ABSTRACT
Human Papillomavirus (HPV) self-sampling has been implemented successfully as an alternative to traditional forms of cervical cancer screening in low-resource settings. Through Bangladesh's current national cervical cancer screening program, only about 10% of the at-risk population is reached. Thus, Bangladesh is an ideal setting to consider HPV self-sampling to improve cervical cancer prevention efforts. However, the feasibility and acceptability of HPV self-sampling has not been evaluated in Bangladesh. We aimed to understand levels of HPV and cervical cancer knowledge and to evaluate the feasibility and acceptability of HPV self-sampling for cervical cancer screening in a semi-urban Bangladeshi community. Participants were recruited from a local clinic; 164 women completed a cross-sectional questionnaire about attitudes towards screening, and cervical cancer and HPV risk factor knowledge, and provided self-collected cervical samples for high-risk HPV testing. Of the participants, 4.3% tested positive for high-risk HPV and were referred for appropriate follow-up care. Nearly all participants had heard of cervical cancer, though specific knowledge was quite low. Self-sampling for high-risk HPV testing had high rates of acceptability, high rates of convenience, and very little discomfort and embarrassment reported in this study population, making implementing HPV self-sampling as a form of cervical cancer screening in Bangladesh appear feasible.
ABSTRACT
Exposures to environmental arsenic (As) and polycyclic aromatic hydrocarbons (PAH) have been shown to independently cause dysregulation of immune function. Little data exists on the associations between combined exposures to As and PAH with immunotoxicity in humans. In this work we examined associations between As and PAH exposures with lymphoid cell populations in human peripheral blood mononuclear cells (PBMC), as well as alterations in differentiation and activation of B and T cells. Two hundred men, participating in the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh, were selected for the present study based on their exposure to As from drinking water and their cigarette smoking status. Blood and urine samples were collected from study participants. We utilized multiparameter flow cytometry in PBMC to identify immune cells (B, T, monocytes, NK) as well as the T-helper (Th) cell subsets (Th1, Th2, Th17, and Tregs) following ex vivo activation. We did not find evidence of interactions between As and PAH exposures. However, individual exposures (As or PAH) were associated with changes to immune cell populations, including Th cell subsets. Arsenic exposure was associated with an increase in the percentage of Th cells, and dose dependent changes in monocytes, NKT cells and a monocyte subset. Within the Th cell subset we found that Arsenic exposure was also associated with a significant increase in the percentage of circulating proinflammatory Th17 cells. PAH exposure was associated with changes in T cells, monocytes and T memory (Tmem) cells and with changes in Th, Th1, Th2 and Th17 subsets all of which were non-monotonic (dose dependent). Alterations of immune cell populations caused by environmental exposures to As and PAH may result in adverse health outcomes, such as changes in systemic inflammation, immune suppression, or autoimmunity.
Subject(s)
Arsenic/adverse effects , Environmental Exposure/adverse effects , Leukocytes, Mononuclear/immunology , Polycyclic Aromatic Hydrocarbons/adverse effects , Smoke/adverse effects , T-Lymphocyte Subsets/immunology , Humans , Leukocytes, Mononuclear/drug effects , Longitudinal Studies , Male , Middle Aged , T-Lymphocyte Subsets/drug effectsABSTRACT
BACKGROUND: Concentrations of arsenic (As) are elevated in a large proportion of wells in Bangladesh but are spatially variable even within a village. This heterogeneity can enable exposed households to switch to a nearby well lower in As in response to blanket (area-wide) well As testing. OBJECTIVES: We document the evolution of As exposure in Araihazar, Bangladesh following a blanket well testing and education campaign, as well as the installation of a considerable number of low As community wells. METHODS: We use well water and urinary As data collected between 2000 and 2008, along with household interviews extending through 2016, within a 25â¯km2 area of Araihazar upazila for nearly 12,000 participants enrolled in the Health Effects of Arsenic Longitudinal Study (HEALS). We observe changes in participants' well water and urinary As concentrations following interventions to lower their exposure and use logistic regression to determine the factors associated with participants' decisions to switch primary household wells. RESULTS: Urinary As for participants drinking from wells with >100⯵g/L As at baseline declined from a mean of 226⯵g/L at baseline to 173⯵g/L two years later, and further declined to 139⯵g/L over 8â¯years. For comparison, urinary As concentrations for participants drinking from wells with ≤10⯵g/L As remained close to 50⯵g/L throughout. Whereas the interventions only partially reduced exposure, well status with respect to As was predictive of well-switching decisions for at least a decade after the initial testing. Participants with high-As wells were 7 times more likely to switch wells over the first two years and 1.4-1.8 times more likely to switch wells over the ensuing decade. CONCLUSIONS: Arsenic exposure gradually declined following blanket well testing, an education campaign, and the installation of community wells but remained almost three times higher than for a subgroup of the participants drinking from wells with ≤10⯵g/L. In addition, the number of participants with unknown As concentrations in their primary household wells increased substantially over time, indicating the importance of additional well testing as new wells continue to be installed, in addition to other means of reducing As exposure.