Plasminogen binding by group A streptococcal isolates from a region of hyperendemicity for streptococcal skin infection and a high incidence of invasive infection.
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Reports of resurgence in invasive group A streptococcal (GAS) infections come mainly from affluent populations with infrequent exposure to GAS. In the Northern Territory (NT) of Australia, high incidence of invasive GAS disease is secondary to endemic skin infection, serotype M1 clones are rare in invasive infection, the diversity and level of exposure to GAS strains are high, and no particular strains dominate. Expression of a plasminogen-binding GAS M-like protein (PAM) has been associated with skin infection in isolates elsewhere (D. Bessen, C. M. Sotir, T. M. Readdy, and S. K. Hollingshead, J. Infect. Dis. 173:896-900, 1996), and subversion of the host plasminogen system by GAS is thought to contribute to invasion in animal models. Here, we describe the relationship between plasminogen-binding capacity of GAS isolates, PAM genotype, and invasive capacity in 29 GAS isolates belonging to 25 distinct strains from the NT. In the presence of fibrinogen and streptokinase, invasive isolates bound more plasminogen than isolates from uncomplicated infections (P < or = 0.004). Only PAM-positive isolates bound substantial levels of plasminogen by a fibrinogen-streptokinase-independent pathway (direct binding). Despite considerable amino acid sequence variation within the A1 repeat region of PAM where the plasminogen-binding domain maps, the critical lysine residue was conserved. (+info)
Intensity of rainfall and severity of melioidosis, Australia.
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In a 12-year prospective study of 318 culture-confirmed cases of melioidosis from the Top End of the Northern Territory of Australia, rainfall data for individual patient locations were correlated with patient risk factors, clinical parameters, and outcomes. Median rainfall in the 14 days before admission was highest (211 mm) for those dying with melioidosis, in comparison to 110 mm for those surviving (p=0.0002). Median 14-day rainfall was also significantly higher for those with pneumonia. On univariate analysis, a prior 14-day rainfall of 125 mm was significantly correlated with pneumonia (odds ratio [OR] 1.70 [confidence interval [CI] 1.09 to 2.65]), bacteremia (OR 1.93 [CI 1.24 to 3.02]), septic shock (OR 1.94 [CI 1.14 to 3.29]), and death (OR 2.50 [CI 1.36 to 4.57]). On multivariate analysis, rainfall in the 14 days before admission was an independent risk factor for pneumonia (p=0.023), bacteremic pneumonia (p=0.001), septic shock (p=0.005), and death (p<0.0001). Heavy monsoonal rains and winds may cause a shift towards inhalation of Burkholderia pseudomallei. (+info)
Barriers and enablers for implementing general practice training.
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BACKGROUND: The Australian College of Rural and Remote Medicine (ACRRM) curriculum is designed for rural and remote general practice in Australia. We explored the potential for its implementation in the Northern Territory (NT). METHODS: Forty-two doctors who might teach or study the ACRRM curriculum were interviewed on the predicted barriers to the curriculum, strategies to overcome these barriers and a model for curriculum delivery. RESULTS: The themes that emerged were: recognition of the ACRRM fellowship, the structure and content of the curriculum, using the curriculum, and delivery of the curriculum. The current curriculum seemed peripheral to the daily activity of general practice registrars and general practice supervisors. Other barriers to registrar learning in the NT were identified. DISCUSSION: The project outcomes were ways to achieve a better balance of service provision and educational opportunity for general practitioners in training, as well as strategies specific to delivery of the ACRRM curriculum. (+info)
Incidence of group C human rotavirus in central Australia and sequence variation of the VP7 and VP4 genes.
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Human group C rotavirus was identified in central Australia in each of eight years over a 16-year period between 1982 and 1997. Cases occurred either sporadically but over a relatively short period of time or as clustered outbreaks. These are the only reports of human group C rotavirus in Australia other than that of a single case reported approximately 1,800 km away in 1982. The electrophoretic genome profiles of isolates were identical for all those identified within the same year but different between those identified in different years. The VP7 genes of four isolates identified in four different years over a 7-year period between 1987 and 1993, and the VP4 genes of two of these isolates showed relatively little variation in genome and deduced amino acid sequence upon comparison of the equivalent genes between isolates. The sequences were also very similar to those from the corresponding genes from most of the human group C rotavirus isolates from other countries. This continues the observation of a high degree of gene sequence conservation among human group C rotaviruses worldwide. (+info)
Further evaluation of a rapid diagnostic test for melioidosis in an area of endemicity.
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Immunochromatographic test (ICT) kits for the rapid detection of immunoglobulin G (IgG) and IgM antibodies to Burkholderia pseudomallei were compared to the indirect hemagglutination (IHA) assay. In 138 culture-confirmed melioidosis cases, sensitivities were 80, 77, and 88% for IHA, ICT IgG, and ICT IgM, respectively. In a prospective study of 160 consecutive sera samples sent for melioidosis serology, respective specificities were 91, 90, and 69, positive predictive values were 41, 32, and 18, and negative predictive values were 99, 98, and 100%. ICT IgM kits are unreliable for diagnosis of melioidosis, but ICT IgG kits may be useful for diagnosing travelers presenting with possible melioidosis who return from regions where melioidosis is endemic. (+info)
Comparison of a blood-free medium and a filtration technique for the isolation of Campylobacter spp. from diarrhoeal stools of hospitalised patients in central Australia.
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Single specimens of diarrhoeal stool from 676 patients, mostly aboriginals aged less than 5 years, admitted to Alice Springs Hospital, central Australia, for diarrhoea between Sept. 1988 and Feb. 1989, were examined for Campylobacter spp. by culture on a blood-free medium with selective supplement (BFM; Oxoid) and blood agar overlaid with a membrane filter (FM). Campylobacter spp. were isolated on either BFM or FM or both from 225 patients. Campylobacter spp. were isolated on BFM alone from 75 patients and on FM alone from 213 patients (p less than 0.001; chi 2 test). Most campylobacters isolated on BFM were C. jejuni. All C. jejuni subsp. doylei, all "C. upsaliensis" except one, all C. laridis, C. fetus subsp. fetus and several uncharacterised Campylobacter isolates were isolated on FM only. C. jejuni was isolated on BFM but not FM from several patients, and vice versa. Serotyping of C. jejuni and C. coli isolated from both media showed the serotypes recovered from the two media to be different in some patients. In some patients concurrent infection with several species or serotypes (up to five) of Campylobacter, or both, was shown for the first time by the use of FM. We conclude that the use in combination of a selective medium and a non-selective medium with a filtration technique are better than either medium alone for the isolation of Campylobacter spp. (+info)
Out of hospital treatment of patients with melioidosis using ceftazidime in 24 h elastomeric infusors, via peripherally inserted central catheters.
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BACKGROUND: In the tropical north of the Northern Territory, Australia, 25-50 patients are admitted to Royal Darwin Hospital (RDH) each year with Burkholderia pseudomallei infection, or melioidosis. Treatment consists of initial intensive therapy with 2-4 weeks of intravenous antibiotics. Clinical improvement may occur early and patients often prefer to be managed out of hospital in the Hospital in the Home (HITH). OBJECTIVES: To evaluate safety and efficacy of HITH management of patients with melioidosis. METHODS: A prospective observational study of our standard management which consists of 24 h infusions of ceftazidime infused through a peripherally inserted central catheter (PICC) line, plus oral sulphamethoxazole trimethoprim. Treatment is administered in the home, which may be in Darwin, regional areas or remote communities, or in a self-care unit located in the hospital grounds. RESULTS: From February 1998 to December 2001 150 patients were admitted to RDH with culture confirmed B. pseudomallei infection. Of these, 73 patients were treated with 24 h infusions of ceftazidime, of which 70 patients were managed by HITH. Complications of treatment include a PICC line complication rate of 10.6/1000 days in situ. Nine patients had relapse or recrudescence of disease, nearly all as a result of poor adherence to subsequent oral eradication therapy, these patients were all re-treated successfully. One patient remains infected with B. pseudomallei. CONCLUSION: This clinical outcome study suggests that out of hospital management of melioidosis with 24 h infusions of ceftazidime via a PICC line is safe and effective. (+info)
Epidemiology of community-acquired and nosocomial bloodstream infections in tropical Australia: a 12-month prospective study.
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OBJECTIVES: To define the relative incidence of organisms causing blood stream infections in a tropical setting with a very low prevalence of human immunodeficiency virus infection (<1%). METHODS: A 12-month prospective study of blood stream infections in 2000 at Royal Darwin Hospital in the tropical north of Australia. RESULTS: Significant isolates were grown from 257 sets of blood cultures. Staphylococcus aureus was the most common isolate overall (28%); 26% of these were methicillin-resistant (MRSA). Escherichia coli was the most common cause of community-acquired bacteraemia. Burkholderia pseudomallei caused 32% of community acquired, bacteraemic pneumonia; 6% of bacteraemias overall. Vancomycin-resistant enterococci were not isolated. Crude mortality rates (13% overall; 9% attributable mortality) were lower than in most comparable studies. CONCLUSIONS: The major difference between these findings and surveys performed elsewhere is the presence of B. pseudomallei as a significant cause of bacteraemic community-acquired pneumonia. Our results demonstrate the effects of local environmental and patient characteristics on the range of organisms causing blood stream infections, and emphasize the important role of local microbiology laboratories in guiding empiric antibiotic therapy. (+info)