ABSTRACT
Dengue virus(DENV) has been identified by World Health Organization as a major public health problem in tropical and subtropical regions. In recent years, dengue outbreaks have become more and more frequent in the world. In 2019, dengue outbreaks of varying degrees have occurred in the Philippines, Thailand, Bangladesh, Myanmar and Chongqing City in China. The laboratory diagnostic method of DENV is of great significance to the prevention and control of dengue epidemic. Therefore, the methods and strategies of DENV laboratory diagnosis are reviewed in this paper. By reviewing the traditional diagnostic methods and looking forward to the emerging diagnostic strategies, this paper aims to provide a reference to select the appropriate laboratory diagnostic scheme for the outbreak of dengue.
ABSTRACT
Objective To analyze vitamin D concentration and its association with body composition of children in Huairou district of Beijing, to provide evidence for evaluation and improvement of nutritional status of vitamin D in children. Methods Totally, 381 children aged 7-11 years were recruited in Huairou district of Beijing(40.3°N). Samples of overnight fasting venous blood (drawn between 0630 and 0900) were obtained in late March. Serum 25-hydroxyvitamin D [25(OH)D] concentration was determined by ELISA kits (IDS Ltd, UK). Body composition indices of the whole body, the distal and proximal forearm were measured using dual-energy X-ray absorptiometry (DEXA, Norland, US A). Results The average serum 25 (OH) D concentration of all subjects was (44.4±12.5) nmol/L. The percentage of vitamin D insufficient [serum 25(OH) D≤ 50 nmol/L ] reached as high as 68.5% (261 people). The 25 (OH) D concentration of boys (46.3 nmol/L± 13.3 nmol/L) was significantly higher than that of girls (42.0 nmol/L±11.1 nmol/L), (t=3.38,P< 0.01). Between the serum 25(OH)D concentration and lean body mass of proximal forearm, distal forearm, whole body, and four limbs, significant positive correlations (r=0.13-0.19,P<0.05) were observed. After age, gender, height and weight were under controlled for, correlations between the serum 25(OH)D concentration and lean body mass at proximal forearm, and the two lower limbs still existed (r=0.12-0.14,P<0.05). The serum 25(OH)D concentration, the percentage of body fat at proximal forearm, and distal forearm were negatively correlated (r=-0.14, P<0.05;r=-0.11, P< 0.05). However, after adjusting for confounding effects, this correlation disappeared. No significant correlation between the serum 25 (OH)D concentration and body fat was observed at any position. Conclusion Vitamin D deficiency was common in children of suburb area of Beijing. Vitamin D status was positively associated with the lean body mass.