Unusual cases of chlamydiosis in psittacine birds.

Avian chlamydiosis is a common disease found in domesticated and nondomesticated avian species caused by several species of chlamydiae including but not limited to Chlamydia psittaci, Chlamydia avium, Chlamydia gallinacea, Chlamydia buteonis, and Chlamydia ibidis. Generally, early in the disease course, birds present with mild nonspecific clinical signs associated with gastrointestinal and respiratory tract disease. During end-stage disease, birds may present in a severe state of emaciation, dehydration, and/or acute death with no known history of prior illness. Between 2000 and 2009, 14 unusual cases of avian chlamydiosis were submitted to the California Animal Health and Food Safety Laboratory System. Histologic lesions noted in the 14 birds included meningoencephalomyelitis (3 of 13, 23%), otitis media (3 of 8), bursitis (9 of 11, 81%), nephritis (8 of 13, 61%), and orchitis (1 of 8). Corresponding immunopositive chlamydiae intracytoplasmic inclusions were detected in all tissues. Positive immunolabeling was detected in optic nerves (5 of 10, 50%), meninges (5 of 13, 38%), and endothelial cells (14 of 14, 100%) in the absence of significant microscopic lesions. This study highlights unusual gross, histological, and immunohistochemical findings of chlamydiosis in psittacines and highlights the importance of a thorough diagnostic approach when confirming or excluding chlamydiosis in psittacine birds.

Fungal Rhinosinusitis Caused by a Curvularia sp. Infection in a Female Sumatran Orangutan: A Case Report.

Mycotic nasal cavity and paranasal sinus infections in non-human primates (NHPs) are relatively uncommon diseases of the upper respiratory tract. This case study describes the clinical and pathological features as well as the diagnostic techniques and interventions applied to treat the associated disease. A 23-year-old primiparous female Sumatran orangutan residing at Perth Zoo in Western Australia developed intermittent episodes of right-sided epistaxis. An ulcerative nasal mass was identified from a diagnostic endoscopy. The mass was initially biopsied and showed the morphological characteristics of a dematiaceous fungal organism upon a histological examination. There were prominent mucosal and submucosal granulomatous infiltrates containing histocytes, giant cells, and lymphocytes admixed with fewer numbers of neutrophils and eosinophils surrounding the fungal organism. The organism was identified as Curvularia sp. by the fungal characteristics associated with the histopathology, culture growth, and PCR analysis. The mass was subsequently removed with endoscopic sinus surgery (ESS) and the orangutan was medically treated with itraconazole for several months. The recovery was uneventful and the orangutan returned to full health.

First report of Cryptosporidium parvum in a dromedary camel calf from Western Australia.

Cryptosporidium is an important enteric parasite that can contribute large numbers of infectious oocysts to drinking water catchments. As a result of its resistance to disinfectants including chlorine, it has been responsible for numerous waterborne outbreaks of gastroenteritis. Wildlife and livestock play an important role in the transmission of Cryptosporidium in the environment. Studies conducted outside Australia have indicated that camels may also play a role in the transmission of zoonotic species of Cryptosporidium. Despite Australia being home to the world's largest camel herd, nothing is known about the prevalence and species of Cryptosporidium infecting camels in this country. In the present study, C. parvum was identified by PCR amplification and sequencing of a formalin-fixed intestinal tissue specimen from a one-week old dromedary camel (Camelus dromedarius). Subtyping analysis at the glycoprotein 60 (gp60) locus identified C. parvum subtype IIaA17G2R1, which is a common zoonotic subtype reported in humans and animals worldwide. Histopathological findings also confirmed the presence of large numbers of variably-sized (1-3 µm in diameter) circular basophilic protozoa - consistent with Cryptosporidium spp.- adherent to the mucosal surface and occasionally free within the lumen. Further analysis of the prevalence and species of Cryptosporidium in camel populations across Australia are essential to better understand their potential for contamination of drinking water catchments.

The effect of reinfection and mixed Trypanosoma cruzi infections on disease progression in mice.

The progression of Chagas disease (CD) varies significantly from host to host and is affected by multiple factors. In particular, mixed strain infections and reinfections have the potential to exacerbate disease progression subsequently affecting clinical management of patients with CD. Consequently, an associated reduction in therapeutic intervention and poor prognosis may occur due to this exacerbated disease state. This study investigated the effects of mixed strain infections and reinfection with Trypanosoma cruzi in mice, using two isolates from different discrete typing units, TcI (C8 clone 1) and TcIV (10R26). There were no significant differences in mortality rate, body weight or body condition among mice infected with either C8 clone 1, 10R26, or a mixture of both isolates. However, the parasite was found in a significantly greater number of host organs in mice infected with a mixture of isolates, and the histopathological response to infection was significantly greater in mice infected with C8 clone 1 alone, and C8 clone 1+10R26 mixed infections than in mice infected with 10R26 alone. To investigate the effects of reinfection, mice received either a double exposure to C8 clone 1; a double exposure to 10R26; exposure to C8 clone 1 followed by 10R26; or exposure to 10R26 followed by C8 clone 1. Compared to single infection groups, mortality was significantly increased, while survival time, body weight and body condition were all significantly decreased across all reinfection groups, with no significant differences among these groups. The mortality rate over all reinfection groups was 63.6%, compared to 0% in single infection groups, however there was no evidence of a greater histopathological response to infection. These results suggest firstly, that the C8 clone 1 isolate is more virulent than the 10R26 isolate, and secondly, that a more disseminated infection may occur with a mixture of isolates than with single isolates, although there is no evidence that mixed infections have a greater pathological effect. By contrast, reinfections do have major effects on host survivability and thus disease outcome. This confirms previous research demonstrating spontaneous deaths following reinfection, a phenomenon that to our knowledge has only been reported once before.