Burkholderia cepacia: An Outbreak in the Peritoneal Dialysis Unit.

Burkholderia cepacia is a ubiquitous, opportunistic, environmental gram-negative bacillus which most commonly affects cystic fibrosis and immunocompromised patients. Rarely, it can cause peritoneal dialysis (PD) exit-site infection (ESI). Information relating to predisposing factors, clinical course, and treatment options for B. cepacia ESIs is limited. Although reports of B. cepacia healthcare-associated infections exist, outbreaks in PD units have not previously been reported. A recent outbreak of B. cepacia ESI in our PD unit provided a unique opportunity to study B. cepacia ESIs and to outline an approach to investigating such an outbreak.After unexpectedly identifying B. cepacia as the cause of PD catheter ESIs in 3 patients over an 11-week period, we began systematically screening our PD population for B. cepacia exit-site colonization. A further 6 patients were found to be affected, 3 with asymptomatic colonization and 3 with symptomatic B. cepacia ESI. Four of the 6 developed tunnel infections requiring multiple courses of antibiotic treatment, and 3 patients required catheter removal; 2 patients with symptomatic ESIs without tunnel involvement responded to oral and topical antibiotics. Further investigation implicated 4% chlorhexidine aqueous bodywash used by all patients as the probable source of the outbreak.This is the first reported outbreak of B. cepacia ESIs. We noted an association between diabetes mellitus and refractory/more extensive infection. Our experience suggests that isolated ESIs can be treated successfully with oral antibiotics whereas tunnel infections generally require catheter removal.

Suboptimal performance of rotavirus testing in a vaccinated community population should prompt laboratories to review their rotavirus testing algorithms in response to changes in disease prevalence.

Rotavirus vaccine has reduced disease prevalence in many countries. Consequently, we aimed to assess the reliability of a rotavirus immunoassay in the community population of Auckland and Northland, New Zealand. Between 22 October 2015 and 31 December 2016, 2873 fecal samples were tested by enzyme immunoassay (EIA, Rotascreen II, Microgen, UK) from 2748 patients (median age 8 years, range 0-101 years). Eighty-nine (3.1%) samples were reactive; 86 samples were tested by a second method. Rotavirus was confirmed in 49/86 (57%). Positive rotavirus EIAs were more likely to be confirmed in samples from cases ≥1 year of age (positive predictive value [PPV] 61%, 95% confidence interval [CI] 50-72%, P = 0.049) and in spring/summer (PPV 67%, 95% CI 55-78%, P = 0.003). Reactive rotavirus tests required confirmatory testing regardless of demographic, vaccine, or seasonal factors; a review of rotavirus testing algorithms may be necessary in other vaccinated community populations.

Association between antimicrobial locks for hemodialysis central venous catheters and antibiotic resistance.

Antimicrobial locks (AMLs) are effective in preventing catheter-associated bloodstream infections (CABSI) in hemodialysis (HD) patients, but may increase antibiotic resistance. In our center, gentamicin-heparin locks have been used for all HD central venous catheters since July 1, 2004. We previously reported a significant reduction in CABSI rates, but a short-term trend to increased gentamicin resistance among coagulase-negative staphylococci (CNS). We present a further 3-year follow-up study of bacterial resistance in our dialysis center. We examined the susceptibility of bacterial isolates from CABSI from July 1, 2006 to July 31, 2009, restricting analyses to CNS, gram-negative bacilli, and Staphylococcus aureus. We compared the frequency of gentamicin resistance in these isolates between four groups: CABSI in HD patients, non-CABSI in HD patients, peritonitis in peritoneal dialysis (PD) patients, and bloodstream infection in the non-end-stage kidney failure general population. For CNS isolates, the frequency of gentamicin resistance was similar between the CABSI and PD peritonitis groups, but higher in both groups than the general population. The pattern was similar for S. aureus although the differences were of borderline statistical significance. The frequency of gentamicin resistance among gram-negative bacilli isolates did not differ between groups. Gentamicin resistance was more common than expected in CNS and possibly S. aureus isolates from CABSI, although this resistance may be part of a generally higher frequency of antibiotic resistance in the dialysis population, rather than a direct result of AML use. AMLs remain a valuable clinical tool although surveillance is needed to ensure that benefits continue to outweigh risks.

Effect of antimicrobial locks for tunneled hemodialysis catheters on bloodstream infection and bacterial resistance: a quality improvement report.

BACKGROUND: Catheter-restricted antimicrobial lock (AML) use reduces catheter-associated bloodstream infection (CA-BSI) in clinical trial settings, but may not be as effective in clinical settings and may increase bacterial resistance. DESIGN: Quality improvement report analyzed using a cross-sectional time series (unbalanced panel) design. SETTING & PARTICIPANTS: The study cohort comprised all prevalent adults treated with hemodialysis through a tunneled catheter for any, but not necessarily all, of the time from January 1, 2003, to June 30, 2006, in Manukau City, New Zealand (135,346 catheter-days, 404 tunneled catheters, 320 patients). QUALITY IMPROVEMENT PLAN: Catheter-restricted AMLs (heparin plus gentamicin) for all tunneled catheters from July 1, 2004. MEASURES: Repeated observations of CA-BSI, hospitalization, tunneled catheter removal, and death from CA-BSI analyzed by using generalized estimating equations with a single level of clustering for each tunneled catheter and patterns of bacterial resistance analyzed by using simple descriptive statistics. RESULTS: AML use was associated with reductions in rates of CA-BSI and hospitalization for CA-BSI by 52% and 69% for patients with tunneled catheters locked continuously with AMLs since their insertion compared with those with tunneled catheters that were not, respectively. AML exposure also was associated with a trend to increased gentamicin resistance amongst coagulase-negative staphylococci isolates, a pattern similar to that observed for BSIs in our general hemodialysis population in which tunneled catheters were not the source of BSI, but different from that in the general non-end-stage renal disease population in the region. LIMITATIONS: This is an uncontrolled observational study and cannot prove causality. The follow-up period of 18 months is longer than for other studies, but still too short to definitely answer whether AML use drives bacterial resistance. CONCLUSIONS: A change to use of AMLs may improve clinical outcomes; however, additional study of associated bacterial resistance is needed before AML use becomes standard care.

First case of Mycobacterium heckeshornense lymphadenitis.

Mycobacterium heckeshornense is a slow-growing nontuberculous mycobacterium first characterized in 2000. It is reported to cause lung disease and tenosynovitis. We report a case of isolated massive axillary lymphadenopathy in an elderly woman, where histology showed necrotizing granulomata and M. heckeshornense was isolated as the causative organism.