We found associations between specific scalp diseases, hairstyles, gender, and age. These associations need further study, better to elucidate determinants and to improve disease prevention and treatment.

SettingThis study was conducted in a high tuberculosis (TB) burden area in Worcester, South Africa, with a notified all TB incidence rate of 1,400/100,000.Main ObjectiveTo compare the predictive value of a baseline tuberculin skin test (TST) with that of the QuantiFERON TB Gold (In-tube) assay (QFT) for subsequent microbiologically confirmed TB disease among adolescents.MethodsAdolescents aged 12–18 years were recruited from high schools in the study area. At baseline, blood was drawn for QFT and a TST administered. Participants were followed up for up to 3.8 years for incident TB disease (median 2.4 years).ResultsAfter exclusions, 5244 (82.4%) of 6,363 adolescents enrolled, were analysed. The TB incidence rate was 0.60 cases per 100 person years (pyrs) (95% CI 0.43–0.82) for baseline TST positive (≥5 mm) participants and 0.64 cases per 100 pyrs (95% CI 0.45–0.87) for baseline QFT positive participants. TB incidence rates were 0.22 per 100 pyrs (0.11–0.39) and 0.22 per 100 pyrs (0.12–0.38) among those with a negative baseline TST and QFT respectively. Sensitivity for incident TB disease was 76.9% for TST and 75.0% for QFT (p = 0.81). Positive predictive value was 1.4% for TST and 1.5% for QFT.ConclusionPositive TST and QFT tests were moderately sensitive predictors of progression to microbiologically confirmed TB disease. There was no significant difference in the predictive ability of these tests for TB disease amongst adolescents in this high burden setting. Therefore, these findings do not support use of QFT in preference to TST to predict the risk of TB disease in this study population.

The prevalence of asthma and allergic disease in children has been increasing in developed countries, but there is little information on these trends in Africa. The aim of this study was to assess time trends in the symptoms of asthma, allergic rhinitis, and atopic eczema among South African adolescents. The study was carried out by comparing cross-sectional data from two International Study of Asthma and Allergies in Childhood (ISAAC phase I and phase III) questionnaire based surveys conducted 7 yr apart of self-reported symptoms in 13- to 14-yr-old adolescents. In both surveys, schools in the same geographical area in Cape Town, South Africa, were randomly selected. A school-based sample of 5178 (in 1995) and 5037 (in 2002) pupils participated. The 12-month prevalence of wheezing (16% vs. 20.3%), exercise-induced wheeze (21.5% vs. 32.5%), nocturnal cough (23.6% vs. 36.6%), sleep disturbance due to wheeze (9.6% vs. 16%), or severe wheeze (5.1% vs. 7.8%) increased significantly, as measured by the written questionnaire. A rise in asthma symptoms was confirmed by the video questionnaire responses, in which the 12-month prevalence of wheezing (6.5% vs.11.2%), exercise-induced wheeze (11.5% vs. 13.9%), nocturnal wheeze (3.9% vs. 5.3%), nocturnal cough (11.6% vs. 19.2%), or severe wheeze (5% vs. 7%) also increased significantly. There was a small increase in the percentage of children diagnosed with asthma from 1995 to 2002 (13.1% vs. 14.4%), this was not significant. The 12-month prevalence of symptoms of allergic rhinitis (30.4% vs. 38.5%), rhinoconjunctivitis (17.6% vs. 24.3%) and eczema (11.8% vs. 19.4%) also increased significantly. An increase in the prevalence of allergic symptoms occurred in girls and boys. Limitation of daily activity from nasal symptoms (22.3% vs. 37.8%) and sleep disturbance because of eczema (8.4% vs. 15.7%) increasingly affected quality of life on the quality of life. Symptoms of asthma, allergic rhinitis and atopic eczema in adolescents have increased over the past 7 yr in this geographical area. Allergic diseases are common in this group of adolescents and increasingly impair their quality of life.

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We found associations between hairstyle and disease in our population of schoolchildren. AKN appears to be associated with frequently cut natural hair and TA with relaxed hair. These associations need further study for purposes of disease prevention.

Asthma and obesity are both chronic conditions and their prevalences have risen in affluent societies. A positive association between asthma and being overweight or obese has been reported in children and women, but associations in men are less clearly described. The objective of this study was to explore the association between body mass index (BMI) and asthma in men and women of diverse ethnic and socioeconomic background living in New York State, USA. In this study, we analyzed cross-sectional data on 5524 subjects aged 18 years and older who were interviewed by telephone in the 1996 and 1997 New York State Behavioral Risk Factor Surveillance System. Asthma (doctor-diagnosed), and weight and height were self-reported. BMI (kg/m2) was used as a measure of adiposity. Weighted logistic regression analysis, with stratification by gender and age, was used to examine the relationship between asthma prevalence and BMI, adjusting for race/ethnicity, education, health insurance, time since last physical examination, physical activity and smoking status. The results showed that the prevalence of asthma was 4.6% (CI: 3.6-5.5%) among men and 8.1% (CI: 7.1-9.1%) among women. In women, the prevalence of asthma was significantly increased in those with a BMI 25 kg/m2 or higher (BMI 25-27.5: OR = 1.76, 95% CI: 1.06-2.94; BMI 27.5-29.9: OR = 2.45, 95% CI: 1.41-4.25; BMI > or = 30: OR = 2.67, 95% CI: 1.66-4.29) when compared to the reference category (BMI: 22-24.9 kg/m2). In men, the prevalence of asthma was increased in the lowest weight category, BMI < 22 kg/m2 (OR = 3.05, 95% CI: 1.37-6.78) and in the highest category, BMI > or = 30 kg/m2 (OR = 2.92, 95% CI: 1.39-6.14). This U-shaped association persisted when restricting the analysis to men who had never smoked and was more pronounced for those between 18 and 49 years of age. In conclusion, this cross-sectional study showed that men and women differ significantly in the association between BMI and asthma prevalence only with respect to the lowest weight category. While women had a monotonic association, men showed a U-shaped relationship, indicating that both extremes of weight are associated with a higher prevalence of asthma.

To identify modifiable risk factors for wheezing illness in childhood, the associations between current asthma or wheezing and factors such as household smoking, damp and dietary salt preference were measured in a questionnaire-based prevalence study of schoolchildren 7 to 9 yr of age in Cape Town. In a random sample of 15 schools, questionnaires were completed by parents of 1,955 children, from which 368 cases and 294 controls were selected on the basis of reported asthma diagnosis or symptoms. Urinary cotinine concentrations were measured, and the parents were interviewed. An exposure-response relationship between the urinary cotinine creatinine ratio and asthma/wheeze was observed. In multivariate analysis, predictors of asthma/wheeze were hay fever (odds ratio [OR] - 5.30; 95% confidence interval [CI] = 3.16 to 8.89), eczema (OR = 2.19; 95% CI = 1.33-3.62), parental asthma (OR = 1.77; 95% CI = 1.11 to 2.84), absence of paternal contribution to income (OR = 1.72; 95% CI = 1.17 to 2.54), maternal smoking in pregnancy (OR = 1.87; 95% CI = 1.25 to 2.81), and each additional household smoker (OR = 1.15; 95% CI = 1.01 to 1.30). Findings were similar, with higher odds ratios for most variables, except number of household smokers, when the group was restricted to children with parent-reported asthma. The findings confirm that household smoking is an important modifiable risk factor in asthma/wheeze among young schoolchildren, and they suggest that maternal smoking in pregnancy and current household exposure are independent contributors to this effect.

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