The use of a geographical information system (GIS) to evaluate the distribution of tuberculosis in a high-incidence community

CITATION: Beyers, N. et al. 1996. The use of a geographical information system (GIS) to evaluate the distribution of tuberculosis in a high-incidence community. South African Medical Journal, 86(1):40-44.The original publication is available at http://www.samj.org.zaObjective. 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.Publisher’s versio

Book Reviews

Book Review 1Book Title: Modern Coloproctology: Surgical Grand Rounds from St Mark's HospitalBook Authors: Robin Phillips & John Northover (Eds.)pp. 195. illustrated. London: Edward Arnold. 1993. ISBN 0-340-55258-1Book Review 2Book Title: Diagnostic Molecular Pathology: A Practical Approach. Vol. I & IIBook Authors: C.S. Herringron & J.O'D. McGee (Eds.)Pp. Vol. I xviii + 270; Vol. II xvi + 217. Cape Town: Oxford University Press. 1992. ISBN Vol. I 0-19-963236-7, Vol. II 0-19-963238-3.Book Review 3Book Title: Training Therapy: Prophylaxis and RehabilitationBook Authors: Rolf Gustavsen & Renate Streeck2nd revised ed. Pp. viii + 230. Illustrated. Stuttgart: George Thieme Verlag. 1993. ISBN 3-13-672502-6.Book Review 4Book Title: Handbook of Bereavement: Theory, Research and InterventionBook Authors: Margaret S. Stroebe, Wolfgang Stroebe & Robert O. Hansson (Eds.)Pp. xii + 546. Cambridge: Cambridge University Press. 1993. ISBN 0-521-39315-9 hardback, ISBN 0-52144853-0 paperback.Book Review 5Book Title: Atlas of Gynecologic PathologyBook Authors: J. Donald Woodruff, Teresita L. Angruaco & Tim H. Pannley (Eds.)pp.321. New York: Raven Press. 1993. ISBN 0-7817-0056-6.Book Review 6Book Title: Our Planet, Our Health: Report of the WHO Commission on Health and EnvironmentBook Author: World Health OrganisationPp. 282. Geneva. 1992. ISBN 92-4-156148-3.Book Review 7Book Title: Neonatal Tetanus Elimination Field Guide. Technical Paper No 35Book Author: Pan American Health OrganisationPp. v +37. Washington: Pan American Health Organisation. 1993. ISBN 92-75-13035-3

Mosaic plasmids and mosaic replicons: Evolutionary lessons from the analysis of genetic diversity in IncFII-related replicons

The alpha replicons of the multi-replicon plasmids pGSH500 and pLV1402 have been characterized by DNA sequence analysis. Analysis of the DNA sequence of a 3672 bp HindIII fragment from pFDT100, which contains the pGSH500 alpha replicon, revealed similarity to a number of replicons belonging to, or related to, those of the IncFII family. The replicon region contains copA, tapA, repA and oriR, and replication initiation and termination sites are related to those from the IncFII replicon of R1. A copB gene was found to lie upstream of the HindIII site in the parental plasmid pGSH500. Downstream of oriR, a 707 bp region shows 72·6 identity to a region of the Escherichia coli chromosome at 43·3', suggesting this region of pGSH500 may have been incorporated into the plasmid during a past chromosomal recombination event. Oligonucleotide primers homologous to consensus regions in the copB and repA genes, and the oriR regions from a number of IncFII-related replicons were used to amplify replication regions from pLV1402. Analysis of the amplified regions has shown the presence of copB, copA, tapA and repA genes. Phylogenetic analysis of Rep protein sequences from the RepFIIA family of antisense-control-regulated replicons revealed the presence of three distinct subgroups of Rep proteins. Comparative analysis of DNA and protein sequences from members of the RepFIIA family provides evidence supporting the roles of both non-selective divergence in co-integrate (multi-replicon) plasmids and Chi-mediated-recombination in replicon evolution, and in particular, that such processes may have been widespread in the evolution of the RepFIIA family