Occurrence and molecular prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African wildlife: A systematic review and meta-analysis.

INTRODUCTION: Tick-borne pathogens (TBPs) constitute an emerging threat to public and animal health especially in the African continent, where land-use change, and wildlife loss are creating new opportunities for disease transmission. A review of TBPs with a focus on ticks determined the epidemiology of Rhipicephalus ticks in heartwater and the affinity of each Rickettsia species for different tick genera. We conducted a systematic review and meta-analysis to collect, map and estimate the molecular prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African wildlife. MATERIALS AND METHODS: Relevant scientific articles were retrieved from five databases: PubMed, ScienceDirect, Scopus, Ovid and OAIster. Publications were selected according to pre-determined exclusion criteria and evaluated for risk of bias using the appraisal tool for cross-sectional studies (AXIS). We conducted an initial descriptive analysis followed by a meta-analysis to estimate the molecular prevalence of each pathogen. Subgroup analysis and meta-regression models were employed to unravel associations with disease determinants. Finally, the quality of evidence of every estimate was finally assessed. RESULTS: Out of 577 retrieved papers, a total of 41 papers were included in the qualitative analysis and 27 in the meta-analysis. We retrieved 21 Anaplasmataceae species, six Rickettsiaceae species and Coxiella burnetii. Meta-analysis was performed for a total of 11 target pathogens. Anaplasma marginale, Ehrlichia ruminantium and Anaplasma centrale were the most prevalent in African bovids (13.9 %, CI: 0-52.4 %; 20.9 %, CI: 4.1-46.2 %; 13.9 %, CI: 0-68.7 %, respectively). Estimated TBPs prevalences were further stratified per animal order, family, species and sampling country. DISCUSSION: We discussed the presence of a sylvatic cycle for A. marginale and E. ruminantium in wild African bovids, the need to investigate A. phagocytophilum in African rodents and non-human primates as well as E. canis in the tissues of wild carnivores, and a lack of data and characterization of Rickettsia species and C. burnetii. CONCLUSION: Given the lack of epidemiological data on wildlife diseases, the current work can serve as a starting point for future epidemiological and/or experimental studies.

Occurrence of blood-borne tick-transmitted parasites in common tsessebe (Damaliscus lunatus) antelope in Northern Cape Province, South Africa.

Blood samples were collected from 71 tsessebes relocated from the deproclaimed Vaalbos National Park to Mokala National Park, South Africa. DNA was extracted from the samples and the reverse line blot (RLB) hybridization technique was used to detect and identify any haemoparasites present. Six samples hybridized to the Theileria/Babesia genus-specific probe, the Theileria genus-specific probe and the Theileria sp. (sable) probe, while 3/6 also hybridized to the Theileria separata probe. Full-length 18S rRNA genes of the Theileria spp. detected were amplified, cloned and sequenced. Two novel Theileria 18S rRNA gene sequences were identified which are phylogenetically very closely related to both Theileria sp. (sable) and T. separata. All animals appeared to be in good health. It seems likely, therefore, that these Theileria spp. do not cause disease under normal circumstances. Nevertheless, care should be taken when translocating wild animals, as introduction of novel piroplasm parasites into new areas could cause clinical disease and losses in naïve wildlife and domestic animals, and new parasite species could become established in areas in which they previously did not occur.

Putative clinical piroplasmosis in a Burchell's zebra (Equus quagga burchelli).

A 10-year-old tame zebra gelding was presented after suffering from lethargy, nervousness, reported anaemia and icterus as well as a decreased appetite. These symptoms were seen over some months, with changing severity. The animal was immobilised, treated, and blood specimens were submitted for haematology and biochemistry. This report describes molecular characterisation of Theileria equi recovered from this animal, as well as the clinical findings, treatment and historical relevance of piroplasmosis in zebra in southern Africa.

Molecular characterisation of Babesia gibsoni infection from a pit-bull terrier pup recently imported into South Africa.

Canine babesiosis caused by Babesia gibsoni was diagnosed in a 3-month-old Pit-bull pup during a routine clinical examination. Diagnosis was confirmed by way of smear examination, PCR, Reverse Line Blot (RLB) and sequence analysis which showed 100% homology with B. gibsoni (Japan AB118032) and Babesia sp. (Oklahoma) (AF205636). Haematology showed moderate anaemia and severe thrombocytopenia. Treatment was initiated with diminazene aceturate (Berenil RTU) followed by 2 doses of imidocarb diproprionate (Forray-65) 3 days and 14 days later, respectively. Babesia gibsoni DNA was still detectable 2 weeks post-treatment on the PCR/RLB test. A 10-day course of combination drug therapy using atovaquone and azithromycin was initiated. Blood samples taken on Day 1 and Day 40 after completion of treatment were negative for B. gibsoni DNA on PCR/RLB test. The implications of a possible introduction of B. gibsoni into South Africa are discussed.