Israel Medical Association Journal

Background: Data regarding the validity of self-reported weight and height in adolescents are conflicting.

Objectives: To evaluate the validity of self-reported weight and height among 13–14 year old schoolchildren. 

Methods: We conducted a cross-sectional study of 517 schoolchildren aged 13–14 years and compared self-reported and measured weight and height by gender, population group, parental education and crowdedness.

Results: Females under-reported their weight on average by 0.79 ± 5.46 kg (P = 0.03), resulting in underestimation of the body mass index with borderline significance (mean difference 0.28 ± 2.26 kg/m², P = 0.06). Males over-reported their height on average by 0.75 ± 5.81 cm (P = 0.03). Children from less crowded homes (≤ 1 person per room) overestimated their height more than children from more crowded homes, resulting in a significant underestimation of BMI[1] (mean difference between reported BMI and measured values was 0.30 ± 2.36 kg/m², P = 0.04). Measured BMI was a significant predictor of the difference between self-reported and measured BMI, adjusted for gender, population group, parents' education, and crowdedness (β = -0.3, P < 0.0001). As a result of this reporting bias, only 54.9% of children with overweight and obesity (BMI ≥ 85th percentile) were classified correctly, while 6.3% of children were wrongly classified as overweight and obese. The largest difference in BMI was observed in obese females (4.40 ± 4.34) followed by overweight females (2.18 ± 1.95) and underweight females (-1.38 ± 1.75). Similar findings were observed for males, where the largest difference was found among obese males (2.83 ± 3.44).

Conclusions: Studies based on self-reported weight and height in adolescents may be biased. Attempts should be made to correct this bias, based on the available data for each population.

Background: Food-borne pharyngitis outbreaks causing substantial morbidity have been documented.

Objectives: To investigate an outbreak of food-borne Streptococcus beta hemolyticus group A pharyngitis among employees of a high-tech company.

Methods: We received a report on an unusually high rate of morbidity among employees of a company in September 2003. The Tel Aviv District Health Office conducted an epidemiological investigation of the outbreak.

Results: Among the 278 people who attended a company party, 83 people became ill. The overall attack rate was 29.8%. Information was available on 174 of 193 employees and family members who attended the party and worked in the Tel Aviv district. Forty-six of them became ill (attack rate 26.4%). The secondary attack rate was 3.8%. Most cases developed symptoms 24–48 hours following the event. Seven cases had throat cultures positive for Streptococcus beta hemolyticus group A. Three items were significantly associated with becoming sick: spring chicken (odds ratio 2.26, 95% confidence interval 1.11–4.63, P = 0.02), vegetable salad (OR[1] 2.88 95%CI[2] 1.40–5.94, P = 0.003) and corn (OR 7.73, 95%CI 3.18–18.80, P < 0.001). Eating corn remained significantly associated with pharyngitis after controlling for other food items consumed.

Conclusions: We describe the epidemiological investigation of a large food-borne outbreak of Streptococcus beta hemolyticus group A pharyngitis most probably transmitted by corn. No previous publication has implicated corn. Food handlers and the public should be aware that they can transmit diseases to others.. Physicians should be aware that streptococcal pharyngitis could be a food-borne disease and that outbreaks in a non-confined setting may be easily missed.