Changing epidemiology of catheter-related bloodstream infections in neutropenic oncohematological patients

Background We aimed to describe the epidemiology of catheter-related bloodstream infections (CRBSIs) in onco-hematological neutropenic patients during a 25-year study period, to evaluate the risk factors for Gram-negative bacilli (GNB) CRBSI, as well as rates of inappropriate empirical antibiotic treatments (IEAT) and mortality. Materials/Methods All consecutive episodes of CRBSIs were prospectively collected (1994–2018). Changing epidemiology was evaluated comparing five-year time spans. A multivariate regression model was built to evaluate risk factors for GNB CRBSIs. Results 482 monomicrobial CRBSIs were documented. The proportion of CRBSIs among all BSIs decreased over time from 41.2% to 15.8% (p<0.001). CRBSIs epidemiology has been changing: the rate of GNB increased over time (from 11.9% to 29.4%; p<0.001), as well as the absolute number and rate of multidrug-resistant (MDR) GNB (from 9.5% to 40.0%; p = 0.039). P. aeruginosa increased and comprised up to 40% of all GNB. Independent factors related with GNB-CRBSIs were: longer duration of in-situ catheter (OR 1.007; 95%CI 1.004–1.011), older age (OR 1.016; 95%CI 1.001–1.033), prior antibiotic treatment with penicillins (OR 2.716; 95%CI 1.306–5.403), and current antibiotic treatment with glycopeptides (OR 1.931; 95%CI 1.001–3.306). IEATs were administered to 30.7% of patients, with the highest percentage among MDR P. aeruginosa (76.9%) and S. maltophillia (92.9%). Mortality rate was greater among GNB than GPC-CRBSI (14.4% vs 5.4%; p = 0.002), with mortality increasing over time (from 4.5% to 11.2%; p = 0.003). Conclusion A significant shift towards GNB-CRBSIs was observed. Secondarily, and coinciding with an increasing number of GNB-MDR infections, mortality increased over time.

Higher Mortality in Bacteremic Sepsis - A Propensity Score Matched Study

BackgroundSepsis is a highly heterogenous disease which needs to be thoroughly mapped. The aim of this study was to describe characteristics and outcome for critically ill patients with sepsis-3 with either culture-positive or -negative sepsis.Methods Patients with severe sepsis or septic shock were retrospectively identified in the local quality registry from a general mixed Intensive Care Unit (ICU) at a University Hospital in 2007-2014. Data were collected through manual review of medical charts. Patients were included if they fulfilled sepsis-3 criteria and at least one blood culture was sampled ±48h from ICU admission. In a propensity score analysis bacteremic and non-bacteremic patients were matched 1:1 with regard to age, comorbidities, site of infection and antimicrobial therapy prior to blood cultures. A Latent Class Analysis (LCA) was performed to identify unmeasured class membership.Results784 patients were identified as treated in the ICU with a sepsis diagnosis. Blood cultures were missing in 140 excluded patients and additionally 95 patients did not fulfill a sepsis diagnosis and were also excluded. In total 549 patients were included, 295 (54%) with bacteremia, 90 (16%) were non-bacteremic but had relevant pathogens detected from another body location and in 164 (30%) no relevant pathogen was detected in microbial samples. After the propensity score analysis (n=172 in each group) 90-day mortality was higher in bacteremic patients, 47%, than in non-bacteremic patients, 36%, p =0.04. Patients without antibiotic treatment before sample collection (n=352) were more often bacteremic, 63%. Non-bacteremic patients without prior antibiotic treatment had lower mortality, 31% (n=129), compared to non-bacteremic patients with prior antibiotic treatment, 51% (n=124), p <0.01.The LCA identified 8 classes, with different mortality rates, where pathogen detection in microbial sampleswere important factors for class distinction andoutcome.ConclusionsBacteremic patients had higher mortality than their non-bacteremic counter-parts. Bacteremia is more common in sepsis than previously reported, when studied in a clinical review. Clinical chart review should be considered gold standard since a significant proportion of the patients in the proposed sepsis cohort, did not have sepsis, but would have been included in ICD- or electronic health record (EHR) algorithm approaches.

Higher Mortality in Bacteremic Sepsis - A Propensity Score Matched Study

BackgroundSepsis is a highly heterogenous disease which needs to be thoroughly mapped. The aim of this study was to describe characteristics and outcome for critically ill patients with sepsis-3 with either culture-positive or -negative sepsis.Methods Patients with severe sepsis or septic shock were retrospectively identified in the local quality registry from a general mixed Intensive Care Unit (ICU) at a University Hospital in 2007-2014. Data were collected through manual review of medical charts. Patients were included if they fulfilled sepsis-3 criteria and at least one blood culture was sampled ±48h from ICU admission. In a propensity score analysis bacteremic and non-bacteremic patients were matched 1:1 with regard to age, comorbidities, site of infection and antimicrobial therapy prior to blood cultures. A Latent Class Analysis (LCA) was performed to identify unmeasured class membership.Results784 patients were identified as treated in the ICU with a sepsis diagnosis. Blood cultures were missing in 140 excluded patients and additionally 95 patients did not fulfill a sepsis diagnosis and were also excluded. In total 549 patients were included, 295 (54%) with bacteremia, 90 (16%) were non-bacteremic but had relevant pathogens detected from another body location and in 164 (30%) no relevant pathogen was detected in microbial samples. After the propensity score analysis (n=172 in each group) 90-day mortality was higher in bacteremic patients, 47%, than in non-bacteremic patients, 36%, p =0.04. Patients without antibiotic treatment before sample collection (n=352) were more often bacteremic, 63%. Non-bacteremic patients without prior antibiotic treatment had lower mortality, 31% (n=129), compared to non-bacteremic patients with prior antibiotic treatment, 51% (n=124), p <0.01.The LCA identified 8 classes, with different mortality rates, where pathogen detection in microbial sampleswere important factors for class distinction andoutcome.ConclusionsBacteremic patients had higher mortality than their non-bacteremic counter-parts. Bacteremia is more common in sepsis than previously reported, when studied in a clinical review. Clinical chart review should be considered gold standard since a significant proportion of the patients in the proposed sepsis cohort, did not have sepsis, but would have been included in ICD- or electronic health record (EHR) algorithm approaches.

Comparison of results obtained by widal agglutination test & polymerase chain reaction among clinically suspected typhoid fever cases

The diagnosis of typhoid fever currently depends on isolation of Salmonella Typhi from blood. The sensitivity of blood culture is very low due to prior antibiotic treatment which is a common practice in Bangladesh. The sensitivity of blood culture also decreases at later stage of the disease. Widal test is the most utilized test in Bangladesh next to blood culture because it is inexpensive, less invasive. But the result of the test is controversial due to false negative & false positive results in some cases. In this study, a recently introduced polymerase chain reaction-based technique (which has 100% specificity for S. Typhi) was compared with widal test among 80 clinically suspected typhoid fever cases. Among 80 cases, the respective figures of positivity for PCR & widal test were 70% & 43.75% respectively. It can be concluded that PCR based technique is more sensitive & much superior to widal for diagnosis of typhoid fever. DOI: http://dx.doi.org/10.3329/bjpp.v30i2.22683 Bangladesh J Physiol Pharmacol 2014; 30(2): 46-50

The microbiology and the efficacy of antibiotic-based medical treatment of chronic rhinosinusitis in Singapore

BACKGROUND: Medical therapy including appropriate antibiotic treatment is advocated for the management of chronic rhinosinusitis (CRS), with sinus surgery reserved for treatment failures. This study investigates the microbiology of CRS and their response to culture-directed antibiotic treatment. METHODS: Sinus aspirates of mucopus from 172 consecutive CRS patients, with (n=89) and without (n=83) previous antibiotic treatment, were obtained for bacterial culture at their first visit. Medical treatment which included initial empirical and subsequent culture-directed antibiotics was instituted. Endoscopic sinus surgery (FESS) was performed for patients with persistent CRS and/or complications of CRS. A follow-up of 12 months was scheduled for all patients. RESULTS: One hundred and twenty (69.8%) patients were treated successfully by with antibiotic-based medical therapy. Thirty-eight patients (22.1%) did not respond to medical treatment and eventually underwent FESS. The incidence of CRS with nasal polyps (CRSwNP) was higher in FESS group (n=13, 34.2%) than patients with medical treatment only (n=9, 6.7%). Staphylococcus aureus was the most common pathogen (n=43, 25%) and amongst patients with no prior antibiotic treatment, the incidence was higher in patients with CRSwNP (n=8, 53 %) than CRS without NP (CRSwoNP) (n=20, 27%). The rate of sensitivity of the cultured microbes to amoxicillin with clavulanate and cephalosporins was 78% and 70%, respectively. CONCLUSION: The microbiology of CRS in Singapore is described. Staphylococcus aureus appears to be the most common bacterial isolates in both CRS with and without nasal polyps. Medical treatment with CRS using culture-directed antibiotics is effective in the majority of patients, especially in patients without nasal polyps.

How long should cerebrospinal fluid cultures be held to detect shunt infections?

Object Infections of CSF hardware may be indolent, and some patients have received antibiotic treatment for various reasons before CSF is obtained to check for a shunt infection. At present, there are few data in the literature to guide the decision as to how long to hold CSF specimens when attempting to diagnose hardware infections, and institutions vary in the duration at which cultures are considered “final.” Methods The authors reviewed the microbiology data from CSF specimens obtained from shunts, ventriculostomies, reservoirs, and lumbar drains at their institution over a 36-month period to discover how long after collection cultures became positive. The authors also sought to discover whether this time was affected by prior treatment with antibiotics. Results Of 158 positive CSF specimens obtained from hardware, the time to recovery ranged between 1–10 days, with a mean of 3.02 days (SD 2.37 days, 95% CI 2.66–3.38 days). One hundred and twenty-seven positive specimens were associated with clinical infections, and ~ 25% of these grew organisms after > 3 days, with some as long as 10 days after specimens were obtained. The most common organisms grown from individual patients were coagulase-negative Staphylococcus spp (34 cultures), Propionibacterium spp (21), Bacillus spp (6), Pseudomonas aeruginosa (4), and Staphylococcus aureus (4 cultures). Mean and maximum days to recovery were different across species, with S. aureus showing the shortest and Propionibacterium spp showing the longest incubation times. There appeared to be no significant difference in the time to recovery between specimens obtained in patients who had received prior antibiotic treatment versus those who had not. Conclusions A substantial number of positive CSF specimens obtained in patients with clinical infections grew bacteria after > 3 days, with some requiring as long as 10 days. Thus, a routine 10-day observation period for CSF specimens can be justified.