[An experience of hepatitis B control in a rural area in Far North Cameroon]. / Une expérience de lutte contre l'hépatite B en zone rurale à l'extrême nord du Cameroun.

Experience of four years of control of the transmission of hepatitis B in a rural area in Far North Cameroon is presented: (i) prevention of mother to child transmission, (ii) HBsAg screening before blood transfusion, (iii) detection of HIV/HBV co-infections, (iv) protection of healthcare workers. The prevalence of HBsAg is very high in the four populations studied: 18.2% of pregnant women, 16.9% of candidate for blood donation, 14.4% of people living with HIV and 18 % of healthcare workers. Despite limited resources, effective actions are possible. Prevention of mother to child transmission of HBV with vaccination at birth has been set up, with bottlenecks - similar to those observed in HIV - but decreasing over the study. The screening of all potential blood donors has been reached over the years for HIV, HBsAg and HCV, which has led to the eviction of one out of five potential blood donors. Screening of healthcare workers reminded us that adult protection is based on a very early vaccination and not when hiring, even if it is possible to diagnose rare adults eligible for vaccination by research of anti-HBc antibody. A program of hepatitis B control, essential in Africa, appears feasible in rural areas in a framework of an overall improvement in care delivery.

[Viral markers of hepatitis B, C and D and HB vaccination status of a health care team in a rural district of Cameroon]. / Marqueurs d'infection par virus des hépatites B, C et D et vaccination contre l'hépatite B chez des personnels de santé d'un district rural du Cameroun.

UNLABELLED: Ninety-three health care workers (HCW) in the Tokombere sahelian district volunteered to participate in a trial to investigate viral markers of hepatitis B, C, and D and HB vaccination status. METHODS: . Sera were tested using the Vikia HBsAg kit followed by CMIA for detection of HBsAg, anti-HBs, anti-HBc, and anti-HCV. HBsAg-positive HCW were tested for HBV-DNA, anti-HDV, and, if positive for anti-HDV, HDV-RNA. RESULTS: Analysis of anti-HBc positivity indicated that 91% of HCW had been infected by HBV, regardless of vaccination history. Vikia HBsAg results were confirmed by chemiluminescent microparticle immunoassay (CMIA) in all HCW and were positive in 17 HCW with virus load >2000 IU/mL in 6 and HDV co-infection in 6. Anti-HCV was found in 6 HCW. Among the 55 HCW that had not been vaccinated, only 3 needed vaccination because of anti-HBc negativity. Among HCW considered for HBV treatment, one patient presenting HBV/HDV co-infection was excluded after diagnosis of hepatocarcinoma. CONCLUSION: Systematic HB vaccination of new HCW appears unnecessary in this rural region of Africa. Anti-HBc screening is cost-effective for identifying HCW requiring vaccination. Vikia HBsAg is effective for point-of-care screening. We underline the need for universal early (preferably neonatal) HB vaccination and for availability of anti-HBV drug in limited-resource countries.

[Measure of effectiveness and adherence to antiretroviral therapy in HIV-infected patients in Cameroon]. / Mesure de l'efficacité et de l'observance du traitement antirétroviral chez des patients infectés par le VIH au Cameroun.

OBJECTIVE: The aim of the study was to identify the most useful clinical criteria to measure effectiveness and adherence to antiretroviral treatment in a rural area of Cameroon. PATIENTS AND METHOD: All patients under antiretroviral therapy followed for at least 3 months at the Tokombéré UPEC hospital were eligible. Therapeutic failure was defined according to clinical criteria including weight, Karnofsky's index, or occurrence of WHO stage IV conditions. The criteria for drug adherence were based on patient statement (drugs taken over the last 4 days) and pharmacy-controlled drug delivery. Patient sociodemographic characteristics were collected via a questionnaire. RESULTS: Fifty-six patients were included, most of whom were at AIDS stage on treatment initiation. The mean duration of antiretroviral therapy was 1 year. 21, 10, and 19% of patients were in therapeutic failure according to "weight", "Karnofsky's index", and "WHO stage IV", respectively. Non-adherence was reported in 5% of patients according to the declarative method and 20% according to pharmacy controlled drug delivery. Weight modification during treatment was significantly correlated with the evolution of Karnofsky's index (p=0.03). A significant correlation between therapeutic failure and non-observance was only found when using the weight criterion and the declarative method (p=0.004). CONCLUSION: The effectiveness and adherence to antiretroviral therapy can be evaluated by simple clinical criteria. Using these criteria can be recommended in rural areas until access to biological follow-up becomes available in developing countries.

[Herpes simplex virus vaccines: perspectives]. / Vaccination antiherpès simplex virus: perspectives.

PURPOSE: Despite effective antiviral therapy, infection with herpes simplex virus (HSV) is a critical public health issue, particularly genital herpes by its social and psychological burden and its contribution to the neonatal herpes and possibly to the HIV/AIDS pandemic. CURRENT KNOWLEDGE: Many prophylactic and therapeutic vaccination approaches have been explored but no effective vaccine is presently available. In fact, as members of the Herpesviridae family, both HSV-1 and 2 types have genes involved in immune evasion. FUTURE PROSPECTS: Further research is needed to define determinants of immunity in order to design more effective vaccines.

P-glycoprotein in blood CD4 cells of HIV-1-infected patients treated with protease inhibitors.

OBJECTIVE: Many factors are involved in the virological failure of antiretroviral treatments such as low pharmacological plasma levels of drugs, poor adherence to therapy and emergence of viral resistance. P-glycoprotein (P-gp) has been demonstrated to play a role in multidrug resistance in the therapy of solid tumours, haematological malignancies and Plasmodium falciparum infection. HIV-1 protease inhibitors (PIs) have been described to be substrates of P-gp. In vitro and in vivo studies performed in mice have demonstrated that P-gp may affect the oral bioavailability and intracellular accumulation of PIs. P-gps have been detected on peripheral CD4 blood cells in HIV-1-infected, but antiretroviral-naive patients. METHOD: We quantified P-gp expression and performed functional tests of P-gp activity in the CD4 cells in HIV-1-infected patients, with and without virological failure, treated with PIs, and in healthy patients (control group). RESULT: Out of the 18 HIV-infected patients studied, P-gp expression and function were found in the CD4 cells of six patients (four of 10 without, and two of eight with virological failure). Out of the 43 healthy patients studied, P-gp expression and function were found in the CD4 cells of 11 patients (26%). We found P-gp in peripheral CD4 cells of patients treated with PIs, with and without virological failure, within the same frequency than in antiretroviral naive patients or than in non HIV-infected patients. CONCLUSIONS: P-gp expression in peripheral CD4 blood cells does not seem to be enhanced by PI treatment and does not seem to be linked particularly to virological failures. These facts do not preclude of the role of P-gp on PI absorption or efficacy in other compartments of the body such as gut, lymph nodes or brain in HIV-1 PI-treated patients.

[Genital herpes and pregnancy. Preventive measures for neonatal HSV infections: 1993 consensus conference and new proposals]. / Herpès génital et grossesse. Mesures de prévention de l'herpès du nouveau-né: conférence de consensus de 1993 et nouvelles propositions.

The following document contains four parts The proposals distinguish four maternal situations It is proposed that cesarean section and aciclovir prophylaxis be reserved for women in the first two situations. The proposals also encourage systematic use of condoms during pregnancy and information for the mother before discharge from the maternity ward concerning surveillance of the newborn at risk. Systematic serology tests for HSV type 1 or 2 or PCR are not proposed.

Effects of cyclosporine and hydrocortisone on Kaposi's sarcoma-associated herpesvirus genome replication and cell apoptosis induction.

BACKGROUND: Iatrogenic immunosuppressed patients are at increased risk for development of various cancers that comprise Kaposi's sarcoma (KS). METHODS: To investigate the direct impact of immunosuppressive agents on Kaposi's sarcoma-associated herpesvirus (KSHV) and KS development, we quantified the effects of cyclosporine (CsA) and hydrocortisone (HC) on KSHV genome replication and the consequences on the cell survival. RESULTS: In the presence of phorbol ester 12-O-tetradecanoyl phorbol-13-acetate, we observed an increase of intracellular and extracellular KSHV DNA concomitantly with an increase of gp (glycoprotein) K8.1 expression, indicating KSHV genome replication. This replication was accompanied by cell apoptosis. In comparison, in the presence of CsA, HC, or both, we did not observe any effect on KSHV replication or gp K8.1 expression. CONCLUSION: Our results suggest that immunosuppressive agents such as HC and CsA do not activate the lytic cycle of KSHV and do not modify the cell survival thus promoting cancer progression by a direct cellular effect.

Clinical and virologic characterization of acyclovir-resistant varicella-zoster viruses isolated from 11 patients with acquired immunodeficiency syndrome.

We studied the clinical resistance to acyclovir of infections with varicella-zoster viruses (VZV) in patients with acquired immunodeficiency syndrome, and we correlated it to virologic analyses. Eleven patients with VZV infections (treated with acyclovir, 30 mg/kg/day, given intravenously, or 4 g/day, given orally) were included in the study because of the failure of 10 days of acyclovir therapy. Susceptibility of VZV isolates to acyclovir was tested using a plaque reduction assay to determine the 50% inhibitory concentration (IC(50)) of acyclovir and the SI(50) (IC(50) of the patient isolate/IC(50) of the reference strain) to acyclovir. The thymidine kinase (TK) gene, which supports the resistance, was sequenced on amplified products. Only 3 patients had a significant increase in the IC(50), as compared with the IC(50) of the reference strain (SI(50) of > or =4), and a mutation in the TK gene. For the other 8 patients, the clinical resistance was not confirmed by the virologic results: the SI(50) was < 4, and no mutation was detected in the TK gene. Because no acyclovir-resistant strain appeared during a shorter period of time, we suggest an increase in the duration of the treatment to 21 days before acyclovir resistance is suspected.

Resistance profile and cross-resistance of HIV-1 among patients failing a non-nucleoside reverse transcriptase inhibitor-containing regimen.

The objectives were to determine the resistance profile and the rate of cross-resistance in HIV-1 infected patients failing an efavirenz or a nevirapine or a nevirapine then efavirenz containing regimens, and to investigate if zidovudine and more generally thymidine analog nucleosides lead to a particular genotypic pattern in nevirapine failing patients. A study was conducted in 104 patients with virological rebound to a non-nucleoside reverse transcriptase inhibitors (NNRTI) regimen (efavirenz n = 39, nevirapine n = 46 and nevirapine then efavirenz n = 19). Genotypic resistance testing was carried out of detectable plasma HIV-1 RNA (> 200 copies/ml). Among the 104 patients studied, only two patients failed to respond to the nevirapine regimen without selection of a NNRTI resistance mutation. All patients failing an efavirenz regimen harboured mutations conferring cross-resistance to nevirapine (K103N, Y188L, G190S). Among patients failing the nevirapine regimen and presenting with NNRTI mutations, 35 (80%) harboured mutations conferring cross-resistance to efavirenz (K101E, K103N, Y188L) and 9 (20%) harboured mutations conferring resistance to nevirapine alone (V106A and Y181C). In patients failing nevirapine then efavirenz therapy, all NNRTI resistance profile led to cross-resistance to all available NNRTIs. Among patients receiving nevirapine, the selection of mutations associated with a cross-resistance to efavirenz was more frequent statistically when a thymidine nucleoside analog (zidovudine or stavudine) was used in the regimen (P = 0.02). In conclusion, 100% of patients developed cross-resistance to nevirapine and efavirenz after treatment by efavirenz and 80% after treatment by nevirapine. The use of a thymidine analog concomitantly with nevirapine leads to the preferential selection of cross-resistance NNRTI mutations.

Efficacy of dideoxynucleosides against human foamy virus and relationship to its reverse transcriptase amino acid sequence and structure.

Human foamy virus (HFV), a retrovirus of simian origin which occasionally infects humans, is the basis of retroviral vectors in development for gene therapy. Clinical considerations of how to treat patients developing an uncontrolled infection by either HFV or HFV-based vectors need to be raised. We determined the susceptibility of the HFV to dideoxynucleosides and found that only zidovudine was equally efficient against the replication of human immunodeficiency virus type 1 (HIV-1) and HFV. By contrast, zalcitabine (ddC), lamivudine (3TC), stavudine (d4T), and didanosine (ddI) were 3-, 3-, 30-, and 46-fold less efficient against HFV than against HIV-1, respectively. Some amino acid residues known to be involved in HIV-1 resistance to ddC, 3TC, d4T, and ddI were found at homologous positions of HFV reverse transcriptase (RT). These critical amino acids are located at the same positions in the three-dimensional structure of HIV-1 and HFV RT, suggesting that both enzymes share common patterns of inhibition.

Prevalence and conditions of selection of E44D/A and V118I human immunodeficiency virus type 1 reverse transcriptase mutations in clinical practice.

Recently, it has been shown that a new mutational pattern (the E44D/A and/or V118I mutation) confers moderate phenotypic lamivudine resistance in the absence of the M184V mutation. The E44D/A and/or the V118I mutation does not exist in drug-naive patients, and the prevalence increases with the number of treatment regimens and lamivudine experience. The mutations can preexist in nucleoside-experienced but lamivudine-naive patients. They are always associated with zidovudine resistance-associated mutations, even in the absence of M184V. These mutations are more stable than the M184V substitution during antiretroviral treatment interruptions.

Hepatitis virus infections in heart transplant recipients: epidemiology, natural history, characteristics, and impact on survival.

BACKGROUND & AIMS: We have observed a high prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in heart transplant recipients (HTRs). The aim of this study was to assess the epidemiology, natural history, and clinical and biological characteristics of viral hepatitis in HTRs. METHODS: From 1983 to 1992, 874 patients underwent heart transplantation at the Pitié-Salpêtrière Hospital, Paris, France, 459 of whom qualified for analysis. A total of 140 patients had posttransplantation hepatitis B, C, or non-A-E. Sixty-nine patients developed HBV infection, 49 HCV infection, 11 HBV-HCV coinfection, and 11 non-A-E hepatitis. RESULTS: HBV was transmitted nosocomially from patient to patient, most likely during endomyocardial biopsies. HCV was mainly transmitted through blood transfusions or the transplanted organ. Clinical and biological findings after 2 years of follow-up showed that 3 patients with an HBV genotype A precore mutant had severe or subfulminant hepatitis and that patients with HBV and HCV infection always progressed to chronicity. In general, patients had mild alanine aminotransferase level increases, a high level of viral replication, and few severe histologic lesions, except for patients infected by precore HBV mutants. Patients coinfected by HBV and HCV tended to have more severe liver lesions. The survival rate 5 years after transplantation in patients with viral hepatitis (HBV, 81%; HCV, 89%; HBV and HCV coinfection, 100%; non-A-E hepatitis, 73%) was similar to that in patients without liver test abnormalities (76%). The actuarial survival curve was also similar in patients with or without liver test abnormalities. CONCLUSIONS: In our experience, histologic liver lesions do not progress rapidly in patients with post-heart transplant infection caused by HBV or HCV. HBV or HCV infection seems to have little impact on the 5-year survival rate of HTRs.

Comparative analysis of translation efficiencies of hepatitis C virus 5' untranslated regions among intraindividual quasispecies present in chronic infection: opposite behaviors depending on cell type.

Hepatitis C virus (HCV) RNA translation initiation is dependent on the presence of an internal ribosome entry site (IRES) that is found mostly in its 5' untranslated region (5' UTR). While exhibiting the most highly conserved sequence within the genome, the 5' UTR accumulates small differences, which may be of biological and clinical importance. In this study, using a bicistronic dual luciferase expression system, we have examined the sequence of 5' UTRs from quasispecies characterized in the serum of a patient chronically infected with HCV genotype 1a and its corresponding translational activity. Sequence heterogeneity between IRES elements led to important changes in their translation efficiency both in vitro and in different cell cultures lines, implying that interactions of RNA with related transacting factors may vary according to cell type. These data suggest that variants occasionally carried by the serum prior to reinfection could be selected toward different compartments of the same infected organism, thus favoring the hypothesis of HCV multiple tropism.

Susceptibility of human herpesvirus 6 to antiviral compounds by flow cytometry analysis.

BACKGROUND: The emergence of human herpesvirus 6 (HHV-6) as a human pathogen led to the possibility of specific therapy against HHV-6 and the development of standardized susceptibility assays of HHV-6 to antivirals. METHODS: We have developed a flow cytometry method to analyze the multiplication of the HST strain of human herpesvirus 6 (HHV-6) variant B in vitro using monoclonal antibodies specific to virus proteins. This method was subsequently used to determine the sensitivity of HST multiplication in MT4 cells to four antiviral compounds of three different classes: acyclovir (ACV) and ganciclovir (GCV), two acyclic guanosine analogs; cedofovir (CDV), an acyclic nucleoside phosphonate; and phosphonoformic acid (PFA), a pyrophosphate analog. RESULTS: The 50% inhibitory concentrations (IC(50)) of ACV, GCV, CDV, and PFA determined by flow cytometry assay were 25.3, 6.4, 0.95, and 6.0 microM, respectively (5.7, 1.6, 0.3, and 1.8 microg/ml, respectively). These data together with the results of cytotoxicity assays confirmed the high efficiency and selectivity of CDV and PFA against HHV-6 B in vitro, suggested by previous results. CONCLUSIONS: Our flow cytometric assay appeared as a reproducible specific method to characterize HHV-6 susceptibility to antiviral compounds. It can be considered as a convenient alternative to the other immunologic and DNA hybridization assays used for that purpose.

Preferential associations of alleles of three distinct genes argue for the existence of two prototype variants of human herpesvirus 7.

We had previously described six distinct alleles of the glycoprotein B (gB) gene of human herpesvirus 7 (HHV-7). The genetic changes corresponding to these alleles did not affect gB gene transcription or translation in in vitro assays. The study of distinct HHV-7-positive human samples showed preferential associations of some gB alleles with some alleles of two other genes, distantly located on the HHV-7 genome, coding for the phosphoprotein p100 (p100) and the major capsid protein (MCP). Two allele combinations, corresponding to 44 and 31% of the samples studied, respectively, were interpreted as the genetic signatures of two major prototype HHV-7 variants.

Point mutations in the varicella-zoster virus DNA polymerase gene confers resistance to foscarnet and slow growth phenotype.

Seven independent laboratory mutants were derived from seven distinct wild-type varicella-zoster virus (VZV) isolates after exposure to increasing concentrations of foscarnet (PFA) and were found to be resistant to this drug. Single base changes resulting in amino acid substitutions were observed in the nucleotide sequence of the DNA polymerase gene of each PFA-resistant mutant. The mutations were found to occur within the domain II (Arg-665 --> Gly for strains vrMOR and vrVER; Val-666 --> Leu for vrLEB; Gln-692 --> Arg for vrOLI) and domain III (Arg-806 --> Ser for vrABD; Leu-809 --> Ser for vrALI and vrCHA) of DNA polymerase gene. In addition, the PFA-resistant mutants exhibited a phenotype characterized by slow growth, the strains showing a marked delay in immediate-early antigen plaque formation compared with the wild-type VZV from which they were derived. These results may have implications for successful isolation and characterization of PFA-resistant strains from clinical samples containing mixed viral populations.

Polymorphism of the human immunodeficiency virus type 1 (HIV-1) protease gene and response of HIV-1-infected patients to a protease inhibitor.

In order to analyze the impact of protease gene polymorphism on response to regimens containing a protease inhibitor, the entire protease coding domain from 58 human immunodeficiency virus type 1 (HIV-1)-infected patients who were protease inhibitor naive was sequenced before therapy was started. Plasma HIV-1 RNA levels were measured at baseline and at month 3 and month 6 after treatment. All patients were treated with a combination of two reverse transcriptase inhibitors and a protease inhibitor (saquinavir EOF [n = 28], ritonavir [n = 16], or indinavir [n = 14]). Before treatment, 30 different positions whose codons differed from the subtype B consensus sequence were observed. Major mutations associated with protease inhibitor resistance were not observed. No statistical correlation between the number of amino acid differences and the treatment efficacy at month 3 (-2.4 log) or month 6 (-2.7 log) was observed. At baseline, genotypic analysis of the HIV-1 protease gene of patients who have never received a protease inhibitor does not allow prediction of the efficacy of regimens containing a protease inhibitor.

[Polymorphism of protease genes in patients infected with HIV-1 and response to therapy including a protease inhibitor]. / Etude du polymorphisme du gène de la protéase de patients infectés par le VIH-1 et réponse à un traitement comprenant un inhibiteur de la protéase.

Protease inhibitors (PIs) are recently introduced drugs that have improved the survival of HIV-infected patients when given in combination with two reverse transcriptase inhibitors. The HIV-1 protease gene is naturally highly polymorphic. Selection pressure due to IP use can result in major or minor resistance-associated mutations (RAMs). This study investigated whether presence before IP therapy of minor RAMs on the protease gene predicts the virological response. Of the 58 PI-naive patients included in the study, 12 had received two nucleoside reverse transcriptor inhibitors, 14 had received indinavir, 16 ritonavir, and 28 saquinavir-SGC. Viral load was measured on D0 (prior to PI initiation) and at M3 and M6 (Roche Monitor 1.5 with 200 and 20 copies/ml as the thresholds). The protease gene was fully sequenced on D0 using the ABI 377 automatic sequencer after RNA amplification by nested RT-PCR. None of the viral strains exhibited major mutations, but 57 of 58 (98%) had at least one minor mutation (median number of substitutions, 4), 60% had 1 to 4 substitutions, and 40% had 5 to 9 substitutions. Substitutions seen with a prevalence > 20% were located at codons 15, 35, 37, 41, 63, and 77. Numbers of substitutions at M3 and M6 were not correlated with viral load or the nature of the PI used, and neither were they significantly different between patients with more or fewer than 20 copies/ml. These data suggest that the protease genotype at PI initiation does not predict the efficacy of a regimen including a PI and is of no assistance in deciding whether or not to include a PI in a triple combination regimen.

The influence of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma.

To assess the clinical and biological benefit of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma (KS), 13 patients with AIDS-associated Kaposi's sarcoma (five pulmonary KS and eight cutaneous KS) were prospectively followed for a mean duration of 12 months. Six patients were treated with specific anti-KS chemotherapy before or simultaneously with the introduction of antiretroviral therapy. Clinical response was assessed according to the AIDS Clinical Trial Group (ACTG) criteria. CD4 cell counts, plasma HIV-1 RNA and human herpesvirus 8 (HHV-8) viraemia were measured at baseline and at different points. Among patients with pulmonary KS, we observed three complete responses (CR), one partial response (PR) and one progression. The median survival time after the diagnosis of pulmonary KS was 15 months with a median duration of the response after the discontinuation of specific chemotherapy for KS of 8 months. Among patients with cutaneous KS, we observed four CR, three PR and one stable response. A complete response was significantly associated with a reversal in HHV-8 viraemia (five of six vs. one of six; P = 0.02, Mann-Whitney test).