Environmental health and household demographics impacting biosand filter maintenance and diarrhea in Guatemala: an application of structural equation modeling.

In rural health development practice, engineers and scientists must recognize the complex interactions that influence individuals' contact with disease-causing pathogens and understand how household habits may impact the adoption and long-term sustainability of new technology. The goal of this study was to measure the effect of various environmental health factors and household demographics on the operation and maintenance of the Biosand filter (Centre for Affordable Water and Sanitation Technology, Calgary, Alberta, Canada) and diarrhea health burden in the region. In July and August 2010, randomized household surveys (n = 286) were completed in rural Guatemala detailing water access, sanitation availability, hygiene practice, socio-economic status, education level, filter operation and maintenance, and diarrhea health burden of the home. A hypothesized structural equation model was developed based on a review of published research and tested using the surveyed data. Model-derived parameter estimates indicated that: (a) proper personal hygiene practices significantly promote proper filter operation and maintenance; and (b) higher household education level, proper filter operation and maintenance, and improved water supply significantly reduce diarrhea health burden. Additionally, a high level of unexplained variance in diarrhea indicated the filter, though protective of health, is not the only factor influencing diarrhea.

Lead levels in new enamel household paints from Asia, Africa and South America.

In 2006 a report on the analysis for lead in 80 new residential paints from four countries in Asia revealed high levels in three of the countries (China, India and Malaysia) and low levels in a fourth country (Singapore) where a lead in paint regulation was enforced. The authors warned of the possible export of lead-painted consumer products to the United States and other countries and the dangers the lead paint represented to children in the countries where it was available for purchase. The need for a worldwide ban on the use of lead in paints was emphasized to prevent an increase in exposure and disease from this very preventable environmental source. Since the earlier paper almost 300 additional new paint samples have been collected from the four initial countries plus 8 additional countries, three from Asia, three from Africa and two from South America. During the intervening time period two million toys and other items imported into the United States were recalled because the lead content exceeded the United States standard. High lead paints were detected in all 12 countries. The average lead concentration by country ranged from 6988 (Singapore) to 31,960ppm (Ecuador). One multinational company sold high lead paint in one country through January 2007 but sold low lead paint later in 2007 indicating that a major change to cease adding lead to their paints had occurred. However, the finding that almost one-third of the samples would meet the new United States standard for new paint of 90ppm, suggests that the technology is already available in at least 11 of the 12 countries to produce low lead enamel paints for domestic use. The need remains urgent to establish effective worldwide controls to prevent the needless poisoning of millions of children from this preventable exposure.

Epidemiology of necrotizing enterocolitis temporal clustering in two neonatology practices.

OBJECTIVE: To develop a statistical method for defining clusters of necrotizing enterocolitis (NEC) cases in the neonatal intensive care unit (NICU). STUDY DESIGN: The study group included 2782 infants weighing 401 to 1500 g at birth born between 1996 and 2004. NEC was defined as Bell stage II or III. Two statistical methods were used to define "disease clusters": a modified scan test and a comparison of observed and expected incidence density rates (IDRs) of NEC at each NICU. RESULTS: The proportion of infants with NEC was similar in the 2 NICUs (7.1% vs 7.7%; P = .6), as was the expected IDR of NEC (1.39/1000 patient-days vs 1.32/1000 patient-days; P = .72). Twelve temporal clusters of NEC were identified in the 2 NICUs, representing 18% of 203 total NEC cases during the study period. No seasonal/secular trends were noted for NEC rates or identified clusters. Potential NEC clusters of > or =3 cases at either NICU had a >75% likelihood of being a true NEC cluster. CONCLUSIONS: No operational definition of NEC cluster exists. This study introduces methods to use in prospective surveillance and to guide studies investigating etiologic relevance. Using the proposed methods, statistically significant clusters (ie, potential outbreaks) of NEC within NICUs can be identified early, providing an opportunity for early implementation of cluster investigation protocols.

The interval between menarche and age of first sexual intercourse as a risk factor for subsequent HPV infection in adolescent and young adult women.

We sought to determine whether the interval between menarche and age of first sexual intercourse is associated with subsequent human papilloma virus (HPV) infection and if so, whether the association is independent of the age of first sexual intercourse. Female university students completed a survey and were screened for cervicovaginal HPV infection. HPV-positive subjects were matched to HPV-negative subjects (n = 504). Mean subject age was 20.4 +/- 2.1 years, age of first sexual intercourse 16.7 +/- 1.8 years, and interval 4.4 +/- 2.0 years. The interval was associated with HPV infection, but the association became nonsignificant in univariate stratified analyses and multivariate models estimating the association between the interval and HPV infection. A short interval is associated with HPV infection, but the association is not independent of age of first sexual intercourse. Age of first sexual intercourse should be considered an important and identifiable risk factor for subsequent HPV infection in research and clinical settings.