1
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Lynar SA, Robinson CH, Boutlis CS, Commons RJ. Risk factors for mortality in patients with diabetic foot infections: a prospective cohort study. Intern Med J 2020; 49:867-873. [PMID: 30515957 DOI: 10.1111/imj.14184] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/18/2018] [Accepted: 11/25/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND An increasing prevalence of diabetes mellitus has led to a high risk of diabetic foot infections (DFI) and associated morbidity. However, little is known about the relationship between DFI and mortality. AIM To investigate the risk of mortality and associated factors in patients with DFI in an Australian context. METHODS A prospective cohort study of inpatients with DFI between May 2012 and October 2016 was done at Royal Darwin Hospital, a tertiary referral hospital for the Top End of the Northern Territory. Primary outcome was 1-year mortality with Cox regression analysis undertaken to assess risk factors for mortality. RESULTS Four hundred and thirteen consecutive adult diabetic patients with 737 admissions were referred to the High-Risk Foot Service for DFI. Cumulative risk of mortality at 1 year was 8.9% (95% confidence interval (CI) 6.4-12.2). On univariable analysis, mortality was associated with older age (hazard ratio (HR) per year increase 1.08, 95% CI 1.06-1.11, P = 0.001), haemodialysis (HR 3.64, 1.74-7.62, P < 0.001), isolation of Pseudomonas aeruginosa (HR 2.32, 1.05-5.12, P = 0.04) and ischaemic heart disease (HR 2.05, 1.04-4.07, P = 0.04), while indigenous status (HR 0.48, 0.25-0.95, P = 0.04) and HbA1c > 7% (HR 0.45, 0.20-0.99, P < 0.05) were protective. After adjusting for confounders, independent risk factors for mortality were haemodialysis (adjusted HR 5.76, 95% CI 2.28-14.59, P < 0.001) and older age (adjusted HR 1.09, 1.06-1.13, P < 0.001). Patients on haemodialysis had a cumulative risk of mortality of 24.5% (95% CI 14.0-40.8) at 1 year. CONCLUSION There is a high risk of mortality associated with DFI, substantially increased in patients undergoing haemodialysis, highlighting the importance of early and dedicated interventions targeted at this high-risk group.
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Affiliation(s)
- Sarah A Lynar
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Claire H Robinson
- High-Risk Foot Service, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Department of Infectious Diseases, Canberra Hospital, Canberra, Australian Capital Territory, Australia
| | - Robert J Commons
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
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2
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Downton TD, Willcocks BJ, Boutlis CS. Acute myopericarditis in a patient recently started on mesalazine for Crohn disease. Intern Med J 2019; 49:676-677. [DOI: 10.1111/imj.14273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/02/2018] [Indexed: 12/01/2022]
Affiliation(s)
- Teesha D. Downton
- Division of MedicineRoyal Darwin Hospital Darwin Northern Territory Australia
| | - Briony J. Willcocks
- Division of MedicineRoyal Darwin Hospital Darwin Northern Territory Australia
| | - Craig S. Boutlis
- Department of Infectious DiseasesThe Canberra Hospital Canberra Australian Capital Territory Australia
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3
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Bond SE, Chubaty AJ, Adhikari S, Miyakis S, Boutlis CS, Yeo WW, Batterham MJ, Dickson C, McMullan BJ, Mostaghim M, Li-Yan Hui S, Clezy KR, Konecny P. Outcomes of multisite antimicrobial stewardship programme implementation with a shared clinical decision support system. J Antimicrob Chemother 2018; 72:2110-2118. [PMID: 28333302 DOI: 10.1093/jac/dkx080] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/21/2017] [Indexed: 01/08/2023] Open
Abstract
Background Studies evaluating antimicrobial stewardship programmes (ASPs) supported by computerized clinical decision support systems (CDSSs) have predominantly been conducted in single site metropolitan hospitals. Objectives To examine outcomes of multisite ASP implementation supported by a centrally deployed CDSS. Methods An interrupted time series study was conducted across five hospitals in New South Wales, Australia, from 2010 to 2014. Outcomes analysed were: effect of the intervention on targeted antimicrobial use, antimicrobial costs and healthcare-associated Clostridium difficile infection (HCA-CDI) rates. Infection-related length of stay (LOS) and standardized mortality ratios (SMRs) were also assessed. Results Post-intervention, antimicrobials targeted for increased use rose from 223 to 293 defined daily doses (DDDs)/1000 occupied bed days (OBDs)/month (+32%, P < 0.01). Conversely, antimicrobials targeted for decreased use fell from 254 to 196 DDDs/1000 OBDs/month (-23%; P < 0.01). These effects diminished over time. Antimicrobial costs decreased initially (-AUD$64551/month; P < 0.01), then increased (+AUD$7273/month; P < 0.01). HCA-CDI rates decreased post-intervention (-0.2 cases/10 000 OBDs/month; P < 0.01). Proportional LOS reductions for key infections (respiratory from 4.8 to 4.3 days, P < 0.01; septicaemia 6.8 to 6.1 days, P < 0.01) were similar to background LOS reductions (2.1 to 1.9 days). Similarly, infection-related SMRs (observed/expected deaths) decreased (respiratory from 1.1 to 0.75; septicaemia 1.25 to 0.8; background rate 1.19 to 0.90. Conclusions Implementation of a collaborative multisite ASP supported by a centrally deployed CDSS was associated with changes in targeted antimicrobial use, decreased antimicrobial costs, decreased HCA-CDI rates, and no observable increase in LOS or mortality. Ongoing targeted interventions are suggested to promote sustainability.
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Affiliation(s)
| | - Adriana J Chubaty
- Department of Pharmacy, Prince of Wales Hospital, South Eastern Sydney Local Health District, Randwick, New South Wales, Australia
| | - Suman Adhikari
- Department of Pharmacy, St George Hospital, South Eastern Sydney Local Health District, Kogarah, New South Wales, Australia.,St George Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Spiros Miyakis
- School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.,Department of Infectious Diseases, Wollongong Hospital, Illawarra Shoalhaven Local Health District, Wollongong, New South Wales, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Wollongong Hospital, Illawarra Shoalhaven Local Health District, Wollongong, New South Wales, Australia
| | - Wilfred W Yeo
- School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.,Division of Medicine, Illawarra Shoalhaven Local Health District, Wollongong, New South Wales, Australia
| | - Marijka J Batterham
- School of Mathematics and Applied Statistics, University of Wollongong, New South Wales, Australia
| | - Cara Dickson
- Performance Unit, South Eastern Sydney Local Health District, Kogarah, New South Wales, Australia
| | - Brendan J McMullan
- Department of Immunology and Infectious Diseases, Sydney Children's Hospital, Randwick, New South Wales, Australia
| | - Mona Mostaghim
- Department of Pharmacy, Sydney Children's Hospital, Randwick, New South Wales, Australia
| | - Samantha Li-Yan Hui
- Information Management Services Directorate, South Eastern Sydney Local Health District, Randwick, New South Wales, Australia
| | - Kate R Clezy
- Department of Infectious Diseases, Prince of Wales Hospital, South Eastern Sydney Local Health District, Randwick, New South Wales, Australia
| | - Pamela Konecny
- St George Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia.,Department of Infectious Diseases, Immunology & Sexual Health, St George Hospital, South Eastern Sydney Local Health District, Kogarah, New South Wales, Australia
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4
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Davies J, Boutlis CS, Marshall CS, Tong SYC, Davis JS. The unique aspects of chronic hepatitis B infection in Aboriginal and Torres Strait Islander people. Intern Med J 2018; 48:484-485. [PMID: 29623985 DOI: 10.1111/imj.13759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/02/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Jane Davies
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia.,Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Catherine S Marshall
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Steven Y C Tong
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia.,Indigenous Health, The Doherty Institute, Melbourne, Victoria, Australia
| | - Joshua S Davis
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia.,Department of Infectious Diseases, John Hunter Hospital, Newcastle, New South Wales, Australia
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5
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Bond SE, Boutlis CS, Yeo WW, Miyakis S. Impact of an antimicrobial stewardship intervention on appropriateness of prescribing for community-acquired pneumonia in an Australian regional hospital. Intern Med J 2018; 47:582-585. [PMID: 28503879 DOI: 10.1111/imj.13401] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 09/20/2016] [Accepted: 10/19/2016] [Indexed: 11/28/2022]
Abstract
Community-acquired pneumonia (CAP) is the second commonest indication for antibiotic use in Australian hospitals and is therefore a frequent target for antimicrobial stewardship. A single-centre prospective study was conducted in a regional referral hospital comparing management of adult patients with CAP before and after an educational intervention. We demonstrated a reduction in duration of therapy and reduced inappropriate use of ceftriaxone-based regimens for non-severe CAP.
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Affiliation(s)
- Stuart E Bond
- Department of Pharmacy, Wollongong Hospital, Wollongong, New South Wales, Australia.,School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - Wilfred W Yeo
- School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.,Division of Medicine, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - Spiros Miyakis
- School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.,Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia
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6
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Carroll DE, Marr I, Huang GKL, Holt DC, Tong SYC, Boutlis CS. Staphylococcus aureus Prostatic abscess: a clinical case report and a review of the literature. BMC Infect Dis 2017; 17:509. [PMID: 28732492 PMCID: PMC5521102 DOI: 10.1186/s12879-017-2605-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/18/2017] [Indexed: 11/30/2022] Open
Affiliation(s)
- David E Carroll
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia. .,Daisy Hill Hospital, Southern Health and Social Care Trust, Newry, Northern Ireland, United Kingdom. .,The Queen's University of Belfast, Belfast, Northern Ireland, United Kingdom.
| | - Ian Marr
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Territory Pathology, Northern Territory Department of Health, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - G Khai Lin Huang
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Deborah C Holt
- Menzies School of Health Research, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Steven Y C Tong
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Menzies School of Health Research, Charles Darwin University, Casuarina, Northern Territory, Australia.,Victorian Infectious Disease Service, The Royal Melbourne Hospital, Victoria, Australia.,Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Territory Pathology, Northern Territory Department of Health, Royal Darwin Hospital, Darwin, Northern Territory, Australia
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7
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Jones SL, Riordan JW, Glasgow AL, Botes J, Boutlis CS. Two cases of spondylodiscitis caused by Parvimonas micra. Intern Med J 2016; 45:1090-1. [PMID: 26429222 DOI: 10.1111/imj.12877] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 07/22/2015] [Indexed: 11/26/2022]
Affiliation(s)
- S L Jones
- Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - J W Riordan
- Department of Rheumatology, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - A L Glasgow
- Department of Oncology, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - J Botes
- South Eastern Area Laboratory Services, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - C S Boutlis
- Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia.,Graduate School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia
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8
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Bond SE, Boutlis CS, Jansen SG, Miyakis S. Discontinuation of peri-operative gentamicin use for indwelling urinary catheter manipulation in orthopaedic surgery. ANZ J Surg 2016; 87:E199-E203. [PMID: 27255575 DOI: 10.1111/ans.13642] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/28/2016] [Accepted: 05/02/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND Gentamicin has historically been used prior to insertion and removal of indwelling urinary catheters (IDCs) around elective joint replacement surgery to prevent infection; however, this indication is not recognized in the Australian Therapeutic Guidelines: Antibiotic and the paradigm for safe use of gentamicin has shifted. METHODS The antimicrobial stewardship team of a 500 bed tertiary regional hospital performed a retrospective clinical study of gentamicin IDC prophylaxis around total hip and knee arthroplasties. Results were presented to the orthopaedic surgeons. A literature review identified no guidelines to support gentamicin prophylaxis and only a very low risk of bacteraemia associated with IDC insertion/removal in patients with established bacteriuria. Consensus was reached with the surgeons to discontinue this practice. Subsequent prospective data collection was commenced to determine effectiveness, with weekly feedback to the Department Head of Orthopaedics. RESULTS Data from 137 operations pre-intervention (6 months) were compared with 205 operations post-intervention (12 months). The median patient age was 72 years in both groups. Following the intervention, reductions in gentamicin use were demonstrated for IDC insertion (59/137 (42%) to 4/205 (2%), P < 0.01) and removal (39/137 (28%) to 6/205 (3%), P < 0.01). No gentamicin use was observed during the final 40 weeks of the post-intervention period. There were no significant differences between the groups for pre-operative bacteriuria, surgical site infections or acute kidney injury. CONCLUSION A collaborative approach using quality improvement methodology can lead to an evidence-based reappraisal of established practice. Regular rolling audits and timely feedback were useful in sustaining change.
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Affiliation(s)
- Stuart E Bond
- Department of Pharmacy, Wollongong Hospital, Wollongong, New South Wales, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - Stuart G Jansen
- Department of Orthopaedic Surgery, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - Spiros Miyakis
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.,Department of Infectious Diseases, Wollongong Hospital, Wollongong, New South Wales, Australia
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9
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Crawford SJ, Swan CD, Boutlis CS, Reid AB. Candida costochondritis associated with recent intravenous drug use. IDCases 2016; 4:59-61. [PMID: 27182491 PMCID: PMC4857220 DOI: 10.1016/j.idcr.2016.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 11/25/2022] Open
Abstract
Candida osteoarticular infections are being reported with increasing frequency, possibly due to an expanding population at risk. However, Candida costochondritis is uncommon. We report two cases of Candida costochondritis in patients who presented with subacute-onset chest wall swelling and whose only identifiable risk factor was a history of recent intravenous drug use.
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Affiliation(s)
- Simeon J Crawford
- Department of Infectious Diseases, Wollongong Hospital, Crown Street, Wollongong, NSW 2500, Australia
| | - Christopher D Swan
- Department of Infectious Diseases, Wollongong Hospital, Crown Street, Wollongong, NSW 2500, Australia
| | - Craig S Boutlis
- Department of Infectious Diseases, Wollongong Hospital, Crown Street, Wollongong, NSW 2500, Australia; Graduate School of Medicine, University of Wollongong, Wollongong, NSW 2500, Australia
| | - Alistair B Reid
- Department of Infectious Diseases, Wollongong Hospital, Crown Street, Wollongong, NSW 2500, Australia; Graduate School of Medicine, University of Wollongong, Wollongong, NSW 2500, Australia
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10
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Nagaraja V, Stewart TE, Mackay SG, Glenn DW, Wakefield D, Boutlis CS. Supraglottitis due to group Bstreptococcusin an adult with IgG4 and C2 deficiency: A case report and review of the literature. Laryngoscope 2014; 125:852-5. [DOI: 10.1002/lary.24874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/09/2014] [Accepted: 07/18/2014] [Indexed: 11/09/2022]
Affiliation(s)
| | - Thomas E. Stewart
- Division of Surgery; Wollongong Hospital; Wollongong New South Wales Australia
| | - Stuart G. Mackay
- Division of Surgery; Wollongong Hospital; Wollongong New South Wales Australia
| | | | - Denis Wakefield
- School of Medical Sciences; University of New South Wales; Sydney New South Wales Australia
| | - Craig S. Boutlis
- Graduate School of Medicine; University of Wollongong; Wollongong Hospital Wollongong New South Wales Australia
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11
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Abstract
Intussusception is a recognised paediatric presentation in emergency department and primary care settings. The aetiology of intussusception is multifactorial and largely unknown but includes infection in some cases. Yersinia has been the most frequently cited bacterial association in children. Identifying Yersinia affects the role and choice of antibiotics in a child's treatment regimen. This article reports on Australia's first proven case of Yersinia enterocolitica intussusception, and reviews the clinical epidemiology of all known reported cases world-wide.
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Affiliation(s)
- Austin N May
- Infectious Diseases Department, Wollongong Hospital, Wollongong, New South Wales, Australia
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12
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Tong SYC, Lilliebridge RA, Bishop EJ, Cheng AC, Holt DC, McDonald MI, Giffard PM, Currie BJ, Boutlis CS. Clinical correlates of Panton-Valentine leukocidin (PVL), PVL isoforms, and clonal complex in the Staphylococcus aureus population of Northern Australia. J Infect Dis 2010; 202:760-9. [PMID: 20662623 DOI: 10.1086/655396] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Regional differences in the prevalence of Panton-Valentine leukocidin (PVL) and PVL isoform-harboring strains as well as in the local population structure of Staphylococcus aureus may influence the clinical spectrum of S. aureus infections. METHODS Using a prospective collection of S. aureus isolates from northern Australia, we determined differences between infections caused by (1) PVL(+) and PVL(-) isolates, (2) PVL histidine (H) isoform- and PVL arginine (R) isoform-harboring isolates, and (3) different lineages, including the genetically divergent clonal complex (CC) 75 and the PVL(+) CC93. RESULTS PVL(+) isolates comprised 54% (128/239) of community-associated methicillin-resistant isolates and 40% (95/239) of methicillin-susceptible S. aureus (MSSA) isolates. There were 113 H isoform- and 110 R isoform-harboring isolates. PVL was associated with truly community-acquired disease, younger age, and presentation with sepsis. We found no differences in infections due to H isoform-harboring isolates, compared with R isoform-harboring isolates. CC93 was the most prevalent lineage. The genetically divergent CC75 caused clinical disease similar to that of other S. aureus clones. CONCLUSIONS PVL(+) and PVL(-) infections are clearly distinct. MSSA contributes a large but underrecognized burden of PVL(+) disease. Compared with elsewhere in the world, there is a relative abundance of the clade that contains CC93 and CC121 in both northern Australia and Asia.
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Affiliation(s)
- Steven Y C Tong
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia.
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13
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Affiliation(s)
| | | | - Desmond T. Chih
- Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Craig S. Boutlis
- Charles Darwin University, Darwin, Northern Territory, Australia
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14
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Unsworth NB, Stenos J, Graves SR, Faa AG, Cox GE, Dyer JR, Boutlis CS, Lane AM, Shaw MD, Robson J, Nissen MD. Flinders Island spotted fever rickettsioses caused by "marmionii" strain of Rickettsia honei, Eastern Australia. Emerg Infect Dis 2007. [PMID: 17553271 PMCID: PMC2725950 DOI: 10.3201/eid1304.060087] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We report 7 cases of rickettsiosis caused by a new rickettsial strain. Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis, with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the “marmionii” strain of R. honei, in honor of Australian physician and scientist Barrie Marmion.
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Affiliation(s)
- Nathan B Unsworth
- Australian Rickettsial Reference Laboratory, Geelong, Victoria, Australia
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15
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Unsworth NB, Stenos J, Graves SR, Faa AG, Cox GE, Dyer JR, Boutlis CS, Lane AM, Shaw MD, Robson J, Nissen MD. Flinders Island Spotted Fever Rickettsioses Caused by “marmionii” Strain ofRickettsia honei,Eastern Australia. Emerg Infect Dis 2007; 13:566-73. [PMID: 17553271 PMCID: PMC2725950 DOI: 10.3201/eid1304.050087] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the "marmionii" strain of R. honei, in honor of Australian physician and scientist Barrie Marmion.
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Affiliation(s)
- Nathan B. Unsworth
- Australian Rickettsial Reference Laboratory, Geelong, Victoria, Australia
| | - John Stenos
- Australian Rickettsial Reference Laboratory, Geelong, Victoria, Australia
| | - Stephen R. Graves
- Australian Rickettsial Reference Laboratory, Geelong, Victoria, Australia
| | - Antony G. Faa
- Warwick Hospital (Southern Downs Health Services District), Warwick, Queensland, Australia
| | - G. Erika Cox
- Launceston General Hospital, Launceston, Tasmania, Australia
| | - John R. Dyer
- Fremantle Hospital, Fremantle, Western Australia, Australia
| | - Craig S. Boutlis
- Menzies School of Health Research, Darwin, Northern Territory, Australia
| | - Amanda M. Lane
- University of Queensland, Brisbane, Queensland, Australia
| | | | - Jennifer Robson
- Sullivan Nicolaides Pathology, Brisbane, Queensland, Australia
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16
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Abstract
How is it that individuals exposed to intense malaria transmission can tolerate the presence of malaria parasites in their blood at levels that would produce fever in others? In light of evidence discounting a role for nitric oxide or antibodies to plasmodial glycosylphosphatidylinositols in maintaining this tolerant state, refractoriness to toxin-induced Toll-like receptor-mediated signalling has emerged as a likely explanation that links malarial and bacterial endotoxin tolerance. Understanding the mechanisms underlying tolerance and the potential for cross-tolerization has significant implications for understanding the potential for antitoxic vaccine strategies, as well as interactions between different malaria species and between malaria and other human parasites.
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Affiliation(s)
- Craig S Boutlis
- Division of Tropical and Emerging Infectious Diseases, Menzies School of Health Research, Charles Darwin University, PO Box 41096, Casuarina, NT 0811, Australia.
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Lopansri BK, Anstey NM, Stoddard GJ, Mwaikambo ED, Boutlis CS, Tjitra E, Maniboey H, Hobbs MR, Levesque MC, Weinberg JB, Granger DL. Elevated plasma phenylalanine in severe malaria and implications for pathophysiology of neurological complications. Infect Immun 2006; 74:3355-9. [PMID: 16714564 PMCID: PMC1479261 DOI: 10.1128/iai.02106-05] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cerebral malaria is associated with decreased production of nitric oxide and decreased levels of its precursor, l-arginine. Abnormal amino acid metabolism may thus be an important factor in malaria pathogenesis. We sought to determine if other amino acid abnormalities are associated with disease severity in falciparum malaria. Subjects were enrolled in Dar es Salaam, Tanzania (children) (n = 126), and Papua, Indonesia (adults) (n = 156), in two separate studies. Plasma samples were collected from subjects with WHO-defined cerebral malaria (children), all forms of severe malaria (adults), and uncomplicated malaria (children and adults). Healthy children and adults without fever or illness served as controls. Plasma amino acids were measured using reverse-phase high-performance liquid chromatography with fluorescence detection. Several plasma amino acids were significantly lower in the clinical malaria groups than in healthy controls. Despite the differences, phenylalanine was the only amino acid with mean levels outside the normal range (40 to 84 microM) and was markedly elevated in children with cerebral malaria (median [95% confidence interval], 163 [134 to 193] microM; P < 0.0001) and adults with all forms of severe malaria (median [95% confidence interval], 129 [111 to 155] microM; P < 0.0001). In adults who survived severe malaria, phenylalanine levels returned to normal, with clinical improvement (P = 0.0002). Maintenance of plasma phenylalanine homeostasis is disrupted in severe malaria, leading to significant hyperphenylalaninemia. This is likely a result of an acquired abnormality in the function of the liver enzyme phenylalanine hydroxylase. Determination of the mechanism of this abnormality may contribute to the understanding of neurological complications in malaria.
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Affiliation(s)
- Bert K Lopansri
- Division of Infectious Diseases, VA and University of Utah School of Medicine, Salt Lake City, Utah 84132, USA.
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18
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Trenholme KR, Boutlis CS, Kuns R, Lagog M, Bockarie MJ, Gatton ML, Kemp DJ, Good MF, Anstey NM, Gardiner DL. Antibody reactivity to linear epitopes of Plasmodium falciparum cytoadherence-linked asexual gene 9 in asymptomatic children and adults from papua new Guinea. Am J Trop Med Hyg 2005; 72:708-13. [PMID: 15964954 PMCID: PMC2532502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
The cytoadherence-linked asexual gene 9 (clag 9) of Plasmodium falciparum has been implicated in the cytoadherence of infected erythrocytes. To determine the immunogenicity of the clag 9 gene product (CLAG 9 protein) in humans, we measured antibody responses to 11 synthetic CLAG 9 peptides in a group of 177 asymptomatic children and adults subject to intense malaria exposure in Madang, Papua New Guinea. The CLAG 9 peptides were immunogenic in adults and children. Antibody responses to peptides 4 and 10 were high across all age groups and detectable in a majority of children less than five years of age. While CLAG 9 peptides are immunogenic in humans, longitudinal studies will be required to determine the longevity of antibody responses to CLAG 9 and their role in protection from disease.
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Affiliation(s)
- Katharine R Trenholme
- Division of Infectious Diseases and Immunology, The Australian Centre for International and Tropical Health and Nutrition, The Queensland Institute of Medical Research, Brisbane, Queensland, Australia.
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19
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Boutlis CS, Riley EM, Anstey NM, de Souza JB. Glycosylphosphatidylinositols in malaria pathogenesis and immunity: potential for therapeutic inhibition and vaccination. Curr Top Microbiol Immunol 2005; 297:145-85. [PMID: 16265905 DOI: 10.1007/3-540-29967-x_5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glycosylphosphatidylinositols (GPIs) are found in the outer cell membranes of all eukaryotes. GPIs anchor a diverse range of proteins to the surface of Plasmodium falciparum, but may also exist free of protein attachment. In vitro and in vivo studies have established GPIs as likely candidate toxins in malaria, consistent with the prevailing paradigm that attributes induction of inflammatory cytokines, fever and other pathology to parasite toxins released when schizonts rupture. Although evolutionarily conserved, sufficient structural differences appear to exist that impart upon plasmodial GPIs the ability to activate second messengers in mammalian cells and elicit immune responses. In populations exposed to P. falciparum, the antibody response to purified GPIs is characterised by a predominance of immunoglobulin (Ig)G over IgM and an increase in the prevalence, level and persistence of responses with increasing age. It remains unclear, however, if these antibodies or other cellular responses to GPIs mediate anti-toxic immunity in humans; anti-toxic immunity may comprise either reduction in the severity of disease or maintenance of the malaria-tolerant state (i.e. persistent asymptomatic parasitaemia). P. falciparum GPIs are potentially amenable to specific therapeutic inhibition and vaccination; more needs to be known about their dual roles in malaria pathogenesis and protection for these strategies to succeed.
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Affiliation(s)
- C S Boutlis
- International Health Program, Infectious Diseases Division, Menzies School of Health Research, P.O. Box 41096, 0811 Casuarina, NT, Australia.
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20
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Boutlis CS, Weinberg JB, Baker J, Bockarie MJ, Mgone CS, Cheng Q, Anstey NM. Nitric oxide production and nitric oxide synthase activity in malaria-exposed Papua New Guinean children and adults show longitudinal stability and no association with parasitemia. Infect Immun 2004; 72:6932-8. [PMID: 15557614 PMCID: PMC529162 DOI: 10.1128/iai.72.12.6932-6938.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Individuals in areas of intense malaria transmission exhibit resistance (or tolerance) to levels of parasitemia in their blood that would normally be associated with febrile illness in malaria-naive subjects. The resulting level of parasitemia associated with illness (the pyrogenic threshold) is highest in childhood and lowest in adulthood. Clinical parallels between malarial and bacterial endotoxin tolerance have led to the supposition that both share common physiological processes, with nitric oxide (NO) proposed as a candidate mediator. The hypotheses that NO mediates tolerance and blood stage parasite killing in vivo were tested by determining its relationship to age and parasitemia cross-sectionally and longitudinally in a population of 195 children and adults from Papua New Guinea encountering intense malaria exposure. Despite pharmacological clearance of asymptomatic parasitemia, NO production and mononuclear cell NO synthase (NOS) activity were remarkably stable within individuals over time, were not influenced by parasitemia, and varied little with age. These results contrast with previous smaller cross-sectional studies. Baseline NO production and NOS activity did not protect against recurrent parasitemia, consistent with previous data suggesting that NO does not have antiparasitic effects against blood stage infection in vivo. The NO indices studied were markedly higher in specimens from study subjects than in samples from Australian controls, and NOS activity was significantly associated with plasma immunoglobulin E levels, consistent with induction of NO by chronic exposure to other infections and/or host genetic factors. These results suggest that NO is unlikely to mediate killing of blood stage parasites in this setting and is unlikely to be the primary mediator in the acquisition or maintenance of malarial tolerance.
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Affiliation(s)
- Craig S Boutlis
- Menzies School of Health Research, P.O. Box 41096, Casuarina, NT 0811, Australia.
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Hanson JP, Taylor CT, Richards AR, Smith IL, Boutlis CS. Japanese encephalitis acquired near Port Moresby: implications for residents and travellers to Papua New Guinea. Med J Aust 2004; 181:282-3. [PMID: 15347281 DOI: 10.5694/j.1326-5377.2004.tb06274.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Accepted: 06/29/2004] [Indexed: 11/17/2022]
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Boutlis CS, Hobbs MR, Marsh RL, Misukonis MA, Tkachuk AN, Lagog M, Booth J, Granger DL, Bockarie MJ, Mgone CS, Levesque MC, Weinberg JB, Anstey NM. Inducible nitric oxide synthase (NOS2) promoter CCTTT repeat polymorphism: relationship to in vivo nitric oxide production/NOS activity in an asymptomatic malaria-endemic population. Am J Trop Med Hyg 2003; 69:569-73. [PMID: 14740870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
Polymorphisms in the inducible nitric oxide synthase gene (NOS2) promoter have been associated with clinical outcome from malaria. These include a CCTTT repeat (CCTTTn) 2.5 kilobases upstream from the NOS2 transcription start site, and two single nucleotide substitutions: G-->C at position -954 (G-954C), and C-->T at position -1173 (C-1173T). Although hypothesized to influence NO production in vivo, the functional relevance of (CCTTT)n and G-954C is uncertain because disease association studies have yielded inconsistent results. This study found no association between CCTTT repeat number and levels of plasma NO metabolites or peripheral blood mononuclear cell NOS activity in a cohort of asymptomatic malaria-exposed coastal Papua New Guineans 1-60 years old. This suggests that (CCTTT)n does not independently influence NOS2 transcription in vivo. Neither the G-954C nor the C-1173T polymorphisms were identified in this population, indicating the variability and complexity of selection for NOS2 promoter polymorphisms in different malaria-endemic populations.
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Affiliation(s)
- Craig S Boutlis
- International Health Program, Infectious Diseases Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
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23
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Boutlis CS, Lagog M, Chaisavaneeyakorn S, Misukonis MA, Bockarie MJ, Mgone CS, Wang Z, Morahan G, Weinberg JB, Udhayakumar V, Anstey NM. Plasma interleukin-12 in malaria-tolerant papua new guineans: inverse correlation with Plasmodium falciparum parasitemia and peripheral blood mononuclear cell nitric oxide synthase activity. Infect Immun 2003; 71:6354-7. [PMID: 14573655 PMCID: PMC219590 DOI: 10.1128/iai.71.11.6354-6357.2003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interleukin-12 (IL-12) has been inversely associated with disease severity in human and murine malaria, and a polymorphism in the IL-12 p40 subunit gene (IL12B) has been associated with susceptibility to human cerebral malaria and reduced nitric oxide (NO) production. To better define the relationships between IL-12, NO, malaria parasitemia, and IL12B polymorphisms during malarial tolerance, plasma IL-12 levels and peripheral blood mononuclear cell NO synthase (NOS) activity were measured in asymptomatic Papua New Guineans exposed to intense malaria transmission. The IL-12 level was strongly inversely correlated with the density of Plasmodium falciparum parasitemia (rho = -0.45; P < 0.001) and was predicted to decrease by 19% (95% confidence interval [CI], 10 to 27%) for each twofold increase in P. falciparum parasitemia. This is consistent with a suppressive effect of parasitemia on IL-12 production, an effect previously shown in vitro and in rodent models of disease. The IL-12 level was inversely correlated with NOS activity (r = -0.22; P = 0.007), with each twofold increase in NOS activity being predictive of a 25% (95% CI, 7 to 38%) decrease in plasma IL-12 levels. This probably reflects additional down-regulation of IL-12 by the high basal NO production and monocyte NOS expression found in the malaria-tolerant state. Neither the IL-12 level nor NOS activity was associated with either of two IL12B polymorphisms, reflecting the diversity of genetic control over immune responses in different populations.
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Affiliation(s)
- Craig S Boutlis
- International Health Program, Division of Infectious Diseases, Menzies School of Health Research, Northern Territory University, Flinders University Northern Territory Clinical School, Darwin, Australia
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24
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Boutlis CS, Tjitra E, Maniboey H, Misukonis MA, Saunders JR, Suprianto S, Weinberg JB, Anstey NM. Nitric oxide production and mononuclear cell nitric oxide synthase activity in malaria-tolerant Papuan adults. Infect Immun 2003; 71:3682-9. [PMID: 12819048 PMCID: PMC161965 DOI: 10.1128/iai.71.7.3682-3689.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2003] [Revised: 02/21/2003] [Accepted: 03/11/2003] [Indexed: 01/17/2023] Open
Abstract
Individuals living in regions of intense malaria transmission exhibit natural immunity that allows them to be without fever and other symptoms for most of the time despite frequent parasitization. Although this tolerance of parasitemia appears to be more effective in children than in adults (as evidenced by lower parasitemia fever thresholds with age), adults do exhibit a degree of tolerance but the mechanism(s) underlying this are unclear. Asymptomatic malaria-exposed children have higher levels of nitric oxide (NO) than children with severe disease, and NO has been proposed as a mediator of malarial tolerance. However, the ability of highly malaria-exposed asymptomatic adults to generate high-level basal NO is unknown, as is the relationship between NO and malaria tolerance in adults. The relationship between NO and malaria parasitemia was therefore determined in asymptomatic adults from Papua, Indonesia. Adults with Plasmodium falciparum parasitemia had markedly increased basal systemic NO production relative to aparasitemic Papuan controls, who in turn produced more NO than healthy controls from a region without malaria. Immunoglobulin E levels were universally elevated in malaria-exposed Papuan subjects, suggesting that the prevalence of intestinal parasitosis may be high and that nonmalarial infection may also contribute to high basal NO production. Basal peripheral blood mononuclear cell (PBMC) NO synthase activity was elevated in Papuans but poorly correlated with systemic NO production, suggesting that NO production in this setting arises not only from PBMCs but also from other tissue and cellular sources. NO production was associated with and may contribute to malaria tolerance in Papuan adults.
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Affiliation(s)
- Craig S Boutlis
- International Health Program, Division of Infectious Diseases, Menzies School of Health Research, Northern Territory University, Casuarina, Australia
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25
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Hughes AJ, Spithill TW, Smith RE, Boutlis CS, Johnson PDR. Human fasciolosis acquired in an Australian urban setting. Med J Aust 2003; 178:244-5. [PMID: 12603192 DOI: 10.5694/j.1326-5377.2003.tb05174.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2002] [Accepted: 01/08/2003] [Indexed: 11/17/2022]
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Boutlis CS, Fagan PK, Gowda DC, Lagog M, Mgone CS, Bockarie MJ, Anstey NM. Immunoglobulin G (IgG) responses to Plasmodium falciparum glycosylphosphatidylinositols are short-lived and predominantly of the IgG3 subclass. J Infect Dis 2003; 187:862-5. [PMID: 12599061 DOI: 10.1086/367897] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2002] [Revised: 11/02/2002] [Indexed: 11/03/2022] Open
Abstract
The induction of neutralizing immunity to Plasmodium falciparum toxins by vaccination has been proposed as a preventive strategy to limit the severity of malaria. For this approach to be successful, generation of a sustained immune response would be necessary. This study shows that immunoglobulin G (IgG)-subclass responses elicited by the proposed P. falciparum toxin glycosylphosphatidylinositol (GPI) in Papua New Guinean subjects 5-60 years old predominantly involve IgG(3), with a lesser contribution from IgG(1) and an absence of IgG(2) and IgG(4). IgG(3) levels declined sharply within 6 weeks of pharmacological clearance of parasitemia in all subjects, whereas a significant decrease in IgG(1) levels was seen only in subjects < or =19 years old. Because the natural antibody response to P. falciparum GPIs is skewed toward the short-lived IgG(3) subclass, a vaccination strategy with GPI analogues would likely require augmentation by costimulatory molecules, to induce a more persistent anti-GPI response.
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Affiliation(s)
- Craig S Boutlis
- Infectious Diseases Division, Menzies School of Health Research, Darwin, Australia
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27
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Anstey NM, Boutlis CS, Saunders JR. Systemic nitric oxide production in human malaria. I. Analysis of NO metabolites in biological fluids. Methods Mol Med 2003; 72:461-7. [PMID: 12125142 DOI: 10.1385/1-59259-271-6:461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Nicholas M Anstey
- Tropical Medicine and International Health Unit, Menzies School of Health Research, Division of Medicine, Royal Darwin Hospital, Darwin, Australia
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28
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Morahan G, Boutlis CS, Huang D, Pain A, Saunders JR, Hobbs MR, Granger DL, Weinberg JB, Peshu N, Mwaikambo ED, Marsh K, Roberts DJ, Anstey NM. A promoter polymorphism in the gene encoding interleukin-12 p40 (IL12B) is associated with mortality from cerebral malaria and with reduced nitric oxide production. Genes Immun 2002; 3:414-8. [PMID: 12424623 DOI: 10.1038/sj.gene.6363909] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interleukin-12 (IL-12) is an important regulatory cytokine in infection and immunity. Administration of IL-12 may reduce complications of severe malaria in rodents. Polymorphisms in IL12B, the gene encoding the IL-12 p40 subunit, influence the secretion of IL-12 and susceptibility to Type 1 diabetes. We therefore investigated whether IL12B polymorphisms may affect the outcome of severe malaria. Homozygosity for a polymorphism in the IL12B promoter was associated with increased mortality in Tanzanian children having cerebral malaria but not in Kenyan children with severe malaria. Furthermore, homozygotes for the IL12B promotor polymorphism had decreased production of nitric oxide, which is in part regulated by IL-12 activity. These studies suggest that IL12B polymorphisms, via regulation of IL-12 production, may influence the outcome of malaria infection in at least one African population.
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Affiliation(s)
- G Morahan
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.
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Boutlis CS, Gowda DC, Naik RS, Maguire GP, Mgone CS, Bockarie MJ, Lagog M, Ibam E, Lorry K, Anstey NM. Antibodies to Plasmodium falciparum glycosylphosphatidylinositols: inverse association with tolerance of parasitemia in Papua New Guinean children and adults. Infect Immun 2002; 70:5052-7. [PMID: 12183552 PMCID: PMC128285 DOI: 10.1128/iai.70.9.5052-5057.2002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Individuals living in regions of intense malaria transmission exhibit natural immunity that facilitates persistence of parasitemia at controlled densities for much of the time without symptoms. This aspect of immunity has been referred to as malarial "tolerance" and is thought to partly involve inhibition of the chain of events initiated by a parasite toxin(s) that may otherwise result in cytokine release and symptoms such as fever. Antibodies to the candidate Plasmodium falciparum glycosylphosphatidylinositol (GPI) toxin have been viewed as likely mediators of such tolerance. In this study, the relationship between antibodies to P. falciparum GPIs, age, and parasitemia was determined in asymptomatic children and adults living in Madang, Papua New Guinea. The prevalence and intensity of antibody responses increased with age and were lowest in children 1 to 4 years old with the highest-density parasitemias. In children of this age group who were tolerant of parasitemia during the study, only 8.3% had detectable immunoglobulin G (IgG) and none had IgM antibodies to GPI. This suggests that anti-GPI antibodies are unlikely to be the sole mediator of malarial tolerance, especially in children younger than 5 years. Following antimalarial treatment, clearance of parasitemia led to a fall in anti-GPI IgG response in children and adolescents within 6 weeks. As anti-GPI antibodies potentially play a role in protecting against disease progression, our results caution against the treatment of asymptomatic parasitemia and suggest that generation of a sustained antibody response in children poses a challenge to novel antitoxic vaccination strategies.
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Affiliation(s)
- Craig S Boutlis
- Department of Tropical Medicine and International Health, Menzies School of Health Research, Casuarina, Australia
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