WHO Reference Research Articles

Overweight, obesity, weight-related behaviors, and health-related quality of life among high-school students in Turkey.

The purpose of this study was to assess the prevalence of overweight and obesity, and associated socio-demographic and lifestyle behaviors among a sample of high-school students in Turkey. This study also examined the effect of overweight and obesity on health-related quality of life in students. A cross-sectional survey of 1216 adolescents aged 14-18years old was conducted from 2018 to 2019 in Turkey, using questionnaire forms and anthropometric measurements. Classification of BMI was based on the WHO reference weight categories. Factors linked to adolescent obesity were identified using the binary logistic regression model and the degree of association was revealed by determining the odds ratio, at a confidence interval (CI) of 95%. The prevalence of overweight was 26.1%, while that of obese students was 12.8%. Factors associated with being obese included being in the 14-15 age group, being male, having dysfunctional family relationships, spending more than 3h/day on screen time, and performing physical activity (≥ 60min) two times or less per week. Obese adolescents reported significantly lower scores in physical and mental health. In this study, more than one-third of the students were either overweight or obese. Obesity was associated with screen time, physical activity, and family relationship. Obesity in children had a negative impact on their quality of life. Therefore, increasing physical activity, lowering screen time, and having a healthy parent-adolescent relationship could contribute to reducing the prevalence of obesity in overweight/obese students. Level V, descriptive (cross-sectional) study.

Prevalencias de desnutrición global, desmedro, sobrepeso y obesidad: su evolución en niños de Azampay (Catamarca, Argentina)

Prevalence of underweight, stunting, overweight and obesity: their evolution in children from azamPay (catamarca, argentina) Abstract: This study assesses the evolution of underweight, stunting, overweight and obesity prevalence in schoolchildren from Azampay between 1995 and 2004. The sample includes children between 6 and 13 years of age (1995: 32; 2004: 42). The recorded variables were Age (A), Weight (W) and Height (H). Weight-for- age (W//A), Height-for-age (H//A) (WHO reference 2007, -2 SD) and body mass index (BMI) (The International Obesity Task Force, with the values set out therein), were estimated. Epi-Info 6.0 software was used for statistical evaluation (χ 2 p ≤ 0.05%). We observed a drop in underweight to the present (from 11.54% to 3.45%). Likewise, stunting and overweight decreased (the former, from 6.25% to 0%, and the latter from 6.25% to 4.76%). Differences were not statistically significant. Obesity prevalence was zero. Overall, new strategies for survival due to the deterioration of traditional patterns of subsistence, have not adversely affected the growth of children

The relationship between wasting and stunting: a retrospective cohort analysis of longitudinal data in Gambian children from 1976 to 2016

ABSTRACTBackgroundThe etiologic relationship between wasting and stunting is poorly understood, largely because of a lack of high-quality longitudinal data from children at risk of undernutrition.ObjectivesThe aim of this study was to describe the interrelationships between wasting and stunting in children aged <2 y.MethodsThis study involved a retrospective cohort analysis, based on growth-monitoring records spanning 4 decades from clinics in rural Gambia. Anthropometric data collected at scheduled infant welfare clinics were converted to z scores, comprising 64,342 observations on 5160 subjects (median: 12 observations per individual). Children were defined as “wasted” if they had a weight-for-length z score <–2 against the WHO reference and “stunted” if they had a length-for-age z score <–2.ResultsLevels of wasting and stunting were high in this population, peaking at approximately (girls–boys) 12–18% at 10–12 months (wasted) and 37–39% at 24 mo of age (stunted). Infants born at the start of the annual wet season (July–October) showed early growth faltering in weight-for-length z score, putting them at increased risk of subsequent stunting. Using time-lagged observations, being wasted was predictive of stunting (OR: 3.2; 95% CI: 2.7, 3.9), even after accounting for current stunting. Boys were more likely to be wasted, stunted, and concurrently wasted and stunted than girls, as well as being more susceptible to seasonally driven growth deficits.ConclusionsWe provide evidence that stunting is in part a biological response to previous episodes of being wasted. This finding suggests that stunting may represent a deleterious form of adaptation to more overt undernutrition (wasting). This is important from a policy perspective as it suggests we are failing to recognize the importance of wasting simply because it tends to be more acute and treatable. These data suggest that stunted children are not just short children but are children who earlier were more seriously malnourished and who are survivors of a composite process.

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

Objective:The aim of this study was to describe growth during puberty in young people with vertically acquired HIV.Design:Pooled data from 12 paediatric HIV cohorts in Europe and Thailand.Methods:One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1–10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters.Results:At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and −1.2 (IQR: −2.3 to −0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20–0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21–1.78) years later in those starting with HAZ less than −3 compared with HAZ at least −1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than −1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least −1, there was no association with age. Girls and boys who initiated ART with HAZ at least −1 maintained a similar height to the WHO reference mean.Conclusion:Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least −1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age.

Reference genome and comparative genome analysis for the WHO reference strain for Mycobacterium bovis BCG Danish, the present tuberculosis vaccine

BackgroundMycobacterium bovis bacillus Calmette-Guérin (M. bovis BCG) is the only vaccine available against tuberculosis (TB). In an effort to standardize the vaccine production, three substrains, i.e. BCG Danish 1331, Tokyo 172–1 and Russia BCG-1 were established as the WHO reference strains. Both for BCG Tokyo 172–1 as Russia BCG-1, reference genomes exist, not for BCG Danish. In this study, we set out to determine the completely assembled genome sequence for BCG Danish and to establish a workflow for genome characterization of engineering-derived vaccine candidate strains.ResultsBy combining second (Illumina) and third (PacBio) generation sequencing in an integrated genome analysis workflow for BCG, we could construct the completely assembled genome sequence of BCG Danish 1331 (07/270) (and an engineered derivative that is studied as an improved vaccine candidate, a SapM KO), including the resolution of the analytically challenging long duplication regions. We report the presence of a DU1-like duplication in BCG Danish 1331, while this tandem duplication was previously thought to be exclusively restricted to BCG Pasteur. Furthermore, comparative genome analyses of publicly available data for BCG substrains showed the absence of a DU1 in certain BCG Pasteur substrains and the presence of a DU1-like duplication in some BCG China substrains. By integrating publicly available data, we provide an update to the genome features of the commonly used BCG strains.ConclusionsWe demonstrate how this analysis workflow enables the resolution of genome duplications and of the genome of engineered derivatives of the BCG Danish vaccine strain. The BCG Danish WHO reference genome will serve as a reference for future engineered strains and the established workflow can be used to enhance BCG vaccine standardization.

Spatial and demographic disparities in short stature among school children aged 7–18 years: a nation-wide survey in China, 2014

ObjectivesTo identify spatial disparities and demographic characteristics of short stature, we analysed the prevalence of short stature collected in a nationwide health survey.SettingsData were obtained from the 2014 Chinese National...

Prevalence of hypertension among Indian adults: Results from the great India blood pressure survey

ObjectiveHypertension is the most important risk factor for cardiovascular morbidity and mortality. There is limited data on hypertension prevalence in India. This study was conducted to estimate the prevalence of hypertension among Indian adults. MethodsA national level survey was conducted with fixed one-day blood pressure measurement camps across 24 states and union territories of India. Hypertension was defined as systolic blood pressure (BP) ≥140 mmHg or a diastolic BP ≥90 mmHg or on treatment for hypertension. The prevalence was age- and gender-standardized according to the 2011 census population of India. ResultsBlood pressure was recorded for 180,335 participants (33.2% women; mean age 40.6 ± 14.9 years). Among them, 8,898 (4.9%), 99,791 (55.3%), 35,694 (11.9%), 23,084 (12.8%), 9,989 (5.5%), and 2,878 (1.6%) participants were of the age group 18–19, 20–44, 45–54, 55–64, 65–74, and ≥ 75 years, respectively. Overall prevalence of hypertension was 30.7% (95% confidence interval [CI]: 30.5, 30.9) and the prevalence among women was 23.7% (95% CI: 23.3, 24). Prevalence adjusted for 2011 census population and the WHO reference population was 29.7% and 32.8%, respectively. ConclusionThere is a high prevalence of hypertension, with almost one in every three Indian adult affected.

Análisis de las cesáreas en Uruguay por tipo de centro hospitalario

ObjectiveTo analyse on a comparative basis the incidence of caesarean sections among the different health care systems in Uruguay and with respect to the World Health Organization's (WHO) standards, taking into account the medical-obstetric characteristics of the births, particularly, the Robson classification. MethodsWe examine 190,847 births registered by the Perinatal Information System in Uruguay between 2009 and 2014 by type of health care system. Using logit models, we analyse the probability of caesarean section taking into account the Robson classification, other risk factors and the mothers’ characteristics. We compared the caesarean rates predicted by the different subsystems for a common population. Furthermore, we contrast the caesarean rates observed in each subsystem with the rates that resulted if the Uruguayan hospitals followed the guidelines of the sample of WHO reference hospitals. ResultsPrivate health systems in Uruguay exhibit a much higher incidence of caesarean sections than public ones, even after considering the medical-obstetric characteristics of the births. Caesarean rates are more than 75% higher than those observed if the WHO standards are applied. ConclusionsUruguay has a very high incidence of caesarean sections with respect to WHO standards, particularly, in the private sector. This fact is unrelated to the clinical characteristics of the births.

The increase in hemoglobin concentration with altitude varies among human populations

Decreased oxygen availability at high altitude requires physiological adjustments allowing for adequate tissue oxygenation. One such mechanism is a slow increase in the hemoglobin concentration ([Hb]) resulting in elevated [Hb] in high-altitude residents. Diagnosis of anemia at different altitudes requires reference values for [Hb]. Our aim was to establish such values based on published data of residents living at different altitudes by applying meta-analysis and multiple regressions. Results show that [Hb] is increased in all high-altitude residents. However, the magnitude of increase varies among the regions analyzed and among ethnic groups within a region. The highest increase was found in residents of the Andes (1 g/dL/1000 m), but this increment was smaller in all other regions of the world (0.6 g/dL/1000 m). While sufficient data exist for adult males and females showing that sex differences in [Hb] persist with altitude, data for infants, children, and pregnant women are incomplete preventing such analyses. Because WHO reference values were originally based on [Hb] of South American people, we conclude that individual reference values have to be defined for ethnic groups to reliably diagnose anemia and erythrocytosis in high-altitude residents. Future studies need to test their applicability for children of different ages and pregnant women.

A study of growth pattern in regularly transfused thalassaemic children of age group of 2 years to 12 years

Background: ß-thalassemia is an autosomal recessive single gene disorder. Physical growth failure is one of the most important complications of thalassemia. Very few data regarding growth pattern of thalassemic children is available from India especially North East part. Keeping this in mind, present study was undertaken. To study the growth pattern of transfusion dependent thalassaemic children and to compare growth pattern between regularly and irregularly transfused children.Methods: A cross-sectional observational study was done on 38 thalassaemic patients (aged 2 years-12 years) who attended Department of Pediatrics, Assam Medical College Dibrugarh. History, physical examination and investigations were done and filled in predesigned proforma. Anthropometric measurements like weight and height were taken from all patients. Sexual maturity rating was done in girls ≥10 years and boys ≥11 years. Lab parameters included pre-transfusion hemoglobin (Hb), serum ferritin, LFT, RFT, Thyroid profile. Percentile for weight, height and body mass index were calculated using WHO (2007) reference data. Collected data were compared with age and sex matched normal children.Results: About 34.21% transfusion dependent children had under-nutrition and 50% had stunting. 42% had thinness. Stunting was more in irregularly transfused children (81.25%) as compared to regularly transfused children which was highly significant (p&lt;0.001). Under-nutrition among irregularly transfused children was more (40%) compared to regularly transfused children (28.57%). Pubertal spurt was delayed in 66% children. Those who had Hb &lt;5 gm/dl had 100% stunting and under-nutrition.Conclusions: Regular blood transfusion with growth monitoring and appropriate iron chelation (Sr. Ferritin &gt;1000 ng/ml) is of utmost importance in transfusion dependent thalassaemic children.

Comparison of Skin Structural and Functional Parameters in Well-Nourished and Moderately Undernourished Infants

Background: Little is known about the impact of nutrition on the development of skin structure and function in infants. Methods: We investigated epidermal, dermal, and subcutis parameters of aged-matched well-nourished and moderately undernourished infants in this single-center, cross-sectional, noninterventional study using noninvasive methods (skin caliper, 20-MHz sonography, transepidermal water loss, skin pH, and corneometry). Plasma fatty acids were determined as an indicator of nutritional differences. 310 infants from different age groups, i.e., 1 week, 4 weeks, and 6, 9, 12, 24, and 36 months were included. Approximately half of each age group was well-nourished (WHO reference values weight-for-height/length Zscore: –0.75 ≤ Z ≤ 0.75) and the other half was moderately undernourished (–3 ≤ Z < –2). Results: Structural maturational differences in the deeper dermis and subcutis regions of the skin and subtle functional changes in the epidermis were observed in moderately undernourished infants without notable clinical symptoms. Reduced skin barrier function or skin hydration were not observed in the undernourished infants, and skin pH shifted to more acidic values in this group. Conclusion: These findings reveal a greater impact of moderate undernutrition on the development of the dermis and subcutis and suggest that critical epidermal functions such as skin barrier and pH are mostly maintained.

Growth Faltering Among Pre-School Aged Children in the Plains of Nepal (P10-009-19)

ObjectivesGrowth faltering in relation to the WHO reference is common in the first 2 years of life in South Asia. Stunting, defined as an attained height/length-for-age (H/LA) < -2 Z, is limited in its ability to capture this dynamic process. Our aims were to (1) reveal distributions of growth faltering by age in a cohort of preschool Nepali children, and (2) propose a definition of growth faltering that represents early or continued deviated growth that precedes a child reaching < -2 H/LAZ. MethodsWe conducted a mixed longitudinal study in 21 wards of 7 randomly selected sub-districts across the Tarai (plains) of Nepal. Mid-year anthropometry was measured annually from 2013–2016 in children < 71 months (mo) of age. Children with paired data over a ∼1-year interval contributed to any of 6 age groups: < 6 mo [n = 645], 6–11 mo [n = 998], 12–23 mo [n = 744], 24–35 mo [n = 691], 36–47 mo [n = 730] and 48–59 mo [n = 637], reflecting age at the outset of the interval. Sex-specific, annualized growth velocities and incidence rates of growth faltering were calculated for each age. Growth faltering was provisionally defined as an annualized decrement (-△) in H/LA of >0.5 Z, corresponding to a ∼ >1 cm/year slower rate of linear growth than an estimated median velocity on the WHO referent growth curve for children < 6 months at the outset. A -0.5 △H/LAZ cutoff was applied to all ages. ResultsAnnualized △H/LAZ [mean (SD)] was -1.3 (1.2), -0.8 (1.2), -0.3(0.8), 0.0 (0.7), 0.1(0.6), 0.1 (0.5) at each age specified above. Incidence of growth faltering was 79.8%, 66.3%, 40.4%, 11.7%, 4.9%, 2.1% at each respective age. Among infants < 6 mo whose initial LAZ was -1 < x < + 1 (excluding extrema), a △LAZ of < -0.5 or >0 (acceleration) was observed in 85.8% and 3.6%, respectively. ConclusionsGrowth faltering, expressed as an annualized decrement in HAZ >0.5 likely reflects biologically relevant deceleration before children reach < -2 H/LAZ. Two-thirds to 80% of infants in the Tarai of Nepal exhibit growth faltering the year after assessment. By 36 months and older, linear growth, parallels the WHO median attained HA on average, with < 5% appearing to falter, an age at which WHO growth velocity standard curves are lacking. Funding SourcesThe study was funded by USAID via a subaward from Tufts University under the Feed the Future Innovation Lab for Nutrition. Additional assistance was received from Sight and Life and the Gates Foundation.

Semen quality of young men in Switzerland: a nationwide cross-sectional population-based study.

BackgroundSperm counts have been steadily decreasing over the past five decades with regional differences in the Western world. The reasons behind these trends are complex, but numerous insights indicate that environmental and lifestyle factors are important players.ObjectiveTo evaluate semen quality and male reproductive health in Switzerland.Materials and methodsA nationwide cross‐sectional study was conducted on 2523 young men coming from all regions of Switzerland, recruited during military conscription. Semen volume, sperm concentration, motility, and morphology were analyzed. Anatomy of the genital area and testicular volume was recorded. Testicular cancer incidence rates in the general population were retrieved from Swiss regional registries.ResultsMedian sperm concentration adjusted for period of sexual abstinence was 48 million/mL. Comparing with the 5th percentile of the WHO reference values for fertile men, 17% of men had sperm concentration below 15 million/mL, 25% had less than 40% motile spermatozoa, and 43% had less than 4% normal forms. Disparities in semen quality among geographic regions, urbanization rates, and linguistic areas were limited. A larger proportion of men with poor semen quality had been exposed in utero to maternal smoking. Furthermore, testicular cancer incidence rates in the Swiss general population increased significantly between 1980 and 2014.DiscussionFor the first time, a systematic sampling among young men has confirmed that semen quality is affected on a national level. The median sperm concentration measured is among the lowest observed in Europe. No specific geographical differences could be identified. Further studies are needed to determine to what extent the fertility of Swiss men is compromised and to evaluate the impact of environmental and lifestyle factors.ConclusionA significant proportion of Swiss young men display suboptimal semen quality with only 38% having sperm concentration, motility, and morphology values that met WHO semen reference criteria.

Effect of imatinib on growth in children with chronic myeloid leukemia

Imatinib is a preferred drug for pediatric Chronic Myeloid Leukemia (CML). Long-term use has inhibitory effects on other tyrosine kinase pathways causing off-target complications such as growth impairment. Our aim was to evaluate impact of long-term use on longitudinal growth in children with CML in Kerala. We hypothesized that the impact would be lesser compared to Northern India as Kerala has the lowest rates of underweight and stunting, with a high literacy rate and per capita income. Children ≤14 years of age, diagnosed with CML and received imatinib for at least 1 year were included. Girls >9 years of age and boys >11 years were considered pubertal. Height Z scores were derived using WHO AnthroPlus. Paired t test compared difference of Z scores in prepubertal and postpubertal age groups. Height Z scores were compared with mid-parental height and sibling height Z scores. Thirty-six children were included (M = 21; F = 15). Median duration of imatinib exposure was 84 months. Decrease in longitudinal growth affected children in both prepubertal and postpubertal age groups. Decrease in height Z scores was more in prepubertal age group when imatinib therapy was initiated (p = .0018). Of 10 patients currently above 19 years (of whom 8 were in pubertal age and 2 in prepubertal age at start of imatinib) none are stunted. Patient's height Z scores was lesser compared to sibling height Z scores (p = .027). Children on continuous imatinib showed a significant stunting when treatment was initiated during prepubertal age. There is a catch-up of growth as the final height reached is within normal limits of WHO reference values.

Associations between anthropometric indicators in early life and low-grade inflammation, insulin resistance and lipid profile in adolescence

Background and aimsThe long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence. Methods and resultsRetrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents. ConclusionA high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes.

Body mass index and dental caries experience in Nepalese schoolchildren.

The aim was to investigate the severity of untreated dental caries among Nepalese schoolchildren and its association with their body mass index (BMI) using IOTF, WHO and Nepalese growth reference systems. This school-based clinical cross-sectional study was conducted with three WHO index age groups (5- to 6-, 12- and 15-year-olds) in 18 out of 75 districts of Nepal, selected using stratified random sampling. A total of 1135 schoolchildren were included in the study. A validated structured questionnaire was used to assess the children's oral hygiene practices and dietary habits. Clinical oral examinations investigated the status of untreated dental caries in primary and permanent teeth (dt/DT) along with its consequences (pufa/PUFA). Later, the grade of severity of untreated dental caries (GUDC) was determined using both dt/DT and pufa/PUFA. Height (cm), weight (kg), waist circumference (cm) and hip circumference (cm) were measured, and the body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. The findings were presented as proportions, and the chi-square test was performed to compare differences between groups. Generalized linear mixed models with random effects assessed the association between the severity of untreated dental caries and the BMI. According to the IOTF, WHO and Nepalese growth reference systems, the overall proportions of children with a low BMI were 38.6%, 15.4% and 12.8%, and those with a high BMI were 7.9%, 4.6% and 8.4%, respectively. Untreated dental caries was common among the youngest age group and those with infrequent tooth brushing habits or frequent consumption of sweet bakery products, sweets or candy, or tea with sugar. Neither a low nor a high BMI was associated either with dt + DT or with pufa + PUFA, after adjusting for confounders. However, both a low and a high BMI (all three references) were associated with the severity of dental caries or GUDC. Regardless of the growth reference system used, children with either low or high BMI may be at risk of developing untreated dental caries lesions and related consequences. Both underweight and overweight/obese and dental caries share common risk factors, mostly dietary. Preventive and intervention approaches/strategies such as behavioural and dietary modifications should be implemented to improve both children's oral health and their nutrition in Nepal.

Gross alpha/beta radioactivity and radiation dose in thermal and non-thermal spas groundwaters

Gross alpha and gross beta activities have been determined in thermal and non-thermal spas groundwaters (75) occurring at São Paulo and Minas Gerais states in Brazil as they are ingested in public places, bottled and used for bathing purposes, among other. The samples provided from springs and pumped tubular wells drilled at different aquifer systems inserted in Paraná and Southeastern Shield hydrogeological provinces. The WHO guideline reference value proposed in 2011 for the drinking water quality was never reached for the gross alpha activity (0.5 Bq/L) but it was exceeded in 13 groundwater samples for the gross beta activity (1 Bq/L). Available activity concentration data of the natural radionuclides 40K, 228Ra (232Th-daughter), 238U and descendants (234U, 226Ra, 222Rn, 210Pb, 210Po) allowed calculate the total Committed Effective Dose (CED) based on a drinking water ingestion rate of 2 L/day. The WHO reference level of 0.1 mSv per year for the CED was surpassed in a high number of water sources (62 (83%) or 41 (55%), disregarding radon), denoting the relevance of the radiological surveys detailing as much as possible the dissolved radionuclides present in potable waters, despite the analytical difficulties and costs involved.

Improvement in serological diagnosis of pertussis by external quality assessment.

Serological analysis is an essential tool for the diagnosis of pertussis or whooping cough, disease surveillance and the evaluation of vaccine effectiveness against Bordetella pertussis. Accurate measurement of anti-pertussis toxin (anti-PT) IgG antibody levels in sera is essential. These measurements are usually performed using immunological methods such as ELISA and multiplex immunoassays. However, there are a large number of different assay systems available, and therefore standardization and harmonization between the methods are needed to obtain comparable data. In collaboration with ECDC, the EUPert-LabNet network has organized three External Quality Assessment (EQA) schemes (2010, 2012 and 2016), which initially identified the diverse range of techniques and reagents being used throughout Europe. This manuscript discusses the findings of each of the EQA rounds and their impact on the participating laboratories. The studies have shown an increasing number of laboratories (from 65% to 92%) using only the recommended coating antigen, purified PT, in immunoassays, as this allows exact quantification of serum anti-PT IgG and since PT is only produced by Bordetella pertussis this prevents cross-reactivity with other species. There has also been an increase in the numbers of laboratories (from 59% to 92%), including a WHO reference serum in their assays, which allows anti-PT IgG concentrations to be measured in International Units, thus enabling the comparison of results from different methods and laboratories. In addition, manufacturers have also considered these recommendations when they produce commercial ELISA kits. The three EQA rounds have resulted in greater harmonization in methods among different laboratories, showing a significant improvement of the ELISA methods used for serodiagnosis of pertussis.

Early assessment of weight velocity can support frontline health workers in predicting malnutrition in HIV-exposed infants: preliminary results from a DREAM cohort in Malawi.

Children born to HIV-positive mothers are particularly susceptible to malnutrition. Currently, monitoring programs rely on punctual anthropometric measurements to assess child growth. Growth velocities could be an additional tool in identifying critical time windows for prevention and implementation of early intervention for malnutrition. A retrospective analysis was conducted using data from 817 HIV exposed but uninfected children extracted from DREAM program database. By using the WHO reference for growth standards, patterns of weight velocity for different intervals of assessment from one to 18 months of age were explored. Odds ratios and multinomial logistic regressions between selected weight velocity Z-scores thresholds and successive malnutrition indices (at 6, 12, 18 months of age) were calculated. Weight velocity was above the standard mean in the first 3 months, then progressively declined over time. In children with normal nutritional status, significant risks of becoming malnourished (mild malnutrition - underweight [OR 10.8; 95% CI: 4.5-26], chronic malnutrition - stunting [OR 8.3; 95% CI: 2-34.9] and acute malnutrition - wasting [OR 11.7; 95% CI: 1.5-90.5]) started when weight velocity Z-scores <0, at all interval ages. Multinomial regression showed that in the first 6 months, the weight velocity decrements strongly impacted on underweight (OR 17.9; 95% CI: 4-80.7), while the risk of Stunting occurred later at 18 months (OR 8.7; 95% CI: 4.3-17.6), with highest impact at the lowest thresholds. The assessment of weight velocity Z-scores, coupled with the already validated malnutrition indices, can support frontline health workers in early prediction of child malnutrition and performing nutritional counselling in the context of HIV/AIDS and food insecurity.

Prevalence of overweight and obesity in child population. A study of a cohort in Castile and Leon, Spain

IntroductionSeveral studies warn that overweight and obesity have become an epidemic with severe consequences in the population's health. The objective of the present study is to estimate the prevalence of overweight and obesity in Castile and Leon in a sample of children at 6, 11 and 14 years of age, to describe its evolution and its association with life habits and antecedents. Material and methodsObservational study, retrospective cohort, performed by the pediatricians of the Health Sentinel Network. The study is part of a joint Project with the National Research Center on Human Evolution (CENIEH) in Burgos to know the pattern of growth and development of the child population of Castile and Leon. In 2012, a health examination and a retrospective collection were carried out based on the clinical history of a simple of 326 children, from the cohort was born in 1998. ResultsFollowing the WHO references, at age 14 there was 25.3% of boys and 18.5% of girls with overweight. Obesity was estimated to affect the 8.2% and 4.8% of them respectively. At 11 years of age there was the maximum of overweight in girls and of obesity in boys. At the urban-non urban environment, quantity and quality of sleep and the parents’ BMI have been some of the associated factors to weight level of the children. DiscussionIn Castile and Leon, as in other populations of our environment, there is a severe problem of overweight and obesity. For their control it is necessary to deepen understanding of lifestyles and antecedents related to the birth as well as to calculate the growth rate in the pediatric age.