Medicine and Health Sciences Commons^™

A Preliminary Examination Of Elevated Blood Lead Levels In A Rural Georgia County, R. Christopher Rustin, Yu Sun, Chris Calhoun, Christy Kuriatnyk

Environmental Health Sciences Faculty Publications

Background: Rural areas are often viewed as lower risk for lead poisoning and toxic exposures seriously impacting development of the brain and central nervous system; this report examines the prevalence of elevated blood lead levels for children <6 years of age in rural Ben Hill County, GA.

Methods: Lead surveillance data from the Georgia Department of Public Health (DPH) were analyzed using SAS®v-9.3 to calculate the prevalence of elevated blood lead levels (≥5ug/dL) among those children in Ben Hill County who had been tested for lead; the results were compared to Georgia and national data.

Results: A preliminary analysis of 2010-2015 screening data for Ben Hill County indicates that 8.73% …

An Assessment Of Data Related To Inspections Of Risk Factors For Public Swimming Pools, Shanita Shack, Maurice Redmond, R. Christopher Rustin

Environmental Health Sciences Faculty Publications

Background: The Georgia Department of Public Health (DPH) is mandated to ensure that public swimming pools are safe for those who use them. This mandate is carried out by the DPH and local environmental health professionals through regulations and inspections. In 2015, legislation was introduced proposing to reduce the authority of the DPH to inspect certain pool types (apartments, subdivision, condominiums) and thus reduce regulatory protections in place for swimmers. To ensure that the DPH had current information on the risks associated with pools, the EH team, with assistance from a graduate student, analyzed inspection data to evaluate risk factors …

Georgia’S Rapid Expansion Of Mosquito Surveillance In Response To Zika Virus, R. Christopher Rustin, Deonte Martin, Rosmarie Kelly

Environmental Health Sciences Faculty Presentations

Objective: To describe the Georgia Department of Public Health’s (DPH) mosquito surveillance capacity before and after Zika virus was declared a public health emergency, review and compare mosquito surveillance results from 2015 to 2016, and evaluate the risk of autochthonous vector transmission of Zika virus based on 2016 surveillance data of Aedes aegypti and Aedes albopictus mosquitoes.

Introduction: Zika virus was declared an international public health emergency by the World Health Organization on February 1, 2016. With Georgia hosting the world’s busiest international airport and a sub-tropical climate that can support the primary Zika virus vector, Aedes aegypti, and secondary …

Evaluating The Efficiency Of Treatment Comparison In Crossover Design By Allocating Subjects Based On Ranked Auxiliary Variable, Yisong Huang, Hani Samawi, Robert Vogel, Jingjing Yin, Worlanyo E. Gato, Daniel Linder

Biostatistics Faculty Publications

The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary variables for treatment allocation in crossover designs using Latin squares models. We evaluate the improvement of the efficiency in treatment comparisons using the proposed method. Our simulation study reveals that our proposed method provides a more powerful test compared to simple randomization with the same sample size. The proposed method is illustrated by conducting an experiment to compare two different concentrations of titanium dioxide nanofiber …

The Eco-Epidemiology Of Pacific Coast Tick Fever In California, Kerry A. Padgett, Denise L. Bonilla, Marina E. Eremeeva, Carol A. Glaser, Robert S. Lane, Charsey Cole Porse, Martin B. Castro, Sharon L. Messenger, Alex Espinosa, Jill Hacker, Anne Kjemtrup, Bonnie Ryan, Jamesina J. Scott, Renjie Hu, Melissa Hardstone Yoshimizu, Gregory A. Dasch, Vicki Kramer

Environmental Health Sciences Faculty Publications

Rickettsia philipii (type strain “Rickettsia 364D”), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D …

Estimation Of P(X > Y) When X And Y Are Dependent Random Variables Using Different Bivariate Sampling Schemes, Hani M. Samawi, Amal Helu, Haresh Rochani, Jingjing Yin, Daniel Linder

Biostatistics Faculty Publications

The stress-strength models have been intensively investigated in the literature in regards of estimating the reliability θ = P (X > Y) using parametric and nonparametric approaches under different sampling schemes when X and Y are independent random variables. In this paper, we consider the problem of estimating θ when (X, Y) are dependent random variables with a bivariate underlying distribution. The empirical and kernel estimates of θ = P (X > Y), based on bivariate ranked set sampling (BVRSS) are considered, when (X, Y) are paired dependent continuous random variables. The estimators obtained are compared to their counterpart, bivariate simple random …

Rickettsiologist Pavel F. Zdrodovskii: Larger Than Life, And Not Just For His Famous Book, Marina E. Eremeeva, S. N. Shpynov, I. V. Tarasevich

Environmental Health Sciences Faculty Publications

This article highlights the biography and scientific accomplishments of Pavel F. Zdrodovskii and his contributions to understanding the biology, pathogenesis, treatment, prevention and epidemiology of brucellosis, rickettsioses and many other infectious diseases.

Improved Estimation Of Optimal Cut-Off Point Associated With Youden Index Using Ranked Set Sampling, Jingjing Yin, Hani M. Samawi, Daniel Linder

Biostatistics Faculty Publications

A diagnostic cut-off point of a biomarker measurement is needed for classifying a random subject to be either diseased or healthy. However, the cut-off point is usually unknown and needs to be estimated by some optimization criteria. One important criterion is the Youden index, which has been widely adopted in practice. The Youden index, which is defined as the maximum of (sensitivity + specificity −1), directly measures the largest total diagnostic accuracy a biomarker can achieve. Therefore, it is desirable to estimate the optimal cut-off point associated with the Youden index. Sometimes, taking the actual measurements of a biomarker is …

A Test Of Symmetry Based On The Kernel Kullback-Leibler Information With Application To Base Deficit Data, Hani M. Samawi, Robert L. Vogel

Biostatistics Faculty Publications

The assumption of the symmetry of the underlying distribution is important to many statistical inference and modeling procedures. This paper provides a test of symmetry using kernel density estimation and the Kullback-Leibler information. Based on simulation studies, the new test procedure outperforms other tests of symmetry found in the literature, including the Runs Test of Symmetry. We illustrate our new procedure using real data.