During 2007-2008, surveillance of transmitted human immunodeficiency virus (HIV) drug resistance (TDR) was performed following World Health Organization guidance among clients with newly diagnosed HIV infection attending voluntary counseling and testing (VCT) sites in Ho Chi Minh City (HCMC), Vietnam. Moderate (5%-15%) TDR to nonnucleoside reverse-transcriptase inhibitors (NNRTIs) was observed among VCT clients aged 18-21 years. Follow-up surveillance of TDR in HCMC and other geographic regions of Vietnam is warranted. Data generated will guide the national HIV drug resistance surveillance strategy and support selection of current and future first-line antiretroviral therapy and HIV prevention programs.

Background In countries where antiretroviral therapy has been available or is being rapidly expanded, the World Health Organization (WHO) recommends surveillance for transmitted HIV drug resistance (HIVDR) by threshold surveillance methods using specimens from antenatal clinics or voluntary counselling and testing (VCT) sites. The aim of this study was to implement the HIVDR threshold survey in VCT sites in Vietnam, where HIV prevalence is high. Estimating transmitted resistance in the infected population will enable the appropriateness of current antiretroviral drug regimens to be assessed and will inform plans for future HIVDR surveillance. Methods Consecutive blood specimens were collected from 70 newly diagnosed HIV-positive clients 18–24 years of age at two sites in Hanoi, Vietnam. Informed consent and serum specimens were obtained from each eligible client, with serum frozen at -70°C until shipping to Thailand for resistance testing using the TruGene system. Results From February until August 2006, 559 clients were eligible to participate in this survey. Of the 535 clients (95.7%) who agreed to participate, 70 (13%) were HIV-positive and were included in the survey. Of the 70 specimens sent for genotyping, 52 consecutive samples were amplified, 49 of which could be genotyped. Only 1 of 49 genotyped specimens had mutations associated with drug resistance (L74V and Y181C) in the reverse transcriptase gene, indicating that the prevalence of transmitted HIVDR to all drugs and drug classes evaluated was <5%. Conclusion The prevalence of transmitted HIVDR was low in Hanoi as determined using threshold surveillance methods. The Ministry of Health plans to repeat this survey methodology in one more province and to confirm these findings by expanded HIVDR surveillance.

The pure SrTiO3 nanoparticles were synthesized  by sol-gel method and Ag2O loaded SrTiO3 (Ag2O/SrTiO3) was prepared by precipitation method. The obtained samples were characterized with powder X-ray diffraction (XRD), transmission electron microscope (TEM) and UV-visible diffuse reflection spectrum (DRS). The effect of Ag2O loading on the photocatalytic activity of Ag2O/SrTiO3 nanoparticles for the degradation of methyl orange (MO) as amodel pollutant under visible light irradiation was studied. Compared with pure SrTiO3 nanoparticles, the Ag2O/SrTiO3 nanoparticle displayed higher photocatalytic activity for the degradation of methyl orange and the 5 % Ag2O/SrTiO3 photocatalyst exhibited the highest photocatalytic activity.

Titanium dioxide nanocomposites/multi-walled carbon nanotubes (TiO2/MWCNTs) were successfully synthesized by hydrothermal method. The synthesized TiO2/MWCNTs nanocomposites (10, 30 and 50% TiO2/MWCNTs) nanocomposites were characterized with powder X-ray diffraction (XRD), transmission electron microscope(TEM) and UV–visible diffuse reflection spectrum (DRS). The photocatalytic activity of TiO2/MWCNTs nanocomposite for the degradation of Rhodamin B (RhB) under visible light irradiation was studied. Compared with pure TiO2 nanoparticles, the TiO2/MWCNTs nanocomposite displayed higher photocatalytic activity for the degradation of RhB and the 30% TiO2/MWCNTs photocatalyst exhibited the highest photocatalytic activity.