Vascular catheter-related infections: an endemic disease in healthcare institutions. An opinion paper of the Spanish Society of Cardiovascular Infections (SEICAV).

Catheter-related infections (CRI) are a serious healthcare problem due to their potential to cause serious complications, including bacteraemia or infective endocarditis, and to increase patient morbidity and mortality. In addition, these in fections significantly prolong hospital stay and cost. Preventing CRI is crucial and is considered a criterion for quality and safety in healthcare. For these reasons, the Spanish Society of Cardiovascular Infections (SEICAV) has considered it pertinent to review this topic, with experts in different areas including clinical microbiologists, infectious disease specialists, surgeons and nurses. The data were presented at a session held at the Ramón Areces Foundation, which was organised in the form of specific questions grouped into three round tables. The first panel analysed the scale of the problem including epidemiological, clinical and diagnostic aspects; the second panel addressed advances in the treatment of CRI; and the third panel reviewed developments in the prevention of CRI. The recorded session is available on the Areces Foundation website and we believe it maybe of interest not only to health professionals, but also to any non-expert citizen interested in the subject.

Cytomegalovirus reactivation in patients diagnosed with severe COVID-19: A point prevalence study in a general hospital.

OBJECTIVE: To determine the prevalence of CMV reactivation in a population admitted for severe COVID-19 to a general hospital. METHODS: Point prevalence study in all hospitalized patients with severe COVID-19 (admitted either to general wards or ICU). Determination of the presence of CMV DNA in circulating blood. COVID-19 was confirmed in patients with compatible clinical manifestations, usually with pneumonia and a positive nasopharyngeal PCR test. RESULTS: We included 140 hospitalized patients with COVID-19 who consented to participate. A total of 16 patients (11.42%), had circulating CMV-DNA in peripheral blood at the time of the study. Patients with positive CMV viral load were mainly ICU patients (11/37 -29,7%) and only 5/103 cases (4,85%) were hospitalized into general wards. The accumulated doses of corticosteroids (prednisone equivalents) in the study day were (median and IQR) 987.50 mg (396.87-2,454.68) and 187.50 mg (75.00-818.12) respectively in CMV positive and negative patients (p < 0.001). A significant proportion of CMV positive patients were discovered because of the study and were clinically unsuspected by their physicians. The coinfected COVID-CMV positive population had a higher risk of accumulated secondary nosocomially-acquired infections and a worse prognosis. CONCLUSIONS: CMV reactivation should be systematically searched in patients in COVID-19 cases admitted to the ICU.

High incidence of COVID-19 at nursing homes in Madrid, Spain, despite preventive measures.

OBJECTIVE: To assess the impact of COVID-19 at nine nursing homes in Madrid, Spain, during the first wave of COVID-19 infection and lockdown period when preventive measures were taken to avoid transmission among residents. METHODS: Nine hundred forty-two residents and 846 staff members from nine nursing homes participated in the study (April 18 to June 20, 2020). All participants were tested for SARS-CoV-2 in the nasopharynx by PCR and for IgG antibodies detection. Microbiological status at sampling was defined as active infection (positive PCR ± presence of antibodies), past infection (negative PCR + presence of antibodies), or naïve participants (negative PCR + absence of antibodies). RESULTS: Laboratory results helped classify the residents as having active infection (n=224; 23.8%), past infection (n=462; 49.1%), or being naïve (n=256; 27.1%); staff members were actively infected (n=127; 15.1%), had had a past infection (n=290; 34.2%), or were naïve (n=429; 50.7%). Overall, the percentage of participants with COVID-19 was significantly higher in residents than in staff members (72.8% vs 49.2%; P=0.001). The clinical situation of residents vs staff at sampling was as follows: acute manifestations compatible with COVID-19 (7.3% vs 3.9%; P<0.01) and no manifestations of infection (92.7% vs 96.0%; P<0.01). A large proportion of both asymptomatic and symptomatic residents (69.4% vs 86.6%; P=0.015) had positive PCR results (mostly alongside positive IgG determinations). CONCLUSIONS: COVID-19 affects 75% of the residents in nursing homes in Madrid. The high impact in these settings, despite the strict restrictions adopted during the lockdown, demonstrates the ability of SARS-CoV-2 to cause outbreaks.

Increase in the frequency of catheter-related bloodstream infections during the COVID-19 pandemic: a plea for control.

BACKGROUND: The incidence of nosocomial infections including ventilator-associated pneumonia and bacteraemia has been described during the COVID-19 pandemic. However, information regarding the impact of COVID-19 on the incidence of catheter-related bloodstream infections (CR-BSIs) is very limited. AIM: To evaluate the impact of the COVID-19 pandemic in the evolution of CR-BSIs in a large hospital. METHODS: This was a retrospective study comparing the incidence, aetiology and outcome of CR-BSIs during the months of March to May 2019 (pre-pandemic) and 2020 (during the pandemic). FINDINGS: The number of patients with one or more CR-BSIs in 2019 and 2020 were 23 and 58, respectively (1.89 vs 5.53/1000 admissions); P<0.001. Median time from catheter implantation to demonstration of CR-BSI was 27.5 days (range 11.75-126.00 days) in the 2019 cases and 16.0 days (range 11.00-23.50 days) in the 2020 population (P=0.032). CONCLUSIONS: A dramatic increase of CR-BSIs was found during the COVID-19 pandemic. Reinforcement of classic and new preventive measures is necessary.

Fast update of undetected Mycobacterium chimaera infections to reveal unsuspected cases.

Mycobacterium chimaera is involved in a worldwide alert due to contaminated heater-cooler units. A real-time polymerase chain reaction (RT-PCR)-based procedure was implemented to survey undetected cases of M. chimaera infection. PCR was negative in the 59 prosthetic heart valves from patients with PCR-16SrRNA-negative infective endocarditis. PCR identified M. chimaera in one of 15 clinically significant retrospective Mycobacterium avium-Mycobacterium intracellulare complex isolates, which corresponded to a patient who had undergone heart valve replacement in a different institution. Whole-genome sequencing demonstrated that he was the first case in Spain with involvement of the strain responsible for the global outbreak. These results highlight the relevance of retrospective tracking for undetected M. chimaera infections.

The optimal ethanol lock therapy regimen for treatment of biofilm-associated catheter infections: an in-vitro study.

BACKGROUND: Ethanol-based lock therapy (LT) solutions are used as an alternative to antibiotics for the conservative management of catheter-related bloodstream infection. However, no clear consensus on regimen or dose has been reached. AIM: To find the ethanol-based lock solution containing a sufficiently low concentration of ethanol for reduction of the metabolic activity of bacterial and fungal biofilms. METHODS: Using an in-vitro model, three concentrations of ethanol (25%, 40%, 70%) were tested, with and without 60 IU of heparin, at six different time-points and against 24 h preformed biofilms of Staphylococcus aureus ATCC29213, Staphylococcus epidermidis (clinical isolate), Enterococcus faecalis ATCC33186, Candida albicans ATCC14058, and Escherichia coli ATCC25922. The reduction in the metabolic activity of the biofilm was measured using the tetrazolium salt assay and LT was considered to be successful when metabolic activity fell by >90%. Regrowth inhibition was then tested within 24 h and seven days after each LT regimen only at the ethanol concentration of the most successful LT regimen. FINDINGS: The most successful LT was achieved with 40% ethanol + 60 IU of heparin only at 24, 72, and 24 h for seven-day regimens (P < 0.05). However, none of the regimens reached 45% RI within seven days of therapy. CONCLUSION: According to our in-vitro data, an ethanol-based lock solution with 40% ethanol + 60 IU heparin administered daily for 72 h is sufficient to almost eradicate the metabolic activity of bacterial and fungal biofilms. Future studies are needed to study cell regrowth after LT.

Biofilm production is not associated with poor clinical outcome in 485 patients with Staphylococcus aureus bacteraemia.

OBJECTIVES: Staphylococcus aureus biofilm may constitute a major cause of virulence. Our main objective was to analyse whether there was an association between biofilm production and poor outcome in patients with S. aureus bacteraemia. METHODS: We studied 485 S. aureus strains isolated from the blood of patients with bacteraemia from 2012 to 2015. We assessed in vitro biomass production using crystal violet assay and metabolic activity using tetrazolium salt assay. Strains were classified in tertile ranks as follows: low biomass producers, moderate biomass producers, high biomass producers, low metabolic activity, moderate metabolic activity and high metabolic activity. We excluded from analysis strains with moderate crystal violet and tetrazolium salt values. We defined poor outcome as fulfillment of one or more of the following conditions: 30-day attributable mortality, infective endocarditis, persistent bacteraemia and recurrent bacteraemia. RESULTS: Outcome was poor in 199 (41.0%) of 485 S. aureus bacteraemia episodes. The distribution of poor outcome with respect to biomass production and metabolic activity was as follows: low biomass producers, 36.6% vs. high biomass producers, 43.2% (p 0.26); and low metabolic activity, 43.5% vs. high metabolic activity, 36.2% (p 0.91). The presence of methicillin-resistant S. aureus was the only characteristic that was more likely to be present in the high metabolic activity group (17.4% vs. 39.3%, p < 0.001). CONCLUSIONS: Biofilm production, as determined by any of the methods used in the present study, is not associated with poor outcome in patients with S. aureus bacteraemia.

Should non-bacteraemic patients with a colonized catheter receive antimicrobial therapy?

OBJECTIVES: The impact of antimicrobial therapy on the outcomes of patients with colonized catheters and no bacteraemia has not been assessed. This study assessed whether targeted antibiotic therapy is related to a poor outcome in patients with positive cultures of blood drawn through a non-tunnelled central venous catheter (CVC) and without concomitant bacteraemia. METHODS: This was a retrospective study involving adult patients with positive blood cultures drawn through a CVC and negative peripheral vein blood cultures. Patients were classified into two groups: those with clinical improvement and those with a poor outcome. These two groups were compared. The outcome was considered poor in the presence of one or more of the following: death, bacteraemia or other infection due to the same microorganism, and evidence of catheter-related bloodstream infection. RESULTS: A total of 100 patients were included (31 with a poor outcome). The only independent predictors of a poor outcome were a McCabe and Jackson score of 1-2 and a median APACHE score of 5. No association was found between the use of targeted antimicrobial therapy and a poor outcome when its effect was adjusted for the rest of the variables. CONCLUSIONS: This study showed that antimicrobial therapy was not associated with a poor outcome in non-bacteraemic patients with positive blood cultures drawn through a CVC.

Nationwide study on peripheral-venous-catheter-associated-bloodstream infections in internal medicine departments.

BACKGROUND: The use of peripheral venous catheters (PVCs) has increased outside intensive care units, as has the rate of PVC-associated-bloodstream infection (PVC-BSI). PVCs are widely used in internal medicine departments (IMDs), but data on the incidence of PVC-BSI and its characteristics in IMDs are scarce. AIM: To assess the incidence of PVC-BSI episodes detected in IMDs in Spain. METHODS: A one-year multi-centre prospective observational cohort study in 14 Spanish IMDs was undertaken. Adult patients admitted with at least one PVC and bacteraemia were included in the study. Demographic and clinical data were provided by local coordinators. FINDINGS: Seventy episodes of PVC-BSI were recorded, representing an overall rate of 1.64 PVC-BSI episodes/1000 IMD admissions. The mean age of patients was 67.44 (standard deviation 16.72) years. It was estimated that 25.7% of PVCs were no longer necessary. Staphylococcus aureus was the most frequently isolated micro-organism (41.7%). Phlebitis was clinically evident in 44 (62.9%) episodes, and proved to be an independent predictor of catheter insertion in emergency departments (odds ratio 5.44). The crude and attributable mortality rates were 12.9% and 5.7%, respectively. CONCLUSIONS: PVCs carry a significant risk for bacteraemia in Spanish IMDs. Phlebitis is not always clinically evident in patients with bacteraemia in this population. The study findings support the need for educational and interventional preventive measures in both IMDs and emergency departments to reduce the rate of PVC-BSI and associated comorbidities, and costs.

Slicing silicone neonatal vascular catheter tips improves colonization detection by the roll-plate technique.

OBJECTIVE: Silicone neonatal peripherally inserted central catheters (SN-PICCs) are a common cause of catheter-related bloodstream infection (C-RBSI) in neonates. Our objective was to compare the yield of traditional roll-plate technique (TRP), roll-plate after slicing (RPS), and sonication after slicing (SS) for the detection of colonization and C-RBSI in SN-PICCs. METHODS: We prospectively cultured tips from SN-PICCs withdrawn from paediatric patients admitted to our institution with suspicion of infection. We first cultured the catheter tip using TRP and then divided the catheter into two segments. RPS was performed by longitudinally slicing one segment and the fragments were cultured. SS was performed by transversally slicing the other segment followed by culture after sonication. We calculated the validity values of each technique individually by comparing them with the diagnostic standard of colonization and C-RBSI. RESULTS: We included 162 SN-PICCs, 46 of which were colonized. Sensitivity rates for colonization and C-RBSI with TRP, RPS and SS were, respectively, 71.7%, 80.4% and 67.4%; and 74.2%, 90.3% and 77.4%. CONCLUSION: Catheter slicing should be performed before the roll-plate technique to ensure optimal diagnosis on SN-PICCs.

The Tego™ needleless connector for hemodialysis catheters may protect against catheter colonization.

Catheter connectors used in hemodialysis patients are those with open caps to manage high blood flows. However, current guidelines for the prevention of catheter infections recommend closed connectors. Tego™ is a closed connector designed to enable high blood flows. We used an in vitro model to compare the efficacy of Tego™ against contamination with that of standard caps in a real-life practice scenario. The model consisted of 200 blood culture bottles (BCB) with an inserted cannula closed either with Tego™ (100) or with open caps (100). BCB were manipulated using two different methods: under aseptic conditions and with gloves contaminated with a 0.05 McFarland Staphylococcus aureus solution. The BCB were incubated at 37 °C under continuous shaking for up to 7 days or until positive. When a BCB turned positive, 100 µL of the fluid was cultured. The positivity rate and time to positivity of the BCB in each method were compared. Overall, 4.0 % of BCB with Tego™ and 52.0 % of BCB with open caps were positive in the sterile model (p < 0.001), whereas all BCB in the contamination model were positive. We did not find differences regarding the median time (hours) to positivity between Tego™ and the standard cap in the contamination model (19.04 vs. 17.87, p = 0.465). In our model, Tego™ proved to be better than the standard cap for the prevention of contamination when the device was handled under optimal conditions. Moreover, it was as efficient as the standard catheter cap in the contamination model.

Effectiveness of a training program in compliance with recommendations for venous lines care.

BACKGROUND: The impact of training programs on the care and maintenance of venous lines (VL) has been assessed mainly in patients admitted to the intensive care unit (ICU). Data on the impact of such programs in a whole general hospital are scarce. The objective of this study was to assess compliance with VL care after an extensive training program aimed at nurses caring for adult ICU and non-ICU patients. METHODS: We performed 2 point prevalence studies in a general hospital. A specialized nurse visited all hospitalized adult patients, performed a bedside inspection, and reviewed the nursing records for patients with a VL before and after a 1-year training program. The program included an interactive on-line teaching component and distribution of pocket leaflets and posters with recommendations on VL care. RESULTS: Data recorded for the first and second prevalence studies were as follows: number of patients visited, 753 vs. 682; total number of patients with ≥ 1 VL implanted on the visit day, 653 (86.7%) vs 585 (85.8%); catheters considered unnecessary on the study day, 183 (22.9%) vs 48 (7.1%) (p < 0.001); number of catheters with local clinical evidence of infection on the study day, 18 (2.2%) vs 12 (1.8%) (p = 0.52); registration of insertion day (42.3% vs 50.1%; p = 0.003); and registration of day of dressing change (41.2% vs 49.1%; p = 0.003). Maintenance parameters improved more in non-ICU than in ICU patients. CONCLUSION: A multidisciplinary teaching program to improve VL care and compliance with recommendations is effective. Point prevalence studies are easy to carry out and effective at demonstrating increases in compliance, mainly in non-ICU patients.

Nationwide study on the use of intravascular catheters in internal medicine departments.

BACKGROUND: The use of intravascular catheters (IVCs) in intensive care units (ICUs) has been well assessed in recent years. However, a high proportion of these devices are placed in patients outside the ICU, particularly in internal medicine departments (IMDs), where data on the quality of care are scarce. AIM: To assess the use and management of IVCs in IMDs in Spain. METHODS: We performed a point prevalence study of all adult inpatients on 47 IMDs from hospitals of different sizes on one day in June 2013. A local co-ordinator was appointed to assess patients and collect data from each site. FINDINGS: Out of the 2080 adult patients hospitalized on the study day, 1703 (81.9%) had one or more IVCs (95.4% of which were peripheral devices). Infection was detected at the insertion site in 92 catheters (5.0%); 87 patients (5.2%) had signs of sepsis, but only one case was considered to be catheter-related. The local co-ordinators estimated that 19% of the catheters in place were no longer necessary. A daily record of the need for a catheter was available in only 40.6% of cases. CONCLUSION: Our study shows clear opportunities for improvement regarding catheter use and care in Spanish IMDs. Strategies similar to those applied in ICUs should be implemented in IMDs.

Performing Gram stain directly on catheter tips: assessment of the quality of the observation process.

A previous study performed in our institution showed that catheter tip (CT) staining by combining acridine orange and Gram stain (GS) before culture anticipated catheter colonization with exhaustive and careful observation by a highly trained technician. Our objective was to assess the validity values of GS without acridine orange on an external smear of CT for predicting catheter colonization and catheter-related bloodstream infection (C-RBSI). We compared different periods of observation and the results of two technicians with different levels of professional experience. Over a 5-month period, the roll-plate technique was preceded by direct GS of all CTs sent to the microbiology laboratory. The reading was taken at ×100 by two observers with different skill levels. Each observer performed a routine examination (3 min along three longitudinal lines) and an exhaustive examination (5 min along five longitudinal lines). The presence of at least one cell was considered positive. All slides were read before culture results were known. We included a total of 271 CTs from 209 patients. The prevalence of catheter colonization and C-RBSI was 16.2 % and 5.1 %, respectively. Routine and exhaustive examinations revealed only 29.5 % and 40.9 % of colonized catheters, respectively (p < 0.001). In contrast, they revealed high negative predictive values for C-RBSI (96.5 % and 96.3 %, respectively). Our study shows that the yield of GS performed directly on CTs is greater when staining is performed exhaustively. However, the decision to implement this approach in daily routine will depend on the prevalence rate of catheter colonization at each institution.

Routine aspiration of subglottic secretions after major heart surgery: impact on the incidence of ventilator-associated pneumonia.

Aspiration of subglottic secretions (ASS) is recommended in patients requiring mechanical ventilation for ≥48h. We assessed the impact of the introduction of ASS routinely in all patients after major heart surgery in an ecological study comparing ventilator-acquired pneumonia (VAP) incidence, days of mechanical ventilation, and cost of antimicrobial agents before and after the implementation of ASS. Before and after the intervention the results (per 1000 days) were: VAP incidence, 23.92 vs 16.46 (P = 0.04); cost of antimicrobials, €71,384 vs €63,446 (P = 0.002); and days of mechanical ventilation, 507.5 vs 377.5 (P = 0.009). From the moment of induction of anaesthesia all patients undergoing major heart surgery should routinely receive ASS.