Case study: Methadone maintenance treatment in Hanoi, Vietnam

ABSTRACT: Methadone maintenance therapy (MMT) was introduced in the rapidly developing semi-rural district of Tu Liem in Hanoi in December, 2009. Commune police play an integral role in determining which injecting drug users (IDUs) are eligible to commence and continue MMT. This case study highlights the importance of providing training to commune police about MMT to mitigate negative impacts drug law enforcement can have on IDU accessibility to MMT programs.     

International application of sugar-sweetened beverage (SSB) taxation in obesity reduction: Factors that may influence policy effectiveness in country-specific contexts

Sugar-sweetened beverage (SSB) taxation is becoming of increasing interest as a policy aimed at addressing the rising prevalence of obesity in many countries. Preliminary evidence indicates its potential to not only reduce obesity prevalence, but also generate public revenue. However, differences in country-specific contexts create uncertainties in its possible outcomes. This paper urges careful consideration of country-specific characteristics by suggesting three points in particular that may influence the effectiveness of a volume-based soft drink excise tax: population obesity prevalence, soft drink consumption levels, and existing baseline tax rates. Data from 19 countries are compared with regard to each point. The authors suggest that SSB or soft drink taxation policy may be more effective in reducing obesity prevalence where existing obesity prevalence and soft drink consumption levels are high. Conversely, in countries where the baseline tax rate is already considered high, SSB taxation may not have a noticeable impact on consumption patterns or obesity prevalence, and may incur negative feedback from the beverage industry or the general public. Thorough evaluation of these points is recommended prior to adopting SSB or soft drink taxation as an obesity reduction measure in any given country.     

The epidemiology of interpandemic and pandemic influenza in Vietnam, 2007-2010: the Ha Nam household cohort study I

Prospective community-based studies have provided fundamental insights into the epidemiology of influenza in temperate regions, but few comparable studies have been undertaken in the tropics. The authors conducted prospective influenza surveillance and intermittent seroprevalence surveys in a household-based cohort in Vietnam between December 2007 and April 2010, resulting in 1,793 person-seasons of influenza surveillance. Age- and sex-standardized estimates of the risk of acquiring any influenza infection per season in persons 5 years of age or older were 21.1% (95% confidence interval: 17.4, 24.7) in season 1, 26.4% (95% confidence interval: 22.6, 30.2) in season 2, and 17.0% (95% confidence interval: 13.6, 20.4) in season 3. Some individuals experienced multiple episodes of infection with different influenza types/subtypes in the same season (n = 27) or reinfection with the same subtype in different seasons (n = 22). The highest risk of influenza infection was in persons 5-9 years old, in whom the risk of influenza infection per season was 41.8%. Although the highest infection risk was in school-aged children, there were important heterogeneities in the age of infection by subtype and season. These heterogeneities could influence the impact of school closure and childhood vaccination on influenza transmission in tropical areas, such as Vietnam.     

Enhanced biomineralization and protein adsorption capacity of 3D chitosan/hydroxyapatite biomimetic scaffolds applied for bone-tissue engineering

This work presents the enhanced biomineralization and protein adsorption capacity of 3D chitosan/hydroxyapatite (CS/HAp) biomimetic scaffolds synthesized from natural sources applied for bone-tissue engineering (BTE). The scaffolds were prepared by the freeze-drying method, then characterized by X-ray diffraction, scanning electron microscopy, liquid substitution, swelling behavior, and mechanical strength. Fourier transform infrared spectroscopy was also conducted to investigate the interaction between chitosan (CS) and hydroxyapatite (HAp). The biodegradation, biomineralization and protein adsorption capabilities of the scaffolds were evaluated through tests in vitro. Results showed that the 3D CS/HAp scaffolds exhibited highly porous structures with an average pore size of 265 μm, and mean porosity of 75.01%, respectively; the tensile strength of the scaffolds was 2.45 MPa, matching well with that of cancellous bone. The addition of HAp into the CS matrix efficiently decreased the swelling percentage of the CS/HAp scaffolds and retained the suitable degradation rate of the composite scaffolds; the degradation percentage of the CS/HAp scaffolds was 46.37% after 28 days immersed in a physiological solution. The CS/HAp scaffolds demonstrated a higher biomineralization capability than that of the CS scaffolds, releasing a bone-like apatite layer on their surface after 15 days of incubation in simulated body fluids. The presence of HAp mimicking biological apatite in the composite scaffolds facilitated a higher protein adsorption capability, compared to that of the CS scaffolds. The obtained results suggest that the CS/HAp scaffolds have great potential as biocompatible materials for BTE applications.

This work presents the enhanced biomineralization and protein adsorption capacity of 3D chitosan/hydroxyapatite (CS/HAp) biomimetic scaffolds synthesized from natural sources applied for bone-tissue engineering (BTE).