Informal Landscapes of Capetown From Remote Sensing: mapping human traces in landscapes of vulnerability and opportunitiy

African Cities have expanded rapidly and in a fragmented pattern of discontinuous development. In South Africa, cities such as Capetown and Johannesburg include large amounts of open space within their urban footprints and integrate dynamic and often sensitive ecologies. In South Africa, the twin forces of apartheid and modernist urban planning have produced this dispersed pattern. Such a pattern requires that economically disadvantaged residents walk long distances as car ownership is out of reach and public transport is often expensive and inaccessible. Capetown has one of the longest average commute times in the world and much of this commute is by foot. The outcome of such trends is pedestrian networks and a tracery of informal paths that cross vacant, and often dangerous, landscapes. This paper maps these informal pedestrian routes and the open space they path through using aerial photography within a GIS. A GIS network database is developed layering paths, open space and formal routes to understand the role these landscapes play within the peripheral urban landscape. Despite constituting a significant part of cities in developing and developed countries informal landscapes have not been systematically studied. This paper represents an initial step towards such a systematic program of study. Understanding of such landscapes is imperative given the role such landscapes do and can potentially play in emerging cities across the African continent

Detection of HIV type 1 gag-specific CD4(+) T cell responses in acutely infected infants.

Multiple HIV-1-specific cytokine and proliferative responses by CD4(+) T cells have not been studied in acutely infected infants. Using an intracellular cytokine staining assay, 34 untreated clade C HIV-1-infected infants (2-102 days old) were assessed for IFN-gamma, 28/34 for IL-2, and 26/34 for TNF-alpha responses to all HIV-1 proteins. Responses were detected in 29%, 36%, and 15% of infants, respectively. Twelve of the original 34 infants were then studied longitudinally for 14 months to determine the effect of viral load on IFN-gamma Gag-specific responses: seven infants were treated for 1 year, stopped treatment, and resumed when CD4% was < 20 and five infants were treated only when the CD4% was <20. Following treatment cessation, there was an immediate increase in viral load followed by an increase in the magnitude of CD4(+) Gag-specific responses. Despite this, the majority of infants (54%) had to restart treatment by 24 months of age, indicating that the immune responses were antigen driven but not associated with protection. Among untreated infants HIV-specific CD4(+) responses were detected sporadically indicating a dysfunctional immune response in the face of constant exposure to high levels of viremia

Epidemiologic and virologic assessment of the 2009 influenza A (H1N1) pandemic on selected temperate countries in the Southern Hemisphere: Argentina, Australia, Chile, New Zealand and South Africa

Introduction and Setting: Our analysis compares the most comprehensive epidemiologic and virologic surveillance data compiled to date for laboratory-confirmed H1N1pdm patients between 1 April 2009 - 31 January 2010 from five temperate countries in the Southern Hemisphere-Argentina, Australia, Chile, New Zealand, and South Africa. Objective: We evaluate transmission dynamics, indicators of severity, and describe the co-circulation of H1N1pdm with seasonal influenza viruses. Results: In the five countries, H1N1pdm became the predominant influenza strain within weeks of initial detection. South Africa was unique, first experiencing a seasonal H3N2 wave, followed by a distinct H1N1pdm wave. Compared with the 2007 and 2008 influenza seasons, the peak of influenza-like illness (ILI) activity in four of the five countries was 3-6 times higher with peak ILI consultation rates ranging from 35/1,000 consultations/week in Australia to 275/100,000 population/week in New Zealand. Transmission was similar in all countries with the reproductive rate ranging from 1.2-1.6. The median age of patients in all countries increased with increasing severity of disease, 4-14% of all hospitalized cases required critical care, and 26-68% of fatal patients were reported to have ≥1 chronic medical condition. Compared with seasonal influenza, there was a notable downward shift in age among severe cases with the highest population-based hospitalization rates among children <5 years old. National population-based mortality rates ranged from 0.8-1.5/100,000. Conclusions: The difficulty experienced in tracking the progress of the pandemic globally, estimating its severity early on, and comparing information across countries argues for improved routine surveillance and standardization of investigative approaches and data reporting methods