Steven Schofield

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In sub-Saharan Africa, tsetse (Glossina spp.) transmit species of Trypanosoma which threaten 45-50 million cattle with trypanosomiasis. These livestock are subject to various herding practices which may affect biting rates on individual cattle and hence the probability of infection. In Zimbabwe, studies were made of the effect of herd size and composition(More)
Primer sets for five different ungulate loci were used to obtain individual microsatellite DNA profiles for 29 Mashona cattle from a herd in Zimbabwe. There were 3-13 alleles for each locus and, using the entire suite of five loci, each animal within the herd, including closely related individuals, could be unequivocally distinguished. Wild-caught Glossina(More)
In Zimbabwe, observations were made of the behaviour of individual stable flies (Stomoxys spp.) (Diptera: Muscidae) and tsetse (Glossina spp.) (Diptera: Glossinidae) feeding on cattle during the wet (Stomoxys and tsetse) and dry (tsetse only) seasons. For Stomoxys landing on adult cattle, only 27% took a full meal (mean feeding time = 147 s). Most Stomoxys(More)
The attractiveness of 5 male subjects was compared to determine if female black flies were attracted more readily by certain individuals and, if so, to determine the bases of such differences. During 2 yr, in experiments contrasting different groupings of the subjects, 1 subject was consistently the most attractive, whereas another was consistently the(More)
Human subjects were exposed to Simulium venustum (sensu lato) to determine whether biting rates differed among individuals. Tests with S. venustum collected from a CO2-baited target demonstrated that one subject was consistently bitten more often than another. For each individual, biting increased with the differential between skin and ambient temperature.(More)
Studies have demonstrated consistently low stimulation thresholds in the first months following implantation of steroid eluting electrodes. There have been no reported cases of exit block. There is little information on the long-term performance of these leads. Data were collected on 15 patients in whom Medtronic steroid eluting leads (5023 and 4003) had(More)
Current approaches for prevention of tick bites, Lyme disease, and other tick-borne diseases are described. Particular attention is paid to 4 risk-reduction strategies: (i) avoiding risk areas; (ii) personal protective measures that reduce the risk of tick bites or transmission of the agent of Lyme disease, Borrelia burgdorferi; (iii) reducing the number of(More)
Studies were done in Manitoba, Canada, to evaluate the impact of exercise on repellent performance against mosquitoes. Two products containing the active ingredient N,N-diethyl-3-methylbenzamide (deet) were tested; one product was a polymer-based cream (3M Ultrathon Insect Repellent) and the other product was an alcohol-based pump spray formulation (Muskol(More)
Studies were carried out in Manitoba, Canada, to evaluate the efficacy of three repellent products for protection of human subjects against mosquito bites. All test substances contained the active ingredient N,N-diethyl-3-methylbenzamide (deet); two were polymer-based creams (3M Ultrathon Insect Repellent and Morflex DEET Insect Repellent 30) and the third(More)