Anke Bourgeois

Effectiveness and safety of a generic fixed-dose combination of nevirapine, stavudine, and lamivudine in HIV-1-infected adults in Cameroon: open-label multicentre trial

BACKGROUND Generic fixed-dose combinations have been prequalified by WHO to treat HIV-infected patients in resource-limited countries. Despite their widespread use they are, however, not yet recommended by some of the major donor agencies owing to scarcity of clinical data on effectiveness, safety, and quality. We aimed to assess these issues for one of the most frequently prescribed treatments in Africa, a generic fixed-dose combination of nevirapine, stavudine, and lamivudine. METHODS 60 patients were followed in an open-label, 24-week multicentre trial in Cameroon. All patients received one tablet of the fixed-dose combination drug twice daily. The primary outcome measure was the proportion of patients with viral load less than 400 copies per mL at the end of the study period, in an intention-to-treat analysis. FINDINGS At baseline, 92% of patients (n=55) had AIDS; median CD4 count was 118 cells per microL (IQR 78-167) and median plasma HIV-1 RNA was 104?736 copies per mL (40804-243787). The proportion of patients with undetectable viral load (<400 copies per mL) after 24 weeks of treatment was 80% (95% CI 68-89). Median (IQR) change in viral load was -3.1 log10 copies per mL (-2.5 to -3.6) and in CD4 count 83 cells per microL (40-178). The probability of remaining alive or free of new AIDS-defining events was 0.85 (95% CI 0.73-0.92). Frequency of disease progression was 32.0 (95% CI 16.6-61.5), severe adverse effects 17.8 (7.4-42.7), and genotypic resistance mutations 7.1 (1.8-28.4) per 100 person-years. Mean reported adherence rate was 99%. Median drug concentrations in tablets were 96% of expected values for nevirapine, 89% for stavudine, and 99% for lamivudine. INTERPRETATION Our findings lend support to use and funding of a generic fixed-dose combination of nevirapine, stavudine, and lamivudine as first-line antiretroviral treatment in developing countries.

most env and gag subtype A Hiv-1 Viruses Circulating in West and West Central Africa Are Similar to the Prototype Ag Recombinant Virus Ibng

Summary: The genetic subtype was identified in gag and env of 219 HIV‐1‐positive samples collected in different African countries, 44 from Senegal, 55 from Cameroon, 82 from Gabon, and 38 from Djibouti. In total, 20 (9.1%) samples had discordant subtypes between gag and env, 6 of 44 (13.9%) in Senegal, 4 of 55 (7.2%) in Cameroon, 1 of 38 (2.6%) in Djibouti, and 10 of 82 (12.1%) in Gabon. Subtypes A and G were predominantly involved in the recombination events. Phylogenetic tree analysis of gag showed that an important number of the A sequences form a distinct subcluster with the AG‐IBNG prototype strain (a complex A/G mosaic virus): 27 of 32 (84.3%) in Senegal, 12 of 17 (70.6%) in Nigeria, 24 of 39 (61.5%) in Cameroon, and 38 of 70 (54.3%) in Gabon. Full‐length genome analysis of 3 and additional sequences in pol for 10 such strains confirmed that they have a similar complex A/G mosaic genomic structure. These data suggest that in West Africa, most probably between 60% and 84% of the subtype A viruses are recombinant AG‐IBNG viruses. This finding has potential implications on future vaccine, diagnostic, and treatment strategies. The actual and future role of these viruses in the global pandemic must be monitored in all new molecular epidemiologic studies, a discrimination between subtype A and AG‐IBNG‐like viruses is necessary.

Characterization of a Novel Simian Immunodeficiency Virus from Guereza Colobus Monkeys (Colobus guereza) in Cameroon: a New Lineage in the Nonhuman Primate Lentivirus Family

ABSTRACT Exploration of the diversity among primate lentiviruses is necessary to elucidate the origins and evolution of immunodeficiency viruses. During a serological survey in Cameroon, we screened 25 wild-born guereza colobus monkeys (Colobus guereza) and identified 7 with HIV/SIV cross-reactive antibodies. In this study, we describe a novel lentivirus, named SIVcol, prevalent in guereza colobus monkeys. Genetic analysis revealed that SIVcol was very distinct from all other known SIV/HIV isolates, with average amino acid identities of 40% for Gag, 50% for Pol, 28% for Env, and around 25% for proteins encoded by five other genes. Phylogenetic analyses confirmed that SIVcol is genetically distinct from other previously characterized primate lentiviruses and clusters independently, forming a novel lineage, the sixth in the current classification.Cercopithecidae monkeys (Old World monkeys) are subdivided into two subfamilies, the Colobinae and theCercopithecinae, and, so far, allCercopithecidae monkeys from which lentiviruses have been isolated belong to the Cercopithecinae subfamily. Therefore, SIVcol from guereza colobus monkeys (C. guereza) is the first primate lentivirus identified in the Colobinaesubfamily and the divergence of SIVcol may reflect divergence of the host lineage.

Biological and genetic characteristics of HIV infections in Cameroon reveals dual group M and O infections and a correlation between SI-inducing phenotype of the predominant CRF02_AG variant and disease stage.

In Yaounde, Cameroon, HIV-1 group-specific V3 serology on 1469 HIV-positive samples collected between 1996 and 2001 revealed that group O infections remained constant around 1% for 6 years. Only one group N sample was identified and 4.3% reacted with group M and O peptides. Although the sensitivity of the group-specific polymerase chain reaction (PCR) in two genomic regions was not optimal, we confirmed, in at least 6 of 49 (12.2%) dual O/M seropositive samples and in 1 of 9 group O samples, dual infection with group O and M viruses (n = 4) or with group O or M virus and an intergroup recombinant virus (n = 3). Partial env (V3-V5) sequences on a subset of 295 samples showed that at least eight subtypes and five circulating recombinant forms (CRFs) of HIV-1 group M co-circulate; more than 60% were CRF02_AG and 11% had discordant subtype/CRF designations between env and gag. Similarly as for subtype B, the proportion of syncytium-inducing strains increased when CD4 counts were low in CRF02_AG-infected patients. The V3-loop charge was significantly lower for non-syncytium-inducing strains than for syncytium-inducing strains but cannot be used as an individual marker to predict phenotype. The two predominant HIV-1 variants in Africa, CRF02_AG and subtype C, thus have different biological characteristics.

Monitoring of HIV viral loads, CD4 cell counts, and clinical assessments versus clinical monitoring alone for antiretroviral therapy in rural district hospitals in Cameroon (Stratall ANRS 12110/ESTHER): a randomised non-inferiority trial

BACKGROUND Scaling up of antiretroviral therapy in low-resource countries is done on the basis of decentralised, integrated HIV care in rural facilities; however, laboratory monitoring is generally unavailable. We aimed to assess the effectiveness and safety of clinical monitoring alone (CLIN) in terms of non-inferiority to laboratory and clinical monitoring (LAB). METHODS We did a randomised, open-label, non-inferiority trial in nine rural district hospitals in Cameroon. Eligible participants were adults (≥18 years) infected with HIV-1 group M (WHO disease stage 3-4) who had not previously received antiretroviral therapy, and were followed-up for 2 years by health-care workers in routine activities. We randomly assigned participants (1:1) to CLIN or LAB (counts of HIV viral load and CD4 cell every 6 months) groups with a computer-generated list. The primary outcome was non-inferiority of CLIN to LAB in terms of increase in CD4 cell count with a non-inferiority margin of 25%. We did all analyses in participants who attended at least one follow-up visit. This trial is registered with ClinicalTrials.gov, number NCT00301561. FINDINGS 238 (93%) of 256 participants assigned to CLIN and 221 (93%) of 237 assigned to LAB were eligible for analysis. CLIN was not non-inferior to LAB; the mean increase in CD4 cell count was 175 cells per μL (SD 190, 95% CI 151-200) with CLIN and 206 (190, 181-231) with LAB (difference -31 [-63 to 2] and non-inferiority margin -52 [-58 to -45]). Furthermore, in the predefined secondary outcome of treatment changes, 13 participants (6%) in the LAB group switched to second-line regimens whereas no participants in the CLIN group did so (p<0·0001). By contrast, other predefined secondary outcomes were much the same in both groups-viral suppression (<40 copies per mL; 465 [49%] of 952 measurements in CLIN vs 456 [52%] of 884 in LAB), HIV resistance (23 [10%] of 238 participants vs 22 [10%] of 219 participants), mortality (44 [18%] of 238 vs 32 [14%] of 221), disease progression (85 [36%] of 238 vs 64 [29%] of 221), adherence (672 [63%] of 1067 measurements vs 621 [61%] of 1011), loss to follow-up (21 [9%] of 238 vs 17 [8%] of 221), and toxic effects (46 [19%] of 238 vs 56 [25%] of 221). INTERPRETATION Our findings support WHOs recommendation for laboratory monitoring of antiretroviral therapy. However, the small differences that we noted between the strategies suggest that clinical monitoring alone could be used, at least temporarily, to expand antiretroviral therapy in low-resource settings. FUNDING French National Agency for Research on AIDS (ANRS) and Ensemble pour une Solidarité Thérapeutique Hospitalière En Réseau (ESTHER).

Epidemiological and molecular characteristics of HIV infection in Gabon, 1986-1994.

OBJECTIVE To describe trends in the prevalence of HIV-1 infection in different populations in Gabon, and the molecular characteristics of circulating HIV strains. METHODS Data were collected on HIV prevalence through sentinel surveillance surveys in different populations in Libreville (the capital) and in Franceville. In Libreville, a total of 7082 individuals (hospitalized patients, tuberculosis patients, pregnant women, asymptomatic adults, prisoners) were recruited between 1986 and 1994. In Franceville, we tested 771 pregnant women and 886 healthy asymptomatic adults (1986-1988). Sera were screened for HIV antibodies by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot or line immunoassay (LIA). Reactive samples in ELISA were tested for the presence of antibodies to HIV-1 group O viruses by ELISA using V3 peptides from HIV-1 ANT-70 and HIV-1 MVP-5180 followed by confirmation by LIA and a specific Western blot. Seventeen HIV-1 strains were isolated (1988-1993) and a 900 base-pair fragment encoding the env region containing V3, V4, V5 and beginning of gp41 was sequenced and a phylogenetic tree was constructed. RESULTS HIV prevalence was relatively low and remained stable (0.7-1.6% in pregnant women, 2.1-2.2% in the general population). The prevalence was also stable among prisoners (2.1-2.6%). Among hospitalized and tuberculosis patients prevalence was higher and increased (1.8-12.7% and 1.5-16.2%, respectively). Only three sera had antibodies to HIV-1 group O. The 17 HIV-1 strains represent six different genetic subtypes including type O. CONCLUSION Our data from 1986 to 1994 show a stable and low HIV prevalence in Gabon, and a high genetic diversity of HIV-1 strains. This, also observed in Cameroon, is in contrast to that found elsewhere in Africa. Differences in rate of spread of HIV infection are probably explained by interplay between numerous factors. The role of different HIV subtypes in the dynamics of the HIV epidemic should be examined further.

Low Levels of Antiretroviral-Resistant HIV Infection in a Routine Clinic in Cameroon that Uses the World Health Organization (WHO) Public Health Approach to Monitor Antiretroviral Treatment and Adequacy with the WHO Recommendation for Second-Line Treatment

A cross-sectional study, performed at a routine human immunodeficiency virus (HIV)/AIDS clinic in Cameroon that uses the World Health Organization public health approach, showed low rates of virological failure and drug resistance at 12 and 24 months after initiation of antiretroviral therapy. Importantly, the cross-sectional study also showed that the World Health Organization recommendation for second-line treatment would be effective in almost all patients with HIV drug resistance mutations.

No Difference in Clinical Progression between Patients Infected with the Predominant Human Immunodeficiency Virus Type 1 Circulating Recombinant Form (CRF) 02_AG Strain and Patients Not Infected with CRF02_AG, in Western and West-Central Africa: A Four-Year Prospective Multicenter Study

To compare human immunodeficiency virus (HIV) type 1 disease progression in patients infected by the predominant strain circulating recombinant form (CRF) 02_AG in western and west-central Africa and in patients infected by other strains, a prospective multicenter cohort study was conducted in Cameroon and Senegal. Among the 335 patients, a broad HIV-1 group M subtype diversity was observed in the envelope V3-V5 region, but strain CRF02_AG predominated in both Cameroon and Senegal (61.2% and 62.9%, respectively; P<.8). Multivariate analyses showed no difference between patients infected by CRF02 strains and those infected by other strains in terms of survival (adjusted hazards ratio [HR], 1.16; 95% confidence interval [CI], 0.76-1.78; P=.5), clinical disease progression (HR, 0.79; 95% CI, 0.50-1.25; P=.3), or square root CD4 cell decline (regression coefficient, -0.01; 95% CI, -0.82 to 0.81; P=.9). This study suggests that the predominance of HIV-1 CRF02_AG strain in western and west-central Africa should have no major clinical consequences.

Tolerability and Effectiveness of First-Line Regimens Combining Nevirapine and Lamivudine Plus Zidovudine or Stavudine in Cameroon

We compared the tolerability and effectiveness of two major first-line regimens used in resource-limited settings, namely zidovudine-lamivudine-nevirapine and stavudine-lamivudine-nevirapine. HIV-1-infected adults in Cameroon were enrolled in a prospective cohort study between 2001 and 2003. They were eligible if they had AIDS or a CD4 cell count below 350/mm(3), a Karnofsky score over 50%, and no contraindications to antiretroviral treatment. The patients were followed up to 2 years. Of 169 patients, 85 received zidovudine-lamivudine-nevirapine and 84 stavudine-lamivudine-nevirapine. The incidence rates of treatment changes, death, drug resistance, and severe adverse effects were, respectively, 12.0 [95% confidence interval (CI) 7.2-19.9] and 10.9 (CI 6.4-18.3) per 100 person-years; 5.7 (CI 2.8-11.4) and 7.6 (CI 4.2-13.7); 2.9 (CI 1.1-7.7) and 5.0 (CI 2.4-10.6); and 41.7 (CI 30.2-57.6) and 49.1 (CI 36.1-66.6). The Kaplan-Meier curves for the likelihood of remaining on the initial regimen (p = 0.8) and for survival (p = 0.5) did not differ significantly between the groups. In Cox multivariate analysis only a lower baseline CD4 cell count was associated with death (p < 0.001). The proportion of patients with undetectable viral load and the increase in the CD4 cell count were similar in the two groups. Anemia was rare (4% vs. 6%). Five cases of severe peripheral neuropathy and one case of lipodystrophy occurred. This study suggests that the zidovudine-lamivudine-nevirapine combination is a safe first-line treatment, even in settings with few laboratory resources. In view of stavudine toxicity, these results support recommendations calling for a gradual switch from stavudine- to zidovudine-based regimens.

Identification of a New Circulating Recombinant Form of HIV Type 1, CRF11-cpx, Involving Subtypes A, G, J, and CRF01-AE, in Central Africa

In this study, we characterized three full-length genome sequences with a similar mosaic structure from epidemiologically unlinked individuals from Cameroon (97CM-MP818) and the Central African Republic (99CF-MP1298 and 99CF-MP1307). Phylogenetic and recombinant analysis confirmed that the three strains had a similar complex recombinant genome, which we can designate now as CRF11-cpx. This new CRF was composed of successive fragments of subtype A, G, J, and CRF01-AE. The previously reported GR17 virus from a Greek patient infected in the Democratic Republic of Congo (DRC) has a similar structure and should be considered as the prototype strain of CRF11-cpx. This new CRF circulates in Cameroon, Central African Republic, Gabon, and DRC, although the exact prevalences remain to be determined.