Publications

antibiotic susceptibility patterns of mastitis pathogens isolated from bloemfontein dairy herds.	the antibiotic susceptibility patterns of bacteria associated with subclinical mastitis in bloemfontein fresh milk dairy herds were determined. a total of 141 bacterial strains tested, consisted of staphylococcus aureus (93 strains), coagulase negative staphylococci (17), streptococci (12), corynebacterium bovis (8), pseudomonas aeruginosa (7) and enterobacteria (4). antibiotic susceptibility was determined qualitatively using the kirby-bauer disc diffusion method and quantitatively by determini ...	1984	6442736
bacteriophage typing of staphylococcus aureus strains isolated from bloemfontein dairy herds.	bacteriophage typing was performed on 88 coagulase positive staphylococcus aureus strains isolated during a survey of subclinical mastitis in bloemfontein dairy herds. phage typing was performed using two basic international phage typing sets, i.e. the human isolate phage set (hps) and the bovine isolate phage set (bps). the results clearly indicated that the bps could be successfully applied for the phage typing of bovine mastitis s. aureus strains. the majority of the strains was typed as bps ...	1985	3160859
a common-source outbreak of crimean-congo haemorrhagic fever on a dairy farm.	an outbreak of crimean-congo haemorrhagic fever (cchf) on a dairy farm in the orange free state in 1984 is described. forty-six cows were purchased from the western cape province in january 1984; 2 died from the tick-borne disease anaplasmosis in march and a labourer who helped butcher the carcasses became ill a few days later. another cow died at the end of april and within 9 days 4 people who had come into contact with its blood became ill. antibodies to cchf virus were found in the sera of th ...	1985	3933131
bovine trichomoniasis in the north western cape province, western transvaal and the orange free state.	in bulls (n = 2,437) examined by preputial sheath washes, 7.1% were found to be positive for trichomoniasis. the incidence varied from one area to the other, as well as between breeds.	1989	2724290
parasites of cattle in the south western orange free state.	a number of young friesian oxen were slaughtered (one at a time) for parasite recovery for 12 consecutive months, from april 1987 to march 1988, on a farm in the fauresmith district of the south western orange free state. a total of 5 ixodid and one argasid tick species, 2 lice species, plus one nematode species and one cestode species, were recovered. peak numbers of adult hyalomma marginatum rufipes were present from november 1987 to february 1988, while the largest numbers of hyalomma truncat ...	1990	2269986
the virtual absence of culicoides imicola (diptera: ceratopogonidae) in a light-trap survey of the colder, high-lying area of the eastern orange free state, south africa, and implications for the transmission of arboviruses.	altogether 52 078 culicoides biting midges of 35 species were collected during february 1990 and 1993 in 40 light-trap collections made on 17 cattle and/or sheep farms in the bethlehem and fouriesburg districts of the colder, high-lying eastern orange free state. culicoides (avaritia) bolitinos was by far the most abundant species, representing 50.9% of all specimens collected. culicoides (a.) imicola, considered to be the most common stock-associated species in the summer rainfall areas of sout ...	1994	7501364
the distribution of pasteurella haemolytica serotypes among cattle, sheep, and goats in south africa and their association with diseases.	over an 8-year period (september 1986 to march 1994), a total of 497 organ specimens from sheep and goats and 96 from cattle, were received for their isolation of pasteurella haemolytica. they were collected in seven geographical areas in south africa (as it existed before the april 1994 elections). these areas include the eastern cape, transvaal (new name: gauteng), nambia, orange free state (new name: free state), natal (new name: kwazulu-natal), western cape and the northern cape. this invest ...	1995	8668319
the efficacy of used engine oil against ticks on cattle.	the study was conducted in a peri-urban agricultural system at botshabelo, a city in the south-eastern free state. a questionnaire survey revealed that 88.5% of cattle farmers in the area experienced problems related to ticks and tick-borne diseases. because of the cost of commercial acaricides the botshabelo farmers use alternative, cheaper methods of tick control, including the application of used engine oil. the specific aim of the study was to determine whether used engine oil can effectivel ...	1998	10192839
epidemiology of tick-borne diseases of cattle in botshabelo and thaba nchu in the free state province.	a seroepidemiological study was conducted on 151 cattle from the botshabelo and thaba nchu areas in the central free state province of south africa, two areas where small scale, peri-urban cattle farming is practised. an indirect fluorescent antibody test was used to test for babesia bigemina and b. bovis antibodies. to test for anaplasma marginale antibodies a competitive inhibition enzyme-linked immunosorbent assay method was used. there were no significant differences in serological test resu ...	1998	10192841
individual host variations in tick infestations of cattle in a resource-poor community.	relative resistance levels of cattle against tick infestations in the communal grazing area of botshabelo in the south-eastern free state were determined. the objective was to establish whether differences in resistance can be exploited to contribute to tick control methods used by small-scale farmers in resource-poor environments. ten cows (bos taurus crosses) between the ages of 18 months and four years were used and tick counts were conducted once a month over a period of 12 months to compare ...	1998	10192842
tick diversity, abundance and seasonal dynamics in a resource-poor urban environment in the free state province.	the objectives of this study were to determine the diversity, seasonal dynamics and abundance of ticks infesting cattle in urban, small-scale farming communities in and around botshabelo and thaba nchu in the eastern free state province, south africa. a total of ten cattle, ear-tagged for individual identification, were investigated monthly at each of five localities. adult ticks were removed from the right hand side of each animal and placed in containers filled with 70% ethanol. they were subs ...	1998	10192844
assessment of cattle owner's perceptions and expectations, and identification of constraints on production in a peri-urban, resource-poor environment.	this questionnaire survey was conducted amongst 200 farmers in the resource-poor, urban and per-urban environments of botshabelo and thaba nchu towns in the free state province of south africa. the questionnaire was divided into seven sections, namely demography, livestock, cattle, parasites, parasite control, livestock diseases and problems experienced. a total of 87.5% of the livestock owners were not employed (unemployed or pensioner). cattle constituted more than 50% of the live-stock units ...	1999	10486825
gastro-intestinal parasites of cattle in the communal grazing system of botshabelo in the free state.	twelve bonsmara tracer calves (aged 6-12 months) were used to monitor helminth infections in the communal farming system of botshabelo in the free state. one calve was slaughtered each month from december 1995 to november 1996 and processed for helminth recovery. all the calves harboured worms, but the numbers were always low. the order of prevalence of the major parasites was trichostrongylus axei, haemonchus placei, cooperia punctata and cooperia pectinata.	1999	10486833
neurotoxicity in calves induced by the plant, nierembergia hippomanica miers var. violacea millán in south africa.	the plant nierembergia hippomanica var. violacea has been incriminated in field outbreaks of neurotoxicity in calves in the free state province. hepatotoxicity and electrocardiogram (ecg) deviations were induced in a sheep dosed with 5 g/kg dried plant material on four consecutive days. a calf dosed with 2.5 g/kg dried plant material, on two consecutive days, did not show overt clinical changes. voluntary ingestion of approximately 30 g/kg fresh flowering plants by a second calf resulted in nerv ...	1999	10631710
seasonal abundance of adult ixodid ticks infesting cattle belonging to resource-limited farmers in the north-eastern free state province of south africa.	a study was undertaken to determine the seasonal abundance of the ticks infesting cattle owned by resource-limited farmers in the north-eastern free state province of south africa. infestations of boophilus decoloratus koch, 1844, rhipicephalus evertsi evertsi neumann, 1897, rhipicephalus follis donitz, 1910, rhipicephalus gertrudae feldman-muhsam, 1960 and rhipicephalus warburtoni walker & horak, 2000, were monitored on cattle of mixed breeds at monthly intervals from may 1998 to april 1999. hi ...	2002	12092776
a comparison of the vector competence of the biting midges, culicoides (avaritia) bolitinos and c. (a.) imicola, for the bryanston serotype of equine encephalosis virus.	equine encephalosis virus (eev) is widespread and prevalent in southern africa. in this study, the oral susceptibility of culicoides (avaritia) imicola kieffer (diptera: ceratopogonidae) to eev was confirmed. in addition, c. (a.) bolitinos meiswinkel, collected in the high-lying eastern free state, south africa, was systemically infected with the bryanston serotype of eev after feeding through a membrane on artificially infected equine blood containing 4.7 log10 pfu/ml of eev. the mean infectivi ...	2002	12510889
ticks and tick-borne diseases of livestock belonging to resource-poor farmers in the eastern free state of south africa.	the paper provides a summary of three studies conducted in the eastern free state of south africa between 1998 and 2000. in a questionnaire-based study approximately 21% of interviewed resource-poor farmers (n = 150) indicated that they experienced problems with ticks and tick-borne diseases. about 56% of farmers indicated that tick-related problems were most severe in summer, while 32% indicated that the most problems were encountered in winter. about 12% indicated that the tick problems were e ...	2002	14570134
parasitic helminths of veterinary importance in cattle, sheep and goats on communal farms in the northeastern free state, south africa.	the purpose of the study was to record and determine intensities, seasonal incidence and distribution of helminth parasites of veterinary importance that occur in cattle, sheep and goats in the northeastern free state. the study was conducted at harrismith and kestell and in qwa-qwa from march 2000 to may 2001. cattle of various breeds (including bonsmara, simmentaler and friesian), merino sheep and angora goats were sampled. faecal samples were analysed using the mcmaster and visser sieve techn ...	2003	12967050
a sero-epidemiological survey of blood parasites in cattle in the north-eastern free state, south africa.	a survey to determine the incidence of parasites in cattle (n = 386) was conducted in the north eastern free state between august 1999 and july 2000. giemsa-stained blood smears were negative for blood parasites. a total of 94% of the cattle were sero-positive for babesia bigemina by indirect fluorescent antibody test while 87% were sero-positive for anaplasma by enzyme-linked immunosorbent assay. the observation of negative blood smears but high incidence of positive serological results for ana ...	2004	15185577
larval biology of rhipicephalus (boophilus) decoloratus (acarina: ixodidae) in free state province, south africa.	the objective of this study was to determine certain aspects of the biology of rhipicephalus (boophilus) decoloratus larvae under laboratory and field conditions. larvae allowed 48 h to select a vertical questing substrate preferred 90 cm rods in length to those of 60 or 30 cm, while in a separate experiment migration from rods 5 cm or 25 cm in length to rods 45 cm in length continued between 48 h and 72 h after larval release. hatching of the larval progeny of engorged female ticks exposed to a ...	2004	15732460
a survey of tick control methods used by resource-poor farmers in the qwa-qwa area of the eastern free state province, south africa.	a survey conducted in five villages in a resource-poor farming community in qwa-qwa, using the rapid rural appraisal technique and a questionnaire survey, showed that a significant proportion of the farmers (84%) use traditional or alternative methods to control ectoparasites, while 16% use commercial acaricides (chi2 = 7.1; p < or = 0.05). alternative control methods included the use of used engine oil, household disinfectant and paraffin. killing of ticks was the main reason for control (40%), ...	2005	16300193
hosts, seasonality and geographic distribution of the south african tortoise tick, amblyomma marmoreum.	the tortoise tick amblyomma marmoreum was collected from large numbers of reptiles and other animals during the course of numerous surveys conducted in south africa. a total of 1229 ticks, of which 550 were adults, were recovered from 309 reptiles belonging to 13 species, with leopard tortoises, geochelone pardalis being the most heavily infested. the 269 birds sampled harboured 4901 larvae, 217 nymphs and no adult ticks, and the prevalence of infestation was greatest on helmeted guineafowls, nu ...	2006	16715875
prevalence and genetic diversity of anaplasma marginale strains in cattle in south africa.	bovine anaplasmosis, caused by the tick-borne rickettsia anaplasma marginale, is endemic in south africa and results in considerable economic loss to the cattle industry. this study was designed to characterize strains of a. marginale at the molecular level from cattle raised in communal and commercial farms in the north-eastern and south-western regions of the free state province, south africa, that varied in rainfall and vegetation. seroprevalence to a. marginale was determined in 755 cattle b ...	2007	17359443
waste-handling practices at red meat abattoirs in south africa.	abattoir waste disposal must be carefully managed because the wastes can be a source of food-borne diseases (nemerow & dasgupta industrial and hazardous waste treatment, p. 284, van nostrand reinhold, new york, 1991; bradshaw et al. the treatment and handling of wastes, p. 183, the royal society, chapman & hall, london, 1992). disposal of food that has been condemned because it is known to be diseased is of particular concern, and this paper looks at current disposal methods for such waste in th ...	2009	19220989
distribution of endemic and introduced tick species in free state province, south africa.	the distributions of endemic tick vector species as well as the presence of species not endemic to free state province, south africa, were determined during surveys or opportunistic collections from livestock, wildlife and vegetation. amongst endemic ticks, the presence of rhipicephalus appendiculatus was confirmed in the north of the province, whilst rhipicephalus decoloratus was collected at 31 localities mostly in the centre and east, and ixodes rubicundus at 11 localities in the south, south ...	2015	26244582