patients and multiply-transfused patients respectively. There was only 1 sample from the chronic liver disease patients that tested positive for HGV-RNAm HCV-RNA and HBsAg.
Nucleotide sequence analysis of the 5'UTR of HGV-RNA+ revealed that, among the five known HGV genotypic variants, the Philippines isolates are more closely related to the Asian type (lll).
When subjects were infected with HGV alone, the various does not appear to cause clinically significant hepatitis among the subjects. Further studies are warranted to understand the impact of HGV on other infections with either HCV-HBV or both. Future investigations should also focus on studies on viral evolution and continuous monitoring of study for development of clinically significant disease.
To determine the prevalence and genotype of the hepatitis G virus (HGV) in the Philippines2. To determine and compare the prevalence of HGV in the following risk groups: blood donors, intravenous drug users, multiply transfused, hemodialysis patients and patients with chronic liver disease3. To determine the association of HGV with chronic hepatitis B and C4. To determine the nucleotide sequence of the 5'NCR and NS-5 regions of the Philippine HGV isolate and compare this with that of known variants5. To compare the nucleotide sequences between isolates to determine the possibility of occurrences of subtypes