High prevalence of GB virus C strains genetically related to strains with Asian origin in Nicaraguan hemophiliacs

Abstract

The presence of hepatitis GB virus C (GBV-C), also known as hepatitis G virus (HGV), and hepatitis C virus (HCV) were investigated in sera from 45 hemophiliacs from nine locations in Nicaragua using a nested polymerase chain reaction (PCR). Primers used to detect GBV-C and HCV derived from the helicase region and 5'UTR, respectively. Seventeen (38%) patients were positive for GBV-C RNA in serum by PCR. Twelve (27%) patients were positive for HCV RNA by PCR. Six (13%) of these were coinfected with GBV-C. Anti-HCV was detected in all the 12 HCV RNA positive hemophiliacs and in another 14 (31%) individuals, in whom GBV-C RNA was found in 2. Ten patients (22%) lacked markers for both GBV-C and HCV. The mean age of the patients positive for GBV-C but negative for HCV by PCR was significantly lower than for those negative for GBV-C but positive for HCV by PCR (P < 0.05; Student's t-test), indicating that the risk for this group of hemophiliacs to acquire GBV-C infection is higher as compared to the risk of acquiring HCV infection. Eleven GBV-C strains were sequenced in the 5'UTR. Sequence comparison to previously published GBV-C strains revealed that all 11 strains were more similar to Asian strains than to strains of European and African origin. Sequences in the NS5-B region were available for 8 HCV strains, all of which were found to belong to genotype 1a. The similarity of the Nicaraguan GBV-C strains to strains from Asia indicates that the GBV-C strains in the region presumably have an Amerindian origin. It is also considered that the HTLV II strains in the New World aboriginal populations are ancient and brought there by the ancestral Amerindian populations from Asia. Further, the genotype F of hepatitis B virus, known to represent the strains in populations with Amerindian background, predominates in Central American populations with Hispanic background. It remains to be clarified why Amerindian strains of GBV-C as well as of HBV predominate also in populations with mixed ethnic background in Central America.

Diversity of GB virus C/Hepatitis G virus isolates in Singapore: Predominance of group 2a and the Asian group 3 variant

“…The occurrence of GBV-C/HGV RNA in 4.1% of our study population of hemodialysis patients is on the low side of this range. In contrast, the GBV-C/HGV coinfection rate of 19.5% in our cohort of HCV-positive patients is in the middle of the 7%-31% range that has been reported [Gonzalez-Perez et al, 1997;Guilera et al, 1998]. The occurrence of GBV-C/HGV viremia is in this patient group.…”

“…Furthermore, the occurrence of a group 1-like GBV-C/HGV isolate suggests that the spread of GBV-C/HGV from other parts of the world is slow but may increase in the future. Intriguingly, GBV-C/HGV isolates from Nicaragua have been grouped with isolated from Asia, and the possibility that GBV-C/HGV was introduced into this Central American population by the Amerindian migration from Asia did not go unnoticed by the author [Gonzalez-Perez et al, 1997]. Evidence documenting the modes of transmission and clinical significance of GBV-C/HGV are accumulating [Mushahwar and Zukerman, 1998], and hence studies of the diversity and infection rates of GBV-C/HGV will be important in understanding the functioning of this virus.…”

“…This mode of transmission had prompted the need to study the virus's diversity and distribution [Alter et al, 1997a[Alter et al, , 1997b. Firstly, there is a significant coinfection rate with the hepatitis B and C viruses, ranging from 5%-14% for HBV Guilera et al, 1998] and 7%-31% for HCV [Gonzalez-Perez et al, 1997;Guilera et al, 1998]. This suggested shared modes of transmission.…”

Genotypic Variability of Hepatitis Viruses Associated With Chronic Infection and the Development of Hepatocellular Carcinoma

“…62 GBV-C/HGV genotype 3 circulates among Central and South American population groups, a finding that may be related to the Asiatic origin of the American human. 62,63 These findings suggest an old origin of GBV-C/HGV. The long time of coevolution of GBVC/HGV with its human host might in part explain the apparently low pathogenesis of this virus.…”

“…61 Genotype 1 is more prevalent in Africa, genotype 2 in Europe and North America, and genotypes 3, 4, and 5 are found mainly in Asia. 62 GBV-C/HGV genotype 3 circulates among Central and South American population groups, a finding that may be related to the Asiatic origin of the American human. 62,63 These findings suggest an old origin of GBV-C/HGV.…”