Internal medicine journal
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Internal medicine journal · Dec 2005
Severe community-acquired pneumonia: an Australian perspective.
Severe community-acquired pneumonia (CAP) is a common disease with a relatively high mortality. The initial treatment is empirical, based on a broad range of potential pathogens. There are minimal published data describing microbiological causes of pneumonia in Australia. ⋯ Severe CAP requiring ICU admission was associated with a mortality rate of 32%, despite appropriate antimicrobial therapy including a beta-lactam and a macrolide antibiotic in most cases. Causative organisms identified were similar to those found in previous studies. High rates of viral causes (28% of identified pathogens) were noted. Low rates of legionellosis and other atypical causes were found, most probably due to a lack of systematic testing for these agents.
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Internal medicine journal · Dec 2005
ReviewAntibiotics currently used in the treatment of infections caused by Staphylococcus aureus.
Staphylococcal infections are a common and significant clinical problem in medical practice. Most strains of Staphylococcus aureus are now resistant to penicillin, and methicillin-resistant strains of S. aureus (MRSA) are common in hospitals and are emerging in the community. Penicillinase-resistant penicillins (flucloxacillin, dicloxacillin) remain the antibiotics of choice for the management of serious methicillin-susceptible S. aureus (MSSA) infections, but first generation cephalosporins (cefazolin, cephalothin and cephalexin), clindamycin, lincomycin and erythromycin have important therapeutic roles in less serious MSSA infections such as skin and soft tissue infections or in patients with penicillin hypersensitivity, although cephalosporins are contra-indicated in patients with immediate penicillin hypersensitivity (urticaria, angioedema, bronchospasm or anaphylaxis). ⋯ Nosocomial strains of MRSA are typically multi-resistant (mrMRSA), and mrMRSA strains must always be treated with a combination of two oral antimicrobials, typically rifampicin and fusidic acid, because resistance develops rapidly if they are used as single agents. Most community-acquired strains of MRSA in Australia and New Zealand are non multiresistant (nmMRSA), and lincosamides (clindamycin, lincomycin) or cotrimoxazole are the antibiotics of choice for less serious nmMRSA infections such as skin and soft tissue infections. New antibiotics such as linezolid and quinupristin/dalfopristin have good antistaphylococcal activity but are very expensive and should be reserved for patients who fail on or are intolerant of conventional therapy or who have highly resistant strains such as hVISA (heterogenous vancomycin-intermediate S aureus).
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Internal medicine journal · Dec 2005
Randomized Controlled TrialDoubling daily inhaled corticosteroid dose is ineffective in mild to moderately severe attacks of asthma in adults.
Asthma guidelines recommend increasing or doubling inhaled corticosteroid (ICS) dose to treat mild and moderate exacerbations of asthma in adults. ⋯ Doubling daily ICS dose per se is not effective for the treatment of mild to moderately severe exacerbations of asthma in adults. Success may depend on achieved ICS dose. Oral steroids are effective, but side-effects are common. A review of current guidelines may be warranted.
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Internal medicine journal · Dec 2005
ReviewDiagnosis and management of Staphylococcus aureus bacteraemia.
Staphylococcus aureus bacteraemia (SAB) is common. Around 8000 cases occur per year in Australia, of which 60% are hospital- or healthcare-associated. Risk factors for SAB include injectable drug use, haemodialysis, indwelling vascular catheters and immunosuppression. ⋯ However, vancomycin remains the therapy of choice for SAB due to methicillin-resistant strains. Combination therapy with gentamicin may be useful for the first few days of treatment in selected patients, but otherwise there are few data to support the use of combination regimens in SAB. Newer agents such as linezolid and quinupristin/dalfopristin may have a role in selected patients, especially in SAB due to S. aureus strains with reduced susceptibility to vancomycin.
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Internal medicine journal · Dec 2005
ReviewEpidemiology, clinical features and management of infections due to community methicillin-resistant Staphylococcus aureus (cMRSA).
Methicillin-resistant Staphylococcus aureus (MRSA) was initially confined to hospitals, but in the late 1970s appeared in the community in the USA, primarily among intravenous drug users. In the 1990s, community MRSA (cMRSA) strains appeared in multiple areas of the world, and spread extensively. Initially, there were problems with the definition of 'community-acquired', which was exacerbated by the fact that if a time-based definition was used without stratification for risk factors, patients with healthcare-associated MRSA would be counted. ⋯ While cMRSA strains are usually susceptible to most non-beta-lactam antimicrobials, there is a lack of clinical trial data indicating which drugs have superior clinical efficacy. DNA fingerprinting methods have become more sophisticated over the last decade, and have determined that cMRSA strains have probably arisen from virulent methicillin-susceptible strains, most likely by horizontal transfer of methicillin-resistance genes from coagulase negative staphylococci to S. aureus on a limited number of occasions, and these clones have spread extensively throughout the world by person-to-person transmission. In Australia, the dominant cMRSA clones are the Western Australia, Oceania and Queensland strains.