[HIV-1 genetic variants in the Asian part of Russia: a study (2005-2010)].

The HIV-1 genetic variants circulated in the Asian part of the Russian Federation in 2005-2010 were studied. The samples of HIV-1 (427 in total) were collected in Khabarovsk, Magadan, Kurgan, Krasnoyarsk, Noyabr'sk, Yakutsk, Altay, and Tyva. Sequencing of some genome regions followed by the phylogenetic analysis or specific Internet resource sampling were used as the main methods of the HIV subtyping. The domination of the IDU-A HIV-1 genetic variant typical of HIV-infection epidemic in Russia was shown in all regions tested in 2005-2010. This variant prevailed both in IDUs and heterosexuals. In addition to IDU-A, some other HIV-1 genetic variants were found among them: subtype B and recombinant CRF03_AB. The HIV-1 genetic polymorphism in Russia was found to be low. An increase in the genetic distance among studied de novo samples was noted in the Asian part of Russia in 2005-2010 (26-68%) as compared to the European variants in 1996-1999 (10%).

[Molecular epidemiology of HIV-1 strains in the Moscow Region].

The Moscow Region is one of the HIV-1-affected subjects of the Russian Federation; there were 34613 HIV-1-infected subjects as of October 31, 2009. To characterize the molecular epidemiology of HIV-1 in the Moscow Region, the investigators obtained and studied HIV-1 variants from 61 infected subjects of the region, who were major risk groups: intravenous drug users (IDUs) and hetero- and homosexually infected persons. Genetic analysis of HIV-1 variants was carried out by sequencing the gag genes (729 nucleotides in length, including full-length protein p17 and partial p24) andlor env (270 nucleotides in length, V3 region) with further phylogenetic analysis. The findings demonstrated that HIV-1 subtype A variants are dominant in the Moscow Region and detectable in 93.5% of IDUs and 100% of heterosexually infected persons. Phylogenetically (and accordingly epidemiologically) unrelated HIV-1 subtype B strains were revealed in 4 patients, including 2 IDUs.

[The molecular epidemiology of HIV-1 in Belarus in (1996-2004): a predominance of subtype A variants and circulation of subtype B variants].

To study the molecular epidemiology of HIV-1 in Belarus, the genetic sequences of HIV-1 variants were obtained from 50 infected persons, which represented the main stages, risk groups, and geographic areas of the epidemic. The env and gag sequences were studied for HIV-1 variants from 31 persons, the env sequences were for HIV-1 variants from 18 persons, and the gag sequence was for HIV-1 variant from 1 person. Phylogenetic analysis indicated that the sequences of HIV-1 variants from 46 persons were homogenic and evolutionally closely related to IDU-A strains specific for other epidemics in the former Soviet Union are dominating in the epidemic in Belarus. Circulation of epidemiologically unrelated subtype B viruses was also established.

Increasing genotypic and phenotypic selection from the original genomic RNA populations of HIV-1 strains LAI and MN (NM) by peripheral blood mononuclear cell culture, B-cell-line propagation and T-cell-line adaptation.

OBJECTIVE: To address the question of whether T-cell-line adaptation of the original LAI and MN (NM) HIV-1 populations biased the interpretation of the intraindividual and population-wide virus distributions. PATIENTS AND METHODS: HIV-1 genomic RNA coding for the gp120 C2V3 region was obtained from serum samples of patients LAI and MN and compared to the proviral DNA derived from simultaneously sampled peripheral blood mononuclear cells (PBMC) as well as B-and T-cell lines. RESULTS: Two (10%) of 20 clones of HIV-1 LAI RNA and none of 16 clones of the HIV-1 MN RNA carried syncytium-inducing (SI)-determining amino-acid changes. HIV-1 LAI RNA formed on SI and two non-SI (NSI) phylogenetic clusters. The HIV-1 LAI DNA in PBMC included both SI and NSI clones but lacked one NSI cluster and contributed NSI clones to the SI cluster as well as an SI clone to the NSI cluster, indicating the existence of an intermediate SI/NSI genotype. In vitro culture using either primary cells or B-cell lines yielded only SI clones, distributed over two SI/NSI mixed clusters. Long-term propagation in T-cell lines further restricted the clonality and yielded SI clones belonging to only one cluster. On the population level, HIV-1 LAI, MN and BRU sequences all clustered according to the individual host and apart from each other and separate from the epidemiological controls without notable influence of SI/NSI distinction or cell-culture adaptation. CONCLUSION: Our data demonstrate a selection bias during the cell-line adaptation of HIV-1 strains LAI and MN with more impact on phenotypic than on genotypic characteristics.

Evidence for limited within-person evolution of the V3 domain of the HIV-1 envelope in the amsterdam population.

OBJECTIVE: To study the development of the V3 region of the HIV-1 envelope over time, both within subjects and population-wide. METHODS: Direct V3 sequences were obtained from viral RNA from seroconversion samples of 138 individuals [32 intravenous drug users (IVDU), 106 homosexual men], as well as from 5-year follow-up samples of 45 of these individuals (11 IVDU, 34 homosexual men). RESULTS: The population-wide variation of the V3 region in both the seroconversion samples and the 5-year samples steadily increased over consecutive years and were of similar magnitude in each calendar year. The variation in the IVDU group was slightly lower (presumably lagging behind) than in the homosexual group, but also increased over time. The consensus sequence, representing the centre of the swarm of variants, remained almost stationary in 10 years of evolution. The V3 sequences from virions in serum collected 5 years after seroconversion still resembled those from the seroconversion sample, either in overall similarity or in specific (signature) amino acids. Seroconversion and late sequences from a donor-recipient pair were also very similar. CONCLUSIONS: The variation in V3 sequences from seroconversion samples is as large as that in 5-year follow-up samples from the same calendar year, suggesting that there is no strong selection for a particular V3 genotype at transmission. The HIV-1 subtype B quasispecies in a naive population appears to evolve through unbiased expansion around a stationary consensus sequence. Despite its large variability, the V3 region retains many of its individual characteristics after 5 years of infection. This indicates that the sampling moment (relative to the seroconversion data) will not greatly influence the results of phylogenetic analyses.

HIV-1 strains specific for Dutch injecting drug users in heterosexually infected individuals in The Netherlands.

OBJECTIVE: To study the molecular epidemiology of HIV-1 subtype B amongst heterosexually infected individuals in The Netherlands. DESIGN: The study population comprised 54 individuals infected by subtype B viruses through heterosexual contacts. Serum samples were collected between 1988 and 1996. METHODS: Sequences of the gp120 V3 region were obtained from serum samples and analysed by using the signature pattern and phylogenetic methods. RESULTS: In 22 (41%) out of 54 subtype B sequences from heterosexually infected individuals, the synonymous nucleotide substitution in the second glycine codon at the tip of the V3 loop (the GGC pattern), previously identified as specific for Dutch injecting drug users (IDU), was found. The other previously described IDU sequence patterns were observed significantly more often among GGC- than among non-GGC-containing sequences. In addition, we identified another amino-acid change specific for the GGC sequences. In the phylogenetic and principal coordinate analyses, the GGC sequences from heterosexually infected individuals clustered separately from the non-GGC sequences and together with the IDU consensus sequence. Both the nonsynonymous and particularly the synonymous distances amongst the GGC sequences were significantly lower than amongst the non-GGC sequences. CONCLUSIONS: Our data provide evidence for a common origin of the viruses in Dutch IDU and the GGC viruses in heterosexuals. We suggest that a considerable proportion of the viruses in heterosexually infected individuals in The Netherlands may have originated from Dutch IDU.

Simultaneous introduction of distinct HIV-1 subtypes into different risk groups in Russia, Byelorussia and Lithuania.

OBJECTIVE: To investigate genotypes and serotypes of HIV-1 variants in Russia, Byelorussia and Lithuania. PATIENTS AND METHODS: Sera from 20 HIV-1-infected individuals were tested in an enzyme-linked immunosorbent assay (ELISA) with 19 V3 synthetic peptides, and serum HIV-1 V3 RNA was amplified and sequenced. RESULTS: Sequence comparison of the envelope V3 region among specimens tested revealed a 2-29% range nucleotide divergence, with a mean of 19%. Phylogenetic analysis from the homosexual men were shown to belong to subtype B, and all of the heterosexually infected individuals to subtype C. Sequences from the parenterally infected individuals were more heterogeneous. IOn the peptide ELISA three reactivity patterns were found. Serum samples from six out of seven homosexual men showed reactivity to peptides p108 or p110 representing V3 amino-acid sequences found in US/West European HIV-1 isolates. Serum samples from six of seven individuals who had acquired HIV-1 through heterosexual contacts were reactive to peptide p169. Four out of six parenterally infected patients had peak reactivity to p168. CONCLUSION: Distinct HIV-1 variants were found in Russia, Byelorussia and Lithuania, which were introduced simultaneously in the mid-1980s. This diversity was shown to be associated with the route of transmission. Homosexual men appeared to be infected with subtype B and heterosexually infected individuals with subtype C HIV-1 variants. HIV-1 subtypes A, C, D and G were found among parenterally infected individuals.

PIP: HIV-1 variants show a relatively high level of genomic and antigenic diversity. This heterogeneity is particularly high in the V3 domain of envelope glycoprotein gp120, which is implicated in a number of biological properties of HIV-1, including cell tropism, infectivity, and cytopathogenicity; it is also a target for both humoral and cellular immune response. At least nine subtypes of HIV-1 have been identified. Subtypes A-H are phylogenetically equidistant and shown to be geographically associated with different subcontinents. Subtype B is most prevalent in North and South America and western Europe. Subtypes A, C, D, G, and H are found frequently in sub-Saharan countries, while subtype C is also found in India. Subtype E sequences have been found in patients from Thailand and Central Africa, and subtype F has been described in Romania and Brazil. This study reports findings from an investigation of genotypes and serotypes of HIV-1 variants in Russia, Byelorussia, and Lithuania. Sera from 15 HIV-1-infected men and 5 HIV-1-infected females were tested by ELISA with 19 V3 synthetic peptides with amplified and sequenced serum HIV-1 V3 RNA. Sequence comparison of the envelope V3 region among specimens tested revealed a 2-29% range of nucleotide divergence, with a mean of 19%. Distinct variants of HIV-1 were found in Russia, Byelorussia, and Lithuania, which were introduced simultaneously in the mid-1980s. The diversity was shown to be associated with the route of transmission. Homosexual men appeared to be infected with subtype B compared to heterosexually infected individuals with subtype C HIV-1 variants. HIV-1 subtypes A, C, D, and G were found among parenterally-infected individuals. These findings are based upon the three peptide reactivity patterns identified by ELISA. Serum samples from six out of seven homosexual men showed reactivity to peptides p108 or p110 representing V3 amino-acid sequences found in US/West European HIV-1 isolates. Serum samples from six out of seven individuals who had acquired HIV-1 through heterosexual contacts were reactive to peptide p169, and four out of six parenterally infected patients had peak reactivity to p168.

Timing of the HIV-1 subtype C epidemic in Ethiopia based on early virus strains and subsequent virus diversification.

OBJECTIVE: To trace the introduction of HIV-1 subtype C into Ethiopia based on virus diversification during the epidemic. DESIGN: A set of 474 serum samples obtained in Ethiopia in 1982-1985 was tested for HIV-1. HIV-1 env gp120 V3 and gag or pol regions were sequenced and analysed together with sequences from later stages of the epidemic. RESULTS: None of 98 samples from 1982-1983, one of 193 samples from 1984, and one of 183 samples from 1985 were HIV-1 positive. Phylogenetic analysis of virus sequences from positive samples revealed that they belong to the Ethiopian C, and not the C', cluster. Analysis of 81 Ethiopian C V3 sequences from 1984-1997 revealed that the consensus sequence of the Ethiopian epidemic has been stable over time. Both the 1984 and 1985 V3 sequences, in contrast with three out of 27 (11%) of the 1988 and none out of 51 of the 1992-1997 sequences, had no synonymous substitutions compared to the reconstructed common ancestor of the Ethiopian C viruses. A highly significant correlation between sampling years of the V3 sequences and their synonymous distances to the common ancestor was demonstrated. CONCLUSIONS: The increasing genetic heterogeneity together with stable consensus sequence of the Ethiopian HIV-1 C population demonstrates that evolution of the virus population is characterized by an unbiased expansion around a stationary consensus. Based on the rate of synonymous diversification of HIV-1 strains within the Ethiopian population, we were able to estimate 1983 (95% confidence interval, 1980-1984) as the year of HIV-1 C introduction into Ethiopia.

The impact of immigration on env HIV-1 subtype distribution among heterosexuals in the Netherlands: influx of subtype B and non-B strains.

OBJECTIVE: To examine the epidemiological factors influencing the distribution and spread of HIV-1 subtypes among heterosexuals in the Netherlands. METHOD: A nationwide serosurveillance in 21 HIV/AIDS centres from 1997 to 1999 involved 200 individuals for whom the mode of HIV transmission was heterosexual contact or unknown. HIV-1 subtypes were determined by phylogenetic analysis of env V3 sequences and correlated with sociodemographic characteristics of the subjects and their sexual partners. RESULTS: HIV-1 subtype B infection occurred in 121 subjects (60%). Non-B subtypes were identified in 31 (A), 24 (C), 10 (D), six (E), four (F) and three (G) individuals; one had an unclassified subtype. The proportion of subtype B was about 60% in four of the six regions of the Netherlands, but in the Northwest and Southwest regions these proportions were 76% and 46%, respectively. The Surinamese and Antilleans, large immigrant groups, were all infected with subtype B, as were almost all individuals with an unknown source. The proportions of non-B viruses did not change significantly over time in Amsterdam, where subtyping was available from 1988 onward, but a shift in the various subtype B strains was observed, suggesting introductions of new subtype B strains in Amsterdam. CONCLUSION: To date, HIV-1 non-B subtypes in the Netherlands are still found predominantly among heterosexuals with an epidemiological link with sub-Saharan Africa. Despite continuing introductions of non-B subtypes, the B/non-B distribution has been stable over time, most likely as a result of introductions of subtype B strains from Caribbean and South American countries.

Insertion of two amino acids combined with changes in reverse transcriptase containing tyrosine-215 of HIV-1 resistant to multiple nucleoside analogs.

OBJECTIVE: To identify genotypic drug resistance patterns of HIV-1 in patients who were extensively pretreated with anti-HIV drugs and not responding to their current antiretroviral combination therapy. METHODS: Drug susceptibility of the viruses was tested by a phenotypic recombinant virus assay. Genotypic analysis of HIV resistance was performed by sequencing of the amino-terminal part of the corresponding reverse transcriptase (RT) gene (amino acids 1-280) for serum-derived and recombinant viruses. RESULTS: Among viruses from 92 patients studied, three (3%) viruses contained a T215Y amino-acid change as well as a previously unseen combination of an amino-acid change at codon 67 (N-->E/S) and a two amino-acid insertion between codons 68 and 69 of the RT gene of HIV-1. Phenotypic resistance analysis showed high levels of resistance to zidovudine, lamivudine and stavudine (in all patients) and moderate levels of resistance to didanosine and zalcitabine (in two patients), whereas neither serum-derived nor recombinant viruses contained previously known amino-acid changes conferring resistance to didanosine, zalcitabine, lamivudine and stavudine. However, all recombinant viruses contained an insertion of two amino acids between codons 68 and 69 of RT as well as an amino-acid change at codon 67, as was seen in the serum-derived viruses. CONCLUSIONS: Antiretroviral therapy including zidovudine may yield replicating viruses with a two amino-acid insertion in RT in combination with amino-acid changes at codons 67 and 215, which are highly resistant to lamivudine and stavudine on top of zidovudine and have unpredictable susceptibility to didanosine and zalcitabine despite lack of previously reported corresponding resistance-associated amino-acid changes. It is currently unknown what regimens can induce the emergence of this type of multidrug-resistant viruses. This will only be elucidated when resistance assays are capable of detecting these mutants.

Alternative multidrug regimen provides improved suppression of HIV-1 replication over triple therapy.

OBJECTIVE: To compare the viral suppression of two antiretroviral regimens using three drugs or five drugs. DESIGN: Two open-label studies using a three-drug (zidovudine, lamivudine and ritonavir) and a five-drug regimen (zidovudine, lamivudine, abacavir, indinavir and nevirapine) in study-drug-naive patients, except for one in the five-drug study. METHODS: Participants with > or = 10 000 HIV-1 RNA copies/ml in plasma at baseline were compared by means of Kaplan-Meier curves for time to < 50 copies/ml, as well as linear regression analysis for the first phase of decline using log-transformed copy numbers. RESULTS: The elimination rate constants for HIV-1 RNA in 15 participants of the three-drug study were compared with nine participants of the five-drug study. The level of < 50 copies/ml was reached earlier when using the five-drug than when using the three-drug regimen (P log rank = 0.0005): median time to reach this level was 4 weeks and 12 weeks, respectively. No differences were found in HIV-1 RNA elimination rate constants in the first 2 weeks after the initiation of therapy. When the viral load declines were calculated from day 2 onwards, adjusting for differences in pharmacological delay of the drugs used, again no differences in early viral load decline were found between the two regimens. CONCLUSION: With the five drugs used in this study, the median time to reach < 50 HIV-1 RNA copies/ml was 8 weeks shorter than with the three-drug regimen. This finding shows that suppression of viral load in HIV-infection by standard triple-drug therapy can be improved upon.

Using phylogenetic analysis to trace HIV-1 migration among western European injecting drug users seroconverting from 1984 to 1997.

OBJECTIVE: To reconstruct the epidemiological relationships of the HIV epidemics among injecting drug users (IDU) in western Europe. METHODS: HIV env V3 sequences of and epidemiological data were obtained from 145 IDU who seroconverted in three sequential periods: 1984-1988, 1989-1992 and 1993-1997. The sequences were phylogenetically analysed and examined for signature patterns characteristic of northern European IDU, including the conserved GGC codon in the V3 loop. RESULTS: Subpopulations of genetically related HIV strains were observed in Italy, France, Scotland and Spain, in contrast to the Netherlands, Austria and Switzerland. This difference between the two groups of countries suggests that the HIV epidemics amongst IDU in the latter group was caused by multiple virus introductions. In Edinburgh and the surrounding area, most IDU were infected with the same GGC strain over the 12-year study period. The epidemic among IDU in north-western Europe started with GGC viruses, whereas in south-western Europe non-GGC viruses predominated. This geographical separation has faded during the course of the epidemic, most likely because of virus exchange among IDU populations.

Silent mutation in the V3 region characteristic of HIV type 1 env subtype B strains from injecting drug users in the former Soviet Union.

New independent states of the former Soviet Union are facing a rapidly growing epidemic of HIV-1 among injecting drug users (IDUs). This epidemic is caused by three HIV-1 populations, one belonging to HIV-1 subtype A (IDU-A), another to subtype B (IDU-B), and the third being a recombinant of the IDU-A and IDU-B viruses (IDU-A/B, gagA/envB). Each of these populations is characterized by a high level of genetic homogeneity. We identified a unique synonymous nucleotide substitution in the first isoleucine codon at the IHIGPGR motif (ATT), which was observed in the env subtype B V3 sequences derived from IDUs in Russia and the Ukraine. This substitution was observed in none of 179 sequences obtained from IDUs in western Europe, northern America, and Asia. Molecular epidemiological analysis of HIV-1 strains based on this sequence pattern could be useful for tracing the origin and spread of the IDU-B viruses to other countries and risk groups.

Evidence for HIV type 1 strains of U.S. intravenous drug users as founders of AIDS epidemic among intravenous drug users in northern Europe.

To establish an epidemiological link between HIV-1 epidemics in U.S. and European homosexual men and intravenous drug users (IVDUs) we analyzed the HIV-1 gp120 V3 sequences in both risk groups. Signature pattern analysis revealed that the V3 sequences of viruses from IVDUs in Northern Europe are distinguishable from those of homosexual men on the basis of one amino acid and two synonymous nucleotide substitutions, which the most conserved was a synonymous nucleotide substitution in the second glycine codon at the tip of the gp120 V3 loop (GGC). This substitution was seen in 17 of 20 (85%) viruses of IVDUs in Northern Europe, in none of 41 homosexual men in either Europe or the United States, and in 5 of 11 (45%) U.S. IVDUs sequences analyzed. Subsequent phylogenetic and multivariate principal coordinate (PCOORD) analyses showed that 16 of 20 (80%) of the Northern European IVDU sequences clustered together with the 5 U.S. IVDU sequences carrying the GGC substitution and away from the sequences of homosexual men from either Europe or the United States. Taken together with the higher level of heterogeneity of U.S. IVDU sequences compared to the Dutch IVDU sequences taken at the same time, these data present suggestive evidence for a U.S. instead of a European origin of the AIDS epidemic among Northern European IVDUs.

Circulation of subtype A and gagA/envB recombinant HIV type 1 strains among injecting drug users in St. Petersburg, Russia, correlates with geographical origin of infections.

Countries of the former Soviet Union are experiencing an emerging HIV-1 epidemic due to a rapid expansion of HIV-1 among injecting drug users (IDUs). To study the molecular epidemiology of HIV-1 among IDUs in St. Petersburg, Russia, virus sequences were obtained from 22 individuals. Phylogenetic analysis of the env and gag regions revealed circulation of two major HIV-1 populations, one belonging to HIV-1 subtype A, and another being a recombinant of subtype A and B viruses (gagA/envB). Both virus populations were highly homogeneous, with a mean pairwise genetic distance of <2%, and similar to viruses obtained earlier from IDUs in other regions of the former Soviet Union. Distribution of the two major HIV-1 genotypes in St. Petersburg correlated with geographical origin of infections. In one individual, a virus type previously unseen among IDUs was found, which demonstrates the possibility that new viruses are entering this risk group.

Selection by AZT and rapid replacement in the absence of drugs of HIV type 1 resistant to multiple nucleoside analogs.

We studied the intrahost evolution and dynamics of a multidrug-resistant HIV-1, which contains an insertion of two amino acids (aa) and several aa changes within the reverse transcriptase (RT) gene. From an individual receiving intermittent therapy, sequences of 231 full-length molecular clones of HIV-1 RT were obtained from serum-derived viruses at 12 consecutive time points over a period of 6 years, 17 to 20 clones per time point. In the 3.5-year period prior to the first course of therapy, only wild-type (wt) viruses were found. As soon as 6 months after the start of zidovudine (AZT) monotherapy, all viruses contained an insertion of two aa between positions 68 and 69 of the RT and aa changes at positions 67 and 215, a combination conferring resistance to multiple nucleoside analogs. After termination of therapy, the insertion mutants were rapidly and completely replaced by the wt viruses. In turn, the insertion mutants replaced the wt viruses after initiation of therapy with 3TC, d4T, and saquinavir. After termination of triple therapy, the wt viruses completely replaced the mutants within 1 month, which is markedly faster than has been observed earlier for the replacement of AZT-resistant viruses. Fast replacements of the mutant virus populations after termination of therapy indicate gross competitive disadvantage of the insertion mutant in the absence of therapy, which we estimated by using several models. The insertion mutants attained high virus loads, demonstrating that virus load cannot be used as a direct measure of virus fitness.

Subtype-specific sequence variation of the HIV type 1 long terminal repeat and primer-binding site.

We studied sequence differences in regulatory elements of the long terminal repeat (LTR) and primer-binding site (PBS) among various human immunodeficiency virus type 1 (HIV-1) subtypes. Phylogenetic sequence analysis of a fragment of 729 base pairs (bp) covering the Gag-coding region for half of p24 and all of p17 revealed the gag subtype of all 60 viruses included in the study: A (n = 20), B (n = 12), C (n = 7), D (n = 10), E (n = 3), F (n = 4), G (n = 3), and H (n = 1). The subtype was also determined by analysis of a 689-bp fragment comprising the LTR and the PBS motif. Comparison of the LTR versus gag sequences showed a mosaic genome for seven isolates. After analysis of all sequences, we could describe subtype-specific differences in sequences encompassing the regulatory elements of the LTR and the PBS motif.

Timing of the introduction into Ethiopia of subcluster C' of HIV type 1 subtype C.

Viruses circulating in Ethiopia during the 1990s cluster with main subtype C, but a significant subcluster, C', was noted in multiple analyses. This subcluster of subtype C(C') was in a fifty-fifty equilibrium with the main subtype C (Abebe et al., AIDS Res Hum Retroviruses 2000;16:1909-1914). To analyze genetic diversification within the subcluster of HIV-1 subtype C designated C' in the course of the epidemic in Ethiopia, we analyzed 165 env gp120 V3 sequences obtained between 1988 and 1999. We observed a highly significant positive correlation between sampling years of individual sequences and their synonymous distances to the reconstructed common ancestor of the HIV-1 subtype C' subcluster. The extrapolation of the regression line of synonymous distances back to the date when no synonymous heterogeneity was present among the Ethiopian HIV-1 C' population allowed us to estimate 1982 (95% CI, 1980-1983) as the year of the onset of HIV-1 C' genetic diversification and expansion in Ethiopia. These results are in agreement with retrospective epidemiological and serological data, which demonstrated the absence of an HIV-1 epidemic in the Ethiopian population before the 1980s.

Hepatocellular carcinoma in Egyptians with and without a history of hepatitis B virus infection: association with hepatitis C virus (HCV) infection but not with (HCV) RNA level.

The aim of this study was to analyze the association of hepatocellular carcinoma (HCC) with hepatitis C virus (HCV) in Egypt, using hepatitis B virus (HBV) and hepatitis E virus (HEV) as virus controls. In addition, the association of HCC with HCV RNA levels among persons seropositive for HCV was analyzed. We compared 131 patients with proven HCC, 247 with bladder cancer, and 466 healthy hospital employees. Age, sex, and place of residence were recorded to study confounding factors. Among the healthy controls, 16% were seropositive for HCV, 21% for HBV, and 31% for HEV. When healthy controls were age-matched with HCC patients, the latter were significantly (P < 0.001) more often HCV seropositive (67%) than were the controls (30%). The seropositivity for HBV and HEV did not differ significantly in frequency between the two groups. The seropositivity for HCV was also significantly (P < 0.001) more often found in HCC patients (76%) than in BC patients (47%), with seroprevalences for HBV and HEV not differing significantly in these age-matched groups. In HBV-negative HCC and bladder cancer patients, seroprevalence for HCV was significantly (P = 0.002) higher in HCC patients (68%) than in bladder cancer patients (36%). This difference was even more pronounced (P < 0.001) in HBV-positive HCC and bladder cancer patients (78% versus 52%, respectively). Of HCV-seropositive individuals, 49% were HCV RNA positive by branched DNA assay, and of these, 96% were infected by HCV genotype 4. No correlation between HCV RNA load and seropositivity of HBV or age or disease state was found. Infection with HCV and HCV-HBV double infection, but not HBV or HEV infection alone, is strongly correlated with HCC in Egypt.

Epidemiology of HIV-1 and emerging problems.

Broad use of antiretroviral drugs is becoming a factor that is important to consider for understanding the HIV-1 epidemiology. Since 1993, we observe that a proportion of new infections within major risk groups in Amsterdam is caused by azidothymidine (AZT)-resistant viruses. After the introduction of combination therapy in The Netherlands in 1997, new infections with drug-resistant viruses have not been documented. Large-scale monitoring of anti-HIV-1 therapy failures revealed that antiretroviral drugs may yield previously undescribed resistant viruses, which contain a two amino acid insertion (68SS/V69) within their reverse transcriptase genes in combination with mutations at codons 67 and 215. These viruses are highly resistant to AZT, 3TC, and d4T, and moderately resistant to ddI and ddC.