Iodized Salt in Cambodia: Trends from 2008 to 2014

Though the consequences of nutritional iodine deficiency have been known for a long time, in Cambodia its elimination has only become a priority in the last 18 years. The Royal Government of Cambodia initiated the National Sub-Committee for Control of Iodine Deficiency Disorders in 1996 to fight this problem. Using three different surveys providing information across all provinces, we examined the compliance of salt iodization in Cambodia over the last 6 years. Salt samples from the 24 provinces were collect at the household level in 2008 (n = 566) and 2011 (n = 1275) and at the market level in 2014 (n = 1862) and analysed through a wavelength spectrophotometer for iodine content. According to the samples collected, the median iodine content significantly dropped from 22 mg/kg (25th/75th percentile: 2/37 mg/kg) in 2011 to 0 mg/kg in 2014 (25th/75th percentile: 0/8.9 mg/kg) (p < 0.001). The proportion of non-iodized salt within our collected salt drastically increased from 22% in 2011 to 62% in 2014 (p < 0.001). Since the international organizations ceased to support the procurement of iodine, the prevalence of salt compliant with the Cambodian declined within our samples. To date, the current levels of iodine added to tested salt are unsatisfactory as 92% of those salts do not meet the government requirements (99.6% of the coarse salt and 82.4% of the fine salt). This inappropriate iodization could illustrate the lack of periodic monitoring and enforcement from government entities. Therefore, government quality inspection should be reinforced to reduce the quantity of salt not meeting the national requirement.     

Malaria PCR Detection in Cambodian Low-Transmission Settings: Dried Blood Spots versus Venous Blood Samples

In the context of malaria elimination, novel strategies for detecting very low malaria parasite densities in asymptomatic individuals are needed. One of the major limitations of the malaria parasite detection methods is the volume of blood samples being analyzed. The objective of the study was to compare the diagnostic accuracy of a malaria polymerase chain reaction assay, from dried blood spots (DBS, 5 μL) and different volumes of venous blood (50 μL, 200 μL, and 1 mL). The limit of detection of the polymerase chain reaction assay, using calibrated Plasmodium falciparum blood dilutions, showed that venous blood samples (50 μL, 200 μL, 1 mL) combined with Qiagen extraction methods gave a similar threshold of 100 parasites/mL, ∼100-fold lower than 5 μL DBS/Instagene method. On a set of 521 field samples, collected in two different transmission areas in northern Cambodia, no significant difference in the proportion of parasite carriers, regardless of the methods used was found. The 5 μL DBS method missed 27% of the samples detected by the 1 mL venous blood method, but most of the missed parasites carriers were infected by Plasmodium vivax (84%). The remaining missed P. falciparum parasite carriers (N = 3) were only detected in high-transmission areas.     

A full-length recombinant Plasmodium falciparum PfRH5 protein induces inhibitory antibodies that are effective across common PfRH5 genetic variants

The lack of an effective licensed vaccine remains one of the most significant gaps in the portfolio of tools being developed to eliminate Plasmodium falciparum malaria. Vaccines targeting erythrocyte invasion – an essential step for both parasite development and malaria pathogenesis – have faced the particular challenge of genetic diversity. Immunity-driven balancing selection pressure on parasite invasion proteins often results in the presence of multiple, antigenically distinct, variants within a population, leading to variant-specific immune responses. Such variation makes it difficult to design a vaccine that covers the full range of diversity, and could potentially facilitate the evolution of vaccine-resistant parasite strains. In this study, we investigate the effect of genetic diversity on invasion inhibition by antibodies to a high priority P. falciparum invasion candidate antigen, P. falciparum Reticulocyte Binding Protein Homologue 5 (PfRH5). Previous work has shown that virally delivered PfRH5 can induce antibodies that protect against a wide range of genetic variants. Here, we show that a full-length recombinant PfRH5 protein expressed in mammalian cells is biochemically active, as judged by saturable binding to its receptor, basigin, and is able to induce antibodies that strongly inhibit P. falciparum growth and invasion. Whole genome sequencing of 290 clinical P. falciparum isolates from across the world identifies only five non-synonymous PfRH5 SNPs that are present at frequencies of 10% or more in at least one geographical region. Antibodies raised against the 3D7 variant of PfRH5 were able to inhibit nine different P. falciparum strains, which between them included all of the five most common PfRH5 SNPs in this dataset, with no evidence for strain-specific immunity. We conclude that protein-based PfRH5 vaccines are an urgent priority for human efficacy trials.     

Realistic Food-Based Approaches Alone May Not Ensure Dietary Adequacy for Women and Young Children in South-East Asia

Objectives Micronutrient deficiencies, in southeast Asia (SE Asia), remain a public health challenge. We evaluated whether promoting the consumption of locally available nutritious foods, which is a low-risk micronutrient intervention, alone can ensure dietary adequacy, for women of reproductive age and 6–23 m old children. Methods Representative dietary data from Cambodia, Indonesia, Lao PDR, Thailand and Vietnam were analysed using linear programming analysis to identify nutrients that are likely low in personal food environments (problem nutrients), and to formulate food-based recommendations (FBRs) for three to six target populations per country. Results The number of problem nutrients ranged from zero for 12–23 m olds in Indonesia, Thailand and Vietnam to six for pregnant women in Cambodia. The FBRs selected for each target population, if adopted, would ensure a low percentage of the population was at risk of inadequate intakes for five to ten micronutrients, depending on the country and target population. Of the 11 micronutrients modelled, requirements for iron, calcium and folate were most difficult to meet (≥ 10 of the 24 target populations), using FBRs alone. The number of individual FBRs selected per set, for each target population, ranged from three to eight; and often included meat, fish or eggs, liver/organ meats, vegetables and fruits. Conclusions for practice Intervention strategies need to increase access to nutritious foods, including products fortified with micronutrients, in SE Asia, when aiming to ensure dietary adequacy for most individuals in the population.

     

Knowledge about hepatitis and previous exposure to hepatitis viruses in immigrants and refugees from the Mekong Region

OBJECTIVE: Infection with hepatitis B (HBV) and hepatitis C (HCV) viruses is relatively common throughout South-East Asia and chronic infection can lead to severe consequences. This study assesses knowledge about HBV and HCV and estimates the seroprevalence of markers for these viruses in immigrants from Laos and Cambodia. METHODS: Ninety-five Laotian (aged 18-82 years) and 234 Cambodian (15-92 years) immigrants participated in separate community-based surveys conducted during 1998 and 2002, respectively. Participants completed a questionnaire on health status and level of knowledge about viral hepatitis. Blood samples were collected and tested for the presence of HBV and HCV markers. RESULTS: Nine per cent of Laotian and 8% of Cambodian participants were infected with HBV. While 49% of Laotian and 64% of Cambodian participants showed evidence of previous exposure to HBV, 30% and 9%, respectively, were vulnerable to infection. The seroprevalence of antibodies to HCV was 3% in the Laotian and 8% in the Cambodian participants. Between one-fifth and one-third of the Laotians and Cambodians who had heard of HBV and HCV knew of possible transmission routes for the viruses. Most of those with HBV or HCV infection were unaware they were infected. CONCLUSIONS: These findings indicate a significant prevalence of undetected HBV and HCV infections and an urgent need for the provision of culturally relevant information about viral hepatitis in immigrants of South-East Asian origin.     

Psychosocial factors at work and self reported health: comparative results of cross sectional and prospective analyses of the French GAZEL cohort

Background: Psychosocial factors at work have been found to be significant contributors to health, especially cardiovascular health.

Aims: To explore the relation between psychosocial factors at work and self reported health, using cross sectional and prospective analyses for a large occupational cohort of men and women.

Methods: Psychosocial factors at work were evaluated using the Karasek questionnaire, designed to measure psychological demands, decision latitude, social support, and physical demands. Self reported health was used as health outcome. Covariates included chronic diseases, and sociodemographic, occupational, and behavioural factors. The cross sectional and prospective analyses concerned respectively 11 447 and 7664 workers. Men and women were analysed separately.

Results: Cross sectional analysis revealed significant associations between psychological demands, decision latitude, social support, and physical demands, and self reported health for both men and women. Prospective analysis showed that high psychological demands for both genders, low decision authority for men, and low social support and high physical demands for women were predictive of poor self reported health. These results were independent of potential confounding variables.

Conclusions: Results highlight the predictive effects of psychosocial factors at work on self reported health in a one year follow up study. They also underline the need for longitudinal study design and separate analyses for men and women in the field of psychosocial factors at work.

     

Primitive neuroectodermal tumour of the kidney: radiologic-pathological correlations.

A primitive neuroectodermal tumour of the kidney is a rare malignancy. We report the computed tomographic features and the histopathological correlation of such a tumour occurring in a middle-aged man. Although the radiological appearance has significant overlap with other renal tumours, this tumour should be included in the differential diagnosis of a large renal mass in younger patients.