SARS-CoV-2 incidence in secondary schools; the role of national and school-initiated COVID-19 measures.

INTRODUCTION: Our aim was to gain insight into the effect of COVID-19 measures on SARS-CoV-2 incidence in secondary schools and the association with classroom CO2 concentration and airborne contamination. METHODS: Between October 2020-June 2021, 18 schools weekly reported SARS-CoV-2 incidence and completed surveys on school-initiated COVID-19 measures (e.g. improving hygiene or minimizing contacts). CO2 was measured in occupied classrooms twice, and SARS-CoV-2 air contamination longitudinally using electrostatic dust collectors (EDC) and analyzed using RT-qPCR. National COVID-19 policy measures varied during pre-lockdown, lockdown and post-lockdown periods. During the entire study, schools were recommended to improve ventilation. SARS-CoV-2 incidence rate ratios (IRR) were estimated by Generalized Estimating Equation (GEE) models. RESULTS: During 18 weeks follow-up (range: 10-22) SARS-CoV-2 school-incidence decreased during national lockdown (adjusted IRR: 0.41, 95%CI: 0.21-0.80) and post-lockdown (IRR: 0.60, 0.39-0.93) compared to pre-lockdown. School-initiated COVID-19 measures had no additional effect. Pre-lockdown, IRRs per 10% increase in time CO2 exceeded 400, 550 and 800 ppm above outdoor level respectively, were 1.08 (1.00-1.16), 1.10 (1.02-1.19), and 1.08 (0.95-1.22). Post-lockdown, CO2-concentrations were considerably lower and not associated with SARS-CoV-2 incidence. No SARS-CoV-2 RNA was detected in any of the EDC samples. CONCLUSION: During a period with low SARS-CoV-2 population immunity and increased attention to ventilation, with CO2 levels most of the time below acceptable thresholds, only the national policy during and post-lockdown of reduced class-occupancy, stringent quarantine, and contact testing reduced SARS-CoV-2 incidence in Dutch secondary schools. Widespread SARS-CoV-2 air contamination could not be demonstrated in schools under the prevailing conditions during the study.

Lactose after Roux-en-Y gastric bypass for morbid obesity, is it a problem?

BACKGROUND: Roux-en-Y gastric bypass (RYGB) can cause multiple food intolerances and gastrointestinal complaints are frequently reported after dairy consumption. We aimed to determine the prevalence of lactose malabsorption and intolerance, and complaints associated with dairy consumption in daily life, before and after RYGB. METHOD: The lactose breath test (LBT) and lactose tolerance test (LTT) was performed in 84 patients awaiting RYGB surgery and 84 patients after surgery. Gastrointestinal symptoms at baseline and after testing were recorded. Lactose malabsorption was defined as a positive LBT and/or LTT. Lactose intolerance as a positive test combined with an increase of gastrointestinal complains. Dairy consumption in daily life and successive gastrointestinal complaints were registered via a questionnaire. Results of preoperative and postoperative patients were compared. RESULTS: Lactose malabsorption was present in 15 (17.9%) of the preoperative patients and in 25 (29.8%) of the postoperative patients (OR 2.46; 95%CI: 1.08-5.59; p = .03). Of the preoperative patients 6 (7.1%) patients met the criteria for lactose intolerance, compared to 8 (9.5%) patients in the postoperative group (OR 1.48; 95%CI 0.48-4.57; p = .50). Twelve (14.3%) preoperative patients indicated to have gastrointestinal complaints after dairy consumption in daily life versus 45 (53.6%) postoperative patients (p < .01). CONCLUSION: This study shows no increase in patients with proven lactose intolerance after RYGB compared to preoperative patients. Gastrointestinal complaints after dairy consumption in daily life were far more frequently reported by RYGB patients. It is unlikely that all reported gastrointestinal complaints are actually caused by lactose. Other ingredients in dairy, like fat, are possibly contributory.

Ethnic differences in maternal underestimation of offspring's weight: the ABCD study.

OBJECTIVE: To determine the ethnic variation in maternal underestimation of their child's weight status and the explanatory role of socio-economic status (SES), acculturation and parental body mass index (BMI). METHOD: A multi-ethnic sample of 2769 normal or overweight/obese children (underweight children excluded) aged 5-7 years was examined (The Amsterdam Born Child and their Development study), comprising five ethnic subgroups: Dutch (n=1744), African descent (n=184), Turkish (n=86), Moroccan (n=161) and other non-Dutch (n=592). Data on mothers' perception of their child's weight status (5-point scale from 'too low' to 'too high'), SES, acculturation, parental BMI and the children's height and weight were collected. Underestimation was defined by comparing maternal perception with the actual weight status of her child (International Obesity Task Force guidelines). Ethnic differences in underestimation were calculated in the normal weight and overweight/obese categories. RESULTS: Underestimation ranged from 3.6 (Dutch) to 15.7% (Moroccan) in normal-weight children, and from 73.0 (Dutch) to 92.3% (Turkish) in overweight/obese children. After correction for ethnic differences in child's BMI, higher odds ratios (ORs) for underestimation were found in the Turkish (normal weight: OR 6.83; 95% confidence interval (CI) 2.33-20.05 and overweight: OR 2.80; 95% CI 1.12-6.98) and Moroccan (normal weight: OR 11.55; 95% CI 5.28-25.26) groups (reference is the Dutch group). Maternal educational level and immigrant generation largely explained the ethnic differences, with a minor contribution of maternal age. After correction, ORs remained higher in the Moroccan group (OR 4.37; 95% CI 1.79-10.62) among the normal-weight children. CONCLUSION: Mothers frequently underestimate the actual weight status of their child, especially mothers from Turkish or Moroccan origin. Having a lower SES, being first-generation immigrant and a young mother are important determinants in explaining these differences. As weight perceptions may affect weight gain and almost all mothers of overweight/obese children underestimate their child's weight, health professionals should help mothers (particularly those from ethnic minority groups) to acquire a realistic perception of their children's weight status.