Browsing by Author "Zietsman, H. L."

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    The geographical distribution of diagnostic medical and dental X-ray services in South Africa
    (Health & Medical Publishing Group, 1998) Walters, N. M.; Zietsman, H. L.; Bhagwandin, N.
    Aim. The aim of this study was threefold, viz.: (/) to evaluate the availability and accessiblity of medical and dental X-ray services in South Africa; (//) to evaluate geographical information systems (GIS) as a tool for management of health care technologies; and (Hi) to guide policy and develop a process to provide optimal utilisation of X-ray services in South Africa. Methods. Information supplied by the Department of Health on licensed X-ray equipment was integrated with census data and processed with GIS. Four key areas were assessed, viz. distribution, accessibility, age and availability of X-ray services in South Africa. Results. The analysis shows a vast inequity in the distribution of X-ray services on a provincial as well as a district level, although on the national level the distribution of X-ray services meets the World Health Organisation criteria. Conclusion. GIS is a useful tool in evaluating and planning of essential health services/techniques. However, care must be taken in interpreting the data on a macro level, as this masks vast inequities on the district level. Recommendations. The indicators of coverage should be expanded, similar reports should be prepared for the nine provinces, and these data should be integrated into the clinic planning programme. Radiological services should be added to and managed as part of an essential district health care technology package.
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    Surface temperature measurement from space : a case study in the South Western Cape of South Africa
    (South African Society for Enology and Viticulture, 1997-03) Sandham, L. A.; Zietsman, H. L.
    This paper reports on the use of Landsat Thematic Mapper (TM) thermal infrared (TIR) and Transformed Normalised Difference Vegetation Index (TNDVI) data to map summer surface temperature distribution in a portion of the South Western Cape (South Africa). It adopts a ground truth calibration approach, as a possible solution for alleviating the paucity of spatial temperature data. Means and standard deviations of the TIR and transformed NDVI of all pixels within a radius of 120 m around each ground truth point were regressed on spatially collocated surface-observed temperature data. Linear multiple regression analysis showed that mean TIR and standard deviation of TNDVI were effective in accounting for 43 % of variation in surface temperature. The regression equation was used to generate a temperature map at a spatial resolution of 30 m, showing good agreement with expected mesoscale spatial temperature patterns in terms of general climatic principles. The temperature map provides a useful tool for depicting and assessing the spatial variation in daily temperatures, providing information currently unavailable to the fruit-producing farmers in the South Western Cape.
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    The use of a geographical information system (GIS) to evaluate the distribution of tuberculosis in a high-incidence community
    (Health & Medical Publishing Group, 1996) Beyers, Nulda; Gie, R. P.; Zietsman, H. L.; Kunneke, M.; Hauman, J.; Tatley, M.; Donald, P. R.
    Objective. To determine the geographical distribution of tuberculosis in the two Western Cape suburbs with the highest reported incidence of tuberculosis. Design. Descriptive illustrative study. Setting. Two adjacent Western Cape suburbs covering 2.42 km2 with a population of 34 294 and a reported tuberculosis incidence of > 1 000/100 000. Subjects. All patients notified as having tuberculosis over a 10-year period (1985-1994). Interventions. None. Outcome measure. The geographical distribution of the cases was determined using a geographical information system (GIS) and the National Population Census (1991). Results. One thousand eight hundred and thirty-five of the 5 345 dwelling units (34.3%) housed at least 1 case of tuberculosis during the past decade and in 483 houses 3 or more cases occurred. These cases were distributed unevenly through the community, with the tuberculosis incidence per enumerator subdistrict (ESD) varying from 78 to 3 150/100 000 population. Conclusion. In a small area with a high incidence of tuberculosis, the cases are spread unevenly through the community and there are certain houses where tuberculosis occurs repeatedly. This information should be used to direct health services to concentrate on certain high-risk areas.