Pertussis antibody titers in pregnant women's venous blood and cord blood—a survey from three women and children's hospitals in Beijing / 中国新生儿科杂志

Objective To study the levels of antibodies against bordetella pertussis among pregnant women and neonates in Beijing. Method From December 2016 to March 2017, pregnant women and their newborns from three women and children′s hospitals in Beijing were enrolled in this study. 3 ml of venous blood from the mothers and 3 ml of umbilical cord blood from neonates were drawn.Pertussis bacillus IgG antibody (PER-IgG) and pertussis toxin IgG antibody (PT-IgG) were tested using enzyme-linked immunosorbent assay. χ2 test was used to compare the positive rate of pertussis IgG antibodies in maternal and cord blood in the three hospitals. Correlational analyses of the antibodies levels in each hospital were conducted. The demographic characteristics, history of cough during pregnancy and history of DTaP vaccination of the mothers were collected via questionnaires. Result A total of 612 pairs of venous blood and cord blood samples were collected, including 4 mothers delivered twins and 616 cases of cord blood sample were collected. No history of pertussis were found in the 612 mothers. Among the 616 cases of umbilical cord blood, positive rate of PER-IgG was 13.3％ (82/616), positive rate of PT-IgG was 0.5％ (3/616). Among 612 cases of venous blood from the mothers, positive rate of PER-IgG was 7.7％ (47/612), positive rate of PT-IgG was 0.3％ (2/612). Positive rates of PER-IgG and PT-IgG in the mothers′ venous blood were not correlated with their residences (P=0.676 and 0.544). Positive rates of PER-IgG (r=0.842, P<0.001) and PT-IgG (r=0.619, P<0.001) in the mothers′ blood were positively correlated with the positive rate in umbilical cord blood. Conclusion This study shows that the positive rate of PER-IgG is very low in the maternal and umbilical cord blood in Beijing. Positive correlations of PER-IgG and PT-IgG between mother and umbilical cord blood were existed. Most mothers and their newborns do not have enough protection against pertussis.

Survey on vitamin A deficiency in children under-6-years in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the prevalence and spatial distribution of vitamin A deficiency (VAD) in China among children at ages under six years.</p><p><b>METHODS</b>About 8,600 children under 6 years of age in 14 cities and 28 counties of 14 provinces were selected with stratified cluster sampling for survey, including interview with questionnaire for their family information and nutritional status. Blood specimens were collected for measuring serum level of VA with fluorescent spectrophotometry in laboratory.</p><p><b>RESULTS</b>Totally, 8,669 children under 6 (2,877 in urban area and 5,792 in rural area) were surveyed in 14 provinces, with 4,629 males and 4,040 females. Eight cases of night blindness and seven cases of xerophthalmia were found among the children at ages of two to five years. Sixty-one mothers of the children in this group were also found suffering from night blindness. All the cases of night blindness and xerophthalmia both in children and mothers were living in rural areas. Based on their serum levels of VA, 11.7% of the all 1 018 children were diagnosed as VAD, with serum VA concentrations below or equal to 0.70 micro mol/L. Prevalence of VAD was 15.0% and 5.8% in rural (23.3% in the poverty-stricken counties) and urban areas, respectively, and 5.8%, 11.5% and 16.8% in the coastal, inland and remote areas, respectively. The average serum level of VA was 1.20 micro mol/L and 0.99 micro mol/L for urban and rural areas, respectively, with a national average of 1.06 micro mol/L. And, babies under six months of age with an average serum levels of VA < or = 0.70 micro mol/L accounted for 33.4%, and those at ages of four to five years with the same level of VA accounted for 8%. There was significant difference in serum levels of VA between ages, but no significant difference between genders.</p><p><b>CONCLUSION</b>VAD did exist in children of China, especially in the remote and poverty-stricken rural areas and VA supplementation is urgently needed for the children in these regions.</p>

Prevalence of subclinical vitamin A deficiency and its affecting factors in 8 669 children of China / 中华预防医学杂志

<p><b>OBJECTIVE</b>The survey will reveal current status of subclinical vitamin A deficiency (SVAD) and explore its affecting factors in children of China.</p><p><b>METHODS</b>Totally 8 669 children aged under 6 years were randomly selected from 14 provinces for clinical examination, health and dietary questionnaire and serum level of vitamin A measurement with fluorescence method. The cut-off value for SVAD was defined as </= 0.70 micro mol/L.</p><p><b>RESULTS</b>Prevalence of SVAD was 11.7% and that of suspected SVAD 39.2% in all subjects, which decreased with the increase of gross domestic product, average annual family income, mother's schooling and children's age. Prevalence of SVAD and suspected SVAD higher in rural areas (15.0%) than in urban areas (5.2%), and higher in children with a minority mother (22.6%) than in those with a Han nationality mother (8.7%). Prevalence of SVAD and suspected SVAD was higher in children whose blood samples were collected within one week in-taking vitamin A-rich food (12.6%-22.6%) than those in-taking vitamin A daily (4.1%-10.0%), and higher in children suffering from respiratory infection, fever and diarrhea two weeks before their blood collection (15.2%-20.3%) than in those without those diseases (10.1%-11.1%). Logistic regression analysis showed that poor family economic status, living in rural areas, children with a minority mother, younger age, no-dairy milk products intake, and respiratory infection and fever all were risk factors for SVAD.</p><p><b>CONCLUSIONS</b>More than half of children under six years old in China (50.9%) had vitamin A nutrition problem. Varied factors played roles to different extent in SVAD in children.</p>