High Uptake of Exclusive Breastfeeding and Reduced Early Post-Natal HIV Transmission

BACKGROUND. Empirical data showing the clear benefits of exclusive breastfeeding (EBF) for HIV prevention are needed to encourage implementation of lactation support programs for HIV-infected women in low resource settings among whom replacement feeding is unsafe. We conducted a prospective, observational study in Lusaka, Zambia, to test the hypothesis that EBF is associated with a lower risk of postnatal HIV transmission than non-EBF. METHODS AND RESULTS. As part of a randomized trial of early weaning, 958 HIV-infected women and their infants were recruited and all were encouraged to breastfeed exclusively to 4 months. Single-dose nevirapine was provided to prevent transmission. Regular samples were collected from infants to 24 months of age and tested by PCR. Detailed measurements of actual feeding behaviors were collected to examine, in an observational analysis, associations between feeding practices and postnatal HIV transmission. Uptake of EBF was high with 84% of women reporting only EBF cumulatively to 4 months. Post-natal HIV transmission before 4 months was significantly lower (p = 0.004) among EBF (0.040 95% CI: 0.024–0.055) than non-EBF infants (0.102 95% CI: 0.047–0.157); time-dependent Relative Hazard (RH) of transmission due to non-EBF = 3.48 (95% CI: 1.71–7.08). There were no significant differences in the severity of disease between EBF and non-EBF mothers and the association remained significant (RH = 2.68 95% CI: 1.28–5.62) after adjusting for maternal CD4 count, plasma viral load, syphilis screening results and low birth weight. CONCLUSIONS. Non-EBF more than doubles the risk of early postnatal HIV transmission. Programs to support EBF should be expanded universally in low resource settings. EBF is an affordable, feasible, acceptable, safe and sustainable practice that also reduces HIV transmission providing HIV-infected women with a means to protect their children's lives. TRIAL REGISTRATION. ClinicalTrials.gov NCT00310726National Institute of Child Health and Human Development; National Institutes of Health (R01 HD 39611, R01 HD 40777); Centers for Disease Control and Prevention; Global AIDS Program; Glaser Pediatric AIDS Foundation; USAID Country Research (GHS-A-00-00020-00

Same-sex sexual behaviour: US frequency estimates from survey data with simultaneous misreporting and non-response

Survey-based research concerning sexual behaviour almost inevitably confronts the simultaneous problems of misreporting and non-response. These problems lead to disparities among estimates of the number and characteristics of those who engage in same-sex sexual behaviour. This paper proposes a statistical model to consistently estimate the frequency of same-sex sexual behaviour in the presence of non-ignorable misreporting and non-response. The model is fitted using 1991–2000 General Social Survey data. Frequency estimates corrected for simultaneous misreporting and non-response are reported. According to the model, 7.1% of US males and 4.1% of females – 15.8 million individuals – are not exclusively heterosexual. Allowing for misreporting and non-response increases the estimated same-sex frequency by more than four million. The model reveals new patterns between misreporting and non-response probabilities and standard demographic variables such as age and income.

CCDC 665082: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: M.A.Meierhoefer, S.P.Dunn, L.M.Hajiaghamohseni, M.J.Walters, M.C.Embree, S.P.Grant, J.R.Downs, J.D.Townsend, C.R.Metz, C.F.Beam, W.T.Pennington, D.G.VanDerveer, N.D.Camper|2005|J.Heterocycl.Chem.|42|1095|doi:10.1002/jhet.557042060

The built environment and active transportation safety in children and youth: a study protocol

Background: Active transportation, such as walking and biking, is a healthy way for children to explore their environment and develop independence. However, children can be injured while walking and biking. Many cities make changes to the built environment (e.g., traffic calming features, separated bike lanes) to keep people safe. There is some research on how effective these changes are in preventing adult pedestrians and bicyclists from getting hurt, but very little research has been done to show how safe various environments are for children and youth. Our research program will study how features of the built environment affect whether children travel (e.g., to school) using active modes, and whether certain features increase or decrease their likelihood of injury. Methods: First, we will use a cross-sectional study design to estimate associations between objectively measured built environment and objectively measured active transportation to school among child elementary students. We will examine the associations between objectively measured built environment and child and youth pedestrian-motor vehicle collisions (MVCs) and bicyclist-MVCs. We will also use these data to determine the space-time distribution of pedestrian-MVCs and bicyclist-MVCs. Second, we will use a case-crossover design to compare the built environment characteristics of the site where child and youth bicyclists sustain emergency department reported injuries and two randomly selected sites (control sites) along the bicyclist’s route before the injury occurred. Third, to identify implementation strategies for built environment change at the municipal level to encourage active transportation we will conduct: 1) an environmental scan, 2) key informant interviews, 3) focus groups, and 4) a national survey to identify facilitators and barriers for implementing built environment change in municipalities. Finally, we will develop a built environment implementation toolkit to promote active transportation and prevent child pedestrian and bicyclist injuries. Discussion: This program of research will identify the built environment associated with active transportation safety and form an evidence base from which municipalities can draw information to support change. Our team’s national scope will be invaluable in providing information regarding the variability in built environment characteristics and is vital to producing evidence-based recommendations that will increase safe active transportation.Education, Faculty ofMedicine, Faculty ofOther UBCNon UBCKinesiology, School ofPediatrics, Department ofReviewedFacult