Using geographic information systems and spatial and space-time scan statistics for a population-based risk analysis of the 2002 equine West Nile epidemic in six contiguous regions of Texas.

BACKGROUND: In 2002, West Nile virus (WNV) first appeared in Texas. Surveillance data were retrospectively examined to explore the temporal and spatial characteristics of the Texas equine WNV epidemic in 2002. Using Geographic Information Systems (GIS) and the Spatial and Space-Time Scan (SaTScan) statistics, we analyzed 1421 of the reported equine WNV cases from six contiguous state Health Service Regions (HSRs), comprising 158 counties, in western, northern, central and eastern Texas. RESULTS: Two primary epidemic peaks occurred in Epidemiological (Epi) week 35 (August 25 to 31) and Epi week 42 (October 13 to 19) of 2002 in the western and eastern part of the study area, respectively. The SaTScan statistics detected nine non-random spatio-temporal equine case aggregations (mini-outbreaks) and five unique high-risk areas imbedded within the overall epidemic. CONCLUSION: The 2002 Texas equine WNV epidemic occurred in a bi-modal pattern. Some "local hot spots" of the WNV epidemic developed in Texas. The use of GIS and SaTScan can be valuable tools in analyzing on-going surveillance data to identify high-risk areas and shifts in disease clustering within a large geographic area. Such techniques should become increasingly useful and important in future epidemics, as decisions must be made to effectively allocate limited resources.

Human west nile virus neuroinvasive disease in Texas, 2003 epidemic: regional differences.

PURPOSE: Arboviral diseases, such as West Nile virus (WNV) epizootics, tend to be geographically unique because of the biomes that support the vector(s) and reservoir host(s). Understanding such details aids in preventive efforts. We studied the 2003 epidemic of human West Nile neuroinvasive disease (WNND) in Texas because it initially appeared that incidence was not uniform across regions of the state. METHODS: The epidemic was described by age, sex, and region of residence. These variables were used to compare age-specific incidence, standardized cumulative incidence, and age-adjusted relative risk (RR). We verified case data and used routine software, with population estimates from the US Census Bureau. RESULTS: Regardless of sex, risk increased with age. Males had the greater risk (RR, 1.69); however, males aged 5 to 17 years had the greatest RR. Of the five regions compared, two posed more (RRs, 7.98 and 2.14) and one posed less (RR, 0.40) risk than the remainder of the state. Proportions of Culex vector species differed significantly between regions. CONCLUSIONS: During 2003, the risk for WNND varied considerably across Texas. This suggests that various risks for WNV infection deserve additional research for preventive interventions to be regionally appropriate and effective.

Satisfaction with health care and cancer screening practices among women in a largely rural region of West Texas.

BACKGROUND: Satisfaction with medical care has been shown to influence patient behavior, but its effect on the use of preventive services is largely unstudied. This study examined whether women's satisfaction with the accessibility and quality of care was associated with the odds of receiving an annual clinical breast examination, conducting a monthly self-breast examination, or receiving an annual Pap smear. METHODS: A telephone survey was conducted among 675 women in West Texas, an area with a relatively high proportion of rural residents and Hispanics. Multiple logistic regression analyses were performed to model the odds of each screening practice. RESULTS: Women who rated the overall quality of their health care as excellent had a higher odds of receiving an annual clinical breast examination, conducting a monthly self-breast examination, and receiving an annual Pap smear. No rural/urban differences were revealed, but Hispanic women had a lower odds of conducting a self-breast examination than non-Hispanic Whites. CONCLUSIONS: Rural residence and Hispanic ethnicity were largely unassociated with cancer screening practices. Rather than directing outreach programs toward these subgroups, efforts to increase cancer screening among women may need to focus more on improving the quality of primary health care.

Hydration disrupts human stratum corneum ultrastructure.

Using transmission and cryo-scanning electron microscopy, we confirm that extended water exposure leads to extensive disruption of stratum corneum intercellular lipid lamellae. We define the in vivo swelling behavior of the stratum corneum: exposure to water for 4 or 24 h results in a 3- or 4-fold expansion of the stratum corneum thickness, respectively. Corneocytes swell uniformly with the exception of the outermost and inner two to four corneocyte layers, which swell less. We show that hydration induces large pools of water in the intercellular space, pools that can exceed the size of water-swollen corneocytes. By 4 h of water exposure there are numerous small and large intercellular pools of water ("cisternae") present throughout the stratum corneum, and at 24 h these cisternae substantially increase in size. Within cisternae the lipid structure is disrupted by lamellar delamination ("roll-up"). Cisternae appear to be disk-shaped structures that do not obviously communicate. Cisternae appear to contain considerable lipidic and other material and to contain a substantial fluid volume that can rival the volume of the dry stratum corneum. Similar results are obtained following urine exposure. With urine exposure, cisternae communicate with salts in the external solution. This study illustrates the disruptive effect of overhydration on the stratum corneum intercellular space, identifies large and numerous unanticipated intercellular cisternal structures, defines the magnitude of stratum corneum swelling, and identifies stratum corneum cell layers that swell less. The study suggests the stratum corneum is a more chaotic structure than previously envisioned, and provides a framework for better understanding desquamation, irritancy, and percutaneous transport.

Are rural residents and Hispanics less satisfied with medical care? Evidence from the Permian Basin.

Few population-based studies of consumers' perceptions of health care quality have included both rural residents and Hispanics. Using data collected through a random-digit telephone survey of households in the Permian Basin region of west Texas, an area with a relatively high percentage of Mexican Americans, we tested for rural/urban and ethnic differences in satisfaction with medical care. The study had several limitations, but the findings suggest that rural residents of this region rate the quality of their medical care overall more negatively than do their urban counterparts. No ethnic differences were found when controlling for demographic, social, economic, and health-status characteristics. Other factors, including part-time employment, a lack of continuous health insurance coverage, and poor health status appear to have a stronger, negative relationship with satisfaction. The collection and reporting of more specific measures of interpersonal and technical quality would further enable policy-makers, managers, and clinicians to better serve their patient populations.