Central Slip Repair using Trans-articular K-wires: A Comparative Study.

Central slip disruption may lead to PIP joint dysfunction causing significant morbidity. Existing evidence for any specific surgical management of these injuries is limited but does favor early mobilization of the PIP joint. Aim: To assess the functional outcome in a cohort of patients undergoing central slip repair with internal K-wire proximal interphalangeal joint splinting and complete immobilization against those with external splinting only. Methods: A single center retrospective analysis of all patients that underwent operative central slip repair in our institution over a 5-year period. Data were collected via the HIPE database and clinical notes. Data relating to demographics as well as range of motion, total active motion {(TAM) (TAM%)} score, and hand therapy rehabilitation type were analyzed. Results: The study population was n = 44 patients. N = 33 patients were treated without a K-wire and n = 11 treated with a K-wire. There was a male predominance, 81.8% (n = 36). Mean age was 40.4 years. There was no significant difference in the mean TAM achieved at final measurement between the "no K-wire" and the "K-wire" treatment groups [no K-wire 202.1° (standard deviations (SD) 40.0) vs. K-wire 187.4° (SD 28.2), p = 0.208]. The "no K-wire group" achieved a mean TAM % of 78.0 (SD 11.4) and the "K-wire group" achieved a mean TAM % of 72.1 (SD 10.8); no statistically significant difference in mean scores was observed between groups. Conclusion: Our study has shown comparable functional outcomes between those having complete joint immobilization with internal K-wire splinting and those that are externally splinted only following central slip repair.

Factors associated with SARS-CoV-2 infection in patients attending an acute hospital ambulatory assessment unit.

To describe the factors associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in mild-to-moderate patients attending for assessment. This observational study was conducted in a Model 4 tertiary referral center in Ireland. All patients referred for SARS-CoV-2 assessment over a 4-week period were included. Patient demographics, presenting symptoms, comorbidities, medications, and outcomes (including length of stay, discharge, and mortality) were collected. Two hundred and seventy-nine patients were assessed. These patients were predominantly female (62%) with a median age of 50 years (SD 16.9). Nineteen (6.8%) patients had SARS-CoV-2 detected. Dysgeusia was associated with a 16-fold increased prediction of SARS-CoV-2 positivity (p = .001; OR, 16.8; 95% CI, 3.82-73.84). Thirteen patients with SARS-COV-2 detected (68.4%) were admitted, in contrast with 38.1% (99/260) of patients with SARS-CoV-2 non-detectable or not tested (p = .001). Female patients were more likely to be hospitalized (p = .01) as were current and ex-smokers (p = .05). We describe olfactory disturbance and fever as the main presenting features in SARS-CoV-2 infection. These patients are more likely to be hospitalized with increased length of stay; however, they make up a minority of the patients assessed. "Non-detectable" patients remain likely to require prolonged hospitalization. Knowledge of predictors of hospitalization in a "non-detectable" cohort will aid future planning and discussion of patient assessment in a SARS-CoV-2 era.

Epidemiology and impact of Neospora caninum infection in three Queensland tropical dairy herds.

This study investigated the epidemiology of Neospora caninum in three tropical dairy herds in North Queensland, Australia. All animals in the herds were bled, and the sera were tested by ELISA for N. caninum antibodies. Herd records were examined, and the number of calves carried to term and the number of abortions which occurred over the lifetime of each animal were recorded to determine the abortion rate for each animal. Pedigrees were constructed for two of the herds to investigate whether vertical transmission was occurring. The seroprevalence of N. caninum ranged from 23% to 34%. The abortion rate in seropositive animals was significantly (p < 0.001) higher than in seronegative animals in all three herds (12-20.1% cf. 3.6-7%). Overall, the probability of a calf being seropositive was 3.5 times higher when the dam was also seropositive than when the dam was seronegative. Subsequent selective breeding employed by one herd reduced the N. caninum seroprevalence from 23% to 5% over a 9-year period. This study shows that N. caninum infection is prevalent in North Queensland dairy cattle, and both post-natal infection and vertical transmission are common.

Pathology associated with endogenous development of haematozoa in birds from southeast Queensland.

A study was undertaken on the pathology and associated schizont morphology of apicomplexan species of avian haematozoa. Some 32 birds from the families Artamidae, Meliphagidae, Oriolidae, Podargidae, Columbidae, Alcedinidae and Psittacidae were identified as having schizonts in various tissues. Based on blood stages observed, the probable relationship to tissue stages was considered. The majority of schizonts were referable to the genera Leucocytozoon and Haemoproteus. The comparative morphology of tissue stages previously described in the literature is discussed and the involvement of protozoa other than haematozoa considered. The naturally occurring infections in wild birds described in this study represent previously unreported data on the life-cycle stages involved. Some schizonts measured up to 640 microm. While pathological changes in some hosts were noticeable, in others no significant findings were observed. The role of endogenous stages in avian morbidity is discussed briefly.

Phylogenetic relationships of Hepatozoon (Haemogregarina) boigae, Hepatozoon sp., Haemogregarina clelandi and Haemoproteus chelodina from Australian reptiles to other Apicomplexa based on cladistic analyses of ultrastructural and life-cycle characters.

The phylogeny of representative haemozoan species of the phylum Apicomplexa was reconstructed by cladistic analyses of ultrastructural and life-cycle characteristics. The analysis incorporated 4 apicomplexans previously not included in phylogenetic reconstructions: Haemogregarina clelandi from the Brisbane River tortoise (Emydura signata), Hepatozoon sp. from the slaty grey snake (Stegonotus cucullatus), Hepatozoon (Haemogregarina) boigae from the brown tree snake (Boiga irregularis), and Haemoproteus chelodina from the saw-shelled tortoise (Elseya latisternum). There was no apparent correlation between parasite phylogeny and that of their vertebrate hosts, but there appeared to be some relationship between parasites and their intermediate hosts, suggestive of parasite/vector co-evolution.

Ultrastructure of Hepatozoon boigae (Mackerras, 1961) nov. comb. from brown tree snakes, Boiga irregularis, from northern Australia.

Intraerythrocytic bodies identified as haemogregarine gamonts were found in 29% of 97 brown tree snakes (Boiga irregularis) examined during a haematological survey of reptiles in Australasia during 1994-1998. The morphological characteristics of the parasites were consistent with those of Haemogregarina boigae Mackerras, 1961, although the gamonts were slightly larger and lacked red caps but contained distinctive polar grey capsules. Gamonts did not distend host cells but laterally displaced their nuclei. They were contained within parasitophorous vacuoles and possessed typical apicomplexan organelles, including a conoid, polar rings, rhoptries and micronemes. Schizonts producing up to 30 merozoites were detected in endothelial cells of the lungs of 11 snakes. The absence of erythrocytic schizogony suggests the parasites belong to the genus Hepatozoon. Electron microscopy also revealed the presence of curious encapsulated organisms in degenerating erythrocytes. These stages did not possess apical complex organelles and were surrounded by thick walls containing circumferential junctions and interposed strips reminiscent of oocyst sutures.

Phylogenetic relationships of Trypanosoma chelodina and Trypanosoma binneyi from Australian tortoises and platypuses inferred from small subunit rRNA analyses.

Trypanosome infections are often difficult to detect by conventional microscopy and their pleomorphy often confounds differential diagnosis. Molecular techniques are now being used to diagnose infections and to determine phylogenetic relationships between species. Complete small subunit rRNA gene sequences were determined for isolates of Trypanosoma chelodina from the Brisbane River tortoise (Emydura signata), the saw-shelled tortoise (Elseya latisternum), and the eastern snake-necked tortoise (Chelodina longicollis) from southeast Queensland, Australia. Partial sequence data were also obtained for T. binneyi from a platypus (Ornithorhynchus anatinus) from Tasmania. Phylogenetic relationships between T. chelodina, T. binneyi and other species were examined by maximum parsimony and likelihood methods. The Australian tortoise and platypus trypanosomes did not exhibit any close phylogenetic relationships with those of mammals, reptiles or amphibians, but were closely related to each other, and to fish trypanosomes. This contra-indicates their co-evolution with their vertebrate hosts but does not exclude co-evolution with different groups of invertebrate vectors, notably insects and leeches.

Four new species of Macropodinium (Ciliophora: Litostomatea) from Australian wallabies and pademelons.

Samples of Macropodinium spp. were collected from 3 new macropodid species: from 21 of 28 (75%) black-striped wallabies (Macropus dorsalis); 10 of 11 (91%) swamp wallabies (Wallabia bicolor); and 22 of 43 (51%) Tasmanian pademelons (Thylogale billardierii). The examination of ciliate morphology by silver impregnation and scanning electron microscopy led to the redescription of the genus Macropodinium and the description of 4 new species: Ma. tricresta sp. nov. and Ma. spinosus sp. nov. from M. dorsalis; Ma. maira sp. nov. from T. billardierii; and M. bicolor sp. nov. from W. bicolor; each species was strictly host specific. Cellular orientation was reinterpreted on the basis of vestibular morphology and it is concluded that Macropodinium spp. are laterally rather than dorso-ventrally compressed. The striated groove is thus dorso-ventral rather than lateral. Oral ciliation consisted of up to three bands: an adoral band composed of oblique kineties; a vestibular band of longitudinal kineties; and a preoral band of longitudinal kineties. Somatic ciliation occurred in two longitudinal bands: a dense band composed of several parallel kineties on the left side of the dorso-ventral groove; and a sparse band composed of a single kinety on the right internal side of the dorso-ventral groove. Few structures were homologous to those of other litostome ciliates, and thus the relationship of Macropodinium to other litostomes cannot yet be clearly defined.

Evidence for an independent radiation of endosymbiotic litostome ciliates within Australian marsupial herbivores.

The recent discovery of isotrichid-like ciliates occurring as endosymbionts in macropodid marsupials posed interesting questions in regard to both their phyletic origin (all previous records confined to eutherian mammals) and their morphological evolution (Australian forms possibly representing missing links between previously described genera). The SSU rRNA gene was sequenced for three species (Dasytricha dehorityi, D. dogieli, and Bitricha tasmaniensis) and aligned against representatives of all major ciliate classes. The Australian species did not group with the other isotrichid species but instead formed an independent radiation. Discrepancies between recent global phylogenies of the phylum Ciliophora were examined by manipulation of the aligned sequence data set. Sources of conflict between these studies did not stem from differences in outgroup choice or phylogenetic reconstruction methods. Differences in the application of confidence limits and primary sequence alignment have probably resulted in the reporting of spurious associations which are not supported by more conservative confidence or alignment methodology. At present, the ciliate subphylum Intramacronucleata is an unresolved polytomy which may be due to deficiencies in the SSU rRNA gene sequence dataset or indicate that the ciliates radiated into their extant classes by rapid burst-like evolution.

Novel isotrichid ciliates endosymbiotic in Australian macropodid marsupials.

Samples of foregut content were collected from 86 macropodid marsupials and examined for the presence of endosymbiotic ciliates. Four host species were examined: Macropus giganteus (eastern grey kangaroo), M. fuliginosus (western grey kangaroo), M. robustus (common wallaroo) and Thylogale billardierii (Tasmanian pademelon). Ciliate morphology was determined by microscopical examination of live and silver-impregnated specimens. Isotrichid ciliates were detected in 51 (59%) of the 86 animals examined. Five new species and one new genus are described. Three of the species belong to the genus Dasytricha Schuberg, 1888; D. dehorityi n. sp. from M. giganteus, D. dogieli n. sp. from M. robustus and D. mundayi n. sp. from T. billardierii. Bitricha n. g. is characterised by the possession of two fields of somatic ciliation, a transverse ventral and a longitudinal dorsal field. B. oblata n. sp. is described from M. giganteus and M. fuliginosus and B. tasmaniensis n. sp. is described from T. billardierii. The occurrence of isotrichid ciliates in both metatherian and eutherian mammals suggests that the family either evolved prior to the divergence of the mammalian lineages or switched hosts from one group to the other following host diversification.

Immune and pathophysiological responses to different strains of Giardia duodenalis in neonatal mice.

Numerous studies have demonstrated various strain differences between Giardia isolates, but little is known about the immunology and pathogenesis of infections. This study aimed to compare host responses to strains of Giardi duodenalis differing in levels of virulence and pathogenicity and, by doing so, elucidate the mechanisms via which pathogenic strains establish infections. Marked differences were found in the infection dynamics, histopathological responses and serum antibody responses of neonatal mice infected with either G. duodenalis strain BRIS/83/HEPU/106 (isolated from a human) or BRIS/95/HEPU/2041 (isolated from a sulphur-crested cockatoo, Cacatua galerita). Infections with the bird strain were more intense (6.7-times greater) and persisted longer (by 14days) than infections with the human strain. The bird strain was more pathogenic and caused greater pathophysiological alteration to the gut mucosa, including increased villous atrophy, hyperplasia of goblet cells and vacuolated epithelial cells. Mice infected with the bird strain produced less serum anti-Giardia IgA and IgM, but more total (non-specific) serum IgA than those infected with the human strain of Giardia. This suggests that avian G. duodenalis strains are infective for mammalian hosts and may contribute to zoonotic infections. Furthermore, infection of mice with BRIS/95/HEPU/2041 serves as a good experimental model to provide further insight into the mechanisms via which G. duodenalis causes disease.

Incidental finding of Myxobolus spores (protozoa: myxozoa) in stool samples from patients with gastrointestinal symptoms.

Myxozoan spores were detected in fecal samples from three patients presenting with abdominal pain and/or diarrhea. The spores were identical to those of Myxobolus plectroplites, a previously described pathogen from the freshwater fish Plectroplites ambiguus. All patients had recently eaten fish caught from local waters, and frozen fillets of such fish were found to be infected with M. plectroplites cysts. The passage of spores unchanged through the alimentary tract suggests they were incidental findings unrelated to clinical symptoms, especially since other enteric pathogens were present in two patients.

Perspectives on the biodiversity of parasitic protozoa in Australia.

Biodiversity is a term applied to described the number, variety and variability of organisms. Its colloquial application is usually as a measure of species diversity of species richness. Thus, the concepts of "species" and "species boundaries" are integral to any discussion on biodiversity, and with them, the basal question of what constitutes meaningful variation. Protozoan taxonomy is an evolving mix of morphological and molecular characters, and is based largely on decisions made intuitively and arbitrarily using multiple characters. Where to draw species boundaries has become more difficult in the face of a bewildering level of variation uncovered in recent years, due largely to an increase in the resolution of our taxonomic techniques (e.g., ultrastructural and genetic studies). A major challenge for contemporary protozoan taxonomists is to update the existing systematic framework to incorporate our current level of knowledge and to decide on the relative importance of parasite morphology, genetics and biology to the concept of the protozoan "species". This task is compounded by the relative paucity of information on our endemic protozoan parasites. In Australia, even in vertebrate hosts, little is known of the biodiversity of parasitic protozoa. Not surprisingly, what knowledge we do have is linked to clinical disease, e.g., detailed knowledge of some species of coccidia and of some enteric ciliates, flagellates and amoebae of mammals. We have some knowledge of a few species of haemosporidia of reptiles and birds but, even here, molecular studies and experimental work are required to identify species boundaries. In view of these limitations, the best estimate of the biodiversity of Australia's parasitic protozoa in at least the vertebrate fauna of Australia, is that less than one third of the total species have been discovered to date.

Cochlosoma infections in finches.

OBJECTIVE: To survey finches in pet shops for Cochlosoma infection and evaluate the efficacy of antiprotozoal therapy with metronidazole or ronidazole. DESIGN: A survey of pet shop finches and drug efficacy trials. PROCEDURE: Finches in pet shops were randomly selected and their faeces examined microscopically for motile Cochlosoma sp trophozoites. Drug trials were carried out on 60 adult finches with naturally occurring infections. Body weight was measured and the faeces of each bird was examined for trophozoites at the beginning and 7 days after the end of treatment. In some birds, additional daily faecal examinations were done until three consecutive negative results were obtained. Metronidazole was administered at various dose rates by crop gavage or in drinking water to eight groups of five to ten finches each. Ronidazole was given in water for 7 days to ten finches. In addition, six finches whose faeces tested positive were necropsied and their tissues collected for histological examination. RESULTS: Motile flagellates in the faeces were identified as C anatis-like protozoa. Red-headed parrot-finches, Bengalese and Lady Gould finches were found to be most commonly infected. Cochlosoma sp was also found in the blue-faced parrot-finch, zebra finch, painted finch, nutmeg mannikin and double-barred finch. Metronidazole and ronidazole were found to be effective against Cochlosoma sp. Histological findings on infected adult finches were normal, except for the presence of numerous flagellates between the colorectal villi and cloacal mucosal folds. CONCLUSIONS: Cochlosoma anatis-like organisms can infect several species of finches and in adult finches are confined to the colorectum and cloaca. Infection in adult finches was mostly subclinical and could be treated effectively with metronidazole or ronidazole.

New host record for the entodiniomorphid ciliate, Troglodytella abrassarti, from siamangs (Hylobates syndactylus).

Examination of faecal samples from several diarrhoeic siamangs Hylobates syndactylus (Anthropoidea: Hylobatidae) revealed the presence of numerous entodiniomorphid ciliates whose morphological and ultrastructural characteristics were consistent with those of Troglodytella abrassarti previously recorded from chimpanzees, orangutans and gorillas (Anthropoidea: Pongidae).

Incidental finding of a microsporidian parasite from an AIDS patient.

Light microscopic examination of feces from a human immunodeficiency virus-positive patient with chronic diarrhea, anorexia, and lethargy revealed the presence of numerous refractile bodies resembling microsporidian spores. They were subsequently identified as belonging to the genus Nosema on the basis of their ultrastructural characteristics. However, the microsporidia were enclosed within striated muscle cells, suggesting that they were probably ingested in food; thus, this represented an incidental finding rather than a true infection.