PARSA awards to DVTD staff members

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Don't let sleeping dogs lie: unravelling the identity and taxonomy of Babesia canis, Babesia rossi and Babesia vogeli

For most of the 20th century the causative agent of canine babesiosis, wherever it occurred in the world, was commonly referred to as Babesia canis. Early research, from the 1890s to the 1930s, had shown that there were three distinctly different vector-specific parasite entities occurring in specific geographical regions, that host response to infection ranged from subclinical to acute, and that immunity to one stock of the parasite did not necessarily protect against infection with other stocks. This substantial body of knowledge was overlooked or ignored for 50 years. In this review the first records and descriptions of the disease in four geographical regions were traced: sub-Saharan Africa, Europe, North Africa and Asia. Research leading to identification of the specific tick vector species involved is documented. Evidence is given of the growing realisation that there were substantial biological differences between stocks originating from different geographical regions. Etymological provenance for Babesia vogeli is proposed.http://www.parasitesandvectors.comhj2020Veterinary Tropical Disease

A century of teaching veterinary parasitology in South Africa – Lessons learnt

Finding a healthy balance between classical parasitology and clinical veterinary medicine remains a challenge. Veterinary Parasitology, of vital interest in sub-Saharan Africa, has always featured prominently at the Faculty of Veterinary Science, University of Pretoria (founded in 1920). The faculty was initially an integral part of the Onderstepoort Veterinary Institute (OVI), and parasitology was taught by specialist researchers from OVI – a cult of total coverage prevailed. Presenting three separate courses – ectoparasitology, helminthology and protozoology – continued for many decades. From 1949 to 1973 an attendance course in veterinary parasitology was presented in the final academic year. This was revived in 1995, with a “refresher” in parasitology for final-year students (during their clinic rotation), including diagnostic parasite identification and problem-solving group discussions (prepared and led by students). Student contact time (including practical classes and assessments), initially 80 h/discipline/year, was gradually reduced. A species-based approach (introduced in 1998) had a major impact - an introductory course in general parasitology was followed by fragmented lectures in the subsequent 2 years on key parasitic diseases in the species-based subjects. In 2013 the curriculum reverted to being discipline-based, i.e. all aspects of parasitology and parasitic diseases covered during one academic year. The 3 sub-disciplines are included in a 2-semester course, with a total contact time of 100 h, which barely meets the minimum recommended by the WAAVP. Various lessons learnt are discussed.http://www.elsevier.com/locate/vetpar2019-03-15hj2018Veterinary Tropical Disease

Descriptions of incisors of known-age Cape mountain zebras, Equus zebra zebra, from the Mountain Zebra National Park

Twelve sets of incisors of Cape mountain zebras, 9 of which were from known-age individuals ranging in age from 11 months to 19 years, from the Mountain Zebra National Park, are described and depicted to illustrate not only the eruption and replacement sequence, but also the changes with increasing age in the configuration of the occlusal surfaces and of the infundibulum. Infundibula persist in maxillary incisors longer than in mandibular incisors. Shallow infundibula were still present in the maxillary incisors of a 19-year-o1d mare at least 4 years later than in plains zebras, E. burchelli, from the Kruger National Park. The physiological life span of Cape mountain zebras appears to be at least 26 years.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

Babesia species of domestic cats : molecular characterization has opened Pandora's box

This is the first comprehensive review of the literature pertaining to Babesia species reported from domestic cats. Description of the four species (Babesia felis, Babesia cati, Babesia herpailuri, and Babesia pantherae) named based on morphology and/or host specificity is documented. Feline babesiosis is of major veterinary concern only in South Africa. Reports of the rare occurrence of feline babesiosis cases in Europe (France, Germany, Poland, and Spain) and Asia (Israel, India, and Pakistan) are documented. Molecular characterization has revealed that cats can harbor a variety of Babesia species. The previous practice of referring to all piroplasms, especially small ones, seen on feline blood smears as B. felis is therefore no longer tenable. The near-full-length 18S rRNA gene sequences entered into GenBank in 2001 (accession no. AF244912) are designated as definitive for B. felis sensu stricto. All published literature relating to molecular characterization of feline Babesia species that could be traced was critically assessed. Four Babesia species are now known to be involved in causing feline babesiosis in South Africa: the closely related B. felis s.s. and Babesia leo (clade I), Babesia lengau (clade II), and Babesia species cat Western Cape (clade VI, Babesia s.s.). Clade VI also includes Babesia canis presentii and Babesia hongkongensis reported from cats in Asia. Six other Babesia species have been reported from domestic cats: the dog-associated B. canis s.s., Babesia gibsoni, and B. vogeli, as well as Babesia lohae, Babesia microti, and Babesia vulpes. Phylogenetic relationships of all named species were assessed and are presented as trees. The relatively high prevalence of B. vogeli in clinically healthy cats (16%in Brazil, 13%on St Kitts, and 8.1%in Portugal) suggests that immunocompetent cats can harbor the infection with no discernible untoward effects. Reports of occurrence of B. felis and other Babesia species in domestic cats should be accepted only if they are supported by credible molecular provenance.https://www.frontiersin.org/journals/veterinary-science#am2020Veterinary Tropical Disease

Geographic range of vector-borne infections and their vectors : the role of African wildlife

The role of African wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. In Africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. The indigenous African pathogens with transboundary potential, such as Rift Valley fever virus, African horse sickness virus, bluetongue virus, lumpy skin disease virus, African swine fever virus, and blood-borne parasites have received the most attention. There is no evidence for persistent vector-borne viral infections in African wildlife. For some viral infections, wildlife may act as a reservoir through the inter-epidemic circulation of viruses with mild or subclinical manifestations. Wildlife may also act as introductory or transporting hosts when moved to new regions, e.g. for lumpy skin disease virus, Rift Valley fever virus and West Nile virus. Wildlife may also act as amplifying hosts when exposed to viruses in the early part of the warm season when vectors are active, with spillover to domestic animals later in the season, e.g. with bluetongue and African horse sickness. Some tick species found on domestic animals are more abundant on wildlife hosts; some depend on wildlife hosts to complete their life cycle. Since the endemic stability of a disease depends on a sufficiently large tick population to ensure that domestic animals become infected at an early age, the presence of wildlife hosts that augment tick numbers may be beneficial. Many wild ungulate species are reservoirs of Anaplasma spp., while the role of wildlife in the epidemiology of heartwater (Ehrlichia ruminantium infection) has not been elucidated. Wild ungulates are not usually reservoirs of piroplasms that affect livestock; however, there are two exceptions: zebra, which are reservoirs of Babesia caballi and Theileria equi, and buffalo, which are reservoirs of Theileria parva. The latter causes Corridor disease when transmitted from buffalo to cattle, but this appears to be a self-limiting condition, at least in southern Africa. Wild animals are important reservoirs of tsetse-transmitted Trypanosoma spp. infection. The distribution and abundance of some tsetse species, e.g. Glossina morsitans and G. pallidipes, are closely related to the occurrence of their preferred wildlife hosts.http://www.oie.int/en/publications-and-documentation/scientific-and-technical-review-free-accessam201

Description of 3 new species of Eimeria (Apicomplexa: Eimeriidae) from springbok (Antidorcas marsupialis) in Namibia

We document morphological descriptions for 3 newly described Eimeria spp. that infect springbok (Antidorcas marsupialis). Eimeria antidorcasi n. sp. oocysts are ovoid, with average size (n 5 346) 26.2 6 18.8 (19.2–33.5 6 13.1– 26.5) mm, a length/width ratio of 1.4 (1.2–2.0), a micropyle, and a polar granule sometimes present. Sporocysts are ovoid (n 5 336), 11.3 6 7.3 (6.0–14.6 6 5.2–9.8) mm, with a length/width ratio of 1.5 (1.1–2.0), a Stieda body, a prominent, ovoid sporocyst residuum, and one refractile body per sporozoite. Eimeria versfeldi n. sp. oocysts are ellipsoid (n 5 136), 38.9 6 26.6 (27.8–48.2 6 21.2–31.0) mm, with a length/width ratio of 1.5 (1.2–2.0), a micropyle cap with submicropylar material, and 2–4 polar granules. Sporocysts are elongate-ovoid (n 5 132), 18.3 6 9.2 (13.2–22.8 6 6.8– 11.2) mm, with a length/width ratio of 2.0 (1.3–2.5), a Stieda body, a small sporocyst residuum present, and an evident nucleus and two refractile bodies per sporozoite. Eimeria gasawayi n. sp. oocysts are subspheroid (n 5 87), 14.8 6 13.6 (11.5–20.0 6 11.1–18.2) mm, with a length/width ratio of 1.1 (1.0–1.2), and no micropyle. Sporocysts are elongate-ovoid (n 5 82), 9.0 6 4.6 (5.5–12.5 6 3.6–6.4) mm, with a length/width ratio of 2.0 (1.3–2.4), a small Stieda body, and an irregularly shaped sporocyst residuum present. These are the first Eimeria spp. described from springbok.This research was conducted as part of a Ph.D. dissertation at the University of California, Berkeley.A Fulbright fellowship, Andrew and Mary Thompson Rocca Scholarships, the Professor Earl Storie Memorial Scholarship, the G. Fitzgarrald Martin Scholarship, and a grant from the Department of Environmental Science, Policy and Management to W.C.T., and National Institutes of Health grant GM83863 to W.M.G.http://www.bioone.org/loi/copaam2016Veterinary Tropical Disease

Ticks (Acari : Ixodidae) infesting cattle and African buffaloes in the Tsavo conservation area, Kenya

Several ixodid tick species are shared between domestic cattle and African buffaloes (Syncerus caffer). So too, are a number of tick-borne diseases. The aim of the study was to compare the species composition of ticks that infest cattle and buffaloes utilising the same habitat within the Tsavo Conservation Area, Kenya. To this end, 25 cattle and 62 buffaloes were each opportunistically sampled for ticks on a single occasion in February 2010. Eight species, namely Amblyomma gemma, Amblyomma lepidum, Hyalomma albiparmatum, Hyalomma rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus pravus and Rhipicephalus pulchellus infested both cattle and buffaloes. Three species, Rhipicephalus (Boophilus) sp., Rhipicephalus kochi, and Rhipicephalus muehlensi were collected only from cattle, and three species, Hyalomma impeltatum, Rhipicephalus humeralis and Rhipicephalus praetextatus were present only on buffaloes. The attachment sites of the various tick species were also recorded. New locality records for H. impeltatum and H. truncatum and the first confirmed locality record for Rhipicephalus praetextatus sensu stricto in Kenya were documented.Grants from the National Research Foundation to BLP and IGHhttp://www.ojvr.orgam2013ab201

Piroplasm parasites of white rhinoceroses (Ceratotherium simum) in the Kruger National Park, and their relation to anaemia

As part of a larger survey to map the geographical distribution of Babesia and Theileria parasites in the southern African rhinoceros population, white rhinoceroses were sampled during routine immobilisations in the Kruger National Park. Polymerase chain reaction (PCR) and reverse line blot (RLB) hybridisation assays were used to screen for the presence of piroplasms and complete blood counts were used to assess associated changes in clinical parameters. Of the 195 rhinoceroses sampled, 71 (36.4 %) tested positive for the presence of Theileria bicornis, with no significant change in the haematological parameters measured, while 18 (9.2 %) tested positive for Theileria equi. None of the rhinoceroses sampled tested positive for Babesia bicornis, a parasite associated with mortalities in black rhinoceroses.Grant: National Research Foundation, Funding: Wildlife Group of the South African Veterinary Associationhttp://www.journals.co.za/ej/ejour_savet.htmlab201

Occurrence of Babesia felis and Babesia leo in various wild felid species and domestic cats in Southern Africa, based on reverse line blot analysis

Reverse line blot (RLB) is a hybridization assay that can be used to detect various blood parasites and differentiate between them. Results, using the RLB, showed that Babesia felis and Babesia leo occurred as single or mixed infections in various felid species, but most frequently in domestic cats and lions, respectively. Prevalence of infection in free-ranging cheetahs in Namibia was low (7, 5%), whereas 50% of free-ranging lions in South Africa and Swaziland were infected. A large number (52, 9%) of samples tested positive only for Babesia, neither B. felis nor B. leo. This could be an indication of at least one further, as yet undescribed, Babesia species in felids.Mrs. Gerty Pretorius (Clinical Pathology Section, Department of Companion Animal Clinical Studies), and Prof. Moritz van Vuuren (Department of Veterinary Tropical Diseases) submitted blood specimens. This report emanates from project 36-5-613 which was approved by the Research Committee of the Faculty of Veterinary Science and the Animal Use and Care Committee of the University of Pretoria