Stephen D.A. Smith

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OBJECTIVE To explore whether early analysis of spatial data may result in identification of variables associated with epidemic spread of foot and mouth disease. SAMPLE POPULATION 37 farms with infected cattle (ie, case farms) reported within the first 6 days of the 2001 Uruguayan foot-and-mouth disease epidemic. PROCEDURE A georeferenced database was(More)
Disease clusters were retrospectively explored at national level using a geo-referenced dataset from the 2001 Uruguayan Foot-and-Mouth Disease (FMD) epidemic. Disease location and time (first 11 epidemic weeks) were analysed across 250 counties (of which 160 were infected), without and with control for human mobility related factors (human population and(More)
The ability of Boophilus microplus strains to be susceptible (-) or resistant (+) to amidines (Am), synthetic pyrethroids (SP), and/or organo-phosphates (OP) (or acaricide profiles) was investigated in 217 southeastern Mexican cattle ranches (located in the states of Yucatán, Quintana Roo, and Tabasco). Three questions were asked: (1) whether acaricide(More)
The daily progression of the 2006 (January-June) Nigerian avian influenza (AI H5N1) epidemic was assessed in relation to both spatial variables and the generation interval of the invading virus. Proximity to the highway network appeared to promote epidemic dispersal: from the first AI generation interval onwards > 20% of all cases were located at < 5 km(More)
Though alcohol and prescription drug abuse are well studied in older adults, there is little information regarding illicit drug use in older adults. We investigated illicit drug use in older adults presenting to an inner city emergency department in Los Angeles over a 10-month period. Of 3,417 adults over 50 presenting to the Emergency Department (ED),(More)
Geo-referenced data from the 2001 Uruguayan foot-and-mouth disease (FMD) epidemic were explored to assess whether spatial analysis could lead to cost-benefit based policies. Four variables were analysed: (i) location and size of 4022 individual rural land parcels, of which 574 were infected over 60 days, (ii) animal density, (iii) percentage of dairy farms(More)
In the Solitary Islands Marine Park (northern NSW, Australia), the tubebuilding polychaete worm Chaetopterus sp. forms dense aggregations which measure up to 2 m in diameter and 25 cm in thickness. Worm patches are present at all of the main islands and are particularly conspicuous in sheltered aspects at depths of 8–10 m. Coral cover and diversity are also(More)
BACKGROUND A method that assesses bacterial spatial dissemination was explored. It measures microbial genotypes (defined by electrophoretic patterns or EP), host, location (farm), interfarm Euclidean distance, and time. Its proof of concept (construct and internal validity) was evaluated using a dataset that included 113 Staphylococcus aureus EPs from 1126(More)
When an exotic infectious disease invades a susceptible environment, protection zones are enforced. Historically, such zones have been shaped as circles of equal radius (ER), centred on the location of infected premises. Because the ER policy seems to assume that epidemic dissemination is driven by a similar number of secondary cases generated per primary(More)
OBJECTIVE To evaluate the influence of individual spatial units (ie, counties) on the epidemic spread of foot-and-mouth disease (FMD) virus. SAMPLE POPULATION 163 counties in Uruguay where there was an outbreak of FMD between April 23 and July 11, 2001. PROCEDURE A geographically referenced database was created, and the distance between counties (13,203(More)