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The aim of this study was to assess the seroprevalence, viremia, genotype distribution, and demographic history of hepatitis C virus (HCV) in the Republic of the Congo. Testing was carried out on sera samples collected in 2005 from 807 Bantus belonging to the Kongo, Teke, and Ngala subgroups and 80 Pygmies. Positive HCV serology was found in 50 (5.6%) individuals including31 (60%) who were viremic. Seroprevalence increased with age with a cutoff at 50 years:2.8% 50. Twenty-one strains belonged to four described subtypes, that is, 4c in eight cases, 4h in two, 4k in three, and 4r in eight. Ten strains could not be assigned to any known subtype and may represent six new variants, that is, subtype 4 in five cases and subtype 2 in one. Evolutionary analysis of subtype 4c and 4r sequences indicated a period of enhanced transmission in the mid-twentieth century probably due to iatrogenic causes. This study underlines the high genetic diversity of strains in the Republic of the Congo with nine subtypes 4 and one subtype 2.

TTV and TTMV (recently assigned to the floating genus Anellovirus) infect human populations (including healthy individuals) at high prevalence (>80%). They display notably high levels of genetic diversity, but very little is known regarding the distribution of Anellovirus genetic groups in human populations. We analyzed the distribution of the major genetic groups of TTV and TTMV in healthy voluntary blood donors using group-independent and group-specific PCR amplifications systems, combined with sequence determination and phylogenetic analysis. Analysis of Anellovirus groups revealed a non-random pattern of group distribution with a predominant prevalence of TTV phylogenetic groups 1, 3, and 5, and of TTMV group 1. Multiple co-infections were observed. In addition, TTMV sequences exhibiting a high genetic divergence with reference sequences were identified. This study provided the first picture of the genetic distribution of the major phylogenetic groups of members of the genus Anellovirus in a cohort of French voluntary blood donors. Obtaining such data from a reference population comprising healthy individuals was an essential step that will allow the subsequent comparative analysis of cohorts including patients with well-characterized diseases, in order to identify any possible relationship between Anellovirus infection and human diseases.

TT virus-like minivirus (TLMV) was recently discovered as a human circovirus. Little is known about its natural history and molecular epidemiology. A study of TLMV infection is described in a population of French hemodialysis patients. TLMV DNA was tested by seminested PCR system located in the noncoding region in 81 patients divided into seven groups according to the origin of their renal disease. Quantitation of TLMV DNA in serum was carried out. Sequences from 28 patients were compared with 40 sequences retrieved from databases and 53 TLMV sequences cloned from the serum of a single patient. The prevalence of TLMV DNA in hemodialysis patients was 95.1%. In this study, 24 samples (29.6%) presented viral loads of > 125 equivalents of plasmid (Ep)/ml, and only 6 (7.8%) had viral loads of > 125 × 102 Ep/ml. A significant correlation (P 125 × 102 Ep/ml and the neoplastic origin of end-stage renal disease. Analysis of 53 sequences cloned from a single individual demonstrated high sequence variability, as shown by the genetic distance of 40.2%. This genetic distance is comparable to that between the most divergent sequences of TLMV reported to date (43.5%). These data suggest that TLMV viral load is possibly related to the level of immunocompetence of hemodialysis patients; the genetic diversity of TLMV is extremely high; and co-infection by different strains is possible. J. Med. Virol. 67:630–635, 2002. © 2002 Wiley-Liss, Inc.

The aim of this study was to assess the seroprevalence, viremia, genotype distribution, and demographic history of hepatitis C virus (HCV) in the Republic of the Congo. Testing was carried out on sera samples collected in 2005 from 807 Bantus belonging to the Kongo, Teke, and Ngala subgroups and 80 Pygmies. Positive HCV serology was found in 50 (5.6%) individuals including 31 (60%) who were viremic. Seroprevalence increased with age with a cutoff at 50 years: 2.8%50 versus 12%50. Twenty-one strains belonged to four described subtypes, that is, 4c in eight cases, 4h in two, 4k in three, and 4r in eight. Ten strains could not be assigned to any known subtype and may represent six new variants, that is, subtype 4 in five cases and subtype 2 in one. Evolutionary analysis of subtype 4c and 4r sequences indicated a period of enhanced transmission in the mid-twentieth century probably due to iatrogenic causes. This study underlines the high genetic diversity of strains in the Republic of the Congo with nine subtypes 4 and one subtype 2.