Last data update: Aug 15, 2025. (Total: 49733 publications since 2009)
| Records 1-30 (of 34 Records) |
| Query Trace: Ope M[original query] |
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| Epidemiology and response to the COVID-19 pandemic in the Dadaab Refugee Camp Complex, Kenya, March 2020-December 2022
Ope M , Musyoka R , Kosar A , Osman M , Hassan A , Mohammed H , Munyua P , Juma B , Hunsperger E , Mohammed S , Burton J , Eidex RB . Travel Med Infect Dis 2024 63 102785 INTRODUCTION: Refugee settings may increase the risk of SARS-CoV-2 infection and death, yet data on the response to the pandemic in these populations is scarce. METHODS: We describe interventions to mitigate SARS-CoV-2 transmission in Dadaab Refugee Camp Complex, Kenya and performed descriptive analyses using March 2020 to December 2022 data from Kenya's national SARS-CoV-2 repository and line list of positive cases maintained by United Nations High Commissioner for Refugees (UNHCR). We calculated case fatality rates (CFR) and attack rates per 100,000 (AR) using the 2019 national census and population statistics from UNHCR and compared them to national figures. RESULTS: SARS-CoV-2 infection was first reported in April and May 2020, among host community members and refugees respectively. Of 964 laboratory-confirmed cases, 700 (72.6 %) were refugees. The AR was 82.7 (95 % CI 72.6-92.8) for host community members, 228.3 (95 % CI 211.3-245.4) for refugees and 721.1 (95 % CI 718.7-723.5) nationally. The CFR was 1.5 % (95 % CI 0.15-3.18) for host community members, 1.76 % (95 % CI 1.71-1.80) nationally and 7.4 % (95 % CI 5.4-9.4) for refugees. Mitigation measures implemented by the Government of Kenya, UNHCR and partners during the pandemic included multisectoral coordination, movement restrictions, mass gathering bans, and health promotion. Social distancing, symptom screening and mandatory mask usage were enforced during mass gatherings. Testing capacity was bolstered, quarantine and isolation facilities established, and vaccination initiated. CONCLUSIONS: Despite a low AR and UNHCR's swift and comprehensive response, refugees' CFR was high, underscoring their vulnerability and need for targeted interventions during epidemic responses. |
| Gestational organophosphate esters (OPEs) and executive function in adolescence: The HOME Study
Vuong AM , Percy Z , Yang W , Godbole AM , Ospina M , Calafat AM , Cecil KM , Lanphear BP , Braun JM , Yolton K , Chen A . Environ Res 2024 120239
BACKGROUND: Evidence from toxicological studies indicate organophosphate esters (OPEs) are neurotoxic, but few epidemiological studies investigated associations between gestational OPEs and executive function. OBJECTIVE: To examine the associations between gestational concentrations of OPE urinary metabolites and executive function at 12 years METHODS: We used data from 223 mother-adolescent dyads from the Health Outcomes of Measures of the Environment (HOME) Study. Women provided spot urine samples at 16 weeks gestation, 26 weeks gestation, and at delivery for quantification of bis(1,3-dichloro-2-propyl) phosphate, bis-2-chloroethyl phosphate (BCEP), diphenyl phosphate (DPHP), and di-n-butyl phosphate (DNBP). Executive function was assessed at age 12 years using the parent- and self-report Behavior Rating Inventory of Executive Function (BRIEF2). Covariate-adjusted associations between specific gravity-corrected OPEs and BRIEF2 scores were estimated using multiple informant models. Bayesian Kernel Machine Regression (BKMR) was used to assess the impact of all OPEs simultaneously. RESULTS: Parent- and self-report BRIEF2 indices and composite scores were weakly to moderately correlated (r(s)=0.32-0.41). A natural-log unit increase in BCEP at 26 weeks was associated with approximately a 1-point increase on the self-report Cognitive Regulation Index [CRI] (95% CI 0.4, 2.3), the Emotion Regulation Index [ERI] (95% CI 0.3, 2.2), and the Global Executive Composite [GEC] (95% CI 0.4, 2.2), indicating poorer performance. Higher DPHP at 16 weeks was associated with lower parent-report GEC score (β=-1.1, 95% CI -2.3, -0.003). BKMR identified BCEP and DNBP at 26 weeks as important contributors to CRI and ERI, respectively. CONCLUSION: OPE metabolites during gestational development, particularly BCEP, may influence adolescent executive function. However, since the FDR p-values failed to reach statistical significance, additional studies would benefit from using larger cohorts. |
| Exposure to organophosphate ester flame retardants and plasticizers and associations with preeclampsia and blood pressure in pregnancy
Lueth AJ , Bommarito PA , Stevens DR , Welch BM , Cantonwine DE , Ospina M , Calafat AM , Meeker JD , McElrath TF , Ferguson KK . Environ Res 2024 262 119910 BACKGROUND: Organophosphate esters (OPEs), flame retardants and plasticizers found widely in consumer products, may impact vascularization processes in pregnancy. Yet, the association between maternal exposure to OPEs and both preeclampsia and blood pressure during pregnancy remains understudied. METHODS: Within the LIFECODES Fetal Growth Study (N = 900), we quantified 8 OPE metabolites from maternal urine collected at up to 3 time points during pregnancy and created within-subject geometric means. Outcomes included diagnosis of preeclampsia and longitudinal systolic (SBP) and diastolic (DBP) blood pressure measurements (mean = 14 per participant). Cox proportional hazards models were used to estimate associations between OPE metabolites and preeclampsia. Associations between average OPE metabolite concentrations and repeated blood pressure measurements were estimated using generalized estimating equations. RESULTS: Five OPE metabolites were detected in at least 60% of samples; 3 metabolites detected less frequently (5-39%) were examined in an exploratory analysis as ever vs. never detectable in pregnancy. There were 46 cases of preeclampsia in our study population. Associations between OPE metabolites and preeclampsia were null. We noted several divergent associations between OPE metabolites and longitudinal blood pressure measurements. An interquartile range (IQR) difference in average bis(2-chloroethyl) phosphate concentrations was associated with a decrease in SBP (-0.81 mmHg, 95% confidence interval [CI]: -1.62, 0.00), and, conversely, bis(1-chloro-2-propyl) phosphate was associated with a slight increase in SBP (0.94 mmHg, 95% CI: 0.28, 1.61). We also noted a decrease in SBP in association with several metabolites with low detection frequency. CONCLUSIONS: We observed null associations between OPE metabolites and preeclampsia, but some positive and some inverse associations with blood pressure in pregnancy. While our study was well-designed to assess associations with blood pressure, future studies with a larger number of preeclampsia cases may be better poised to investigate the association between OPE metabolites and phenotypes of this heterogenous hypertensive disorder of pregnancy. |
| Organophosphate ester flame retardants and plasticizers in relation to fetal growth in the LIFECODES Fetal Growth Study
Bommarito PA , Stevens DR , Welch BM , Ospina M , Calafat AM , Meeker JD , Cantonwine DE , McElrath TF , Ferguson KK . Environ Health Perspect 2024 132 (7) 77001 BACKGROUND: Organophosphate esters (OPEs), used ubiquitously as flame retardants and plasticizers in consumer products, are suspected of having developmental toxicity. OBJECTIVES: Our study aimed to estimate associations between prenatal exposure to OPEs and fetal growth, including both ultrasound (head circumference, abdominal circumference, femur length, and estimated fetal weight) and delivery [birth weight z-score, small-for-gestational age (SGA), and large-for-gestational age (LGA)] measures of growth. METHODS: In the LIFECODES Fetal Growth Study (2008-2018), an enriched case-cohort of 900 babies born at the small and large ends of the growth spectrum, we quantified OPE biomarkers in three urine samples per pregnant participant and abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-averaged log-transformed OPE biomarkers and repeated ultrasound measures of fetal growth using linear mixed-effects models, and delivery measures of fetal growth using linear (birth weight) and logistic (SGA and LGA) regression models. RESULTS: Most OPE biomarkers were positively associated with at least one ultrasound measure of fetal growth, but associations with delivery measures were largely null. For example, an interquartile range (IQR; 1.31 ng/mL) increase in bis(2-chloroethyl) phosphate concentration was associated with larger z-scores in head circumference [mean difference (difference): 0.09; 95% confidence interval (CI): 0.01, 0.17], abdominal circumference (difference: 0.10; 95% CI: 0.02, 0.18), femur length (difference: 0.11; 95% CI: 0.03, 0.19), and estimated fetal weight (difference: 0.13; 95% CI: 0.04, 0.22) but not birth weight (difference: 0.04; 95% CI: - 0.08, 0.17). At delivery, an IQR (1.00 ng/mL) increase in diphenyl phosphate (DPHP) concentration was associated with an SGA birth (odds ratio: 1.46; 95% CI: 1.10, 1.94). CONCLUSIONS: In a large prospective cohort, gestational OPE exposures were associated with larger fetal size during pregnancy, but associations at delivery were null. DPHP concentrations were associated with heightened risk of an SGA birth. These findings suggest that OPE exposure may affect fetal development. https://doi.org/10.1289/EHP14647. |
| Biomarkers of organophosphate and polybrominated diphenyl ether (PBDE) flame retardants of American workers and associations with inhalation and dermal exposures
Estill CF , Mayer AC , Chen IC , Slone J , LaGuardia MJ , Jayatilaka N , Ospina M , Sjodin A , Calafat AM . Environ Sci Technol 2024 This study evaluated workers' exposures to flame retardants, including polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs), and other brominated flame retardants (BFRs), in various industries. The study aimed to characterize OPE metabolite urinary concentrations and PBDE serum concentrations among workers from different industries, compare these concentrations between industries and the general population, and evaluate the likely route of exposure (dermal or inhalation). The results showed that workers from chemical manufacturing had significantly higher (p <0.05) urinary concentrations of OPE metabolites compared to other industries. Spray polyurethane foam workers had significantly higher (p <0.05) urinary concentrations of bis(1-chloro-2-propyl) phosphate (BCPP) compared to other industries. Electronic scrap workers had higher serum concentrations of certain PBDE congeners compared to the general population. Correlations were observed between hand wipe samples and air samples containing specific flame-retardant parent chemicals and urinary metabolite concentrations for some industries, suggesting both dermal absorption and inhalation as primary routes of exposure for OPEs. Overall, this study provides insights into occupational exposure to flame retardants in different industries and highlights the need for further research on emerging flame retardants and exposure reduction interventions. |
| Epidemiology of SARS-CoV-2 in Kakuma Refugee Camp Complex, Kenya, 2020-2021(1)
Ope M , Musyoka R , Kiogora J , Wambugu J , Hunsperger E , Emukule GO , Munyua P , Juma B , Simiyu E , Gagnidze L , Burton J , Eidex RB . Emerg Infect Dis 2024 30 (5) 900-907 Understanding SARS-CoV-2 infection in populations at increased risk for poor health is critical to reducing disease. We describe the epidemiology of SARS-CoV-2 infection in Kakuma Refugee Camp Complex, Kenya. We performed descriptive analyses of SARS-CoV-2 infection in the camp and surrounding community during March 16, 2020‒December 31, 2021. We identified cases in accordance with national guidelines.We estimated fatality ratios and attack rates over time using locally weighted scatterplot smoothing for refugees, host community members, and national population. Of the 18,864 SARS-CoV-2 tests performed, 1,024 were positive, collected from 664 refugees and 360 host community members. Attack rates were 325.0/100,000 population (CFR 2.9%) for refugees,150.2/100,000 population (CFR 1.11%) for community, and 628.8/100,000 population (CFR 1.83%) nationwide. During 2020-2021, refugees experienced a lower attack rate but higher CFR than the national population, underscoring the need to prioritize SARS-CoV-2 mitigation measures, including vaccination. |
| Patterns of urinary organophosphate ester metabolite trajectories in children: the HOME Study
Yang W , Braun JM , Vuong AM , Percy Z , Xu Y , Xie C , Deka R , Calafat AM , Ospina M , Yolton K , Cecil KM , Lanphear BP , Chen A . J Expo Sci Environ Epidemiol 2023 BACKGROUND: Organophosphate esters (OPEs) have replaced flame retardant polybrominated diphenyl ethers as flame retardants in consumer products, but few longitudinal studies have characterized childhood OPE exposure. OBJECTIVE: We aimed to examine the exposure pattern of urinary OPE metabolites in children. METHODS: We quantified three urinary OPE metabolites five times in children (1, 2, 3, 5, 8 years) from 312 mother-child pairs in the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio, USA. We examined the associations of average maternal OPE metabolite concentrations with OPE metabolite concentrations in childhood, characterized childhood OPE trajectories with latent class growth analysis (LCGA), and examined factors related to trajectory membership. RESULTS: Bis(2-chloroethyl) phosphate (BCEP) had the lowest median concentrations over time (0.66-0.97 mg/L) while the median concentrations of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) increased with age (1.44-3.80 mg/L). The median concentrations of diphenyl phosphate (DPHP) fluctuated between 1.96 and 2.69 mg/L. Intraclass correlation coefficients for urinary metabolites measured at five time points indicated high variability within individuals (0.13-0.24). Average maternal urinary BCEP and BDCIPP were associated with concentrations in early childhood. Maternal education, the birth year of the child, and having a carpet in the main activity room were associated with BCEP and BDCIPP trajectory while none of the factors were associated with DPHP trajectory. SIGNIFICANCE: The trajectory analysis showed different patterns of urinary OPE metabolite concentrations, suggesting the need to collect multiple samples to adequately reflect OPE exposure. IMPACT STATEMENT: In this well-established cohort, we evaluated the patterns of urinary OPE metabolites in children ages 1-8 years. The number of repeated measures over childhood has not been achieved in prior studies. Our results suggested the high variability of urinary OPE metabolites within individuals. Maternal metabolite concentrations during pregnancy were related to child concentrations at ages 1-3 years. BCEP, BDCIPP, and DPHP demonstrated different trajectories in children, which suggests that multiple samples may be required to capture OPE exposure patterns in childhood. |
| Temporal trends and predictors of gestational exposure to organophosphate ester flame retardants and plasticizers
Bommarito PA , Friedman A , Welch BM , Cantonwine DE , Ospina M , Calafat AM , Meeker JD , McElrath TF , Ferguson KK . Environ Int 2023 180 108194 BACKGROUND: Organophosphate esters (OPEs), used as flame retardants and plasticizers, are chemicals of concern for maternal and infant health. Prior studies examining temporal trends and predictors of OPE exposure are primarily limited by small sample sizes. OBJECTIVES: Characterize temporal trends and predictors of OPE exposure biomarkers. METHODS: We determined urinary concentrations of eight biomarkers of OPE exposure at three timepoints during pregnancy for participants in the LIFECODES Fetal Growth Study (n = 900), a nested case-cohort recruited between 2007 and 2018. We examined biomarker concentrations, their variability during pregnancy, and temporal trends over the study period. In addition, we identified sociodemographic and pregnancy characteristics associated with biomarker concentrations. Analyses were conducted using both the within-subject pregnancy geometric means and biomarker concentrations measured at individual study visits. RESULTS: Five OPE biomarkers were detected in at least 60% of the study participants. Biomarkers were not strongly correlated with one another and intraclass correlation coefficients, measuring within-subject variability during pregnancy, ranged from 0.27 to 0.51. Biomarkers exhibited varying temporal trends across study years. For example, bis(1-chloro-2-propyl) phosphate (BCIPP) increased monotonically, whereas bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), displayed non-monotonic trends with concentrations that peaked between 2011 and 2014. We observed associations between sociodemographic characteristics and OPE biomarkers. In general, concentrations of most OPE biomarkers were higher among participants from racial and ethnic minority populations, participants who were younger, had higher pre-pregnancy body mass index (BMI), and less than a college degree. We observed consistent results using either averaged or visit-specific biomarker concentrations. SIGNIFICANCE: We observed widespread exposure to several OPEs and OPE biomarkers displayed varying temporal trends in pregnant people from 2007 to 2018. Concentrations of most OPE biomarkers varied according to sociodemographic factors, suggesting higher burdens of exposure among participants with higher pre-pregnancy BMI, those belonging to racial and ethnic minority populations, and lower educational attainment. |
| Early-life exposure to a mixture of organophosphate esters and child behavior
Percy Z , Chen A , Sucharew H , Yang W , Vuong AM , Braun JM , Lanphear B , Ospina M , Calafat AM , Cecil KM , Xu Y , Yolton K . Int J Hyg Environ Health 2023 250 114162 Organophosphate esters (OPEs), widely used as flame retardants and plasticizers for commercial and residential purposes, are suspected of being neurotoxic. We aimed to assess exposure to an OPE mixture in early life and its relationship to parent-reported child behavior. We measured urinary concentrations of three OPE metabolites, bis-2-chloroethyl phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP), at pregnancy (16 and 26 weeks of gestation and delivery) and postnatal time points (ages 1, 2, 3, and 5 years) in the Health Outcomes and Measures of the Environment Study, a longitudinal pregnancy and birth cohort in Cincinnati, Ohio, USA (enrolled 2003-2006, n = 219). We used latent variable analysis in structural equations models and quantile g-computation to investigate associations of a mixture of the three OPE metabolites with parent-reported child behaviors at 3 and 8 years, measured using the Behavioral Assessment System for Children, Second Edition. Higher log-transformed urinary OPE latent variable values at 16 weeks were associated with fewer externalizing problem behaviors (ß = -5.74; 95% CI = -11.24, -0.24) and fewer overall behavioral problems at age 3 years (ß = -5.26; 95% CI = -10.33, -0.19), whereas having higher OPEs at delivery was associated with poorer overall behavioral problems at age 3 years (ß = 2.87; 95% CI = 0.13, 5.61). OPE latent variable values at 16 weeks, 26 weeks, and delivery were not associated with child behavior at 8 years. However, higher OPE latent variable values at 3 years were associated with fewer externalizing behaviors at 8 years (ß = -2.62; 95% CI = -5.13, -0.12). The quantile g-computation estimates had directions largely consistent with the latent variable analysis results. Pregnancy and postnatal urinary OPE metabolite mixtures were associated with child internalizing, externalizing, and overall negative behaviors at 3 and 8 years, but we did not identify a consistent pattern in terms of the direction of the effects or a particularly sensitive time point. |
| Associations of gestational exposure to organophosphate esters with gestational age and neonatal anthropometric measures: The HOME study
Yang W , Braun JM , Vuong AM , Percy Z , Xu Y , Xie C , Deka R , Calafat AM , Ospina M , Burris HH , Yolton K , Cecil KM , Lanphear BP , Chen A . Environ Pollut 2022 316 120516 Organophosphate esters (OPEs) are developmental toxicants in experimental studies of animals, but limited evidence is available in humans. We included 340 mother-infant pairs in the Health Outcomes and Measures of the Environment (HOME) Study (Cincinnati, Ohio, USA) for the analysis. We evaluated gestational exposure to OPEs with gestation age at birth and newborn anthropometric measures. We quantified four OPE urinary metabolites at 16 weeks and 26 weeks of gestation. We extracted gestational age at birth, newborn weight, length, and head circumference from the chart review. We calculated z-scores for these anthropometric measures and the ponderal index. We used multiple informant models to examine the associations between repeated OPE measurements and the outcomes. We used modified Poisson regression to estimate the association of gestational exposure to OPEs with preterm birth. We also explored effect modification by infant sex and the potential mediation effect by the highest maternal blood pressure and glucose levels. We found that bis(2-chloroethyl) phosphate (BCEP) at 16 weeks and diphenyl phosphate at 26 weeks of pregnancy were positively associated with gestational age and inversely associated with preterm birth. In female newborns, BCEP at 16 weeks was inversely related to birth weight and length z-scores. In male newborns, we observed negative associations of 26-week di-n-butyl phosphate with the ponderal index at birth. No mediation by the highest maternal blood pressure or glucose levels during pregnancy was identified. In this cohort, gestational exposure to some OPEs was associated with gestational age, preterm birth, and neonatal anthropometric measures. Certain associations tended to be window- and infant sex-specific. |
| Gestational exposure to organophosphate esters and infant anthropometric measures in the first 4weeks after birth
Yang W , Braun JM , Vuong AM , Percy Z , Xu Y , Xie C , Deka R , Calafat AM , Ospina M , Burris HH , Yolton K , Cecil KM , Lanphear BP , Chen A . Sci Total Environ 2022 857 159322
BACKGROUND: Few studies have examined whether gestational exposure to organophosphate esters (OPEs), widely used chemicals with potential endocrine-disrupting potency and developmental toxicity, is associated with impaired infant growth. METHODS: We analyzed data from 329 mother-infant pairs in the Health Outcomes and Measures of the Environment (HOME) Study (2003-2006, Cincinnati, Ohio, USA). We quantified concentrations of four OPE metabolites in maternal urine collected at 16 and 26 weeks of gestation, and at delivery. We calculated z-scores using 2006 World Health Organization (WHO) child growth standards for the 4-week anthropometric measures (weight, length, and head circumference), the ponderal index, and weekly growth rates. We used multiple informant models to examine window-specific associations between individual OPE metabolites and anthropometric outcomes. We further modeled OPEs as a mixture for window-specific associations with 4-week anthropometric outcomes using mean field variational Bayesian inference procedure for lagged kernel machine regression (MFVB-LKMR). We stratified the models by infant sex. RESULTS: Diphenyl phosphate (DPHP) in mothers at 16 weeks, and bis(2-chloroethyl) phosphate (BCEP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) at delivery were positively associated with z-scores of weight, length, and head circumference in all infants at 4 weeks of age. After stratifying by infant sex, positive associations were only observed in males for DPHP at 16 weeks and BCEP at delivery and in females for BDCIPP at delivery. Negative associations not present in all infants were observed in males for di-n-butyl phosphate (DNBP) at 26 weeks of gestation with weight z-score and DPHP at delivery with head circumference z-score. Results were generally similar using MFVB-LKMR models with more conservative 95 % credible intervals. We did not identify consistent associations of gestational OPE metabolite concentrations with the ponderal index and weekly growth rates. CONCLUSION: In this cohort, exposure to OPEs during gestation was associated with altered infant anthropometry at 4 weeks after birth. |
| Childhood urinary organophosphate esters and cognitive abilities in a longitudinal cohort study
Percy Z , Chen A , Yang W , Braun JM , Lanphear B , Ospina M , Calafat AM , Xie C , Cecil K , Vuong AM , Xu Y , Yolton K . Environ Res 2022 215 114265 The use of organophosphate esters (OPEs) as flame retardants, which has increased over the past two decades, raises concerns that OPEs may be harmful to humans, especially children. Animal studies and some human studies have reported that OPEs may adversely impact brain development, but few human studies evaluated OPE exposure during early childhood and neurodevelopmental outcomes. We aimed to fill this knowledge gap with the present study on urinary OPE metabolite concentrations at ages 1-5 years and cognitive abilities at 8 years. We used data of 223 children from the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio. The point estimates for bis-2-chloroethyl-phosphate (BCEP) and bis(1,3-dichloro-2-propyl)-phosphate (BDCIPP) in association with IQ tended to be small and positive, while the point estimates for diphenyl-phosphate (DPHP) were small and negative, with 95% CIs including the null. However, we did find that socioeconomic status (SES) variables modified associations between OPEs and child IQ, with adverse OPE-IQ associations being stronger in socioeconomically disadvantaged children than in others. We identified an additional 1- to 2-point decrease in Full Scale IQ for every log-unit increase in BDCIPP, BCEP, and DPHP among those with lower maternal education, non-white race, lower income, or living in more deprived neighborhoods. We observed similar results for the Perceptual Reasoning, Verbal Comprehension, and Working Memory Index Scores. We suspect that there is residual confounding related to socioeconomic disadvantage, which was not captured with the available SES variables typically used in epidemiologic studies. |
| Early life organophosphate ester exposures and bone health at age 12years: The Health Outcomes and Measures of the Environment (HOME) study
Calafat AM , Ospina M . Sci Total Environ 2022 851 158246 BACKGROUND: No human studies have evaluated early life organophosphate ester (OPE) exposures with bone health outcomes, despite evidence of osteotoxicity. OBJECTIVES: We assessed associations of urinary OPE metabolites measured across early life with areal bone mineral density (aBMD) and bone mineral content (BMC) at age 12 years. METHODS: Among 223 mother-child dyads enrolled in the Health Outcomes and Measures of the Environment (HOME) Study, we quantified concentrations of bis-2-chloroethyl phosphate (BCEP), bis-(1,3-dichloro-2-propyl) (BDCIPP), di-n-butyl phosphate (DnBP), and diphenyl phosphate (DPHP) in urine collected from mothers during pregnancy and children at ages 1, 2, 3, 5, and 8 years. At age 12 years, we performed dual energy x-ray absorptiometry and calculated aBMD and BMC z-scores at six skeletal sites. We estimated overall and sex-stratified BMD/BMC z-score differences per interquartile range (IQR) increase in OPE concentrations at multiple exposure timepoints: gestation (average) and 1-3 (average), 5, and 8 years. RESULTS: In adjusted models, overall associations of BCEP and BDCIPP with total hip and 1/3rd distal radius aBMD and BMC varied significantly by exposure timepoint, as did BDCIPP with whole body aBMD. For example, differences (95 % CI) in total hip aBMD z-score per IQR increase in BDCIPP were 0.33 (0.01, 0.64), -0.10 (-0.34, 0.14), -0.18 (-0.40, 0.05), and 0.14 (-0.09, 0.38) for concentrations during gestation and at 1-3, 5, and 8 years, respectively. Overall DnBP and DPHP associations were generally null at all timepoints. We observed sex-specific associations for some timepoints and skeletal sites. For example, an IQR increase in 8-year DPHP was associated with a 0.21 (0.05, 0.38) greater total hip aBMD z-score among females but -0.19 (-0.43, 0.05) lower z-score among males. DISCUSSION: Early life OPE exposures may be associated with sex- and exposure period-dependent alterations in early adolescent bone mineral accrual and strength. |
| Maternal urinary organophosphate ester metabolite concentrations and glucose tolerance during pregnancy: The HOME Study
Yang W , Braun JM , Vuong AM , Percy Z , Xu Y , Xie C , Deka R , Calafat AM , Ospina M , Yolton K , Cecil KM , Lanphear BP , Chen A . Int J Hyg Environ Health 2022 245 114026
BACKGROUND: Endocrine-disrupting chemicals may alter glucose homeostasis, especially during pregnancy. Biomonitoring studies suggest ubiquitous human exposure to organophosphate esters (OPEs), chemicals with endocrine-disrupting capabilities. Few studies have examined the association between maternal exposure to OPEs and blood glucose during pregnancy. METHODS: With data from 301 pregnant women in the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio, USA, we examined whether OPE concentrations were associated with changes in blood glucose. We quantified four OPE metabolites in maternal spot urine samples collected at 16- and 26-weeks pregnancy. We extracted results from the glucose challenge test (GCT) and oral glucose tolerance test (OGTT) via medical chart review. Women with GCT ≥ 140 mg/dL or any abnormal values in OGTT (≥ 95 mg/dL fasting glucose, ≥ 180 mg/dL 1-h glucose, ≥ 155 mg/dL 2-h glucose, ≥ 140 mg/dL 3-h glucose) were defined as having elevated glucose levels. We used linear regression and Bayesian Kernel Machine Regression (BKMR) to estimate the associations of individual OPE metabolites and OPE mixtures with blood glucose levels during pregnancy. We used modified Poisson regression to estimate the associations of OPE metabolite concentrations with elevated glucose levels. We further examined effect measure modification by maternal characteristics (age, pre-pregnancy body mass index [BMI], and race/ethnicity). RESULTS: Diphenyl phosphate (DPHP) had the highest geometric mean concentration of the urinary OPE metabolites (1.83 μg/L at 16 weeks, 1.24 μg/L at 26 weeks). Thirty women (10.0%) had elevated glucose levels. Individual OPE metabolites or their mixtures were not significantly associated with continuous GCT results. We did not observe effect measure modification by maternal age, pre-pregnancy BMI categories, or race/ethnicity. Compared with women in the 1st tertile of average DPHP of 16- and 26 weeks of pregnancy, women in the 3rd tertile tended to have a reduced risk of elevated glucose levels (RR = 0.41, 95% CI = 0.16-1.06, p for trend = 0.06). CONCLUSION: In this cohort, maternal urinary OPE metabolite concentrations were weakly associated with blood glucose levels during pregnancy. |
| Maternal urinary OPE metabolite concentrations and blood pressure during pregnancy: The HOME study
Yang W , Braun JM , Vuong AM , Percy Z , Xu Y , Xie C , Deka R , Calafat AM , Ospina M , Werner E , Yolton K , Cecil KM , Lanphear BP , Chen A . Environ Res 2021 207 112220 BACKGROUND: Few studies have examined the association between maternal exposure to organophosphate esters (OPEs) and systolic/diastolic blood pressure (SBP/DBP) during pregnancy. METHODS: We analyzed data from 346 women with a singleton live birth in the HOME Study, a prospective birth cohort in Cincinnati, Ohio, USA. We quantified four OPE metabolites in maternal spot urine samples collected at 16 and 26 weeks pregnancy, standardized by specific gravity. We calculated intraclass correlation coefficients (ICCs). We extracted the first two recorded BP measurements (<20 weeks), the two highest recorded BP measurements (≥20 weeks), and diagnoses of hypertensive disorders of pregnancy (HDP) via chart review. Women with two BP measurements ≥140/90 mmHg or HDP noted in the chart at ≥20 weeks pregnancy were defined as HDP cases. We used linear mixed models and modified Poisson regression with covariate adjustment to estimate associations between OPE concentrations as continuous variables or in tertiles with maternal BP and HDP. RESULTS: ICCs of OPEs were 0.17-0.45. Diphenyl phosphate (DPHP) had the highest geometric mean concentration among OPE metabolites. Increasing the average bis(2-chloroethyl) phosphate (BCEP) concentrations were positively associated with two highest recorded DBP ≥20 weeks pregnancy. Compared with women in the 1st DPHP tertile, women in the 3rd tertile at 16 weeks pregnancy had 1.72 mmHg (95% CI: 0.01, 3.59) higher DBP <20 weeks pregnancy, and women in the 3rd tertile of the average DPHP concentrations had 2.25 mmHg (95% CI: 0.25, 4.25) higher DBP ≥20 weeks pregnancy. 33 women (9.5%) were identified with HDP. Di-n-butyl phosphate (DNBP) concentrations at 16 weeks were positively associated with HDP, with borderline significance (RR = 2.98, 95% CI 0.97-9.15). Other OPE metabolites were not significantly associated with HDP. CONCLUSION: Maternal urinary BCEP and DPHP concentrations were associated with increased BP during pregnancy. Maternal urinary DNBP concentrations were associated with HDP, with borderline significance. |
| Prenatal exposure to a mixture of organophosphate esters and intelligence among 8-year-old children of the HOME Study
Percy Z , Vuong AM , Xu Y , Xie C , Ospina M , Calafat AM , Lanphear BP , Braun JM , Cecil KM , Dietrich KN , Chen A , Yolton K . Neurotoxicology 2021 87 149-155
Many environmental chemicals are being identified as suspected neurotoxicants based on the findings of both experimental and epidemiological studies. Organophosphate esters (OPEs), which are among the chemicals that have replaced neurotoxic polybrominated diphenyl ethers (PBDEs) after 2004, have also become an important public health topic as evidence regarding their potential for early-life neurotoxicity is growing. In 233 mother child pairs from Cincinnati, OH, we measured concentrations of the OPE metabolites bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis-2-chloroethyl phosphate (BCEP), diphenyl phosphate (DPHP), and di-n-butyl phosphate (DNBP) in the urine of pregnant women at 16 and 26 weeks gestation and at delivery. At age 8 years, we assessed children's cognition using the Wechsler Intelligence Scale for Children-IV. In models adjusted for maternal race, income, body mass index, and IQ, maternal urinary BCEP was associated with a modest increase in child full-scale IQ (ß: 0.81 per a ln-unit BCEP increase; 95 % CI: 0.00, 1.61) while other OPEs were not associated with changes in full-scale IQ or any IQ subscales. Maternal serum PBDE concentrations did not confound the relationships between urinary OPE metabolites and child IQ. Using Bayesian kernel machine regression, we did not find that concentrations of a mixture of OPE metabolites during gestation was associated with any child cognition measures. The results of this study are not consistent with other published work, and a larger sample size would be beneficial to explore potential associations more fully. Therefore, additional studies are necessary to continue studying prenatal OPE exposure and child neurodevelopment and behavior. |
| Maternal Urinary Organophosphate Esters and Alterations in Maternal and Neonatal Thyroid Hormones
Percy Z , Vuong AM , Xu Y , Xie C , Ospina M , Calafat AM , Hoofnagle A , Lanphear BP , Braun JM , Cecil KM , Dietrich KN , Yolton K , Chen A . Am J Epidemiol 2021 190 (9) 1793-1802 Production of organophosphate esters (OPEs), which represent a major flame retardant class present in consumer goods, has risen over the past two decades. Experimental studies suggest that OPEs may be associated with thyroid hormone disruption, but few human studies have examined this association. We quantified OPE metabolites in the urine of 298 pregnant women in the Health Outcomes and Measures of the Environment Study from Cincinnati, Ohio (enrolled 2003-2006) at three time points (16 and 26 weeks' gestation, delivery), and thyroid hormones in 16-week maternal and newborn cord sera. Urinary bis(1,3-dichloro-2-propyl)-phosphate concentrations were generally associated with decreased triiodothyronine and thyroxine and increased thyroid stimulating hormone in maternal and newborn thyroid hormones in quartile dose-response analyses and multiple informant models. There was weaker evidence for thyroid hormone alterations in association with diphenyl-phosphate and di-n-butyl-phosphate. Bis-2-chloroethyl-phosphate was not associated with alterations in thyroid hormones in any analyses. We did not observe any evidence of effect modification by infant sex. These results suggest that gestational exposure to some OPEs may influence maternal and neonatal thyroid function, although replication in other cohorts is needed. |
| Nigeria's public health response to the COVID-19 pandemic: January to May 2020.
Dan-Nwafor C , Ochu CL , Elimian K , Oladejo J , Ilori E , Umeokonkwo C , Steinhardt L , Igumbor E , Wagai J , Okwor T , Aderinola O , Mba N , Hassan A , Dalhat M , Jinadu K , Badaru S , Arinze C , Jafiya A , Disu Y , Saleh F , Abubakar A , Obiekea C , Yinka-Ogunleye A , Naidoo D , Namara G , Muhammad S , Ipadeola O , Ofoegbunam C , Ogunbode O , Akatobi C , Alagi M , Yashe R , Crawford E , Okunromade O , Aniaku E , Mba S , Agogo E , Olugbile M , Eneh C , Ahumibe A , Nwachukwu W , Ibekwe P , Adejoro OO , Ukponu W , Olayinka A , Okudo I , Aruna O , Yusuf F , Alex-Okoh M , Fawole T , Alaka A , Muntari H , Yennan S , Atteh R , Balogun M , Waziri N , Ogunniyi A , Ebhodaghe B , Lokossou V , Abudulaziz M , Adebiyi B , Abayomi A , Abudus-Salam I , Omilabu S , Lawal L , Kawu M , Muhammad B , Tsanyawa A , Soyinka F , Coker T , Alabi O , Joannis T , Dalhatu I , Swaminathan M , Salako B , Abubakar I , Fiona B , Nguku P , Aliyu SH , Ihekweazu C . J Glob Health 2020 10 (2) 020399 The novel coronavirus disease 2019, COVID-19, which is caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2) [1] was first reported in December 2019 by Chinese Health Authorities following an outbreak of pneumonia of unknown origin in Wuhan, Hubei Province [2,3]. SARS-CoV-2 is likely of zoonotic origin, similar to SARS and Middle East Respiratory Syndrome (MERS), and transmitted between humans through respiratory droplets and fomites. Since its emergence, it has rapidly spread globally [4]. |
| Maternal urinary concentrations of organophosphate ester metabolites: associations with gestational weight gain, early life anthropometry, and infant eating behaviors among mothers-infant pairs in Rhode Island
Crawford KA , Hawley N , Calafat AM , Jayatilaka NK , Froehlich RJ , Has P , Gallagher LG , Savitz DA , Braun JM , Werner EF , Romano ME . Environ Health 2020 19 (1) 97 BACKGROUND: Organophosphate esters (OPEs)-used as flame retardants and plasticizers-are associated with adverse pregnancy outcomes such as reduced fecundity and live births and increased preterm delivery. OPEs may interfere with growth and metabolism via endocrine-disruption, but few studies have investigated endocrine-related outcomes. The objective of this pilot study (n = 56 mother-infant pairs) was to evaluate associations of OPEs with gestational weight gain (GWG), gestational age at delivery, infant anthropometry, and infant feeding behaviors. METHODS: We quantified OPE metabolites (bis-2-chloroethyl phosphate [BCEP], bis (1,3-dichloro-2-propyl) phosphate [BDCPP], diphenyl phosphate [DPHP]) in pooled maternal spot urine collected throughout pregnancy (~ 12, 28, and 35 weeks' gestation). We obtained maternal sociodemographic characteristics from questionnaires administered at enrollment and perinatal characteristics from medical record abstraction. Trained research assistants measured infant weight, length, head and abdominal circumferences, and skinfold thicknesses at birth and 6 weeks postpartum. Mothers reported infant feeding behavior via the Baby Eating Behavior Questionnaire (BEBQ). Using multiple linear regression, we assessed associations of log(2)-transformed maternal urinary OPE metabolites with GWG, gestational age at delivery, infant anthropometry at birth, weekly growth rate, and BEBQ scores at 6 weeks postpartum. We used linear mixed effects (LME) models to analyze overall infant anthropometry during the first 6 weeks of life. Additionally, we considered effect modification by infant sex. RESULTS: We observed weak positive associations between all OPE metabolites and GWG. In LME models, BDCPP was associated with increased infant length (β = 0.44 cm, 95%CI = 0.01, 0.87) and weight in males (β = 0.14 kg, 95%CI = 0.03, 0.24). BDCPP was also associated with increased food responsiveness (β = 0.23, 95%CI = 0.06, 0.40). DPHP was inversely associated with infant abdominal circumference (β = - 0.50 cm, 95%CI = - 0.86, - 0.14) and female weight (β = - 0.19 kg, 95%CI = - 0.36, - 0.02), but positively associated with weekly growth in iliac skinfold thickness (β = 0.10 mm/wk., 95%CI = 0.02, 0.19). Further, DPHP was weakly associated with increased feeding speed. BCEP was associated with greater infant thigh skinfold thickness (β = 0.34 mm, 95%CI = 0.16, 0.52) and subscapular skinfold thickness in males (β = 0.14 mm, 95%CI = 0.002, 0.28). CONCLUSIONS: Collectively, these findings suggest that select OPEs may affect infant anthropometry and feeding behavior, with the most compelling evidence for BDCPP and DPHP. |
| Organophosphate esters in a cohort of pregnant women: Variability and predictors of exposure
Percy Z , Vuong AM , Ospina M , Calafat AM , La Guardia MJ , Xu Y , Hale RC , Dietrich KN , Xie C , Lanphear BP , Braun JM , Cecil KM , Yolton K , Chen A . Environ Res 2020 184 109255 Organophosphate esters (OPEs) are a group of chemicals used as flame retardants and plasticizers that replaced polybrominated diphenyl ethers in consumer products such as furniture and electronics. To characterize exposure to OPEs during fetal development, we measured urinary OPE metabolite concentrations in women twice during pregnancy (16 and 26 weeks' gestation) and at delivery (n = 357). We also previously quantified house dust OPE parent compound concentrations at 20 weeks' gestation (n = 317). Diphenyl phosphate (DPHP) had the highest geometric mean urinary concentrations (1.5-2.3 mug/g creatinine), followed by bis(1,3-dichloro-2-propyl) phosphate (BDCIPP; 0.75-0.99 mug/g creatinine), and bis(2-chloroethyl) phosphate (BCEP; 0.72-0.97 mug/g creatinine), while dibutyl phosphate (DNBP) had the lowest concentrations (0.25-0.28 mug/g creatinine). Urinary OPE metabolites were moderately correlated with each other at 26 weeks (rs: 0.23-0.38, p < 0.001) while the correlations at 16 weeks and delivery were slightly weaker. Intra-class correlations for urinary metabolites measured at three time points were poor (0.16-0.34), indicating high variability within individuals. Dust concentrations of OPE parent compounds were associated with BCEP, BDCIPP, and DPHP concentrations in urine at some but not all time points. In linear mixed models of urinary OPE metabolite concentrations, household size was inversely associated with BCEP concentrations, and being non-white was associated with lower BDCIPP and DPHP concentrations. Urine samples collected in the summer had the highest OPE metabolite concentrations. This study highlights the need to collect multiple urine samples during pregnancy to define exposure patterns and investigate potential periods of susceptibility. |
| An exploratory analysis of urinary organophosphate ester metabolites and oxidative stress among pregnant women in Puerto Rico
Ingle ME , Watkins D , Rosario Z , VelezVega CM , Calafat AM , Ospina M , Ferguson KK , Cordero JF , Alshawabkeh A , Meeker JD . Sci Total Environ 2019 703 134798 BACKGROUND: Organophosphate esters (OPEs) are used as flame retardants and plasticizers. Oxidative stress, the imbalance of reactive oxygen species and antioxidants, measured prenatally has been associated with adverse birth outcomes including preeclampsia and preterm birth. We are the first study to investigate the relationship between OPEs and oxidative stress among pregnant women. METHODS: Pregnant women 18-40 yrs. were recruited in Northern Puerto Rico (n=47) between 2011 and 2015. OPE concentrations of: bis(2-chloroethyl) phosphate (BCEtP), bis(1-chloro-2-propyl) phosphate (BCPP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), dibutyl phosphate (DNBP), and diphenyl phosphate (DPHP) and biomarkers for oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane were measured in urine up to three times during pregnancy. Associations between oxidative stress biomarkers and OPEs were assessed using linear mixed models adjusted for specific gravity, age, BMI, and income. RESULTS: Metabolites BCEtP, BDCPP, and DPHP were frequently detected (>97%). OPE metabolite concentrations remained stable over time (Intraclass correlation coefficients (ICCs): 0.51-0.60). Metabolites BCEtP, BCPP, and DPHP were associated with an increase in 8-isoprostane and OHdG. An interquartile range (IQR) increase in BDCPP was associated with a 21% increase in 8-isoprostane (p<0.01), while and IQR increase in DPHP and BCPP was associated with a 12% increase (p=0.04, p=0.08, respectively). IQR increases in BDCPP and DPHP were also associated with an 18 and 19% increase in OHdG, respectively (p<0.01). CONCLUSION: OPE metabolites were frequently detected and our results suggest that exposure to OPEs is associated with higher levels of oxidative stress. Further investigation into these relationships and birth outcomes is warranted. |
| Cholera outbreak in Dadaab refugee camp, Kenya - November 2015-June 2016
Golicha Q , Shetty S , Nasiblov O , Hussein A , Wainaina E , Obonyo M , Macharia D , Musyoka RN , Abdille H , Ope M , Joseph R , Kabugi W , Kiogora J , Said M , Boru W , Galgalo T , Lowther SA , Juma B , Mugoh R , Wamola N , Onyango C , Gura Z , Widdowson MA , DeCock KM , Burton JW . MMWR Morb Mortal Wkly Rep 2018 67 (34) 958-961 Dadaab Refugee camp in Garissa County, Kenya, hosts nearly 340,000 refugees in five subcamps (Dagahaley, Hagadera, Ifo, Ifo2, and Kambioos) (1). On November 18 and 19, 2015, during an ongoing national cholera outbreak (2), two camp residents were evaluated for acute watery diarrhea (three or more stools in </=24 hours); Vibrio cholerae serogroup O1 serotype Ogawa was isolated from stool specimens collected from both patients. Within 1 week of the report of index cases, an additional 45 cases of acute watery diarrhea were reported. The United Nations High Commissioner for Refugees and their health-sector partners coordinated the cholera response, community outreach and water, sanitation, and hygiene (WASH) activities; Medecins Sans Frontieres and the International Rescue Committee were involved in management of cholera treatment centers; CDC performed laboratory confirmation of cases and undertook GIS mapping and postoutbreak response assessment; and the Garissa County Government and the Kenya Ministry of Health conducted a case-control study. To prevent future cholera outbreaks, improvements to WASH and enhanced disease surveillance systems in Dadaab camp and the surrounding area are needed. |
| A digital microfluidic system for serological immunoassays in remote settings
Ng AHC , Fobel R , Fobel C , Lamanna J , Rackus DG , Summers A , Dixon C , Dryden MDM , Lam C , Ho M , Mufti NS , Lee V , Asri MAM , Sykes EA , Chamberlain MD , Joseph R , Ope M , Scobie HM , Knipes A , Rota PA , Marano N , Chege PM , Njuguna M , Nzunza R , Kisangau N , Kiogora J , Karuingi M , Burton JW , Borus P , Lam E , Wheeler AR . Sci Transl Med 2018 10 (438) Serosurveys are useful for assessing population susceptibility to vaccine-preventable disease outbreaks. Although at-risk populations in remote areas could benefit from this type of information, they face several logistical barriers to implementation, such as lack of access to centralized laboratories, cold storage, and transport of samples. We describe a potential solution: a compact and portable, field-deployable, point-of-care system relying on digital microfluidics that can rapidly test a small volume of capillary blood for disease-specific antibodies. This system uses inexpensive, inkjet-printed digital microfluidic cartridges together with an integrated instrument to perform enzyme-linked immunosorbent assays (ELISAs). We performed a field validation of the system's analytical performance at Kakuma refugee camp, a remote setting in northwestern Kenya, where we tested children aged 9 to 59 months and caregivers for measles and rubella immunoglobulin G (IgG). The IgG assays were determined to have sensitivities of 86% [95% confidence interval (CI), 79 to 91% (measles)] and 81% [95% CI, 73 to 88% (rubella)] and specificities of 80% [95% CI, 49 to 94% (measles)] and 91% [95% CI, 76 to 97% (rubella)] (measles, n = 140; rubella, n = 135) compared with reference tests (measles IgG and rubella IgG ELISAs from Siemens Enzygnost) conducted in a centralized laboratory. These results demonstrate a potential role for this point-of-care system in global serological surveillance, particularly in remote areas with limited access to centralized laboratories. |
| Evaluation of the field performance of ImmunoCard STAT! rapid diagnostic test for rotavirus in Dadaab refugee camp and at the Kenya-Somalia Border
Ope M , Nyoka R , Unshur A , Oyier FO , Mowlid SA , Owino B , Ochieng SB , Okello CI , Montgomery JM , Wagacha B , Galev A , Abdow A , Esona MD , Tate J , Fitter D , Cookson ST , Arunmozhi B , Marano N . Am J Trop Med Hyg 2017 96 (6) 1302-1306 Rotavirus commonly causes diarrhea in children, leading to hospitalization and even death. Rapid diagnostic tests are feasible alternatives for determining rotavirus outbreaks in refugee camps that have inadequate laboratory capacity.We evaluated the field performance of ImmunoCard STAT! Rotavirus (ICS-RV) in Dadaab Refugee Camp and at the Kenya-Somalia border. From May to December 2014, we prospectively enrolled children aged < 5 years hospitalized with acute diarrhea, defined as >= 3 episodes of loose stool in 24 hours for < 7 days. Stool samples were collected and tested by trained surveillance clerks using ICS-RV per manufacturer's instructions. The field performance characteristics of ICS-RV were evaluated against the gold standard test, PremierTM Rotaclone enzyme immunoassay. The operational characteristics were evaluated usingWorld Health Organization (WHO) ASSURED criteria to determine whether ICS-RV is appropriate as a point-of-care test by administering a standard questionnaire and observing surveillance clerks performing the test. We enrolled 213 patients with a median age of 10 months (range = 1-48); 58.2%weremale. A total of 71 (33.3%) and 60 (28.2%) patients tested positive for rotavirus infection by immunoassay and ICS-RV, respectively. The sensitivity, specificity, and positive and negative predictive values of ICS-RV compared with the immunoassay were 83.1% (95% confidence interval [CI] = 72.3-91.0), 99.3% (95% CI = 96.1-100), 98.3% (95% CI = 91.1-100), and 92.1% (95% CI = 86.6-95.5), respectively. The ICS-RV fulfilled theWHO ASSURED criteria for point-of-care testing. ICS-RV is a field-ready point-of-care test with good field performance and operational characteristics. It can be useful in determining rotavirus outbreaks in resource-limited settings. |
| Notes from the field: Splenomegaly of unknown etiology in Congolese refugees applying for resettlement to the United States - Uganda, 2015
Goers M , Ope MO , Samuels A , Gitu N , Akandwanaho S , Nabwami G , Nyoka R , Cetron MS , Dalal W , Conroy AL , Cantey P , John C , Naoum M , Weinberg M , Marano N , Stauffer W . MMWR Morb Mortal Wkly Rep 2016 65 (35) 943-944 Approximately 70,000-90,000 refugees are resettled to the United States each year, and during the next 5 years, 50,000 Congolese refugees are expected to arrive in the United States. The International Organization for Migration (IOM) performs refugee medical examinations overseas for the U.S. Refugee Resettlement Program. In 2014, IOM reported that a large number of U.S.-bound Congolese refugees from Uganda had spleens that were enlarged on examination. During two evaluations of refugee populations in western Uganda in March and July 2015, refugees with splenomegaly on physical examination were offered additional assessment and treatment, including abdominal ultrasonography and laboratory testing. Among 987 persons screened, 145 (14.7%) had splenomegaly and received further testing. Among the 145 patients with splenomegaly, 63.4% were aged 5-17 years (median = 14.8 years). There was some evidence of family clustering, with 33 (22.7%) of the 145 cases occurring in families. |
| A rapid assessment of drinking water quality in informal settlements after a cholera outbreak in Nairobi, Kenya
Blanton E , Wilhelm N , O'Reilly C , Muhonja E , Karoki S , Ope M , Langat D , Omolo J , Wamola N , Oundo J , Hoekstra R , Ayers T , De Cock K , Breiman R , Mintz E , Lantagne D . J Water Health 2015 13 (3) 714-25 Populations living in informal settlements with inadequate water and sanitation infrastructure are at risk of epidemic disease. In 2010, we conducted 398 household surveys in two informal settlements in Nairobi, Kenya with isolated cholera cases. We tested source and household water for free chlorine residual (FCR) and Escherichia coli in approximately 200 households. International guidelines are ≥0.5 mg/L FCR at source, ≥0.2 mg/L at household, and <1 E. coli/100 mL. In these two settlements, 82% and 38% of water sources met FCR guidelines; and 7% and 8% were contaminated with E. coli, respectively. In household stored water, 82% and 35% met FCR guidelines and 11% and 32% were contaminated with E. coli, respectively. Source water FCR ≥0.5 mg/L (p = 0.003) and reported purchase of a household water treatment product (p = 0.002) were associated with increases in likelihood that household stored water had ≥0.2 mg/L FCR, which was associated with a lower likelihood of E. coli contamination (p < 0.001). These results challenge the assumption that water quality in informal settlements is universally poor and the route of disease transmission, and highlight that providing centralized water with ≥0.5 mg/L FCR or (if not feasible) household water treatment technologies reduces the risk of waterborne cholera transmission in informal settlements. |
| Rotavirus enteritis in Dadaab refugee camps: implications for immunization programs in Kenya and Resettlement Countries
Ope M , Ochieng SB , Tabu C , Marano N . Clin Infect Dis 2014 59 (1) v-vi The section listed above, written by members of the CDC's Division of Global Migration and Quarantine and focusing on globally mobile populations and infectious disease outbreaks, is freely available online only, in this issue of Clinical Infectious Diseases at (http://cid.oxfordjournals.org). |
| A national cholera epidemic with high case fatality rates--Kenya 2009
Loharikar A , Briere E , Ope M , Langat D , Njeru I , Gathigi L , Makayotto L , Ismail AM , Thuranira M , Abade A , Amwayi S , Omolo J , Oundo J , De Cock KM , Breiman RF , Ayers T , Mintz E , O'Reilly CE . J Infect Dis 2013 208 Suppl 1 S69-77 BACKGROUND: Cholera remains endemic in sub-Saharan Africa. We characterized the 2009 cholera outbreaks in Kenya and evaluated the response. METHODS: We analyzed surveillance data and estimated case fatality rates (CFRs). Households in 2 districts, East Pokot (224 cases; CFR = 11.7%) and Turkana South (1493 cases; CFR = 1.0%), were surveyed. We randomly selected 15 villages and 8 households per village in each district. Healthcare workers at 27 health facilities (HFs) were surveyed in both districts. RESULTS:. In 2009, cholera outbreaks caused a reported 11 425 cases and 264 deaths in Kenya. Data were available from 44 districts for 6893 (60%) cases. District CFRs ranged from 0% to 14.3%. Surveyed household respondents (n = 240) were aware of cholera (97.5%) and oral rehydration solution (ORS) (87.9%). Cholera deaths were reported more frequently from East Pokot (n = 120) than Turkana South (n = 120) households (20.7% vs. 12.3%). The average travel time to a HF was 31 hours in East Pokot compared with 2 hours in Turkana South. Fewer respondents in East Pokot (9.8%) than in Turkana South (33.9%) stated that ORS was available in their village. ORS or intravenous fluid shortages occurred in 20 (76.9%) surveyed HFs. CONCLUSIONS: High CFRs in Kenya are related to healthcare access disparities, including availability of rehydration supplies. |
| Global and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: a systematic analysis
Nair H , Simoes EA , Rudan I , Gessner BD , Azziz-Baumgartner E , Zhang JS , Feikin DR , Mackenzie GA , Moisi JC , Roca A , Baggett HC , Zaman SM , Singleton RJ , Lucero MG , Chandran A , Gentile A , Cohen C , Krishnan A , Bhutta ZA , Arguedas A , Clara AW , Andrade AL , Ope M , Ruvinsky RO , Hortal M , McCracken JP , Madhi SA , Bruce N , Qazi SA , Morris SS , El Arifeen S , Weber MW , Scott JA , Brooks WA , Breiman RF , Campbell H . Lancet 2013 381 (9875) 1380-90 BACKGROUND: The annual number of hospital admissions and in-hospital deaths due to severe acute lower respiratory infections (ALRI) in young children worldwide is unknown. We aimed to estimate the incidence of admissions and deaths for such infections in children younger than 5 years in 2010. METHODS: We estimated the incidence of admissions for severe and very severe ALRI in children younger than 5 years, stratified by age and region, with data from a systematic review of studies published between Jan 1, 1990, and March 31, 2012, and from 28 unpublished population-based studies. We applied these incidence estimates to population estimates for 2010, to calculate the global and regional burden in children admitted with severe ALRI in that year. We estimated in-hospital mortality due to severe and very severe ALRI by combining incidence estimates with case fatality ratios from hospital-based studies. FINDINGS: We identified 89 eligible studies and estimated that in 2010, 11.9 million (95% CI 10.3-13.9 million) episodes of severe and 3.0 million (2.1-4.2 million) episodes of very severe ALRI resulted in hospital admissions in young children worldwide. Incidence was higher in boys than in girls, the sex disparity being greatest in South Asian studies. On the basis of data from 37 hospital studies reporting case fatality ratios for severe ALRI, we estimated that roughly 265,000 (95% CI 160,000-450,000) in-hospital deaths took place in young children, with 99% of these deaths in developing countries. Therefore, the data suggest that although 62% of children with severe ALRI are treated in hospitals, 81% of deaths happen outside hospitals. INTERPRETATION: Severe ALRI is a substantial burden on health services worldwide and a major cause of hospital referral and admission in young children. Improved hospital access and reduced inequities, such as those related to sex and rural status, could substantially decrease mortality related to such infection. Community-based management of severe disease could be an important complementary strategy to reduce pneumonia mortality and health inequities. FUNDING: WHO. |
| Association of the CT values of real-time PCR of viral upper respiratory tract infection with clinical severity, Kenya
Fuller JA , Njenga MK , Bigogo G , Aura B , Ope MO , Nderitu L , Wakhule L , Erdman DD , Breiman RF , Feikin DR . J Med Virol 2013 85 (5) 924-32 Quantitative real-time polymerase chain reaction (qRT-PCR) assay of the upper respiratory tract is used increasingly to diagnose lower respiratory tract infections. The cycle threshold (CT) values of qRT-PCR are continuous, semi-quantitative measurements of viral load, although interpretation of diagnostic qRT-PCR results are often categorized as positive, indeterminate, or negative, obscuring potentially useful clinical interpretation of CT values. From 2008 to 2010, naso/oropharyngeal swabs were collected from outpatients with influenza-like illness, inpatients with severe respiratory illness, and asymptomatic controls in rural Kenya. CT values of positive specimens (i.e., CT values < 40.0) were compared by clinical severity category for five viruses using Mann-Whitney U-test and logistic regression. Among children <5 years old we tested with respiratory syncytial virus (RSV), inpatients had lower median CT values (27.2) than controls (35.8, P = 0.008) and outpatients (34.7, P < 0.001). Among children and older patients infected with influenza virus, outpatients had the lowest median CT values (29.8 and 24.1, respectively) compared with controls (P = 0.193 for children, P < 0.001 for older participants) and inpatients (P = 0.009 for children, P < 0.001 for older participants). All differences remained significant in logistic regression when controlling for age, days since onset, and coinfection. CT values were similar for adenovirus, human metapneumovirus, and parainfluenza virus in all severity groups. In conclusion, the CT values from the qRT-PCR of upper respiratory tract specimens were associated with clinical severity for some respiratory viruses. (J. Med. Virol. 85:924-932, 2013. (c) 2013 Wiley Periodicals, Inc.) |
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