15 research outputs found
Babesia lengau associated with cerebral and haemolytic babesiosis in two domestic cats
Background: Although reported sporadically from various countries, feline babesiosis appears to be a significant
clinical entity only in South Africa, where Babesia felis is usually incriminated as the causative agent. Babesia lengau,
recently described from asymptomatic cheetahs, has now possibly been incriminated as the causative agent in two
severe clinical cases in domestic cats.
Findings: Both cats were euthanised in extremis. While typical feline babesiosis in South Africa is an afebrile
disease with a chronic manifestation, there was acute onset of severe clinical signs in both cats and their body
temperatures were above the normal range when they were presented for treatment. Haemolytic anaemia was
confirmed in one case. To our knowledge, this is the first report of cerebral babesiosis in cats.
On reverse line blot 18S rDNA PCR products obtained from both cats showed positive hybridization profiles with
the B. lengau species-specific probe. The two partial parasite 18S rRNA gene sequences obtained, showed high
sequence similarity (99.9%) to B. lengau. In a representative tree constructed by the neighbor-joining method
using the two-parameter model of Kimura the two obtained partial 18S rDNA sequences and that of B. lengau
formed a monophyletic group with B. conradae and sequences previously isolated from humans and wildlife in
the western USA.
Conclusion: All clinical cases of feline babesiosis in South Africa are not necessarily caused by B. felis. Other
piroplasms, e.g. B. lengau, may be incriminated in clinical cases, especially those occurring outside the known
endemic area.South African National Research Foundation grant (NRF grant GUN 2069496
The pathology of pathogenic theileriosis in African wild artiodactyls
The published literature on schizont-“transforming,” or pathogenic theileriosis, in African wild artiodactyls is dated and based on
limited information. Here the authors review the taxonomy, diagnosis, epidemiology, hematology, pathology, and aspects of
control in various species. Molecular studies based on 18S and 16S rRNA gene sequences have shown that African wild artiodactyls
are commonly infected with diverse Theileria spp., as well as nontheilerial hemoprotozoa and rickettsia-like bacteria, and
coinfections with pathogenic and nonpathogenic Theileria species are often recorded. Although theileriosis is still confusingly
referred to as cytauxzoonosis in many species, the validity of a separate Cytauxzoon genus in artiodactyls is debated. The epidemiology
of theileriosis is complex; the likelihood of fatal disease depends on the interplay of parasite, vertebrate host, tick
vector, and environmental factors. Roan calves (Hippotragus equinus) and stressed animals of all host species are more susceptible
to fatal theileriosis. Even though regenerative anemia is common, peripheral blood piroplasm parasitemia does not correlate with
disease severity. Other than anemia, common macroscopic lesions include icterus, hemorrhages (mucosal, serosal, and tissue),
fluid effusions into body cavities, lung edema, and variably sized raised cream-colored foci of leukocyte infiltration in multiple
organs. Histopathologic findings include vasocentric hyperproliferation and lysis of atypical leukocytes with associated intracellular
schizonts, parenchymal necrosis, hemorrhage, thromboembolism, and edema. Immunophenotyping is required to establish
the identity of the schizont-transformed leukocytes in wild ungulates. Throughout the review, we propose avenues for future
research by comparing existing knowledge on selected aspects of theileriosis in domestic livestock with that in African wild
artiodactyls.http://journals.sagepub.com/home/vetam2020Paraclinical SciencesVeterinary Tropical Disease
Results of significant predictors of haemonchosis deaths.
<p>Results of significant predictors of haemonchosis deaths.</p
Map of Western Kenya showing the 4 agro-ecological zones and the 20 study sub-locations (in red).
<p>The study area comprised sub-locations falling within a 45 km radius from Busia town where the IDEAL project laboratory was located.</p
Plot of time to death for ECF and haemonchus deaths, the two main causes of calf mortality causing 33 and 10 deaths respectively.
<p>More than 80% of ECF deaths were observed in calves below 6 months of age, whereas most deaths attributed to haemonchosis were in calves older than 6 months.</p
Map showing number of deaths attributable to haemonchosis by sub-location.
<p>In total, 10 of 88 deaths were attributed to haemonchosis.</p
List of covariates tested for their relationship with mortality due to ECF and haemonchosis.
<p>For infectious factors, the diagnostic tests (in bold) used are recorded against pathogens identified.</p