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

As part of the larger survey to map the geographical distribution of Babesia and Theileria parasites in the Southern African rhinoceros population, white rhinoceroses were sampled during routine immobilizations in the Kruger National Park. Polymerase Chain Reaction (PCR) and Reverse Line Blot (RLB) hybridization assays were used to screen for the presence of haemoprotozoa and complete blood counts were used to assess associated changes in clinical parameters. Of the 195 rhinoceroses sampled, 36.4% tested positive for the presence of Theileria bicornis, with no significant change in the haematological parameters measured. None of the rhinoceroses sampled tested positive for Babesia bicornis, the parasite linked to mortalities in black rhinoceroses. CopyrightDissertation (MSc)--University of Pretoria, 2009.Veterinary Tropical Diseasesunrestricte

Equal contributions of feline immunodeficiency virus and coinfections to morbidity in African lions

Feline immunodeficiency virus (FIV) is a pathogenic lentivirus related to human and simian immunodeficiency viruses that has been associated with AIDS-like pathologies in domestic and wild cats, as well as in hyenas. Despite known pathologies, progressive immunosuppression and ill health effects driven by these lentiviruses in association with other secondary infections remain understudied in free-ranging species. Here, the role of coinfections by gastrointestinal parasites and tick-borne hemoparasites for FIV disease progression was explored in 195 free-ranging African lions (Panthera leo) living in Kruger National Park (KNP), South Africa. Using statistical methodology, we evaluated the effects of FIV on a range of health indicators to explore how direct and indirect effects of FIV and associated coinfections align to determine lion health outcomes. Findings show direct negative effects of FIV on host immunity and nutritional status, and exacerbation of aggressive behaviors, conditions which may increase exposure/susceptibility to other secondary infections. When taken together, the contribution of coinfecting parasites to morbidity in lions is of similar magnitude as direct effects of FIV infection alone, suggesting that the particular coinfection assemblage may play a role in mediating disease progression within natural lion populations

Heavy metals in muscle tissue of healthy crocodiles from the Kruger National Park, South Africa

Mass mortality of Nile crocodile (Crocodylus niloticus) occurred in the Olifants River of the Kruger National Park (KNP) in 2008 from pansteatitis, a condition in which body fat becomes yellow and inflamed. Much research has been carried out, but the cause(s) of the outbreak in the KNP remains unknown (Ashton, 2010; Ferreira & Pienaar, 2011; Woodborne et al., 2012; Bouwman et al., 2014). Anthropogenic factors such as heavy metal pollution have been suggested as a potential cause (e.g. Bouwman et al., 2014). We found only three studies from Africa on heavy metals in wild crocodiles (Table 1). The aim of this study was to assess the concentrations of heavy metals and metalloids in wild and apparently healthy crocodiles in the KNP.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-20282017-12-31hb2017Paraclinical Science

The occurrence of Trichinella zimbabwensis in naturally infected wild crocodiles (Crocodylus niloticus) from the Kruger National Park, South Africa

Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in Zimbabwe, Mozambique, Ethiopia and South Africa, as well as monitor lizards (Varanus niloticus) in Zimbabwe. The reports on natural infections were mostly accidental rather than structured surveys and involved very few animals. Previous surveillance studies in South Africa reported a 38.5% prevalence of T. zimbabwensis among wild crocodiles tested from the Mpumalanga province and Kruger National Park (KNP). No studies have been conducted to date on the geographical distribution and occurrence of T. zimbabwensis in wild crocodiles and varans in countries in southern Africa. Recent outbreaks of pansteatitis in crocodile populations of the KNP, South Africa, provided an opportunity to conduct a more structured survey aimed at elucidating the occurrence and distribution of T. zimbabwensis in culled wild crocodile populations within the KNP. Results from this study showed that T. zimbabwensis occurred in 10 out of 12 culled crocodiles form the KNP. The results also showed that the natural distribution of T. zimbabwensis in crocodiles includes all the major river systems in the KNP. The predilection sites of larvae in muscles followed a different pattern in naturally infected crocodiles compared to observations in experimentally infected mammalian hosts.The authors wish to thank the rangers and scientific services staff of KNP responsible for the capture, euthanasia and transport of crocodiles. Our sincere thanks for the assistance received from the state veterinarian, Nelspruit, with the collection of samples; Dr Huchzermeyer for his assistance with necropsies; the invaluable insight into crocodilian anatomy and physiology provided by Drs Huchzermeyer, Webb, Manolis and Richardson; to Mrs T. La Grange, staff and students of the School for Biological and Conservation Sciences of the University of KwaZulu-Natal for their assistance in testing of samples; the International Trichinella Reference Centre for species confirmation; and Mr F. Koegelenberg for his assistance in the drafting of fig. 1.http://journals.cambridge.org/action/displayJournal?jid=JHLam2013mn201

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

A comparative assessment of adult mosquito trapping methods to estimate spatial patterns of abundance and community composition in southern Africa

Background Assessing adult mosquito populations is an important component of disease surveillance programs and ecosystem health assessments. Inference from adult trapping datasets involves comparing populations across space and time, but comparisons based on different trapping methods may be biased if traps have different efficiencies or sample different subsets of the mosquito community. Methods We compared four widely-used trapping methods for adult mosquito data collection in Kruger National Park (KNP), South Africa: Centers for Disease Control miniature light trap (CDC), Biogents Sentinel trap (BG), Biogents gravid Aedes trap (GAT) and a net trap. We quantified how trap choice and sampling effort influence inferences on the regional distribution of mosquito abundance, richness and community composition. Results The CDC and net traps together collected 96% (47% and 49% individually) of the 955 female mosquitoes sampled and 100% (85% and 78% individually) of the 40 species or species complexes identified. The CDC and net trap also identified similar regional patterns of community composition. However, inference on the regional patterns of abundance differed between these traps because mosquito abundance in the net trap was influenced by variation in weather conditions. The BG and GAT traps collected significantly fewer mosquitoes, limiting regional comparisons of abundance and community composition. Conclusions This study represents the first systematic assessment of trapping methods in natural savanna ecosystems in southern Africa. We recommend the CDC trap or the net trap for future monitoring and surveillance programs

Nematodes found in Nile crocodiles in the Kruger National Park, South Africa, with redescriptions of Multicaecum agile (Wedl, 1861) (Heterocheilidae) and Camallanus kaapstaadi Southwell & Kirshner, 1937 (Camallanidae)

Sixteen Nile crocodiles were collected in the Kruger National Park, South Africa and vicinity during 2010 and 2011. A total of 11 nematode species representing six families were recovered. Heterocheilids were the dominant group, comprising five species, with Dujardinascaris madagascariensis (Chabaud & Caballero, 1966) being the most prevalent (75%), followed by Ingwenascaris sprenti Junker & Mutafchiev, 2017 (68.8%), which was also the second most numerous nematode. While less prevalent (31.3%), Typhlophoros kwenae Junker & Mutafchiev, 2017 was the most abundant species. Micropleura huchzermeyeri Junker & Mutafchiev, 2017 (Micropleuridae) was collected from five crocodiles and Crocodylocapillaria sp. (Capillariidae) occurred in a single host. Three nematodes, Camallanus kaapstaadi Southwell & Kirshner, 1937, Spirocamallanus sp. (both Camallanidae) and Ascarophis sp. (Cystidicolidae), are considered accidental infections, likely ingested with the hosts’ prey. Our findings of D. dujardini (Travassos, 1920), D. madagascariensis and Multicaecum agile (Wedl, 1861) in South Africa constitute new geographical records. Crocodylocapillaria sp. represents a new host and geographical record, while T. kwenae, I. sprenti and M. huchzermeyeri have been described as new species during the course of this survey. Multicaecum agile is here redescribed based on light and scanning electron microscopy. Previously undescribed morphological characters of C. kaapstaadi, typically a parasite of Xenopus spp. (Amphibia: Pipidae), but here found in two Nile crocodiles, are also presented.http://link.springer.com/journal/112302020-06-01hj2019Paraclinical SciencesVeterinary Tropical Disease

Chlorinated, brominated, and fluorinated organic pollutants in Nile crocodile eggs from the Kruger National Park, South Africa

Repeated annual episodes of Nile crocodile deaths in two isolated areas of the Kruger National Park prompted the investigation of possible organohalogen pollutant involvement.Crocodile eggs were collected close to one of the mortality sites (Gorge) as well as from a crocodile farm (CF) as reference. ΣDDT was significantly higher in Gorge (450ng/gwm) than in CF eggs (85ng/gwetmass). Percentage DDT of ΣDDT was significantly higher in CF (14 percent)than in Gorge eggs (5 percent). Mean ΣDDT was almost 70 times higher than mean ΣPCB in Gorge eggs. HCB, β-HCH, mirex, brominated flame retardants (BFRs), and perfluorinated compounds (PFCs) occurred at lower concentrations. We believe that the BFR and PFCs data represent the first published results for any crocodile egg.Thickening of the outer egg shell layer of Gorge eggs was significantly associated with higher concentrations of ΣDDT. Concentrations of ΣDDT and other pollutants were in the same range as eggs from elsewhere,where there were no mortalities. Concentrations of ΣDDT in eggs from healthy Australian crocodiles were of the same orders of magnitude as the current study, making it highly unlikely that the concentrations of pollutants measured in the present study would have caused or substantially contributed towards the mortalities observed.Concerns about reproduction and behaviour remain.As large predators, crocodilians are at the apex of the freshwater aquatic food web.More research is needed to guide measures to manage African freshwater systems so that it will also sustainably accommodate these large, long-lived animals.Ruppert Foundation and Billy duToit.http://www.elsevier.com/locate/ecoenvhb201

Comparison of the lipid properties of healthy and pansteatitis-affected African sharptooth catfish, Clarias gariepinus (Burchell), and the role of diet in pansteatitis outbreaks in the Olifants River in the Kruger National Park, South Africa

Pansteatitis has been identified in wild populations of sharptooth catfish, Clarias gariepinus (Burchell), and Nile crocodiles, Crocodylus niloticus Laurenti, inhabiting the same waters in the Olifants River Gorge in the Kruger National Park, South Africa. Mesenteric and pectoral fat tissue was investigated microscopically and by fatty acid analysis in healthy and pansteatitis-affected catfish from both captive and wild populations. Variation in fatty acid composition between pectoral and mesenteric fat was noted. Composition of mesenteric fat differed between fish from various localities as a result of differences in diet. Pansteatitis in the captive population, resulting from ingestion of high amounts of dietary oxidized fat, reflected higher levels of unsaturated fatty acids within the mesenteric fat. Mesenteric fat of pansteatitisaffected wild catfish was characterized by an increase in moisture content, a decrease in fat content and a decrease in stearic and linoleic acids. The n-3 to n-6 fatty acid ratio of mesenteric fat was higher in pansteatitis-affected wild catfish than in healthy catfish from the same locality, reflecting higher polyunsaturated fat intake by pansteatitisaffected fish. The possible role of alien, invasive,phytoplankton-feeding silver carp, Hypophthalmichthys molitrix (Valenciennes), in the aetiology of pansteatitis in both catfish and crocodiles in the Olifants Gorge is discussed.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2761hb2014mn201

Steatitis in wild sharptooth catfish, Clarias gariepinus (Burchell), in the Olifants and Lower Letaba rivers in the Kruger National Park, South Africa

Large numbers of adult Nile crocodiles, Crocodylus niloticus (Laurenti), died from pansteatitis during autumn and winter 2008 in the lower Letaba and Olifants River gorge in the Kruger National Park, South Africa. Consequently, the health status of fish from these waters was investigated. The study presents the pathological findings in fish inhabiting these rivers within the boundaries of the Park. Changes typical of steatitis were diagnosed in many of the larger specimens of sharptooth catfish, Clarias gariepinus (Burchell), caught within the Olifants River gorge. These fish carried large amounts of mesenteric fat with characteristic small brown granulomata within the adipose tissue. Necrosis and inflammation of the adipose tissues, with characteristic ceroid accumulation within the resultant granulomata and the associated aggregation of ceroid-containing macrophages, were demonstrated histologically and were typical of steatitis. Other changes included mild thickening and pallor of the gill tissues and swollen, orange, fatty livers. Focal hepatic lipidosis was demonstrated histologically, and special stains revealed storage of large amounts of iron in the livers. Blood smears revealed chromatin clumping in erythrocyte nuclei and nuclear and cell membrane irregularities. This is the first record of steatitis in wild-caught C. gariepinus.The Water Research Commission, South Africa, Consultancy K8/948.http://www.wiley.com/bw/journal.asp?ref=0140-7775mn201