For nearly 50 years the ixodid tick Hyalomma marginatum turanicum, reputedly introduced into South Africa on imported Persian sheep, has been considered identical to the Asian Hyalomma (Euhyalomma) marginatum turanicum Pomerantzev, 1946. Comparisons of this tick with the Asian H. (E.) m. turanicum and other subspecies of Hyalomma (Euhyalomma) marginatum, however, reveal that it is an old taxon, namely Hyalomma rufipes glabrum Delpy, 1949. It is hereby reinstated as Hyalomma (Euhyalomma) glabrum, and its adults are redescribed and its immature stages described for the first time. The preferred hosts of its adults are large herbivores such as zebras, gems bok and eland, on which it occurs during summer. The preferred hosts of its immature stages are scrub hares and ground-frequenting birds, on which it is present during autumn and winter. Data on its distribution and possible disease relationships are also provided.

For nearly 50 years the ixodid tick Hyalomma marginatum turanicum, reputedly introduced into South Africa on imported Persian sheep, has been considered identical to the Asian Hyalomma (Euhyalomma) marginatum turanicum Pomerantzev, 1946. Comparisons of this tick with the Asian H. (E.) m. turanicum and other subspecies of Hyalomma (Euhyalomma) marginatum, however, reveal that it is an old taxon, namely Hyalomma rufipes glabrum Delpy, 1949. It is hereby reinstated as Hyalomma (Euhyalomma) glabrum, and its adults are redescribed and its immature stages described for the first time. The preferred hosts of its adults are large herbivores such as zebras, gems bok and eland, on which it occurs during summer. The preferred hosts of its immature stages are scrub hares and ground-frequenting birds, on which it is present during autumn and winter. Data on its distribution and possible disease relationships are also provided.

One hundred sheep naturally infected with Theileria lestoquardi were treated with a chloroform extract of the plant Peganum harmala. The treatment was continued for 5 days, the dose of extract being 5 mg/kg per day. Sixty-five of the sheep responded to treatment and recovered but 35 did not and died. The cure rate was 65 %

One hundred sheep naturally infected with Theileria lestoquardi were treated with a chloroform extract of the plant Peganum harmala. The treatment was continued for 5 days, the dose of extract being 5 mg/kg per day. Sixty-five of the sheep responded to treatment and recovered but 35 did not and died. The cure rate was 65 %

Experimental transmissions of cloned Theileria parva in cattle with Rhipicephalus appendiculatus ticks were compared to transmissions with uncloned T. parva during studies on the potential for genetic recombination during syngamy of Theileria to produce antigenic diversity for evasion of bovine immunity. Prevalence and abundance of T. parva infection in adult ticks, which resulted from the feeding of nymphs on the calves, were significantly higher in the uncloned compared to the cloned T. parva. Development of sporoblasts of T. parva in the ticks to produce infective sporozoites was similar. There was no statistically significant difference in the clinical course of infection in cattle between cloned and uncloned T. parva. It was concluded that cloned T. parva has characteristics that reduce its viability during the tick stages of its life cycle.

Experimental transmissions of cloned Theileria parva in cattle with Rhipicephalus appendiculatus ticks were compared to transmissions with uncloned T. parva during studies on the potential for genetic recombination during syngamy of Theileria to produce antigenic diversity for evasion of bovine immunity. Prevalence and abundance of T. parva infection in adult ticks, which resulted from the feeding of nymphs on the calves, were significantly higher in the uncloned compared to the cloned T. parva. Development of sporoblasts of T. parva in the ticks to produce infective sporozoites was similar. There was no statistically significant difference in the clinical course of infection in cattle between cloned and uncloned T. parva. It was concluded that cloned T. parva has characteristics that reduce its viability during the tick stages of its life cycle.

In a large Kenyan production unit the urogenital organs and mammary glands of 771 sows, culled due to recurring swine urogenital disease (SUGD) were subjected to necropsy Necropsy findings were analysed separately according to parity group of the sows [parities 2 (n = 252); 3-5 (n = 250); and > 5 (n = 269)]. Sows of higher parities had more pathological changes in their ovaries, uteri, vaginas, cervices, urinary bladders, kidneys and mammary glands compared to parity 2 sows (P < 0.05 and P < 0.01, respectively). Parity 2 sows had more ovarian degeneration, mucosal hyperaemia, congestion in the bladder, and acute purulent exudative mastitis than parity > 5 sows (P < 0.05 and P < 0.01, respectively).

In a large Kenyan production unit the urogenital organs and mammary glands of 771 sows, culled due to recurring swine urogenital disease (SUGD) were subjected to necropsy Necropsy findings were analysed separately according to parity group of the sows [parities 2 (n = 252); 3-5 (n = 250); and 5 (n = 269)]. Sows of higher parities had more pathological changes in their ovaries, uteri, vaginas, cervices, urinary bladders, kidneys and mammary glands compared to parity 2 sows (P 0.05 and P 0.01, respectively). Parity 2 sows had more ovarian degeneration, mucosal hyperaemia, congestion in the bladder, and acute purulent exudative mastitis than parity 5 sows (P 0.05 and P 0.01, respectively).

Sixteen experimental burn plot replicates, in groups of four, in four landscape zones of the Kruger National Park, South Africa, and from which wildlife are not excluded, have been subjected to fixed, regular burning regimens since 1954. In 1999, a study to determine the effect of burning on ixodid ticks questing for hosts from the vegetation of the plots was initiated, and six sub-plots, with identical histories, within each of two of the burn plot replicates in Combretum collinum / Combretum zeyheyri woodland on granite, were selected. With few exceptions these 12 sub-plots, as well as unburned vegetation adjacent to each of the replicates, were sampled for ticks at monthly intervals for a period of 39 months by dragging with flannel strips. The existing regimen of burning during August or during October on individual sub-plots was continued during this time. A total of 14 tick species was recovered from the plots of which nine could be considered major species. Sufficient numbers for statistical analysis of only eight species were, however, collected. Burning appeared to have little short-term effect on the number of ticks recovered. In the longer term, the response varied from no change, an increase, or a decrease in the numbers of ticks collected each year after burning. Tick species, life cycle, seasonality, questing strategy, host preference and host utilization of the habitat were important determinants of the effect of burning.

Sixteen experimental burn plot replicates, in groups of four, in four landscape zones of the Kruger National Park, South Africa, and from which wildlife are not excluded, have been subjected to fixed, regular burning regimens since 1954. In 1999, a study to determine the effect of burning on ixodid ticks questing for hosts from the vegetation of the plots was initiated, and six sub-plots, with identical histories, within each of two of the burn plot replicates in Combretum collinum / Combretum zeyheyri woodland on granite, were selected. With few exceptions these 12 sub-plots, as well as unburned vegetation adjacent to each of the replicates, were sampled for ticks at monthly intervals for a period of 39 months by dragging with flannel strips. The existing regimen of burning during August or during October on individual sub-plots was continued during this time. A total of 14 tick species was recovered from the plots of which nine could be considered major species. Sufficient numbers for statistical analysis of only eight species were, however, collected. Burning appeared to have little short-term effect on the number of ticks recovered. In the longer term, the response varied from no change, an increase, or a decrease in the numbers of ticks collected each year after burning. Tick species, life cycle, seasonality, questing strategy, host preference and host utilization of the habitat were important determinants of the effect of burning.

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Faecal samples of cattle were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined at monthly intervals from November 1998 to October 2000, a period of 24 months, in six dams and six streams in the highveld and nine dams in the lowveld communal grazing areas. Monthly, each site was sampled for relative snail density, the vegetation cover and type, and physical and chemical properties of the water. Mean monthly rainfall and temperature were recorded. Snails collected at the same time were individually examined for shedding of cercariae of S. mattheei and Schistosoma haematobium. A total of 16 264 (5 418 calves, 5 461 weaners and 5 385 adults) faecal samples were collected during the entire period of study and 734 (4.5 %) were positive for S. mattheei eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), calves compared to adult cattle (P < 0.01) and the wet season compared to the dry season (P < 0.01). Faecal egg output peaked from October/ November to March / April for both years of the study. Bulinus globosus, the snail intermediate host of S. mattheei was recorded from the study sites with the highveld having a significantly higher abundance of the snails than the lowveld (P < 0.01). Monthly densities of B. globosus did not show a clearcut pattern although there were peaks between March / May and September / November. The mean num ber of snails collected was positively correlated with the water plants Nymphaea caerulea and Typha species. Overall, 2.5 % of B. globosus were shedding Schistosoma cercariae. In the highveld, 2.8 % of B. globosus were infected with schistosome cercariae and 1.5 % in the lowveld, with the figures at individual sites ranging from 0-18.8 % in the highveld and from 0-4.5 % in the lowveld. The cercariae recorded here were a mixture of S. mattheei and S. haematobium since they share the same intermediate host. The transmission of Schistosoma cercariae exhibited a marked seasonal pattern, being more intensive during the hot, dry season (September / November).

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Faecal samples of cattle were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined at monthly intervals from November 1998 to October 2000, a period of 24 months, in six dams and six streams in the highveld and nine dams in the lowveld communal grazing areas. Monthly, each site was sampled for relative snail density, the vegetation cover and type, and physical and chemical properties of the water. Mean monthly rainfall and temperature were recorded. Snails collected at the same time were individually examined for shedding of cercariae of S. mattheei and Schistosoma haematobium. A total of 16 264 (5 418 calves, 5 461 weaners and 5 385 adults) faecal samples were collected during the entire period of study and 734 (4.5 %) were positive for S. mattheei eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P 0.001), calves compared to adult cattle (P 0.01) and the wet season compared to the dry season (P 0.01). Faecal egg output peaked from October/ November to March / April for both years of the study. Bulinus globosus, the snail intermediate host of S. mattheei was recorded from the study sites with the highveld having a significantly higher abundance of the snails than the lowveld (P 0.01). Monthly densities of B. globosus did not show a clearcut pattern although there were peaks between March / May and September / November. The mean num ber of snails collected was positively correlated with the water plants Nymphaea caerulea and Typha species. Overall, 2.5 % of B. globosus were shedding Schistosoma cercariae. In the highveld, 2.8 % of B. globosus were infected with schistosome cercariae and 1.5 % in the lowveld, with the figures at individual sites ranging from 0-18.8 % in the highveld and from 0-4.5 % in the lowveld. The cercariae recorded here were a mixture of S. mattheei and S. haematobium since they share the same intermediate host. The transmission of Schistosoma cercariae exhibited a marked seasonal pattern, being more intensive during the hot, dry season (September / November).