Immunisation against Theileria parva in eastern Zambia: influence of maternal antibodies and demonstration of the carrier status

Marcotty, Tanguy; Brandt, J.; Billiouw, M.; Chaka, G.; Losson, Bertrand; Berkvens, Dirk

doi:10.1016/s0304-4017(02)00314-x

Cited by 13 publications

(11 citation statements)

References 17 publications

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“…Moreover, we detected T. parva DNA in ticks (nymphs and adults) collected in the field from an area where most of the animals tested had no piroplasms on blood smears, though positive by PCR, which was consistent with the data obtained under experimental conditions. We observed that nymphal ticks experimentally fed on calf with very low parasitaemia (only detectable by PCR) acquired T. parva infection at a higher rate than previously observed (Marcotty et al, 2002). These findings high-light the inadequacy associated with microscopy-based T. parva screening compared to PCR.…”

Section: Discussionmentioning

confidence: 43%

“…The T. parva infection rate in adult R. appendiculatus ticks feeding on low parasitaemic, T. parva carrier cattle has been observed to be lower than in ticks feeding on calves with acute, high parasitaemic infections (Marcotty et al, 2002;Ogden et al, 2003). These findings suggest that the level of parasitemia in the infected animals contribute to the efficiency of acquisition of T. parva infection by ticks.…”

Section: Discussionmentioning

confidence: 92%

“…It is likely that the resulting carrier cattle after the immunization could act as the main reservoirs of T. parva (Marcotty et al, 2002;Kariuki et al, 1995;Mutugi et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

“…Theileria parva (T. parva) is haemoprotozoan parasite transmitted by the tick Rhipicephalus appendiculatus (R. appendiculatus), causing East Coast fever (ECF) of cattle in several African countries, including Zambia (Billiouw et al, 2002;Geysen et al, 1999;Minjauw et al, 1997). The disease causes high mortality and morbidity, and is considered to be an important constraint to the improvement of the livestock industry in Africa.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, transmission rate of T. parva to ticks was lower when ticks fed on carriers with low-level parasitaemia that had been infected by the simultaneous inoculation of a lethal dose of T. parva stabilates (cryopreserved sporozoites) and injection of a dose of long-acting oxytetracycline (Marcotty et al, 2002). In addition, Young et al (1996) reported that several factors could influence the ability of the vector tick to acquire T.…”

Section: Introductionmentioning

confidence: 99%

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Acquisition and transmission of Theileria parva by vector tick, Rhipicephalus appendiculatus

et al. 2006

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In order to investigate the transmission dynamics of Theileria parva (T. parva) by the brown ear tick, Rhipicephalus appendiculatus (R. appendiculatus), under experimental conditions, detection of T. parva in ticks and cattle was performed by a quantitative real-time PCR assay. A calf inoculated with a T. parva mixture became PCR-positive for T. parva infection on day 8 post-inoculation, and subsequently, nymphal ticks were introduced and maintained to feed on the infected calf for 6 days. Engorged nymphs were collected daily and allowed to molt into adults, and overall, 70.8% (121/171) of the adult ticks acquired the T. parva infection. Furthermore, the T. parva infection rate in ticks under field conditions was monitored by real-time PCR in R. appendiculatus ticks collected from a traditionally-managed pastoral land of Zambia, on which Sanga breed cattle are traditionally reared and the area has endemic East Coast fever (ECF).A total of 70 cattle were randomly selected in the same area and 67 (95.7%) were found to be serologically positive for R. appendiculatus tick antigen (RIM36). Twenty-nine (43.3%) of the 67 serologically positive cattle were real-time PCR-positive for T. parva, although no piroplasms could be detected in the blood smears. Unexpectedly, out of 614 R. appendiculatus nymphal and adult ticks collected by flagging vegetation, 4.1% were positive for T. parva DNA. However, since the rate of transmission of T. parva from infected cattle to ticks and vice versa and the serological evidence of exposure to R. appendiculatus ticks in naturally-exposed cattle were relatively high, it would be wise in such a case to consider vector control as well as vaccination against ECF as control measures.3

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Section: Discussionmentioning

confidence: 43%

Section: Discussionmentioning

confidence: 92%

“…It is likely that the resulting carrier cattle after the immunization could act as the main reservoirs of T. parva (Marcotty et al, 2002;Kariuki et al, 1995;Mutugi et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations