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Chalada M.J.,Central Queensland University | Stenos J.,Australian Rickettsial Reference Laboratory | Bradbury R.S.,Central Queensland University
One Health | Year: 2016

Lyme Borreliosis is a common tick-borne disease of the northern hemisphere caused by the spirochaetes of the Borrelia burgdorferi sensu lato (B. burgdorferi s. l.) complex. It results in multi-organ disease with arthritic, cardiac, neurological and dermatological manifestations. In the last twenty-five years there have been over 500 reports of an Australian Lyme-like syndrome in the scientific literature. However, the diagnoses of Lyme Borreliosis made in these cases have been primarily by clinical presentation and laboratory results of tentative reliability and the true cause of these illnesses remains unknown. A number of animals have been introduced to Australia that may act as B. burgdorferi s. l. reservoirs in Lyme-endemic countries, and there are some Australian Ixodes spp. and Haemaphysalis spp. ticks whose geographical distribution matches that of the Australian Lyme-like cases. Four published studies have searched for Borrelia in Australian ticks, with contradicting results. The cause of the potential Lyme-like disease in Australia remains to be defined. The evidence to date as to whether these illnesses are caused by a Borrelia species, another tick borne pathogen or are due to a novel or unrelated aetiology is summarised in this review. © 2016 The Authors.

Graves S.,Australian Rickettsial Reference Laboratory
Medicine Today | Year: 2013

Australian rickettsial diseases (spotted fevers and typhus) and Q fever are readily treated with antibiotics. The greatest challenge may be to suspect the diagnosis in a patient with fever.

Lockhart M.,Australian Rickettsial Reference Laboratory | Islam A.,NSW Health | Graves S.,NSW Health | Fenwick S.,Murdoch University | Stenos J.,Australian Rickettsial Reference Laboratory
FEMS Immunology and Medical Microbiology | Year: 2012

Coxiella burnetii is an acidophilic, intracellular bacterium that causes the human disease Q fever. In some studies, it is important to distinguish between viable and nonviable C. burnetii. We compared four methods for detecting and measuring viable C. burnetii in biological samples as follows: growth in two different cell culture lines, infection of severe combined immunodeficient (SCID) mice (leading to death) and infection of SCID mice with detection of C. burnetii in their spleen (after euthanasia at day 50 postinfection). Two isolates of C. burnetii were used ('Henzerling' and 'Arandale'). Our in-house qPCR assay for C. burnetii DNA was used as a control. SCID mouse inoculation was more sensitive than cell culture. The assay that detected C. burnetii in SCID mouse spleens was slightly more sensitive than SCID mice deaths alone. Approximately one viable C. burnetii cell could be detected by this method, making it suitable for determining the viability of C. burnetii in a sample. © 2011 Federation of European Microbiological Societies.

Islam A.,Hunter Area Pathology Service | Islam A.,Australian Rickettsial Reference Laboratory | Ferguson J.,Hunter Area Pathology Service | Givney R.,Hunter Area Pathology Service | And 2 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2011

Exposure to Coxiella burnetii is a risk in the Hunter New England (HNE) region of New South Wales (NSW), Australia, based on yearly reported cases of Q fever. We assessed seroprevalence of phase II antibodies to C. burnetii by indirect immunofluorescence assay (IFA; screening at 1/50 dilution) of residents of 24 local government areas (LGA) of the HNE region of NSW. A total of 2,438 randomly selected sera sent to the Hunter Area Pathology Service for routine diagnostic purposes (not Q fever testing) during the period of 2006-2009 were tested. The overall seroprevalence in sample group was 7%. The proportion of males (59%) was higher than females (41%). In age distribution, the largest proportion (37%) of seropositives was in the > 60 years age group. Lower prevalence was observed in 0-9 years (1%) and 10-19 years (5%) age groups. The seroprevalence in different LGAs varied between 0.5% and 22%. It was highest in Guyra (22%), Gunnedah (21%), Tenterfield (18%), and Narrabri (16%), with Newcastle (0.5%), Port Stephens (2%), Lake Macquarie (3%), and Singleton (3%) being the lowest. In most of the LGAs, seroprevalence was between 6% and 12%. This report indicates a considerable exposure to C. burnetii of residents in rural areas of the HNE region and is consistent with the high notification rate for Q fever in this part of Australia. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene.

Hii S.-F.,University of Queensland | Abdad M.Y.,Australian Rickettsial Reference Laboratory | Kopp S.R.,University of Queensland | Stenos J.,Australian Rickettsial Reference Laboratory | And 2 more authors.
Parasites and Vectors | Year: 2013

Background: The recent detection of Rickettsia felis DNA in dogs in Australia suggests that dogs are potential mammalian reservoir hosts for this emerging rickettsia. To date, there is no published report addressing the seroprevalence of R. felis in dogs in Australia. Methods. Antigens for R. felis were produced by inoculating confluent XTC-2 monolayer cell cultures with three pools of cat flea (Ctenocephalides felis) homogenates. Infection was confirmed by real-time (qPCR), conventional or nested PCRs targeting the ompB, gltA, 17 kDa and ompA genes. Two hundred and ninety-two dogs from Southeast Queensland and the Northern Territory were tested for the presence of R. felis antibodies using a microimmunofluorescence (IF) test and the seroprevalence and associated risk factors for exposure were determined using both uni- and multi-variate analyses. Results: Rickettsia felis was successfully isolated in cell culture from all three cat-flea pools. One hundred and forty-eight dogs (50.7%) showed seropositivity with titres ≥64 and 54 (18.5%) with titres ≥128. At antibody titres ≥64, dogs with active ectoparasite control were less likely to be seropositive to R. felis (OR: 2.60; 95% CI: 1.20 - 5.56). Conclusions: This first reported isolation of R. felis in cell culture in Australia allowed for the production of antigen for serological testing of dogs. Results of this serological testing reflects the ubiquitous exposure of dogs to R. felis and advocate for owner vigilance with regards to ectoparasite control on domestic pets. © 2013 Hii et al.; licensee BioMed Central Ltd.

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