Community Based Antiretroviral Treatment in Rural Zimbabwe.

Treatment of HIV has reduced HIV/AIDS-related mortality. Sustaining >90% virologic suppression in sub-Saharan Africa requires decentralized care and prevention services to rural communities. In Zimbabwe, the number of people receiving antiretroviral treatment (ART) has increased rapidly. However, access to treatment monitoring tools such as viral load and drug resistance testing is limited. We assessed virologic treatment outcomes among ART recipients in Nyamutora, a rural community receiving bimonthly ART and prevention services. We enrolled all ART recipients (143) at 6-monthly visits in the Nyamutora community in 2014 and 2015. Whole blood samples were collected in K-EDTA tubes, transported to Harare for CD4 counts and viral load testing, and genotype was obtained in participants with viral loads >1,000 copies/ml. Ages ranged from 2 to 75 years (median 43 years) with a median 42 months on ART at follow-up. Eight of 143 (6%) had viral loads >1,000 copies/ml at one of the 3 visits, 7 on first-line nevirapine (NVP)-based ART and 1 on second-line LPV/r-based ART. Seven participants had sequence data available, and five had drug resistance mutations, K65R, T69N, K101E, K103N, Y181C/I, M184V, and G190A. Virologic failure (p = .001) and drug resistance mutations (p = .01) on first-line NVP-based ART were associated with younger age by univariate exact logistic regression. The participants had high viral suppression (94%) despite less than optimal (NVP based) ART regimens without laboratory monitoring. Virologic failure and drug resistance were higher among children and adolescents. Effective ART delivery to the community achieved high rates of virologic suppression and minimal drug resistance.

The role of resistance in HCV treatment.

The recent development of small molecule compounds that directly inhibit the viral life cycle represents a major milestone for the treatment of chronic hepatitis C virus (HCV) infection. These new drugs that are collectively termed direct-acting antivirals (DAA) include a range of inhibitors of the non-structural (NS) 3/4A protease, NS5B polymerase and NS5A protein. Two NS3/4A protease inhibitors (boceprevir and telaprevir) in combination with pegylated interferon and ribavirin have now been approved for the treatment of chronic HCV genotype 1 infection and cure rates could be increased by 20-30%. However, the majority of DAAs is still in early clinical development. The rapid replication rate of HCV, along with the error-prone polymerase activity leads to a high genetic diversity among HCV virions that includes mutants with reduced susceptibility to DAA-therapy. These resistance-associated variants often occur at very low frequencies. However, during DAA-based treatment, rapid selection of resistance mutations may occur, eventually leading to viral break-through. A number of variants with different levels of resistance have been described in vitro and in vivo for virtually all DAAs. We review the parameters that determine DAA resistance as well as the clinical implications of resistance testing. In addition, the most recent literature and conference data on resistance profiles of DAAs in clinical development and future strategies to avoid the emergence of viral resistance are also discussed.

Hepatoprotective effects and HSV-1 activity of the hydroethanolic extract of Cecropia glaziovii (embaúba-vermelha) against acyclovir-resistant strain.

CONTEXT: Cecropia glaziovii Snethl. (Cecropiaceae), commonly known as "embaúba-vermelha", is widely distributed throughout Latin America and has been reported in Brazilian folk medicine to treat cough, asthma, high blood pressure and inflammation. OBJECTIVE: Investigate the hepatoprotective properties of crude hydroethanolic extract of C. glaziovii as well as its in vitro antioxidant and antiviral (HSV-1 acyclovir resistant strain) activities. MATERIALS AND METHODS: The hepatoprotective effect, the antioxidant properties and antiviral activity of crude hydroethanol extract (RCE40) from C. glaziovii leaves were evaluated by carbon-tetrachloride (CCl(4))-induced hepatotoxicity, by TBARS (thiobarbituric acid reactive species) and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays, respectively. RESULTS: The RCE40 extract (20 mg/kg) inhibited lipid peroxidation on liver in post injury treatment and decreased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In addition, in this protocol the RCE40 (20 mg/kg) enhanced the activity of hepatic enzymes (SOD/CAT) which are involved in combating reactive oxygen species (ROS), suggesting that it possesses the capacity to attenuate the CCl(4)-induced liver damage. Moreover the RCE40 (20 mg/kg) inhibited TBARS formation induced by several different inductors of oxidative stress showing significant antioxidant activity, including physiologically relevant concentration, as low as 2 µg/mL. Concerning antiviral activity, the RCE40 was effective against herpes simplex virus type 1 replication (29R acyclovir resistant strain) with EC(50) = 40 µg/mL and selective index (SI) = 50. DISCUSSION AND CONCLUSION: These results indicate that C. glaziovii could be a good source of antioxidant and anti-HSV-1 lead compounds.

Antiviral treatment of calves persistently infected with bovine viral diarrhoea virus.

BACKGROUND: Animals persistently infected (PI) with bovine viral diarrhoea virus (BVDV) are a key source of viral propagation within and among herds. Currently, no specific therapy exists to treat PI animals. The purpose of this research was to initiate evaluation of the pharmacokinetic and safety data of a novel antiviral agent in BVDV-free calves and to assess the antiviral efficacy of the same agent in PI calves. METHODS: One BVDV-free calf was treated with 2-(2-benzimidazolyl)-5-[4-(2-imidazolino)phenyl]furan dihydrochloride (DB772) once at a dose of 1.6 mg/kg intravenously and one BVDV-free calf was treated three times a day for 6 days at 9.5 mg/kg intravenously. Subsequently, four PI calves were treated intravenously with 12 mg/kg DB772 three times a day for 6 days and two PI control calves were treated with an equivalent volume of diluent only. RESULTS: Prior to antiviral treatment, the virus isolated from each calf was susceptible to DB772 in vitro. The antiviral treatment effectively inhibited virus for 14 days in one calf and at least 3 days in three calves. Subsequent virus isolated from the three calves was resistant to DB772 in vitro. No adverse effects of DB772 administration were detected. CONCLUSIONS: Results demonstrate that DB772 administration is safe and exhibits antiviral properties in PI calves while facilitating the rapid development of viral resistance to this novel therapeutic agent.

Replicative phenotyping adds value to genotypic resistance testing in heavily pre-treated HIV-infected individuals--the Swiss HIV Cohort Study.

BACKGROUND: Replicative phenotypic HIV resistance testing (rPRT) uses recombinant infectious virus to measure viral replication in the presence of antiretroviral drugs. Due to its high sensitivity of detection of viral minorities and its dissecting power for complex viral resistance patterns and mixed virus populations rPRT might help to improve HIV resistance diagnostics, particularly for patients with multiple drug failures. The aim was to investigate whether the addition of rPRT to genotypic resistance testing (GRT) compared to GRT alone is beneficial for obtaining a virological response in heavily pre-treated HIV-infected patients. METHODS: Patients with resistance tests between 2002 and 2006 were followed within the Swiss HIV Cohort Study (SHCS). We assessed patients' virological success after their antiretroviral therapy was switched following resistance testing. Multilevel logistic regression models with SHCS centre as a random effect were used to investigate the association between the type of resistance test and virological response (HIV-1 RNA <50 copies/mL or ≥1.5 log reduction). RESULTS: Of 1158 individuals with resistance tests 221 with GRT+rPRT and 937 with GRT were eligible for analysis. Overall virological response rates were 85.1% for GRT+rPRT and 81.4% for GRT. In the subgroup of patients with >2 previous failures, the odds ratio (OR) for virological response of GRT+rPRT compared to GRT was 1.45 (95% CI 1.00-2.09). Multivariate analyses indicate a significant improvement with GRT+rPRT compared to GRT alone (OR 1.68, 95% CI 1.31-2.15). CONCLUSIONS: In heavily pre-treated patients rPRT-based resistance information adds benefit, contributing to a higher rate of treatment success.

Simian immunodeficiency virus is susceptible to inhibition by carbohydrate-binding agents in a manner similar to that of HIV: implications for further preclinical drug development.

Carbohydrate-binding agents (CBAs), such as the plant lectins Hippeastrum hybrid agglutinin (HHA) and Urtica dioica agglutinin (UDA), but also the nonpeptidic antibiotic pradimicin A (PRM-A), inhibit entry of HIV into its target cells by binding to the glycans of gp120. Given the high sequence identity and similarity between the envelope gp120 glycoproteins of HIV and simian immunodeficiency virus (SIV), the inhibitory activity of a variety of CBAs were evaluated against HIV-1, HIV-2, and SIV. There seemed to be a close correlation for the inhibitory potential of CBAs against HIV-1, HIV-2, and SIV replication in cell culture and syncytia formation in cocultures of persistently SIV-infected HUT-78 cell cultures and uninfected CEM cells. CBAs also inhibit transmission of the SIV to T lymphocytes after capture of the virus by dendritic cell-specific ICAM3-grabbing nonintegrin (DC-SIGN)-expressing cells. A total of 8 different SIV strains were isolated after prolonged HHA, UDA, and PRM-A exposure in virus-infected cell cultures. Each virus isolate consistently contained at least 2 or 3 glycan deletions in its gp120 envelope and showed decreased sensitivity to the CBAs and cross-resistance toward all CBAs. Our data revealed that CBAs afford SIV and HIV-1 inhibition in a similar manner regarding prevention of virus infection, DC-SIGN-directed virus capture-related transmission, and selection of drug-resistant mutant virus strains. Therefore, SIV(mac251)-infected monkeys might represent a relevant animal model to study the efficacy of CBAs in vivo.

The emergence of HIV transmitted resistance in Botswana: "when will the WHO detection threshold be exceeded?".

BACKGROUND: The Botswana antiretroviral program began in 2002 and currently treats 42,000 patients, with a goal of treating 85,000 by 2009. The World Health Organization (WHO) has begun to implement a surveillance system for detecting transmitted resistance that exceeds a threshold of 5%. However, the WHO has not determined when this threshold will be reached. Here we model the Botswana government's treatment plan and predict, to 2009, the likely stochastic evolution of transmitted resistance. METHODS: We developed a model of the stochastic evolution of drug-resistant strains and formulated a birth-death Master equation. We analyzed this equation to obtain an analytical solution of the probabilistic evolutionary trajectory for transmitted resistance, and used treatment and demographic data from Botswana. We determined the temporal dynamics of transmitted resistance as a function of: (i) the transmissibility (i.e., fitness) of the drug-resistant strains that may evolve and (ii) the rate of acquired resistance. RESULTS: Transmitted resistance in Botswana will be unlikely to exceed the WHO's threshold by 2009 even if the rate of acquired resistance is high and the strains that evolve are half as fit as the wild-type strains. However, we also found that transmission of drug-resistant strains in Botswana could increase to approximately 15% by 2009 if the drug-resistant strains that evolve are as fit as the wild-type strains. CONCLUSIONS: Transmitted resistance will only be detected by the WHO (by 2009) if the strains that evolve are extremely fit and acquired resistance is high. Initially after a treatment program is begun a threshold lower than 5% should be used; and we advise that predictions should be made before setting a threshold. Our results indicate that it may be several years before the WHO's surveillance system is likely to detect transmitted resistance in other resource-poor countries that have significantly less ambitious treatment programs than Botswana.

Monitoring drug resistance in chronic hepatitis B virus (HBV)-infected patients during lamivudine therapy: evaluation of performance of INNO-LiPA HBV DR assay.

Sensitive and early detection of emerging hepatitis B virus (HBV) drug resistance may not only help monitor the viral dynamics associated with lamivudine treatment but could also improve therapeutic decision making. This is especially important when new antivirals effective against lamivudine-resistant HBV become available. A total of 159 serum samples from 33 chronic HBV patients receiving lamivudine treatment were analyzed at four centers for the presence of lamivudine-resistant mutations at codons 528 [180] (proposed revised nomenclature according to Stuyver et al. [Hepatology 33:751-757, 2001] shown in brackets), 552 [204], and 555 [207] of the HBV polymerase. Sequencing data were compared with results generated by the INNO-LiPA HBV DR line probe assay (LiPA), an assay based on reverse hybridization of amplified HBV DNA fragments with specific nucleotide probes immobilized on nitrocellulose strips. LiPA provided at least the same information as sequencing for 97.5% of all codons analyzed for codon 528 [180], 95% for codon 552 [204], and 100% for codon 555 [207]. The most common reason for discrepant or indeterminate results (0.4% and 1.5%, respectively) in a small percentage of the population tested could be attributed to polymorphisms not yet covered by LiPA probes. In at least five patients, a mutant could be detected earlier by LiPA than by sequencing. In 15 patients, LiPA detected mixed wild-type and mutant virus populations before viral breakthrough. These results demonstrate that INNO-LiPA HBV DR is a highly sensitive and easily applicable assay for the detection and monitoring of lamivudine-resistant mutations in chronic hepatitis B patients and that the assay is more sensitive than sequencing in detecting mixed mutant and wild-type sequences.