Koch (1844) originally described only the male of Haemaphysalis (Rhipistoma) elliptica (Koch, 1844), which he named Rhipistoma ellipticum. For the past century, however, this name has been considered a junior synonym of Haemaphysalis (Rhipistoma) leachi (Audouin, 1826), or a nomen nudum. We redescribe here the male and larva of H. (R.) elliptica and describe the female and nymph for the first time. Our redescription is based on the male holotype, plus numerous specimens from southern and East Africa. The adults of this tick parasitize domestic and wild carnivores, and the immature stages infest rodents in these regions. For comparative purposes redescriptions of all parasitic stages of H. (R.) leachi are provided. It parasitizes the same hosts as H. (R.) elliptica in Egypt, and in northeastern, Central, West and East Africa.

Koch (1844) originally described only the male of Haemaphysalis (Rhipistoma) elliptica (Koch, 1844), which he named Rhipistoma ellipticum. For the past century, however, this name has been considered a junior synonym of Haemaphysalis (Rhipistoma) leachi (Audouin, 1826), or a nomen nudum. We redescribe here the male and larva of H. (R.) elliptica and describe the female and nymph for the first time. Our redescription is based on the male holotype, plus numerous specimens from southern and East Africa. The adults of this tick parasitize domestic and wild carnivores, and the immature stages infest rodents in these regions. For comparative purposes redescriptions of all parasitic stages of H. (R.) leachi are provided. It parasitizes the same hosts as H. (R.) elliptica in Egypt, and in northeastern, Central, West and East Africa.

Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and nine in the lowveld communal grazing areas of Zimbabwe were examined for gastrointestinal (GI) nematode and cestodes eggs, and coccidia oocysts. Strongyle larvae were identified following culture of pooled faecal samples collected at monthly intervals. The effects of region, age, sex and season on the prevalence of GI nematodes, cestodes and coccidia were determined. Faecal egg and oocyst counts showed an overall prevalence of GI nematodes of 43 %, coccidia 19.8 % and cestodes 4.8 %. A significantly higher prevalence of infection with GI nematodes, cestodes and coccidia was recorded in calves (P < 0.01) than in adults. Pregnant and lactating cows had significantly higher prevalences than bulls, oxen and non-lactating (dry cows) (P < 0.01). The general trend of eggs per gram (epg) of faeces and oocysts per gram (opg) of faeces was associated with the rainfall pattern in the two regions, with high epg and opg being recorded during the wet months. The most prevalent genera of GI nematodes were Cooperia, Haemonchus and Trichostrongylus in that order. Strongyloides papillosus was found exclusively in calves. Haemonchus was significantly more prevalent during the wet season than the dry season (P < 0.01). In contrast, Trichostrongylus was present in significantly (P < 0.01) higher numbers during the dry months than the wet months, while Cooperia and Oesophagostomum revealed no significant differences between the wet and dry season. These findings are discussed with reference to their relevance for strategic control of GI parasites in cattle in communal grazing areas of Zimbabwe.

Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and nine in the lowveld communal grazing areas of Zimbabwe were examined for gastrointestinal (GI) nematode and cestodes eggs, and coccidia oocysts. Strongyle larvae were identified following culture of pooled faecal samples collected at monthly intervals. The effects of region, age, sex and season on the prevalence of GI nematodes, cestodes and coccidia were determined. Faecal egg and oocyst counts showed an overall prevalence of GI nematodes of 43 %, coccidia 19.8 % and cestodes 4.8 %. A significantly higher prevalence of infection with GI nematodes, cestodes and coccidia was recorded in calves (P 0.01) than in adults. Pregnant and lactating cows had significantly higher prevalences than bulls, oxen and non-lactating (dry cows) (P 0.01). The general trend of eggs per gram (epg) of faeces and oocysts per gram (opg) of faeces was associated with the rainfall pattern in the two regions, with high epg and opg being recorded during the wet months. The most prevalent genera of GI nematodes were Cooperia, Haemonchus and Trichostrongylus in that order. Strongyloides papillosus was found exclusively in calves. Haemonchus was significantly more prevalent during the wet season than the dry season (P 0.01). In contrast, Trichostrongylus was present in significantly (P 0.01) higher numbers during the dry months than the wet months, while Cooperia and Oesophagostomum revealed no significant differences between the wet and dry season. These findings are discussed with reference to their relevance for strategic control of GI parasites in cattle in communal grazing areas of Zimbabwe.

A cross-sectional survey of ticks infesting sheep was conducted in Sennar State, Sudan. A total body collection of ticks was carried out at five localities Sennar town, Singa, Dinder, Abu Naama and Um Banein on two types of Desert sheep (Watish and Ashgar) on two farms at each locality at two monthly intervals for one year starting July 2002 to May 2003. Four tick genera and eight species were identified. They were Amblyomma lepidum, Hyalomma anatolicum anatolicum, Hyalomma truncatum, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus camicasi, Rhipicephalus evertsi evertsi, Rhipicephalus guilhoni and Rhipicephalus muhsamae. A significant (P < 0.05) seasonal pattern of activity was observed for A. lepidum and R. guilhoni with peak activity occurring during rainy seasons. The highest mean number of ticks (7.26 + 0.58) was recorded at Abu Naama, while the lowest mean (3.61 + 0.31) was recorded in Sennar. Watish type sheep carried significantly (P < 0.05) more ticks than Ashgar type.

A cross-sectional survey of ticks infesting sheep was conducted in Sennar State, Sudan. A total body collection of ticks was carried out at five localities Sennar town, Singa, Dinder, Abu Naama and Um Banein on two types of Desert sheep (Watish and Ashgar) on two farms at each locality at two monthly intervals for one year starting July 2002 to May 2003. Four tick genera and eight species were identified. They were Amblyomma lepidum, Hyalomma anatolicum anatolicum, Hyalomma truncatum, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus camicasi, Rhipicephalus evertsi evertsi, Rhipicephalus guilhoni and Rhipicephalus muhsamae. A significant (P 0.05) seasonal pattern of activity was observed for A. lepidum and R. guilhoni with peak activity occurring during rainy seasons. The highest mean number of ticks (7.26 + 0.58) was recorded at Abu Naama, while the lowest mean (3.61 + 0.31) was recorded in Sennar. Watish type sheep carried significantly (P 0.05) more ticks than Ashgar type.

The toxic effects of an aqueous extract of Abrus precatorius were studied in 20 male white rats over a period of 18 days. The rats were divided into four groups of five rats per group. Those in Group A served as controls while the rats in Groups B, C and D were dosed per os with 400 mg/kg, 800 mg/kg and 1 600 mg/kg of the extract, respectively. Blood samples were collected for haematological and biochemical analysis and specimens of the liver, kidney and testes were taken for histopathological studies. The study showed that the extract of A. precatorius caused decreased levels of packed cell volume, haemoglobin concentration, red blood cell count, white blood cell count, mean corpuscular volume and mean corpuscular haemoglobin. The extract also resulted in increased levels of total serum protein, albumin, alanine amino transaminase, aspartate amino transferase, alkaline phosphatase and total bilirubin. Histologically, testicular degeneration characterized by decreased numbers of lining cells of the epithelium as well as reduction in sperm cells with presence of scattered Sertoli cells were noted. The study thus showed that aqueous extract of Abrus precatorius is toxic and caution should be exercised in its use for medicinal purpose.

The toxic effects of an aqueous extract of Abrus precatorius were studied in 20 male white rats over a period of 18 days. The rats were divided into four groups of five rats per group. Those in Group A served as controls while the rats in Groups B, C and D were dosed per os with 400 mg/kg, 800 mg/kg and 1 600 mg/kg of the extract, respectively. Blood samples were collected for haematological and biochemical analysis and specimens of the liver, kidney and testes were taken for histopathological studies. The study showed that the extract of A. precatorius caused decreased levels of packed cell volume, haemoglobin concentration, red blood cell count, white blood cell count, mean corpuscular volume and mean corpuscular haemoglobin. The extract also resulted in increased levels of total serum protein, albumin, alanine amino transaminase, aspartate amino transferase, alkaline phosphatase and total bilirubin. Histologically, testicular degeneration characterized by decreased numbers of lining cells of the epithelium as well as reduction in sperm cells with presence of scattered Sertoli cells were noted. The study thus showed that aqueous extract of Abrus precatorius is toxic and caution should be exercised in its use for medicinal purpose.

The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.

The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.

The occurrence of cross-resistance among melarsoprol-resistant Trypanosoma brucei rhodesiense isolates was investigated in this study. The isolates, T. b. rhodesiense KETRI 237, 2538, 1992, 2709, 2694 and 3530, had been obtained from sleeping sickness patients in Kenya and Uganda between 1960 and 1985. Five groups consisting of six mice each were inoculated intraperitoneally with 105 parasites of each isolate, and 24 h later treated with either melarsoprol, homidium chloride, diminazene aceturate or isometamidium chloride. The control group comprised infected but untreated mice. The mice were monitored for cure for a period of 60 days post-treatment. The mean prepatent period in the control mice was 5 days while the mean survival period was 22 days. Five of the stabilates, KETRI 237, 2538, 2709, 2694, and 3530, were confirmed to be melarsoprol resistant. Cross-resistance was observed, with the majority of the isolates being resistant to homidium chloride (5/6) and diminazene aceturate (5/6), but all were sensitive to isometamidium chloride (6/6). However T. b. rhodesiense KETRI 1992, which was previously considered as melarsoprol resistant, was sensitive to all the drugs tested. In conclusion, our study has revealed the existence of cross-resistance among the melarsoprol resistant isolates which could only be cured by isometamidium.

The occurrence of cross-resistance among melarsoprol-resistant Trypanosoma brucei rhodesiense isolates was investigated in this study. The isolates, T. b. rhodesiense KETRI 237, 2538, 1992, 2709, 2694 and 3530, had been obtained from sleeping sickness patients in Kenya and Uganda between 1960 and 1985. Five groups consisting of six mice each were inoculated intraperitoneally with 105 parasites of each isolate, and 24 h later treated with either melarsoprol, homidium chloride, diminazene aceturate or isometamidium chloride. The control group comprised infected but untreated mice. The mice were monitored for cure for a period of 60 days post-treatment. The mean prepatent period in the control mice was 5 days while the mean survival period was 22 days. Five of the stabilates, KETRI 237, 2538, 2709, 2694, and 3530, were confirmed to be melarsoprol resistant. Cross-resistance was observed, with the majority of the isolates being resistant to homidium chloride (5/6) and diminazene aceturate (5/6), but all were sensitive to isometamidium chloride (6/6). However T. b. rhodesiense KETRI 1992, which was previously considered as melarsoprol resistant, was sensitive to all the drugs tested. In conclusion, our study has revealed the existence of cross-resistance among the melarsoprol resistant isolates which could only be cured by isometamidium.