Three cattle, which had been experimentally infected with Theileria parva lawrencei and maintained
as carriers of the infection, were each infested simultaneously with clean nymphal Rhipicephalus appendiculatus
and Rhipicephalus zambeziensis in ear bags on separate ears. After moulting, the ensuing adult
ticks were fed on rabbits for 4 days and their salivary glands were examined for infective stages of the
parasite. Microscopic examination revealed significantly higher infection rates in the salivary glands of
R. zambeziensis than in R. appendiculatus which may indicate an increased vector efficiency of R.
zambeziensis for T. p. lawrencei.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. 
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Blouin, Edmour F.

Stoltsz, Wilhelm Heinrich

The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. 
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Three cattle, which had been experimentally infected with Theileria parva lawrencei and maintained
as carriers of the infection, were each infested simultaneously with clean nymphal Rhipicephalus appendiculatus
and Rhipicephalus zambeziensis in ear bags on separate ears. After moulting, the ensuing adult
ticks were fed on rabbits for 4 days and their salivary glands were examined for infective stages of the
parasite. Microscopic examination revealed significantly higher infection rates in the salivary glands of
R. zambeziensis than in R. appendiculatus which may indicate an increased vector efficiency of R.
zambeziensis for T. p. lawrencei.lmchunu2014mn201

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Onderstepoort J. vet. Res., 54,211-213 (1989) RESEARCH COMMUNICATION COMPARATIVE INFECTION RATES OF THEILERIA PARVA LAWRENCE/IN SALI-VARY GLANDS OF RHIPICEPHALUS APPENDICULATUS AND RHIPICEPHALUS ZAMBEZIENSIS E. F. BLOUIN and W. H. STOLTSZ, Veterinary Research Institute, Onderstepoort 0110 ABSTRACT BLOUIN, E. F. & STOLTSZ, W. H., 1989. Comparative infection rates of Theileria parva lawren-cei in salivary glands of Rhipicephalus appendiculatus and Rhipicephalus zambeziensis. Onderstepoort Journal of Veterinary Research, 56,211-213 (1989). Three cattle, which had been experimentally infected with Theileria parva lawrencei and maintained as carriers of the infection, were each infested simultaneously with clean nymphal Rhipicephalus appen-diculatus and Rhipicephalus zambeziensis in ear bags on separate ears. After moulting. the ensuing adult ticks were fed on rabbits for 4 days and their salivary glands were examined for infective stages of the parasite. Microscopic examination revealed significantly higher infection rates in the salivary glands of R. zambeziensis than in R. appendiculatus which may indicate an increased vector efficiency of R. zambeziensis forT. p . lawrencei. INTRODUCTION Corridor disease, caused by Theileria parva law-rencei, is transmitted from buffalo (Syncerus caffer) to cattle by Rhipicephalus appendiculatus (Neitz, 1955). In the Republic of South Africa (RSA) it is a controlled disease and is endemic to the Kruger National Park and some of the Zululand game reserves (Potgieter, Stoltsz, Blouin & Roos, 1988). Sporadic outbreaks occur on farms bordering on , or in close proximity to, these endemic areas and have thus far always been associated with the presence of buffalo (Bigalke, De Vas & Barrowman, 1976). De Vas (1981) indicated that R. appendiculatus was still considered to be the only known tick species capable of transmitting Corridor disease. Rhipice-phalus zambeziensis was described by Walker, Norval & Corwin (1981) as a new tick species from eastern and southern Africa, including the RSA, which closely resembled R. appendiculatus. R. zam-beziensis is generally found in hotter, drier areas than R. appendiculatus and the 2 species have often been confused in the past (Norvaf, Walker & Col-borne, 1982). In the RSA, the distribution of R. zambeziensis has not been extensively surveyed but it has reportedly occurred on game species in the Kruger National Park (Horak, Potgieter, Walker, De Vas & Boomker, 1983). It is likely that this species is more widely distributed than present data indicate. Lawrence, Norval & Uilenberg (1983) demon-strated that R. zambeziensis was an experimental vector of T. p. lawrencei and that infection rates in salivary glands were high. They also suggested that in certain parts of Zimbabwe R. zambeziensis may be the only vector of T. p. lawrencei. In similar trials, a South African strain of R. zambeziensis has been successfully used in the transmission of T. p. lawrencei between cattle (Potgieter et al., 1988) and infection rates in ticks were also found to be high. Since infection rates in R. appendiculatus fed on cattle are generally low (Young & Purnell , 1973) , a comparison of the infection rates in the 2 tick species was conducted, using 3 T. p. lawrencei carrier cattle. This report presents the results of those trials. MATERIALS AND METHODS Three cattle (Bos taurus and Bos indicus crosses), reared under tick-free conditions at the Veterinary Received 6 March 1989- Editor 211 Research Institute, were infected with the Hluhluwe 3 isolate (De Vas, 1982) of T. p. lawrencei. Details of the infection of individual animals are given in Table 1. Ticks were reared and fed according to the methods of Neitz, Boughton & Walters , 1971. Each of the animals was infested with 300 nymphal R. appendiculatus (Rietvlei cross) (De Vos & Roos, 1981) on 1 ear and 300 R. zambeziensis (Killkenny) (Potgieter et al., 1988) on the other ear. Engorged nymphae were collected and allowed to moult in an acandarium at 25 oc and 85% relative humidity. At approximately 6 weeks post-moulting, 150 of the ensumg adults of each species from each feeding were fed on rabbits. At 4 days post-infestation the ticks were removed. Each tick was placed into a drop of RPMI 1640 medium1 and its dorsal exoskele-ton was cut away. The salivary glands of individual ticks were dissected out and teased onto glass slides. The glands were fixed in Carnoy's fixative , stained with methyl greenlpyronin (Irvin, Boarer, Dobbe-laere, Mahan, Masake & Ocama, 1981) and exam-ined with a light microscope for infective stages of T. p. lawrencei. RESULTS Despite the relatively small numbers of ticks recovered and examined (refer to Table 2), it was clear that significantly higher infection rates were obtained with R. zambeziensis ticks which fed as nymphae on Animals 9512-9 and 9418-5 (Table 2) . The mean number of infected acini per infected tick was also higher in R. zambeziensis than in R. appen-diculatus. No infective stages could be found in any of the ticks fed as nymphae on Animal 9666-0. This result was not surprising, since piroplasms could not be demonstrated microscopicalfy in blood smears of the animal examined during this period. Subinocula-tion of blood from Animal 9666-0 to a splenecto-mized ox did, however, result in a patent parasitae-mia in the latter animal, thus confirming the carrier status. DISCUSSION Chemotherapeutic treatment of cattle involved in Corridor disease outbreaks is not recommended, as this may result in the creation of carrier animals 1 Highveld Biological (Pty) Ltd, P.O. Box 488, Kelvin, 2054, RSA COMPARATIVE INFECTION RATES OF THEILERIA PAR VA LA WRENCEI IN SALIVARY GLANDS TABLE 1 History of the infection of experimental cattle with Theileria parva /awrencei prior to tick feeding Animal No. Method of infection 9512-9 (S) Transmission with adult R. appendiculatus 9660-0 Transmission with adult R . appendiculatus 9418-5 (S) Subinoculation of blood from a ~ i. rbc ~~-= post-infection = splenectomized = red blood cells = post-treatment = mtramuscularly carrier oxt 1 Clexon, Coopers Animal Health Ltd, England ' BW 720C, Coopers Animal Health Ltd. England Chemotherapy Outcome Parvaquone' 10 mg/kg IM on days 11, 13, 26, 28 and 30 p.i . Patent piroplasm parasitaemia 130 days p.t. 111000 rbc** Buparvaquone' 5 mglkg IM at Temporary disappearance of 24 months p.i . * (5 treat- patent parasitaemia. Piroplasms ments at days 0, 2. 4, 7 and reag~ared 150 days p.t. < 10) 111 0 rbc** Parvaquone' 10 mglkg IM on Schizonts intermittentlY observed days 11 and 13 p.i . up to 124 days p.i . 'No patent pnoplasm parasitaemia*** No treatment required Piroplasm rbc** parasitaemia 113000 * Attempt to sterilize piroplasm infection ** Parasitaemia during tria *** Carrier status confirmed after subinoculation of blood to a splenectomized ox t Details of infection given in Potgieter eta/. , 1988 TABLE 2 Comparative infection rates of Theileria parva lawrencei in the salivary glands of Rhipicephalus appendiculatus and Rhipicepha-lus zambeziensis fed on carrier cattle Tick species Animal No. R . appendicularus 9512- 9 9512-9* 9418-5 9666-0 R. zambeziensis 9512-9 9512-9* 9418-5 9666-0 * Second tick feeding 4 months after treatment with buparvaquone (Potgieter, Roos & De Vos, 1985). When such methods are used to establish experimental T. p. lawrencei infections in cattle, piroplasm parasitae-mias are usually very low. Infection rates in R. appendiculatus fed on these carriers are also low. The initial results presented here suggest that R. zambeziensis may be more efficient in picking up low level infections of at least certain isolates ofT. p. lawrencei than R. appendiculatus. Higher yields of tick-derived parasite material for serological and immunological studies have thus been obtained by feeding R. zambeziensis on experimental carrier animals, but only when using animals with micro-scopically detectable parasitaemias. The role that R. zambeziensis plays in the epide-miology of Corridor disease in the RSA can only be evaluated after further information on its distribu-tion and abundance is obtained. It has been noted in Zimbabwe that, in the absence of tick control, R. zambeziensis appears to maintain lower levels of abundance than R. appendiculatus (Norval et al., 1982). The primary concern is that a more efficient vector might enhance the transmission of T. p. /aw-rencei between cattle and increase the possibility of the parasite changing its behaviour to that of T. p. parva as reported by Barnett & Brocklesby (1966) and Young & Purnell (1973). This phenomenon has thus far not been observed in the RSA in field or laboratory observations despite the fact that R. zam-beziensis has probably existed in endemic areas for many years. Adult ticks fed on rabbits Mean No. of infected No. infected/ % infection acini per infected tick No. examined 212 0135 - -0/25 - -4/72 5 4 0160 - -31162 50 18,7 2/28 7 3 40/43 93 28 0157 - -ACKNOWLEDGEMENTS The authors wish to thank Dr F. T . Potgieter for his valuable advice and criticism during the prepara-tion of the manuscript and Mr B. R. Boersema for his assistance in the t1ck feedings. REFERENCES BARNETI. S. F. & BROCKLESBY. D . W., 1966. The passage of Theileria lawrencei (Kenya) through cattle . British Veterinary Joumal, 122,396-409. BIGALKE. R. D ., DEVOS. A. 1. & BARROWMAN. B. R., 1976. The control of some tick-borne diseases in South Africa. Bulle-tin Office International des Epizooties, 86, 89-100. DE Vos. A . 1., 1981. Rhipicephalus appendiculatus: Cause and vector of diseases in Africa. Joumal of the South African Veteri· nary Association, 52, 315- 322. DE Vos. A. 1., 1982. The identity of bovine Theileria spp. in South Africa. M. Med. Vet. thesis, University of Pretoria, Pre-toria, South Africa. DE Vos. A. 1. & Roos. 1. A .. 1981. Observations on the transmission of Theileria mutans in South Africa. Onderste· poort Joumal of Veterinary Research, 48, 1-Q. HORAK.!. G., POTGIETER. F. T ., WALKER. 1. B., DEVOS. V. & BOOMKER. 1., 1983. Ixodid tick burdens of various large rumi-nant species in South African nature reserves. Onderstepoort Joumal of Veterinary Research, 50,221- 228. IRVIN. A . D ., BOARER. C. D., DOBBELAERE. D. A . E . , MAHAN. S. M., MASAKE. R. & 0CAMA. 1. G. R ., 1981. Monitoring Theileria parva infection in adult Rhipicephalus appendiculatus ticks. Parasitology, 82, 137-147. LAWRENCE. 1. A ., NORVAL. R. A. I. & UILENBERG. G ., 1983. Rhipicephalus zambeziensis as a vector of bovine theileriae. Tropical Animal Health and Production, 15, 39-42. NEI1Z. W. 0., 1955. Corridor disease : A fatal form of bovine theileriosis encountered in Zululand. Bulletin of Epizootic Diseases of Africa, 3, 121-123. NEI1Z, W. 0., BOUGHTON, F. & WALTERS, H. S., 1971. Labora-tory investigations on the life cycle of the Karoo paralysis tick (Ixodes rubicundus Neumann, 1904). Onderstepoort Journal of Veterinary Research, 38, 215-224. NORVAL. R. A. I., WALKER. J. B. & COLBORNE, J., 1982. The ecology of Rhipicephalus zambeziensis and Rhipicephalus appendiculatus (Acarina, Ixodidae) with particular reference to Zimbabwe. Onderstepoort Journal of Veterinary Research, 49, 181-190. POTGIETER. F. T ., R OOS. J . A. & DEVOS. A. J., 1985. Implica-tions of chemotherapy of Theileria lawrencei infections (Corri-213 E . F . BLOUIN & W. H. STOLTSZ dor disease) in cattle (Abstract). South African Journal of Science, 81, 44. POTGIETER. F . T., STOLTSZ. W . H., BLOUIN. E. F. & ROOS. J. A., 1988. Corridor disease in South Africa: a review of the current status. Journal of the South African Veterinary Associa-tion, 59, 155-160. WALKER, J. B ., NORVAL, R. A. I. & CORWIN, M. D., 1981. Rhipicephalus zambeziensis sp. nov., a new tick from eastern and southern Africa, together with a redescription of Rhipice-phalus appendiculatus Neumann, 1901 (Acarina, Ixodidae). Onderstepoort Journal of Veterinary Research, 48, 87-104. YOUNG. A. S. & PURNELL, R. E. , 1973. Transmission of Theileria lawrencei (Serengeti) by the ixodid tick , Rhipicephalus appendi-culatus~ Tropical Animal Health and Production, 5, 146-152. 

Comparative infection rates of Theileria parva lawrencei in salivary glands of Rhipicephalus appendiculatus and Rhipicephalus zambeziensis

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Comparative infection rates of Theileria parva lawrencei in salivary glands of Rhipicephalus appendiculatus and Rhipicephalus zambeziensis

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