Echocardiography has minimal yield and may not be warranted in Staphylococcus aureus bacteremia without clinical risk factors for endocarditis.

Current guidelines recommend performing echocardiography in all patients with Staphylococcus aureus bacteremia (SAB), but patients at very low risk of endocarditis may not benefit from this investigation. This study seeks to identify patients at very low risk of endocarditis. A retrospective single-center consecutive case series of patients with SAB was examined. Microbiological and echocardiographic data were used to identify patients with community onset, prolonged bacteremia, and intracardiac prosthetic devices. The diagnostic performance of these criteria for endocarditis as measured against transesophageal echocardiography (TEE) was calculated. 593 episodes of SAB were examined over a period of 6 years. 10 % were excluded from analysis due to death or discharge less than 48 h after the first positive blood culture or no admission to hospital, leaving 532 episodes for analysis. 64 % of the included episodes were investigated with echocardiography: 39 % with TEE and 26 % with transthoracic echocardiography (TTE) only. 16 % of the episodes investigated with echocardiography were demonstrated to have endocarditis. The rate of endocarditis was higher for episodes undergoing TEE (24 %) than TTE only (5 %). There were no instances of endocarditis amongst the 23 episodes investigated with TEE where none of the three risk factors were present. This group represented 57 % of the nosocomial (non-community-onset) episodes investigated with TEE. Patients with none of the three criteria examined in this study have a very low rate of endocarditis and may fall below the test threshold for echocardiography.

International travel in the immunocompromised patient: a cross-sectional survey of travel advice in 254 consecutive patients.

AIMS: Our primary aim was to determine the rate of overseas travel in immunocompromised individuals attending appropriate clinics at an Australian tertiary care hospital. We also aimed to characterise health-seeking behaviour prior to travel and investigated sources of pre-travel advice, compared travel patterns and activities between three specific immunosuppressed groups, and examined pre-immunosuppression patient serology. METHODS: We implemented a cross-sectional survey of patients between February and August 2012. This survey was implemented among three outpatient populations at Monash Medical Centre, an Australian tertiary care hospital. RESULTS: We recruited 254 immunosuppressed adults from three patient populations: human immunodeficiency virus-positive individuals, renal transplant patients and rheumatology patients requiring immunosuppressive therapy. No clinical intervention was performed. In the 10 years preceding the survey, 153 (60.2%) participants reported international travel. Of these, 105 (68.6%) were immunosuppressed at the time of travel. These patients were 47.6% male and 60% Australian born. Forty per cent were visiting friends and relatives as part of their travel. Fifty-four per cent of those immunocompromised at the time of travel were going to high-risk destinations. Pathology files indicated that serological screening was frequently not performed prior to immunosuppression in the renal transplant and rheumatology groups. CONCLUSIONS: Immunocompromised patients often travel to high-risk destinations with limited or inadequate pre-travel preparations. Doctors caring for the immunocompromised should be aware of travel risks, suitable vaccination protocols and when to refer to specialist travel clinics.

Incidence and seroprevalence of dengue virus infections in Australian travellers to Asia.

The purpose of this study was to estimate the incidence density and prevalence of dengue virus infection in Australian travellers to Asia. We conducted a multi-centre prospective cohort study of Australian travellers over a 32-month period. We recruited 467 travellers (≥ 16 years of age) from three travel clinics who intended to travel Asia, and 387 (82.9%) of those travellers completed questionnaires and provide samples pre- and post-travel for serological testing for dengue virus infection. Demographic data, destination countries and history of vaccinations and flavivirus infections were obtained. Serological testing for dengue IgG and IgM by enzyme-linked immunosorbent assay (ELISA) (PanBio assay) was performed. Acute seroconversion for dengue infection was demonstrated in 1.0% of travellers, representing an incidence of 3.4 infections per 10,000 days of travel (95% confidence interval [CI]: 0.9-8.7). The seroprevalence of dengue infection was 4.4% and a greater number of prior trips to Asia was a predictor for dengue seroprevalence (p = 0.019). All travellers experienced subclinical dengue infections and had travelled to India (n = 3) and China (n = 1). This significant attack rate of dengue infection can be used to advise prospective travellers to dengue-endemic countries.

In vitro activities of 'new' and 'conventional' antibiotics against multi-drug resistant Gram negative bacteria from patients in the intensive care unit.

OBJECTIVES: To identify and collect clinical isolates of multi-drug resistant Gram negative bacteria and to perform antimicrobial susceptibility testing using an extended panel of antibiotics including tigecycline, colistin, aztreonam, piperacillin/tazobactam and ampicillin/sulbactam. METHODS: Minimum inhibitory concentrations (MICs) using the Epsilometer test (E-test) methodology were determined for 28 distinct multi-drug resistant Gram negative isolates from patients in the intensive care unit (ICU). RESULTS: Tigecycline had good in vitro activity against Acinetobacter species and Enterobacter cloacae, and colistin had potent in vitro activity against Acinetobacter, E. cloacae and Pseudomonas aeruginosa. Enterobacter cloacae and Serratia marcescens but not P. aeruginosa or Acinetobacter species were susceptible to piperacillin/tazobactam. Ampicillin/sulbactam had poor in vitro activity for most isolates tested. The activity of tigecycline and colistin did not appear to be affected by the presence of extended spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) and aztreonam maintained its in vitro activity against the Enterobacteriaceae tested despite the presence of MBLs. CONCLUSIONS: Tigecycline and colistin have potent in vitro activity and might have useful therapeutic activity in patients with infections due to multi-drug resistant Acinetobacter species and E. cloacae, including those harbouring ESBLs and MBLs. In addition, colistin demonstrated potent in vitro activity against multi-drug resistant P. aeruginosa.

Incidence and risk factors for immune reconstitution inflammatory syndrome in an ethnically diverse HIV type 1-infected cohort.

BACKGROUND: It is estimated that 10%-25% of patients who start highly active antiretroviral therapy (HAART) experience immune reconstitution inflammatory syndrome (IRIS). Our objective was to determine the incidence, clinical spectrum, and predictors of IRIS in an ethnically diverse cohort of patients initiating HAART. METHODS: A retrospective study of all patients starting HAART between 1 January 2000 and 31 August 2002 at a human immunodeficiency virus (HIV) clinic in London was performed. All laboratory measurements and data on antiretroviral therapies were obtained from the clinic database. Medical records were reviewed to identify clinical events consistent with IRIS during the 6 months after HAART was initiated. RESULTS: A total of 199 patients were included, of whom 50.8% were male, 59.3% were black African, 29.1% were white, and 10.5% were black Caribbean. The median baseline CD4 cell count and HIV RNA load were 174x10(6) cells/L (interquartile range [IQR], 82-285x10(6) cells/L) and 37,830 copies/mL (IQR, 4809-149,653 copies/mL), respectively. Forty-four patients (22.7%) experienced an IRIS event at a median of 12 weeks after HAART initiation (IQR, 4-24 weeks after initiation); 22 events (50%) involved genital herpes, 10 (23%) involved genital warts, 4 (9.0%) involved molluscum contagiosum, and 4 (9.0%) involved varicella zoster virus infection. Five patients had mycobacterial infections, 4 had hepatitis B, 1 had Pneumocystis jirovecci infection, and 1 had Kaposi sarcoma. The strongest independent predictors of IRIS were younger age at initiation of HAART (P=.003), baseline CD4 cell percentage of <10% (odds ratio [OR], 2.97; IQR, 1.17-7.55) compared with >15%, and ratio of CD4 cell percentage to CD8 cell percentage of <0.15 (OR, 3.45; 95% confidence interval, 1.27-9.1) compared with >0.3. CONCLUSIONS: Approximately one-quarter of patients who start HAART experience an IRIS event. The majority are dermatological, in particular genital herpes and warts. Patients with advanced immunodeficiency at HAART initiation are at greatest risk of developing IRIS and should be appropriately screened and monitored.