A case of transplacental transmission of Theileria equi in a foal in Trinidad

Georges, Karla; Ezeokoli, C. D.; Sparagano, Olivier; Pargass, Indira; Campbell, Michael H.; d’Abadie, Roger; Yabsley, Michael J.

doi:10.1016/j.vetpar.2010.10.019

Cited by 32 publications

(26 citation statements)

References 12 publications

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“…Indeed, transplacental transmission has been detected for a number of other Theileria spp. including T. equi [22] T. lestoquardi [24] and T. annulata [25] using molecular methods.…”

Section: Discussionmentioning

confidence: 99%

“…Prior studies indicate that transplacental transmission of other Theileria spp. can occur in their respective hosts including T. equi in horses [22, 23], T. lestoquardi in sheep [24] and rarely, T. annulata in cattle [25]. Transplacental transmission of T. orientalis was implicated in the infection and abortion of 100% of calves where the pregnant dams had been experimentally infected via ticks [26], while microscopic studies conducted in Japan suggested that transplacental transmission was occurring in field-affected cattle, but only at a low rate [27].…”

Section: Introductionmentioning

confidence: 99%

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Transplacental transmission of Theileria orientalis occurs at a low rate in field-affected cattle: infection in utero does not appear to be a major cause of abortion

Swilks

Fell

Hammer³

et al. 2017

Parasites Vectors

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BackgroundBovine theileriosis, caused by the haemoprotozoan Theileria orientalis, is an emerging disease in East Asia and Australasia. Previous studies have demonstrated transplacental transmission of various Theileria spp. but molecular confirmation of transplacental transmission of T. orientalis has never been confirmed in the field. In this study, cow-calf (< 48 h old) pairs were sampled across 3 herds; opportunistic samples from aborted foetuses or stillborn calves were also examined. Molecular (multiplex qPCR) and serological (ELISA) methods were used to determine infection prevalence and the presence of anti-Theileria antibodies in each herd. In addition, pregnant heifers and foetal calves were sampled at abattoir and tested for the presence of T. orientalis by qPCR.ResultsThe qPCR results indicated that, even though there was a high prevalence of T. orientalis infection in cows, the rate of transplacental transmission to their calves was low, with only one newborn calf from one herd and one foetus from the abattoir testing positive for T. orientalis DNA. Five aborted foetuses and stillborn calves, 3 of which were derived from a herd experiencing a high number of clinical theileriosis cases at the time of sampling, all tested negative for T. orientalis by qPCR. This suggests that in utero infection of calves with T. orientalis may not be a major driver of abortions during theileriosis outbreaks. Temporal monitoring of 20 calves born to T. orientalis-positive mothers indicated that T. orientalis was detectable in most calves between 10 and 27 days post-partum, consistent with prior field studies on adult cattle introduced to Theileria-affected herds. There was a positive correlation between the ELISA ratio of newborn calves and their mothers within 48 h of calving; however, maternal antibodies were only detectable in some calves and only for 4–4.5 weeks post-partum. All calves displayed high parasite loads peaking at 4–8 weeks post-partum, with only some calves subsequently mounting a detectable adaptive antibody response.ConclusionsThese findings indicate transplacental transmission of T. orientalis appears to play only a minor role in persistence of T. orientalis infection in the field; however calves are highly susceptible to developing high level T. orientalis infections at 4–8 weeks of age regardless of whether maternal antibodies are present post-partum.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2166-9) contains supplementary material, which is available to authorized users.

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“…Indeed, transplacental transmission has been detected for a number of other Theileria spp. including T. equi [22] T. lestoquardi [24] and T. annulata [25] using molecular methods.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Transplacental transmission of Theileria orientalis occurs at a low rate in field-affected cattle: infection in utero does not appear to be a major cause of abortion

Swilks

Fell

Hammer³

et al. 2017

Parasites Vectors

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“…Recrudescence of marked T. equi parasitemia was assumed. Neonatal foals infected in utero with T. equi can present with acute, severe signs . These foals can exhibit clinical signs at birth or can become ill at 2–3 days of age.…”

Section: Clinical Diseasementioning

confidence: 99%

“…56 Placental transmission from infected carrier mares to their fetuses has been documented. 15,[57][58][59] This transmission can result in abortion (most commonly in late gestation), stillbirth, or neonatal infection and can occur across placentas that are histologically normal. The prevalence of this type of transmission is unknown.…”

Section: Pathogenesis (Transmission/life Cycle Ofmentioning

confidence: 99%

Review of Equine Piroplasmosis

Wise

Kappmeyer

Mealey

et al. 2013

Veterinary Internal Medicne

210

243

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Equine piroplasmosis is caused by one of 2 erythrocytic parasites Babesia caballi or Theileria equi. Although the genus of the latter remains controversial, the most recent designation, Theileria, is utilized in this review. Shared pathogenesis includes tick-borne transmission and erythrolysis leading to anemia as the primary clinical outcome. Although both parasites are able to persist indefinitely in their equid hosts, thus far, only B. caballi transmits across tick generations. Pathogenesis further diverges after transmission to equids in that B. caballi immediately infects erythrocytes, whereas T. equi infects peripheral blood mononuclear cells. The recent re-emergence of T. equi in the United States has increased awareness of these tick-borne pathogens, especially in terms of diagnosis and control. This review focuses in part on factors leading to the re-emergence of infection and disease of these globally important pathogens.

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“…Some of the tick vectors that have been implicated in transmission belong to the genera Dermacentor, Rhipicephalus, Amblyomma and Hyalomma (de Waal, 1992;Melhorn and Schein, 1998;Rampersad et al, 2003;Wise et al, 2013). Other viable options for transmission include iatrogenic means (Scoles et al, 2011) and transplacental transmission, reported in T. equi infections (Philips and Otter, 2004;Georges et al, 2011;Chhabra et al, 2012). Clinical presentation of overt disease is commonly associated with T. equi infections.…”

Section: Introductionmentioning

confidence: 99%

A field survey for the seroprevalence of Theileria equi and Babesia caballi in donkeys from Nuu Division, Kenya

Oduori

Onyango²,

Kimari³

et al. 2015

Ticks and Tick-borne Diseases

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Equine piroplasmosis is one of the most significant tick-borne disease of equids. The prevalence of this disease in donkeys of semi-arid Kenya remains largely unexplored. The primary objective of this study was to demonstrate the extent to which donkeys in Nuu division, Kenya have been exposed to the haemoprotozoans Babesia caballi and Theileria equi, the causative agents of equine piroplasmosis. The study also assessed the effect of age and sex on seroprevalence. A stratified sampling approach was used and three hundred and fourteen donkeys were sampled across nine sub-locations in Nuu division, Mwingi district. Serodiagnosis was via competitive inhibition enzyme linked immunosorbent assays (cELISA). The seroprevalence of T. equi was 81.2% (95% CI: 76.4-85.4). There was no significant difference in sub-location seropositivity, gender seropositivity or age related seropositivity. Antibodies against B. caballi were not detected (95% CI: 0-1.2). Findings from this study suggest that T. equi infection is endemic in Nuu division, Mwingi where it exists in a state of endemic stability. Existence of the infection should be communicated to animal health practitioners and donkey owning communities in the area.

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A case of transplacental transmission of Theileria equi in a foal in Trinidad

Cited by 32 publications

References 12 publications

Transplacental transmission of Theileria orientalis occurs at a low rate in field-affected cattle: infection in utero does not appear to be a major cause of abortion

Transplacental transmission of Theileria orientalis occurs at a low rate in field-affected cattle: infection in utero does not appear to be a major cause of abortion

Review of Equine Piroplasmosis

A field survey for the seroprevalence of Theileria equi and Babesia caballi in donkeys from Nuu Division, Kenya

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