Amanda D. Barbosa

Trypanosoma teixeirae: A new species belonging to the T. cruzi clade causing trypanosomosis in an Australian little red flying fox (Pteropus scapulatus)

Abstract Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade.

Epidemiological study of scorpion stings in Belo Horizonte, Minas Gerais state, Brazil, 2005-2009

This retrospective epidemiological study focused on scorpion stings in Belo Horizonte, Minas Gerais State, Brazil, from 2005 to 2009. Data on reported scorpion stings were taken from the National System for Notifiable Diseases (SINAN) and the Epidemiological Surveillance System (SISVE) and patient records from the João XXIII Hospital. There were 2,769 cases of scorpion stings in Belo Horizonte (114.7 cases per 100,000 inhabitants), with a downward trend over time and the highest incidence from August to January. Tityus serrulatus was the species involved in most of the stings. There was no statistical difference in the incidence between male and female victims, and the most frequently affected age bracket was 55 to 64 years. Ninety-six percent of cases evolved to cure, and there were two deaths. It is necessary to improve the reporting process for scorpion stings and to consider the determinants of scorpion stings in order to plan and implement effective public health interventions.

Increased genetic diversity and prevalence of co-infection with Trypanosoma spp. in koalas (Phascolarctos cinereus) and their ticks identified using next-generation sequencing (NGS)

Infections with Trypanosoma spp. have been associated with poor health and decreased survival of koalas (Phascolarctos cinereus), particularly in the presence of concurrent pathogens such as Chlamydia and koala retrovirus. The present study describes the application of a next-generation sequencing (NGS)-based assay to characterise the prevalence and genetic diversity of trypanosome communities in koalas and two native species of ticks (Ixodes holocyclus and I. tasmani) removed from koala hosts. Among 168 koalas tested, 32.2% (95% CI: 25.2–39.8%) were positive for at least one Trypanosoma sp. Previously described Trypanosoma spp. from koalas were identified, including T. irwini (32.1%, 95% CI: 25.2–39.8%), T. gilletti (25%, 95% CI: 18.7–32.3%), T. copemani (27.4%, 95% CI: 20.8–34.8%) and T. vegrandis (10.1%, 95% CI: 6.0–15.7%). Trypanosoma noyesi was detected for the first time in koalas, although at a low prevalence (0.6% 95% CI: 0–3.3%), and a novel species (Trypanosoma sp. AB-2017) was identified at a prevalence of 4.8% (95% CI: 2.1–9.2%). Mixed infections with up to five species were present in 27.4% (95% CI: 21–35%) of the koalas, which was significantly higher than the prevalence of single infections 4.8% (95% CI: 2–9%). Overall, a considerably higher proportion (79.7%) of the Trypanosoma sequences isolated from koala blood samples were identified as T. irwini, suggesting this is the dominant species. Co-infections involving T. gilletti, T. irwini, T. copemani, T. vegrandis and Trypanosoma sp. AB-2017 were also detected in ticks, with T. gilletti and T. copemani being the dominant species within the invertebrate hosts. Direct Sanger sequencing of Trypanosoma 18S rRNA gene amplicons was also performed and results revealed that this method was only able to identify the genotypes with greater amount of reads (according to NGS) within koala samples, which highlights the advantages of NGS in detecting mixed infections. The present study provides new insights on the natural genetic diversity of Trypanosoma communities infecting koalas and constitutes a benchmark for future clinical and epidemiological studies required to quantify the contribution of trypanosome infections on koala survival rates.

Trypanosomiasis in an Australian little red flying fox (Pteropus scapulatus)

Case report An adult female Australian little red flying fox (Pteropus scapulatus) presented with icterus and anaemia. Examination of a blood smear revealed numerous trypanosomes 20.4–30.8 µm long with tapered ends. Necropsy and histological findings were consistent with trypanosome infection of lymphoid tissue and intravascular haemolysis. Sequence and phylogenetic analysis demonstrated this trypanosome species to be genetically distinct and most similar to Trypanosoma minasense and Trypanosoma rangeli (with a genetic distance of 1% at the 18S rRNA locus for both). Conclusion To the authors’ knowledge this is the first report of a trypanosome infection associated with clinical disease in bats.

Distribuição espacial de acidentes escorpiônicos em Belo Horizonte, Minas Gerais, 2005 a 2009

Scorpion sting accidents are a public health problem in Belo Horizonte and veterinarians play an important role in its control program when based on capture, mapping of cases and educational actions with the population. A retrospective epidemiological study was done to analyze the frequency and spatial distribution of scorpion sting cases in Belo Horizonte, between 2005 and 2009, and to associate them with the Health Vulnerability Index (IVS), a regional and composed socio-economic index. Notification data of scorpion sting accidents were used from the National System of Notifiable Diseases (SINAN) and Epidemiological Surveillance System (SISVE) for years 2008 and 2009. For the period between 2005 and 2007 it was necessary to retrieve data from the clinical records of Joao XXIII Hospital (HPSJ XXIII) which were not digitalized in the referred information systems. For georeference and spatial analysis, geographic base EndGeo and features of the programs MapInfo version 10.0, Hotspot Detective and SatScan were used. Between 2005 and 2009 2769 cases of scorpionism, occurred in Belo Horizonte which represents an average incidence of 22.4 cases per 100,000 inhabitants. Among 1924 (69.5%) georeferenced cases, the highest incidence was observed in two Sanitary District (DS). A large concentration of cases was also observed in the areas of the city cemeteries. Two clusters were detected during this period, one in 2005, located in the Northwest and West DS, and another between 2006 and 2007 in the Northwest and Northeast DS. There was no association between higher incidence areas of scorpionism in Belo Horizonte and the areas of higher health risk classified by IVS. It is necessary to improve the reporting process regarding scorpion sting accidents. Another conclusion is that the mapping of cases is a relevant tool to base the targeting of educative actions to the priority areas of Belo Horizonte.

Haematozoa of wild catfishes in northern Australia

Very little is known about the diversity, prevalence, or pathogenicity of haematozoa in Australian freshwater fishes. Blood smears from 189 native catfishes, of six different species, from northern Australia were examined for haematozoa. Haematozoan infections were observed only in fishes from Queensland, at an overall prevalence of 0.191 (95% CI = 0.134–0.265). Intraerythrocytic haemogregarines were present in Neoarius graeffei from the Brisbane River at a prevalence of 0.35 (0.181–0.567). Trypanosomes were present in Tandanus species from four rivers, at prevalences ranging from 0.111 (0.020–0.330) to 1 (0.635–1), and in N. graeffei from one river in Queensland, at a prevalence of 0.063 (0.003–0.305). The haematozoans observed appeared to have little impact on their hosts. Tandanus spp. were significantly more likely to be infected with trypanosomes, suggesting a high parasite-host specificity. This is the first widespread survey of wild Australian freshwater catfishes for haematozoa, resulting in the first report of haemogregarines from Australian freshwater fish, and the first report of trypanosomes from Neoarius graeffei and Tandanus tropicanus.

An Australian dog diagnosed with an exotic tick-borne infection: Should Australia still be considered free from Hepatozoon canis?

Recent molecular and sero-surveillance studies of the tick-borne pathogen Hepatozoon canis have identified new hosts, potential vector species, and have revealed that H. canis is more widespread than previously thought. We report the first diagnosed case of canine hepatozoonosis in Australia from a Maremma Sheepdog in Sarina, Queensland. Hepatozoon canis was detected with blood smear examination and 18S rRNA sequencing. It is unknown when or how the organism was introduced into Australia, which raises questions about border biosecurity policies and the H. canis infection status of its potential vectors and hosts in Australia. Surveillance for this pathogen is required to determine whether H. canis has established in Australia.