Variability in hand contamination based on serial measurements: implications for assessment of hand-cleansing behavior and disease risk.

Measuring hand contamination at critical times, such as eating, can be challenging. We examined whether hand contamination measured at random, such as on arrival (initial), predicts contamination at critical times. Mothers of young children in Bangladesh rinsed both hands in 200 mL of Ringer's solution. We compared results of serial samples with respect to fecal coliform counts. Among 39 mothers, the geometric mean of fecal coliforms was 307 colony-forming units (cfu)/100 mL at initial collection and 3,001 cfu/100 mL during critical times (P = 0.0006). There was no correlation between initial and critical time fecal coliform counts (R = 0.13, P = 0.43). The mean difference between initial and critical time counts was 3.5 (standard deviation = 1.4) on the log base-10 scale. Contamination of the same subjects' hands varied substantially within a few hours. Because hand contamination measured at random cannot reliably predict hand contamination at times of potential pathogen transmission, single random hand rinses are not valid proxy measures for handwashing behavior.

Environmental and lifestyle factors associated with perceived facial age in Chinese women.

Perceived facial age has been proposed as a biomarker of ageing with 'looking young for one's age' linked to physical and cognitive functioning and to increased survival for Caucasians. We have investigated the environmental and lifestyle factors associated with perceived facial ageing in Chinese women. Facial photographs were collected from 250 Chinese women, aged 25-70 years in Shanghai, China. Perceived facial age was determined and related to chronological age for each participant. Lifestyle and health information was collected by questionnaire. Bivariate analyses (controlling for chronological age) identified and quantified lifestyle variables associated with perceived facial age. Independent predictors of perceived age were identified by multivariate modelling. Factors which significantly associated with looking younger for one's chronological age included greater years of education (p<0.001), fewer household members (p=0.027), menopausal status (p=0.020), frequency of visiting one's doctor (p=0.013), working indoors (p<0.001), spending less time in the sun (p=0.015), moderate levels of physical activity (p=0.004), higher frequency of teeth cleaning (p<0.001) and more frequent use of facial care products: cleanser (p<0.001); moisturiser (p=0.016) or night cream (p=0.016). Overall, 36.5% of the variation in the difference between perceived and chronological age could be explained by a combination of chronological age and 6 independent lifestyle variables. We have thus identified and quantified a number of factors associated with younger appearance in Chinese women. Presentation of these factors in the context of facial appearance could provide significant motivation for the adoption of a range of healthy behaviours at the level of both individuals and populations.

Is structured observation a valid technique to measure handwashing behavior? Use of acceleration sensors embedded in soap to assess reactivity to structured observation.

Structured observation is often used to evaluate handwashing behavior. We assessed reactivity to structured observation in rural Bangladesh by distributing soap containing acceleration sensors and performing structured observation 4 days later. Sensors recorded the number of times soap was moved. In 45 participating households, the median number of sensor soap movements during the 5-hour time block on pre-observation days was 3.7 (range 0.3-10.6). During the structured observation, the median number of sensor soap movements was 5.0 (range 0-18.0), a 35% increase, P = 0.0004. Compared with the same 5-hour time block on pre-observation days, the number of sensor soap movements increased during structured observation by ≥ 20% in 62% of households, and by ≥ 100% in 22% of households. The increase in sensor soap movements during structured observation, compared with pre-observation days, indicates substantial reactivity to the presence of the observer. These findings call into question the validity of structured observation for measurement of handwashing behavior.

Dietary nutrient intakes and skin-aging appearance among middle-aged American women.

BACKGROUND: Nutritional factors play a key role in normal dermatologic functioning. However, little is known about the effects of diet on skin-aging appearance. OBJECTIVE: We evaluated the associations between nutrient intakes and skin-aging appearance. DESIGN: Using data from the first National Health and Nutrition Examination Survey, we examined associations between nutrient intakes and skin aging in 4025 women (40-74 y). Nutrients were estimated from a 24-h recall. Clinical examinations of the skin were conducted by dermatologists. Skin-aging appearance was defined as having a wrinkled appearance, senile dryness, and skin atrophy. RESULTS: Higher vitamin C intakes were associated with a lower likelihood of a wrinkled appearance [odds ratio (OR) 0.89; 95% CI: 0.82, 0.96] and senile dryness (OR: 0.93; 95% CI: 0.87, 0.99). Higher linoleic acid intakes were associated with a lower likelihood of senile dryness (OR: 0.75; 95% CI: 0.64, 0.88) and skin atrophy (OR: 0.78; 95% CI 0.65, 0.95). A 17-g increase in fat and a 50-g increase in carbohydrate intakes increased the likelihood of a wrinkled appearance (OR: 1.28 and 1.36, respectively) and skin atrophy (OR: 1.37 and 1.33, respectively). These associations were independent of age, race, education, sunlight exposure, income, menopausal status, body mass index, supplement use, physical activity, and energy intake. CONCLUSIONS: Higher intakes of vitamin C and linoleic acid and lower intakes of fats and carbohydrates are associated with better skin-aging appearance. Promoting healthy dietary behaviors may have additional benefit for skin appearance in addition to other health outcomes in the population.