Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB)

BACKGROUND : Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. METHODS : The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. RESULTS : Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. CONCLUSION : The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target.http://ehp.niehs.nih.gov/hb201

Prostate Cancer in Southern Africa: Does Africa Hold Untapped Potential to Add Value to the Current Understanding of a Common Disease?

Prostate cancer (PCa) is the most common cancer diagnosis in men from economically stable countries and is a leading cause of cancer-related death.1 However, the population with the highest reported incidence and mortality rates globally are African Americans. Although the lifetime risk of a cancer diagnosis (one in two) or cancerassociated mortality (one in four) is no different for American men of African or European heritage, the figures are dramatically skewed for PCa.2 Incidence and mortality rates are 1.6- and 2.4-fold greater for African Americans than for European Americans, respectively.3 Additional clinical parameters exasperated in African Americans are higher serum prostate-specific antigen (PSA) levels population wide and at diagnosis, younger age at diagnosis, shorter PSA doubling before surgery, higher tumor grade and volume at surgery, higher incidence of anteriorally located tumors (more challenging to obtain a biopsy sample), and faster growing tumors (greater potential for metastasis).4-10 Although African American men have the greatest PCa burden globally, the relationship to men from Africa is less clear. We present the challenges and largely overlooked potential to address the impact of PCa within Africa. We provide commentary from our experiences as the clinical (M.S.R.B.) and scientific (V.M.H.) directors of the Southern African Prostate Cancer Study (SAPCS).The Cancer Association of South Africa (V.M.H. and M.S.R.B.). V.M.H. is further supported by the University of Sydney Foundation and Petre Foundation as Chair of Prostate Cancer Research, Australia.http://ascopubs.org/journal/jgoam2017School of Health Systems and Public Health (SHSPH