Browsing by Author "Roberts ST"

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    Spatial patterns of incident malaria cases and their household contacts in a single clinic catchment area of Chongwe District, Zambia.
    (2015-Aug-07) Pinchoff J; Henostroza G; Carter BS; Roberts ST; Hatwiinda S; Hamainza B; Hawela M; Curriero FC; Icahn School of Medicine at Mt Sinai, 1428 Madison Avenue, New York, NY, 10029, USA. bryan.carter@mssm.edu.; Centre for Infectious Disease Research Zambia, 5032 Great North Road, Lusaka, Zambia. Sisa.Hatwiinda@cidrz.org.; Ministry of Health, National Malaria Control Centre, Chainama Hospital, College Grounds, Off Great East Road, PO Box 32509, Lusaka, Zambia. Bossbusk@gmail.com.; Department of Epidemiology, University of Washington School of Public Health, Box 357236, Seattle, WA, 98165, USA. str24@uw.edu.; University of Alabama at Birmingham, 1900 University Boulevard, Birmingham, AL, 35294, USA. germanh@uab.edu.; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA. Jpinchoff@gmail.com.; Centre for Infectious Disease Research Zambia, 5032 Great North Road, Lusaka, Zambia. germanh@uab.edu.; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA. fcurriero@jhu.edu.; Ministry of Health, National Malaria Control Centre, Chainama Hospital, College Grounds, Off Great East Road, PO Box 32509, Lusaka, Zambia. mhawela@yahoo.co.uk.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
    BACKGROUND: Reactive case detection (RACD) for malaria is a strategy that may be used to complement passive surveillance, as passive surveillance fails to identify infections that are asymptomatic or do not seek care. The spatial and seasonal patterns of incident (index) cases reported at a single clinic in Chongwe District were explored. METHODS: A RACD strategy was implemented from June 2012 to June 2013 in a single catchment area in Chongwe District. Incident (index) cases recorded at the clinic were followed up at their household, and all household contacts were tested for malaria using rapid diagnostic tests (RDTs). GPS coordinates were taken at each index household. Spatial analyses were conducted to assess characteristics related to clustering, cluster detection and spatial variation in risk of index houses. Effects of season (rainy versus dry), distance to the clinic and distance to the main road were considered as modifying factors. Lastly, logistic regression was used to identify factors associated with the proportion of household contacts testing RDT positive. RESULTS: A total of 426 index households were enrolled, with 1,621 household contacts (45% RDT positive). Two space-time clusters were identified in the rainy season, with ten times and six times higher risk than expected. Significantly increased spatial clustering of index households was found in the rainy season as compared to the dry season (based on K-function methodology). However, no seasonal difference in mapped spatial intensity of index households was identified. Logistic regression analysis identified two main factors associated with a higher proportion of RDT positive household contacts. There was a 41% increased odds of RDT positive household contacts in households where the index case was under 5 years of age [OR = 1.41, 95% confidence intervals (1.15, 1.73)]. For every 500-m increase in distance from the road, there was a 5% increased odds of RDT positive household contacts [OR = 1.05 (1.02, 1.07)], controlling for season. DISCUSSION: Areas of increased report of malaria persist after controlling for distance to the clinic and main road. Clinic-based interventions will miss asymptomatic, non-care seeking infections located farther from the road. RACD may identify additional infections missed at the clinic.
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    Tuberculosis and HIV control in sub-Saharan African prisons: "thinking outside the prison cell".
    (2012-May-15) Reid SE; Topp SM; Turnbull ER; Hatwiinda S; Harris JB; Maggard KR; Roberts ST; Krüüner A; Morse JC; Kapata N; Chisela C; Henostroza G; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. stewart.reid@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
    Tuberculosis is one of the fastest-growing epidemics in prison populations in sub-Saharan Africa (SSA), constituting a threat to both inmates and the wider community. Various factors have contributed to the breakdown of tuberculosis control in prison facilities in SSA, including slow and insensitive diagnostics, failing prison infrastructure, inadequate funding, and weak prevention and treatment interventions for human immunodeficiency virus (HIV). In this article, we describe the challenges inherent in current approaches to tuberculosis control in prisons and consider the alternatives. We argue that although improved implementation of conventional tuberculosis control activities is necessary, considerable investment in a broader range of public health interventions, including infrastructure and staffing upgrades, cutting-edge tuberculosis diagnostics, and combination prevention for HIV, will be equally critical. This combination response to tuberculosis in prisons will be essential for tackling existing and nascent prison tuberculosis epidemics and will require high-level political support and financing.