Saturday, October 17, 2009

 

Staphylococcus aureus bacteraemia: a major cause of mortality in Australia and New Zealand.

Staphylococcus aureus bacteraemia: a major cause of mortality in Australia and New Zealand.

Med J Aust. 2009 Oct 5

Women's and Children's Hospital, Adelaide, SA, Australia. john.turnidge@health.sa.gov.au.

OBJECTIVE:

To document the types of, and mortality from, Staphylococcus aureus bacteraemia in Australia and New Zealand, and determine factors associated with mortality.

DESIGN AND SETTING:

Prospective observational study in 27 independent or hospital pathology laboratories in Australia (24) and New Zealand (3), employing a web-based database to prospectively record demographic features, selected risk factors, principal antibiotic treatment and mortality data on all patients with positive blood cultures for S. aureus from June 2007 to May 2008.

MAIN OUTCOME MEASURE:

30-day all-cause mortality.

RESULTS:

1994 episodes of S. aureus bacteraemia were identified, and complete 30-day follow-up data were available for 1865. Most episodes had their onset in the community (60.8%; 95% CI, 58.7%-63.0%). Methicillin-resistant S. aureus (MRSA) caused 450 episodes (24.1%; 95% CI, 22.2%-25.9%), and 123 of these (27.3%) had a susceptibility profile consistent with community-associated MRSA. All-cause mortality at 30 days was 20.6% (95% CI, 18.8%-22.5%). On univariate analysis, increased mortality was significantly associated with older age, European ethnicity, MRSA infection, infections not originating from a medical device, sepsis syndrome, pneumonia/empyema, and treatment with a glycopeptide or other non-beta-lactam antibiotic. On multivariable analysis, independent predictors of mortality were age, sepsis syndrome, pneumonia/empyema, device-associated infection with a secondary focus, left-sided endocarditis, and treatment with a glycopeptide such as vancomycin, but not MRSA infection.

CONCLUSIONS:

S. aureus bacteraemia is a common infection in both the community and hospitals in Australia and New Zealand, and is associated with appreciable mortality. Invasive MRSA infection may be more life-threatening, partly because of the inferior efficacy of the standard treatment, vancomycin. National web-based surveillance of S. aureus bacteraemia and its outcomes is not only important but also easily achievable.

eMedical Journal of Australia

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Sunday, October 11, 2009

 

Emerging Infections in Burns

Emerging Infections in Burns

Surg Infect (Larchmt). 2009 Oct 7

Ludwik K. Branski,*

*These authors contributed equally to this work.

Ahmed Al-Mousawi,*
Haidy Rivero,*
Marc G. Jeschke,
Arthur P. Sanford, and
David N. Herndon
Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals
for Children, Galveston, Texas.
Address correspondence to:

Dr. David N. Herndon - Shriners Hospitals for Children - 815 Market St.
Galveston, TX 77550

Abstract Background:

Patients who suffer severe burns are at higher risk for local
and systemic infections. In recent years, emerging resistant
pathogens have forced burn care providers world wide to search
for alternative forms of treatment. Multidrug-resistant
Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter
spp., and various fungal strains have been the major contributors
to the increase in morbidity and mortality rates. Multi-drug-resistant
S. aureus remains the major cause of gram-positive burn wound
infections world wide. Treatment strategies include rigorous
isolation protocols and new types of antibiotics where necessary.

Methods:

We reviewed 398 severely burned patients (burns >40% total
body surface area [TBSA]) admitted to our hospital between
2000 and 2006. Patients who did not contract multi-drug-resistant
gram-negative organisms during their hospital course and received
our standard antibiotic regimen-vancomycin and
piperacillin/tazobactam-served as controls (piperacillin/tazobactam;
n = 280). The treatment group consisted of patients who, during
their acute hospital stay, developed infections with multi-drug-resistant
gram-negative pathogens and were treated with vancomycin and
colistin for at least three days (colistin; n = 118).

Results:

Gram-negative organisms continue to cause the most severe
infections in burn patients. Colistin has re-emerged as a highly
effective antibiotic against multiresistant Pseudomonas and
Acinetobacter infections of burns.

Patients who required colistin therapy had a significantly
larger average total and full-thickness burn than patients
treated with piperacillin/tazobactam and vancomycin, and the
mortality rate was significantly higher in the colistin group
(p less then 0.05). However, there was no significant difference
between the colistin and piperacillin/tazobactam groups in the
incidence of neurotoxicity, hepatic toxicity, or nephrotoxicity.

The main fungal pathogens in burn patients are Candida spp.,
Aspergillus spp., and Fusarium spp. A definitive diagnosis is
more difficult to obtain than in bacterial infections. Amphotericin B
and voriconazole remain the two most important anti-fungal
substances in our practice.

Conclusions:

Innovations in fluid management, ventilatory support, surgical
care, and antimicrobial therapy have contributed to a significant
reduction in morbidity and mortality rates in burn patients.

Vancomycin and clindamycin are the two most important
reserve antibiotics for methicillin-resistant Staphylococcus
aureus infection.

Oxazolidinones and streptogramins have showed high effectiveness
against gram-positive infections. Colistin has re-emerged as a
highly effective antibiotic against multiresistant Pseudomonas
and Acinetobacter infections.

Current challenges include Candida, Aspergillus, and molds. The
development of new agents, prudent and appropriate use of
antibiotics, and better infection control protocols are paramount
in the ongoing battle against multi-resistant organisms.

MaryAnnLiebert

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