The ability of Rhipicephalus appendiculatus (Acarina: Ixodidae) stocks in Kenya to become infected with Theileria parva

1992 ◽  
Vol 82 (3) ◽  
pp. 349-353 ◽  
Author(s):  
S.S. Kubasu
Keyword(s):  
Salivary Glands ◽  
Rhipicephalus Appendiculatus ◽  
The Other ◽  
Laboratory Population ◽  
Theileria Parva ◽  
European Breed

AbstractEight steers of European breed, Bos taurus type which were shown to be negative for antibodies against Theileria parva, were divided into two groups of four animals each. Animals in one group were inoculated with 0.5 ml undiluted tick-derived T. p. parva Muguga strain and animals in the other group were inoculated with 1 ml undiluted tick-derived T. p. parva Kilae strain to infect them. The two infected groups of cattle were simultaneously infested with uninfected nymphal Rhipicephalus appendiculatus Neumann in separate cloth patches. Ticks were from five populations, i.e., four from different geographical zones in Kenya and one laboratory population, in separate cloth patches. After moulting, the adult ticks were fed on rabbits for three days and their salivary glands were examined by microscopy for infective stages of the parasite. This revealed significant differences in the five populations as regards to their susceptibility to Theileria parva parasites.

Tick (Acari: Ixodidae) ecological studies in Tanzania

1986 ◽  
Vol 76 (2) ◽  
pp. 229-246 ◽  
Author(s):  
R. J. Tatchell ◽  
E. Easton
Keyword(s):  
Seasonal Variation ◽  
Host Density ◽  
Dar Es Salaam ◽  
Rhipicephalus Appendiculatus ◽  
Amblyomma Variegatum ◽  
The Other ◽  
Theileria Parva ◽  
Ecological Studies ◽  
Adult Abundance

AbstractTicks were regularly collected from cattle along transects in Sukumaland and the Southern Highlands, Tanzania, and from locations near Tabora, Mbeya, Arusha and Dar es Salaam from 1973 to 1976. Marked seasonal variation in abundance occurred in Rhipicephalus appendiculatus Neumann in the Southern Highlands (but not in Sukumaland) and in Amblyomma variegatum (F.) near Tabora. It was possible to detect Theileria parva antibodies in cattle sera from the Southern Highlands only during the season of R. appendiculatus adult abundance. Despite this there was no evidence of enzootic instability of the disease. The results demonstrate that the behaviour and distributions of these and the other species of ticks found are not fixed and constant but vary according to a complicated interplay of factors as yet imperfectly understood, such as climate and vegetation and host density, susceptibility and grazing habits.

East Coast fever: correlation between the morphology and infectivity of Theileria parva developing in its tick vector

Parasitology ◽  
1973 ◽  
Vol 66 (3) ◽  
pp. 539-544 ◽  
Author(s):  
R.E. Purnell ◽  
C. G. D. Brown ◽  
M. P. Cunningham ◽  
M. J. Burridge ◽  
I. M. Kirimi ◽  
...  
Keyword(s):  
Salivary Glands ◽  
East Coast ◽  
Rhipicephalus Appendiculatus ◽  
East Coast Fever ◽  
Theileria Parva ◽  
Supernatant Fluid ◽  
Tick Vector

Rhipicephalus appendiculatus ticks, infected with Theileria parva, were fed on rabbits and removed at daily intervals for 9 days. Half of the ticks removed were dissected and their salivary glands processed and examined for parasites. The remaining ticks which had been removed were ground up and aliquots of the supernatant fluid thus obtained were injected into East Coast fever susceptible cattle. Cattle injected with supernatant fluids from ticks fed for 4–9 days became infected, and this could be correlated with the histological detection of mature parasites in the corresponding ticks. The most highly infective supernatant fluids were prepared from 5-day-fed ticks. In a second experiment it was shown that female ticks of a variety of weights contained infective particles of T. parva.

Transmission of Theileria parva by a population of Rhipicephalus appendiculatus under simulated natural conditions

Parasitology ◽  
1983 ◽  
Vol 86 (2) ◽  
pp. 255-267 ◽  
Author(s):  
A. S. Young ◽  
B. L. Leitch ◽  
T. T. Dolan ◽  
R. M. Newson ◽  
P. N. Ngumi ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Cold Season ◽  
Rhipicephalus Appendiculatus ◽  
Theileria Parva ◽  
Infected Tick ◽  
Lethal Challenge ◽  
Lethal Infection ◽  
Sexual Stages ◽  
High Parasitaemias

SUMMARYA 2 hectare paddock on the Muguga Estate, Kiambu District of Kenya (altitude 2100 m) free of Theileria parva-iniected ticks was seeded by applying Rhipicephalus appendiculatus nymphs to cattle infected with Theileria parva (Kiambu 4). It was estimated that over 50000 engorged nymphs fell onto the pasture from 4 cattle with high parasitaemias during the cold season (June). Samples of these ticks were placed in plastic cylinders under the vegetation in the paddock and sexual stages of T. parva were detected in gut lumen smears in these samples up to 21 days alter repletion. Zygotes were first observed to transform into kinetes on day 55 and parasites were first detected in salivary glands of adults on day 64. Moulting of the nymphs started on day 60 after repletion and was completed by day 87. Cattle introduced into the paddock showed their first infestation with adult R. appendiculatus on day 64 after repletion of the nymphs and the infestation level gradually increased. On day 76 after repletion, 17% of a sample of adult ticks infesting cattle showed salivary gland infections with T. parva and this increased to over 70% by day 150. From day 360 onwards, a decrease in both the percentage of ticks infected and the number of salivary gland acini infected/tick was noted. In addition, T. parva infections within the salivary glands required a longer period of feeding in the older ticks before they developed into sporozoites. Cycling of Theileria through ticks was prevented by the removal of female ticks before they completed repletion. Lethal challenge levels of T. parva for cattle existed in the paddock up to day 547 after repletion, after which introduced cattle showed no infection or only a sub-lethal infection. Cattle introduced into the paddock on day 808 after repletion showed no evidence of T. parva infection. The tick infestation of introduced cattle decreased markedly from day 368 and infestation had virtually ceased by day 808

The effect of irradiation on the susceptibility of Rhipicephalus appendiculatus ticks to Theileria parva infection

Parasitology ◽  
1981 ◽  
Vol 82 (3) ◽  
pp. 473-479 ◽  
Author(s):  
A. S. Young ◽  
B. L. Leitch ◽  
A. D. Irvin ◽  
D. A. E. Dobbelaere
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Irradiation Dose ◽  
Subsequent Development ◽  
Rhipicephalus Appendiculatus ◽  
Detectable Effect ◽  
Theileria Parva ◽  
Theileria Parva Infection

SUMMARYIrradiation doses of 800 rad. or less had no detectable effect on the subsequent development of unfed nymphal Rhipicephalus appendiculatus ticks. Doses of 1600 rad. or above impaired feeding and moulting and delayed the subsequent development of unfed nymphs. At 6400 rad. no ticks completed their moult. Unfed nymphal R. appendiculatus irradiated at 0, 400, 800 and 1600 rad. were applied to 3 cattle infected with T. parva (Kiambu 4). The Theileria infections in the salivary glands of the resultant adult ticks were assessed and it was found that irradiation doses of 800 rad. or less had little effect on the Theileria infections, but an–irradiation dose of 1600 rad. greatly reduced the level of infection. The numbers of salivary gland acini in ticks of this group were reduced but the percentage of infected acini was similar.

Genes transcribed in the salivary glands of female Rhipicephalus appendiculatus ticks infected with Theileria parva

2004 ◽  
Vol 34 (10) ◽  
pp. 1117-1128 ◽  
Author(s):  
Vishvanath Nene ◽  
Dan Lee ◽  
Simon Kang’a ◽  
Robert Skilton ◽  
Trushar Shah ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Rhipicephalus Appendiculatus ◽  
Theileria Parva
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