Prevalence of Chagas disease in Latin American pregnant women in Madrid, Spain: A multicentre cross-sectional study from 2011 to 2016

OBJECTIVE

The aim of this study is to assess Trypanosoma cruzi infection prevalence among pregnant migrants living in Madrid according to the country of origin and to assess screening coverage in this at-risk population.

METHODS

Retrospective multicentre cross-sectional study conducted from January 2011 to December 2016 in eight Madrid hospitals. Each hospital reviewed their microbiology data records to assess the screening coverage and serological diagnosis in all pregnant women coming from endemic areas.

RESULTS

From 2011 to 2016, 149,470 deliveries were attended at the eight hospitals, and 11,048 pregnant women were screened for Chagas disease. Most cases (93.5%) were in women from Bolivia, who also showed the highest prevalence (12.4%, 95% confidence interval: 9.9-15.0). Pooled prevalence amongst the screened women was 2.9% (95% CI: 1.8-4.1). Chagas disease screening coverage varied greatly between centres, with a pooled mean coverage of 47% (95% CI: 37%-57%; 73% [95% CI: 63%-82%] for those centres with universal screening vs. 10% [95% CI: 6%-15%] for those with a selective screening approach; p < 0.001).

CONCLUSION

Our study provides useful data for policy makers and epidemiologists in a non-endemic area without congenital Chagas screening programmes.

Pneumocystis jirovecii Pneumonia Diagnostic Approach: Real-Life Experience in a Tertiary Centre

Pneumocystis jirovecii pneumonia (PJP) in immunocompromised patients entails high mortality and requires adequate laboratory diagnosis. We compared the performance of a real time-PCR assay against the immunofluorescence assay (IFA) in the routine of a large microbiology laboratory. Different respiratory samples from HIV and non-HIV-infected patients were included. The retrospective analysis used data from September 2015 to April 2018, which included all samples for which a P. jirovecii test was requested. A total of 299 respiratory samples were tested (bronchoalveolar lavage fluid (n = 181), tracheal aspirate (n = 53) and sputum (n = 65)). Forty-eight (16.1%) patients fulfilled the criteria for PJP. Five positive samples (10%) had only colonization. The PCR test was found to have a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96%, 98%, 90% and 99%, compared to 27%, 100%, 100% and 87%, for the IFA, respectively. PJ-PCR sensitivity and specificity were >80% and >90% for all tested respiratory samples. Median cycle threshold values in definite PJP cases were 30 versus 37 in colonized cases (p < 0.05). Thus, the PCR assay is a robust and reliable test for the diagnosis PJP in all respiratory sample types. Ct values of ≥36 could help to exclude PJP diagnosis.

Endotracheal tubes coated with a broad-spectrum antibacterial ceragenin reduce bacterial biofilm in an in vitro bench top model

BACKGROUND

Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds.

OBJECTIVES

We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA).

METHODS

We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy.

RESULTS

The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0-3.3 × 102) versus 3.32 × 109 (6.6 × 108-3.8 × 109), P < 0.001; 0.0 (0.0-5.4 × 103) versus 1.32 × 106 (2.3 × 103-5.0 × 107), P < 0.001; and 8.1 × 105 (8.5 × 101-1.4 × 109) versus 2.7 × 108 (8.6 × 106-1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5-not applicable (NA)] versus 87.9 (60.5-NA), P = 0.05; 9.1 (6.7-NA) versus 62.6 (42.0-NA), P = 0.05; and 97.7 (94.6-NA) versus 187.3 (43.9-NA), P = 0.827.

CONCLUSIONS

We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.

Revisiting nocardiosis at a tertiary care institution: Any change in recent years?

OBJECTIVE

To analyse relevant changes in incidence, clinical and microbiological characteristics of nocardiosis over the last 24 years at the current institution.

MATERIALS AND METHODS

The clinical records of patients with nocardiosis (2006-2018) were reviewed and then compared with a previous cohort (1995-2006). Nocardia isolates were identified by 5'-end-16S-rRNA-gene-PCR targeting the first 500 bp of the gene and sequencing. Susceptibility tests were determined by broth microdilution (CLSI guidelines).

RESULTS

Forty-two patients (64.3% male) with nocardiosis were evaluated in the recent cohort: 51.2% had COPD, 43.9% were on corticosteroid therapy and 31.7% had cancer. The incidence of nocardiosis varied from 6.3 to 7.1/100,000 admissions (p = 0.62). There was a decrease in HIV patients (27% vs. 4.9%, p = 0.01) and solid organ transplantation (SOT) recipients (18.9% vs. 2 .4%, p = 0.01). Cases with pulmonary involvement had increased (70.3% vs. 90.5%, p = 0.04). Nocardia species were similar but the most common were N. cyriacigeorgica (32.4% vs. 40.5%, p = 0.49) and N. farcinica (24.3% vs. 14.3%, p = 0.39). Antibiotic resistance remained stable: cotrimoxazole (10.8% vs. 5.7%, p = 0.68), imipenem (5.4% vs. 5.6%, p = 1.0); amikacin and linezolid were 100% active. No differences were found in breakthrough nocardiosis (21.6% vs. 9.8%, p = 0.21) or related mortality (21.6% vs. 21.4%, p = 1.0). The multivariate analysis confirmed that nocardiosis caused by N. farcinica is a risk factor for poor outcome (p = 0.045).

CONCLUSIONS

Nocardiosis incidence has remained stable. It mainly affected elderly patients with chronic respiratory conditions and those on corticosteroid treatment. Infections in HIV and SOT patients have practically disappeared. Pulmonary involvement remains the most common area to be affected. Nocardiosis caused by N. farcinica is apparently a risk factor for poor clinical outcome.

Can vancomycin lock therapy extend the retention time of infected long-term catheters?

We assessed the success rate of vancomycin catheter lock therapy (VLT) in combination with systemic antimicrobials in patients with staphylococcal catheter-related bloodstream infection (C-RBSI). Over a 6-year period, we retrospectively collected clinical and microbiological data from patients with long-term central venous catheters and staphylococcal C-RBSI who were treated with systemic antimicrobials and VLT. We then assessed the success rate of VLT based on two criteria: 1) catheter retention time> 3 months and 2) catheter in place until end of use. We found 217 staphylococcal C-RBSI episodes, 115 (53.0%) of which were managed with conservative therapy. Of these, 76 (66.1%) were treated with VLT (85.5% coagulase-negative staphylococci and 14.5% Staphylococcus aureus). The success rate of VLT was 42.1% with criterion 1 and 71.1% with criterion 2. We did not find statistically significant differences between success and failure in the majority of the clinical data recorded. We only found differences for crude mortality in criterion 1 and for parenteral nutrition in criterion 2. The success of catheter retention using VLT was moderate, reaching slightly more than 70% when the catheter was kept in place until the end of use.

How should microbiology laboratories interpret cultures of the sonicate of closed needleless connectors?

INTRODUCTION

Our objective was to determine whether there is a cut-off in the needleless connectors' (NCs) cultures that when combined with skin cultures it was as efficient as conventional superficial cultures to rule-out catheter colonization (CC) and catheter-related bloodstream infection (CRBSI).

METHODS

During 10 months, we collected samples and then we analyzed the validity values of skin+NCs cultures for CC and CRBSI considering the best cut-off showing at least >90% of specificity to have a high negative predictive value using a ROC curve.

RESULTS

We collected a total of 167 catheters. The optimal cut-off of NCs culture was 1000cfu/NC. The validity values for CC and CRBSI combining skin cultures and NCs cultures using the selected cut-off were, respectively: S, 42.9%/16.7%; SP, 83.6%/75.8%; PPV, 27.3%/2.5%; and NPV, 91.0%/96.0%.

CONCLUSIONS

The combination of skin cultures and quantitative NCs cultures could be used for ruling-out CC and CRBSI.

Etiology and Prognosis of Pneumonia in Patients with Solid Tumors: A Prospective Cohort of Hospitalized Cases

BACKGROUND

Data on the incidence, etiology, and prognosis of non-ventilator-associated pneumonia in hospitalized patients with solid tumors are scarce. We aimed to study the characteristics of non-ventilator-associated pneumonia in hospitalized patients with solid tumors.

MATERIALS AND METHODS

This was a prospective noninterventional cohort study of pneumonia in patients hospitalized in an oncology ward in a tertiary teaching hospital. Pneumonia was defined according to the American Thoracic Society criteria. Patients were followed for 1 month after diagnosis or until discharge. Survivors were compared with nonsurvivors.

RESULTS

A total of 132 episodes of pneumonia were diagnosed over 1 year (9.8% of admissions to the oncology ward). They were health care-related (67.4%) or hospital-acquired pneumonia (31.8%). Lung cancer was the most common malignancy. An etiology was established in 48/132 episodes (36.4%). Knowing the etiology led to changes in antimicrobial therapy in 58.3%. Subsequent intensive care unit admission was required in 10.6% and was linked to inappropriate empirical therapy. Ten-day mortality was 24.2% and was significantly associated with hypoxia (odds ratio [OR], 2.1). Thirty-day mortality was 46.2%. The independent risk factors for 30-day mortality were hypoxia (OR, 3.3), hospital acquisition (OR, 3.1), and a performance status >1 (OR, 2.6). Only 40% of patients who died within 30 days were terminally ill.

CONCLUSION

Pneumonia is a highly prevalent condition in hospitalized patients with solid tumors, even with nonterminal disease. Etiology is diverse, and poor outcome is linked to inappropriate empirical therapy. Efforts to get the empirical therapy right and reach an etiological diagnosis to subsequently de-escalate are warranted.

IMPLICATIONS FOR PRACTICE

The present study shows that pneumonia is a prevalent infectious complication in patients admitted to oncology wards, with a very high mortality, even in non-terminally ill patients. Etiology is diverse, and etiological diagnosis is reached in fewer than 40% of cases in nonintubated patients. Intensive care unit admission, a marker of poor outcome, is associated with inappropriate empirical therapy. These results suggest that, to improve prognosis, a more precise and appropriate antimicrobial empirical therapy for pneumonia in patients with solid tumors is necessary, together with an effort to reach an etiological diagnosis to facilitate subsequent de-escalation.

Susceptibility of uncommon Candida species to systemic antifungals by the EUCAST methodology

The incidence of infections by uncommon Candida species has increased in recent years, however, in vitro susceptibility data are scarce. Here we assess the susceptibility of C. krusei, C. dubliniensis, C. lusitaniae, and C. guilliermondii complex isolates (n = 120) to antifungal agents by the EUCAST methodology. C. dubliniensis proved to be the most susceptible species, similar to that of C. albicans (P &lt; .05), whereas C. guilliermondii was the least susceptible. Two C. krusei isolates were echinocandin-resistant and harbored a point mutation (L701M) in the FKS1. Some isolates were either fluconazole-resistant (C. lusitaniae, n = 2) or fluconazole non-wild type (C. guilliermondii, n = 3).

Gradient diffusion antibiogram used directly on bronchial aspirates for a rapid diagnosis of ventilator-associated pneumonia

Background

In patients with suspected ventilator-associated pneumonia, a rapid etiological diagnosis is crucial as incorrect or delayed treatment in the first few hours leads to a worse prognosis and a higher mortality rate. This study examines the efficacy of a rapid antibiogram on bronchial aspirates in patients with suspected ventilator-associated pneumonia (VAP).

Methods

The direct gradient diffusion susceptibility testing method (GDM) on respiratory samples was compared with a standard broth microdilution method (BMD) after quantitative cultures in patients with suspicion of VAP. Samples were preselected by Gram staining (for good quality microbiological samples with a predominant single bacterial morphotype). The antibiotics tested were ceftazidime, ceftobiprole, ceftolozane-tazobactam, meropenem, doripenem, and tedizolid.

Results

Over a 16-month study period, 445 bronchial aspirate samples were selected from 1376 samples received at our laboratory from 672 adult patients. By direct plating on Mueller-Hinton agar, we recovered 504 (95.5%) of the 528 microorganisms identified by the standard semiquantitative method. Antimicrobial susceptibility testing by GDM was compared with the BMD method in 472 strains (216 Enterobacteriaceae, 138 P. aeruginosa and 118 S. aureus.) and 1652 individual microorganism-antimicrobial agent combinations. There was total agreement between both methods in 98% of combinations. The Kappa index between both techniques was excellent (over 80%). There was only one potential major error for P. aeruginosa susceptibility to ceftazidime.

Conclusions

The six GDM strips directly placed on plated bronchial aspirates obtained from patients with a suspicion of VAP provided accurate and reliable susceptibility results within 24 h.

A multicentre analysis of Nocardia pneumonia in Spain: 2010-2016

OBJECTIVE

To analyse all cases of Nocardia pneumonia occurring between 2010 and 2016 in five Spanish hospitals.

METHODS

This was a retrospective observational analysis of clinical and microbiological data collected from 55 cases of Nocardia pneumonia.

RESULTS

There were one to 20 cases per hospital and six to nine cases per year. Chronic obstructive pulmonary disease, bronchiectasis, and asthma were the main predisposing underlying respiratory conditions. Thirty-four patients were receiving systemic and/or inhaled corticosteroids prior to infection, eight had neoplasia, and six had haematological malignancies. Clinical and radiological findings were common to pneumonia of other infectious aetiologies, except for the frequent presence of nodules and cavitation. Overall, the 1-year mortality was high (38.2%), and mortality was directly related to the pulmonary disease in 15 patients (27.3%). The most frequently identified species were N. cyriacigeorgica (n=21), N. abscessus (n=8), and N. farcinica (n=5). All Nocardia isolates were susceptible to linezolid and all but two were susceptible to amikacin and trimethoprim-sulfamethoxazole.

CONCLUSIONS

Nocardia pneumonia-associated mortality remains high, probably because of the debilitated status of patients in whom this pathogen is able to cause pulmonary infection.

Prevalence of submicroscopic malaria infection in immigrants living in Spain

BACKGROUND

The importance of submicroscopic malaria infections in high-transmission areas could contribute to maintain the parasite cycle. Regarding non-endemic areas, its importance remains barely understood because parasitaemia in these afebrile patients is usually below the detection limits for microscopy, hence molecular techniques are often needed for its diagnosis. In addition to this, the lack of standardized protocols for the screening of submicroscopic malaria in immigrants from endemic areas may underestimate the infection with Plasmodium spp. The aim of this study was to assess the prevalence of submicroscopic malaria in afebrile immigrants living in a non-endemic area.

METHODS

A prospective, observational, multicentre study was conducted. Afebrile immigrants were included, microscopic observation of Giemsa-stained thin and thick blood smears, and two different molecular techniques detecting Plasmodium spp. were performed. Patients with submicroscopic malaria were defined as patients with negative blood smears and detection of DNA of Plasmodium spp. with one or both molecular techniques. Demographic, clinical, analytical and microbiological features were recorded and univariate analysis by subgroups was carried out with STATA v15.

RESULTS

A total of 244 afebrile immigrants were included in the study. Of them, 14 had a submicroscopic malaria infection, yielding a prevalence of 5.7% (95% confidence interval 3.45-9.40). In 71.4% of the positive PCR/negative microscopy cases, Plasmodium falciparum alone was the main detected species (10 out of the 14 patients) and in 4 cases (28.6%) Plasmodium vivax or Plasmodium ovale were detected. One patient had a mixed infection including three different species.

CONCLUSIONS

The prevalence of submicroscopic malaria in afebrile immigrants was similar to that previously described in Spain. Plasmodium vivax and P. ovale were detected in almost a third of the submicroscopic infections. Screening protocols for afebrile immigrants with molecular techniques could be useful for a proper management of these patients.

Study of the diagnostic accuracy of microbiological techniques in the diagnosis of malaria in the immigrant population in Madrid

Background

Malaria is currently the most important human parasitic disease in the world responsible for high morbidity and mortality. Appropriate diagnostic methods are essential for early detection. Microscopy examination remains the gold standard, although molecular techniques have higher sensitivity and are very useful in cases of low parasitaemia and mixed infections. The objective of this study was to evaluate a new commercial molecular diagnostic technique.

Methods

A prospective, observational, multicentre study was performed between January 2015 and April 2017. All participants were immigrants from malaria-endemic areas, who were divided into two groups: asymptomatic group and symptomatic. Samples from both groups were evaluated by a rapid diagnostic test (ImmunoQuick^® Malaria + 4 RDT), microscopy examination, and two commercial molecular malaria tests (FTD Malaria and FTD Malaria Differentiation), then compared against an in-house reference PCR technique.

Results

In all, 250 patients were included: 164 (65.6%) in the asymptomatic group, and 86 (34.4%) in the symptomatic group. There were seven cases of asymptomatic parasitaemia (prevalence = 2.8%) that were detected only by molecular methods. In the symptomatic group, there were seven cases of submicroscopic malaria. The main species detected was Plasmodium falciparum (96.6%). The commercial molecular technique had higher sensitivity than the other methods (S = 96%) and a high rate of concordance with the in-house reference PCR technique (Kappa score = 0.93).

Conclusions

The molecular techniques, although slower than microscopy, have adequate diagnostic accuracy and are very useful for the detection of P. falciparum in cases with low parasitaemia.

Identification of Nocardia species from clinical isolates using MALDI-TOF mass spectrometry

The identification of Nocardia isolates still represents a challenge for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) despite its acceptance for most bacterial and fungal isolates. In this study we evaluate the identification of Nocardia isolates using direct spotting and an updated database. Overall, 82 Nocardia isolates belonging to 13 species were identified by DNA sequence analysis of the 16S rRNA and secA1 genes. Nine of these well-characterized isolates from 6 Nocardia species were used to create an in-house library. The remaining 73 isolates were directly spotted on the target plate and on-plate protein extraction was performed. The protein spectra obtained were analyzed by MALDI-TOF MS using the BDAL database (Bruker Daltonics) updated with 6,903 MSPs or the combination of this commercial database and our in-house library. As a result, the use of the commercial database alone and in combination with the in-house library yielded 94.5% and 95.9% of correct species-level identifications, respectively, No isolate was misidentified at the genus level with either database. Besides, the use of the in-house library allowed the species-level identification of a N. otitidiscaviarum isolate that could only be identified at the genus-level with a score value <1.6 using the commercial database. In conclusion, the implementation of the direct spotting method and the in-house database provided a high rate of correct species assignment of Nocardia isolates despite the low number of isolates added. Further addition of well-characterized Nocardia isolates may ensure the rapid, accurate and inexpensive identification of most isolates encountered in the routine of the microbiology laboratory.

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.

The misleading effect of serum galactomannan testing in high-risk haematology patients receiving prophylaxis with micafungin

OBJECTIVES

To investigate the performance of the routine serum galactomannan (sGM) assay in the diagnosis of invasive aspergillosis (IA) in high-risk haematology patients receiving prophylaxis with micafungin.

METHODS

Retrospective study including all haematological patients who received prophylaxis with micafungin during high-risk IA episodes (neutropenic patients after chemotherapy for acute myeloid leukaemia/myelodysplastic syndrome; allogeneic haematopoietic stem-cell transplantation during early neutropenic phase or graft-versus-host disease requiring high prednisone doses) and for whom at least one sGM result was available. Episodes were classified as follows: true-positive (positive GM in the context of IA), false-positive (positive GM result in patients who had no evidence of IA), true-negative (negative GM test results and no IA), or false-negative (negative GM test in the context of IA). Non-evaluable patients were excluded.

RESULTS

Among 146 evaluable episodes, four were true-positive in the context of probable breakthrough IA (incidence of breakthrough IA, 2.7%); 111/146 high-risk episodes (76%) were considered true-negative and 31/146 (21.2%) were considered false-positive. No false-negative episodes were detected. All but one of the false-positive episodes were detected in surveillance GM tests, leading to high-resolution CT scans in eight cases (8/31; 25.8%), all of which were negative. The positive predictive and negative predictive values of sGM for surveillance and diagnostic approaches were 3.2% (1/31) and 100% (110/110) and 75% (3/4) and 100% (1/1), respectively.

CONCLUSIONS

Surveillance of asymptomatic patients receiving prophylaxis with micafungin using sGM is unnecessary, because the results are either negative or false-positive. However, sGM remains useful in the diagnosis of breakthrough IA in symptomatic patients during prophylaxis.

Improved method for the detection of catheter colonization and catheter-related bacteremia in newborns

Accurate diagnosis of catheter-related bloodstream infection (CRBSI) is mandatory for hospital infection control. Peripherally inserted central venous catheters (PICCs) are widely used in intensive care units, but studies about procedures for detection of colonization are scarce in neonates. We sequentially processed 372 PICCs by 2 methods, first by the standard roll-plate (RP) technique and then by rubbing catheters on a blood agar plate after being longitudinally split (LS). With both techniques, we detected 133 colonized PICCs. Ninety-four events of CRBSI were diagnosed. The sensitivity, specificity, positive predictive value, and negative predictive value for detection of CRBSI were 58.5%, 92.8%, 73.3%, and 86.9%, respectively, for RP technique and 96.8%, 88.5%, 74.0%, and 98.8%, respectively, for LS technique. The LS technique increased the proportion of detected CRBSI by 38.3%. Neonatal PICC tips should be cultured after cutting them open. This technique is simple and sensitive to detect catheter colonization and also to diagnose CRBSI.

Corrigendum to "sonicating multi-lumen sliced catheter tips after the roll-plate technique improves the detection of catheter colonization in adults" [J. Microbiol. Methods 122 (2016) 20-22]

The Maki technique is the standard method for detecting catheter tip (CT) colonization. However, some "multi-lumen" catheters finish in a vaulted fornix and end at different distances from the CT. Therefore, we compared the traditional Maki technique with the sonication method using several cross-cut fragments of the CT. Our objective was to assess the yield of the Maki technique followed by sonication in the detection of adult CT colonization and catheter-related bloodstream infection (C-RBSI). For 3months, we prospectively performed CT cultures of polyurethane catheters from adult patients admitted to our institution. First, we performed CT culture using the Maki technique on blood agar plates and then sonicated small fragments of CTs in 5ml of BHI followed by culture of 100μl of the sonicate. We included a total of 252 CVCs, with overall colonization and C-RBSI rates of 14.3% (36/252) and 5.9% (15/252). Of the 36 colonized CVCs, 21 (58.3%) were detected both by Maki and sonication, 6 (16.7%) were detected only by Maki technique, and 9 (25.0%) only by sonication method. Among 15 episodes with concomitant bacteremia, both techniques were positive and concordant in 11 cases (73.3%) and in 4 cases (26.7%) sonication was the only positive technique. Our study shows that both techniques are complementary. We recommend sonicating fragments of the CT from patients with bacteremia of unknown origin and a negative CT culture by the Maki technique.

Guideline for dialysate quality of Spanish Society of Nephrology (second edition, 2015)

A Best Practice Guideline about Dialysis fluid purity was developed under the leadership of the Spanish Society of Nephrology in 2004. The second edition revised Guideline considered new evidences and International Standard. The Guideline has established recommendations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. This Guideline is based on the ISO13959, European Pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, European Best Practice Guidelines for Haemodialysis, literature reviews, according to their level of evidence, and the opinion of the expert Spanish group. Two levels of quality of water were defined: purified water and high purified water (ultra pure) and for dialysate: ultra pure dialysate. Regular use of ultra pure dialysate is recommended for all type of hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anaemia and amiloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowable contaminant levels: chemicals (4.1.2), conductivity, microbial and endotoxins (4.1.1): Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (anexos). For microbiological monitoring, R2A medium is recommended, incubated during 7-14 days at a temperature of 17-23°C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality. All suggestions and questions about this Guideline are wellcome to www.senefro.org.

Stickers used for the identification of intravenous lines could be a portal of entry of microorganisms through the catheter: Results from a clinical study

We evaluated the colonization of stickers used to identify intravenous access lines in a clinical practice setting. We isolated the same microorganisms in colonized catheters and on the stickers in 77.8% of cases. Therefore, stickers could be a portal of entry of microorganisms through the catheter. Alternative methods for labeling intravenous lines are required.

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.

Application of real-time PCR for the detection of Strongyloides spp. in clinical samples in a reference center in Spain

Strongyloidiasis is one of the major intestinal helminthic infections in humans with a worldwide distribution, affecting especially tropical and subtropical regions. This disease can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection. Definitive diagnosis of Strongyloides stercoralis infection relies mainly on demonstration of larvae in stool, but at present there is no gold standard for this diagnosis. Our main objective was to evaluate a real-time PCR targeting the 18S rRNA gene of Strongyloides spp. and to compare it with routine parasitological methods. DNA from Strongyloides venezuelensis was used to optimize PCR protocols obtaining an analytical sensitivity of 0.1 pg of parasite DNA per sample. Sensitivity and specificity of real-time PCR on fecal samples from 231 patients screened for suspected strongyloidiasis attending two hospitals in Madrid were 93.8% and 86.5%, respectively. No significant differences were found when comparing Ct-values of positive PCR between parasitological positive and negative samples. This study showed that real-time PCR is an effective tool for diagnosing strongyloidiasis and could be applied in association with parasitological methods in epidemiological studies in endemic areas. It would be also important to assess its performance in immunocompromised populations who are at risk of fatal disease.

Stickers used for identification of intravenous lines may be a source of contamination

This study assessed in an in vitro model the effect of 2% alcohol clorhexidine for the disinfection of stickers used for intravenous line identification. Nonadhesive sticker sides were associated with higher numbers of colony-forming units when manipulation was performed without 2% alcohol clorhexidine disinfection. Future clinical studies are needed to validate these data and design policies for daily sticker disinfection.

A simple and easy in vitro model to test the efficacy of IV lines' needleless connectors against contamination

Background

Hub colonization after manipulation is responsible for 29% to 60% of catheter-related bloodstream infections (C-RBSI). Prevention can be achieved by the use of hub connectors, but its efficacy is generally based on instillation of high concentrations of microorganisms, which do not reflect the real contamination in daily practice. Our purpose was to create an in vitro model lasting long enough to be used for the comparison of the efficacy between various connectors against contamination simulating the real daily handling.

Methods

The model consisted of 40 blood culture bottles with an inserted cannula with a needle-free closed connector. Twice a day, each line was manipulated while instilling 1 mL of two different fluids (saline and propofol). We manipulated the bottles as follows: ten bottles with clean gloves and disinfecting connectors with alcohol (controls), ten bottles with hands (no gloves), ten bottles with gloves impregnated with a 0.5 McFarland (MF) solution of Staphylococcus aureus (SA), and ten bottles with gloves impregnated with a 0.05 MF solution of SA. The bottles were incubated in a BACTEC System at 37°C under continuous agitation up to 10 days. When a bottle turned positive, 100 μL of the fluid was cultured and incubated followed by microorganism identification using standard procedures.

Results

Overall, all bottles in the control group were negative at the end of the incubation time. In the three contamination experiments, almost all (38/40) bottles were positive during the incubation time. We only found differences regarding the median time to positivity (interquartile range (IQR)) between saline and propofol in the manipulation with SA 0.05 MF: 240 h (154.82 to 360.00) vs. 66 h (58.01 to 69.11), p = 0.008.

Conclusions

A daily connector handling with 0.05 McFarland S. aureus solution while instilling saline proved to be a useful model lasting long enough to be used for the comparison of the efficacy of different types of closed needleless connectors against contamination.

Electronic supplementary material

The online version of this article (doi:10.1186/s40635-014-0027-9) contains supplementary material, which is available to authorized users.

Colonization of stickers used for the identification of intravenous lines: results from an in vitro study

BACKGROUND

Clear differentiation of arterial and intravenous (IV) lines is a safety strategy recommended by the World Health Organization, and signaling stickers attached to IV lines are implemented in many institutions. However, the risk of colonization of the stickers' surface has not been evaluated. Our objective was to assess the colonization rate of stickers used for IV lines identification in an in vitro model using 3 different contamination degrees.

METHODS

A set of 30 stickers used for IV lines identification were exposed to low, medium, and high contamination degrees for up to 15 days. Twice a day, a single manipulator vigorously touched the surface of the stickers simulating the daily handling. Surface cultures of all stickers were performed daily. The microorganisms recovered were counted and identified by phenotypic characteristics.

RESULTS

Colonization occurred after 5 days in low and medium manipulation models and after 3 days in the high manipulation model. Nonadhesive sticker sides were associated with greater significant numbers of colony forming units when manipulation was performed without gloves.

CONCLUSION

Stickers used for the identification of IV lines may become potential reservoirs of catheter colonization. Clinical studies to validate these data and design policies of stickers' changes are required.

The risk of catheter-related bloodstream infection after withdrawal of colonized catheters is low

Most episodes of catheter-related bloodstream infection (C-RBSI) are documented before or at the time of catheter withdrawal. The risk of C-RBSI in the period after removing a colonized catheter in patients without bacteremia (late C-RBSI) is unknown. We assessed the risk of developing a late C-RBSI episode in an unselected population with positive catheter tip cultures and analyzed associated risk factors. We analyzed retrospectively all colonized catheter tips between 2003 and 2010 and matched them with blood cultures. C-RBSI episodes were classified as early C-RBSI (positive blood cultures were obtained ≤24 h after catheter withdrawal) or late C-RBSI (positive blood cultures were obtained ≥24 h after catheter withdrawal). We analyzed the risk factors associated with late C-RBSI episodes by comparison with a selected group of early C-RBSI episodes. We collected a total of 17,981 catheter tips: 4,533 (25.2 %) were colonized. Of them, 1,063 (23.5 %) were associated to early C-RBSI episodes and from the remaining 3,470, only 143 (4.1 %) were associated to late C-RBSI episodes. Then, they corresponded to 11.9 % of the total 1,206 C-RBSI episodes. After comparing early and late C-RBSI episodes, we found that late C-RBSI was significantly associated with the presence of methicillin-resistant Staphylococcus aureus (MRSA, p = 0.028) and with higher mortality (p = 0.030). According to our data, patients with colonized catheter tips had a 4.1 % risk of developing late C-RBSI, which was associated with higher crude mortality.

False-positive Aspergillus antigenemia due to blood product conditioning fluids

The presence of Aspergillus antigens in blood transfusion components from different manufacturers was analyzed. Galacomannans were found in transfused patients, pooled platelet concentrates, fresh frozen plasma, and packed red cells collected using Fresenius Kabi bags. Galacomannans were also found in blood collection anticoagulant and platelet additive solution from this manufacturer.

Impact on knowledge and practice of an intervention to control catheter infection in the ICU

Information on the impact of care bundles has been mainly acquired in adult intensive care units (ICUs). However, specific data for educational programs are scarce. Our objective was to analyze the impact of an educational program on the knowledge and prevention of catheter-related bloodstream infection (CRBSI) in two pediatric intensive care units (P-ICUs). A prospective study was carried out at a large teaching institution in Madrid, Spain. Healthcare workers' (HCWs) knowledge of guidelines for the prevention of CRBSI was assessed before and after the educational program using a questionnaire covering 12 issues. A 20-min program was offered to all HCWs on each ICU shift. The incidence density of CRBSI was assessed before, during, and after the educational program. A total of 174 questionnaires were completed by HCWs from both the neonatal ICU (N-ICU) and the P-ICU before the intervention and 54 were completed after the intervention (120 participants were not present during this period). The incidence density of CRBSI before, during, and after the intervention was 6.2, 5.2, and 9.3 in the N-ICU and 2.2, 3.1, and 2.9 in the P-ICU (p > 0.05). A single 20-min educational intervention on the prevention of CRBSI significantly improved HCWs' knowledge, but was not enough to reduce the incidence density of CRBSI.

Guidelines on the treatment of chronic coinfection by Trypanosoma cruzi and HIV outside endemic areas

As a result of population migration, Chagas disease is no longer limited to the North and South American continents. In HIV-infected patients, chronic infection by Trypanosoma cruzi behaves as an opportunistic infection in severely immunosuppressed patients and is responsible for high morbidity and mortality. Unlike other opportunistic infections, information on the natural history, diagnosis, treatment, and prevention of Chagas disease is scarce. Spain has the highest number of cases of Chagas disease outside the North and South American continents, and coinfection with HIV is increasingly prevalent. In this article, the Spanish Society for Tropical Medicine and International Health (Sociedad Española de Medicina Tropical y Salud Internacional) reviews the current situation of coinfection with HIV and T. cruzi infection and provides guidelines on the diagnosis, treatment, and prevention in areas where Chagas disease is not endemic. It also identifies areas of uncertainty where additional research is necessary.

Systematic use of universal 16S rRNA gene polymerase chain reaction (PCR) and sequencing for processing pleural effusions improves conventional culture techniques

Conventional culture of pleural fluid samples frequently provides false-negative results. Universal polymerase chain reaction (PCR) of the 16S ribosomal ribonucleic acid (rRNA) gene (16S PCR) has proven useful in the diagnosis of various bacterial infections. We conducted a prospective study to assess the value of 16S PCR in the etiologic diagnosis of pleural effusion. All pleural fluid samples received for culture were also studied using 16S PCR. Positive samples were sequenced for identification. Clinical records and conventional culture results were analyzed to classify pleural fluid samples as infected or not infected. We studied 723 samples. We excluded 188 samples because they were obtained from a long-term chest tube, there was a diagnosis of mycobacterial infection, or there were insufficient data to classify the episode. Finally, 535 pleural fluid samples were analyzed. According to our criteria, 82 (15.3%) were infected and 453 (84.7%) were not infected. In the infected samples, 16S PCR was positive in 67 samples (81.7%) while conventional culture was positive in 45 (54.9%). There were 4 false positives with 16S PCR (0.9%) and 12 with culture (2.6%). The values for the etiologic diagnosis of bacterial pleural effusion of conventional culture compared with 16S PCR were as follows: sensitivity, 54.9%/81.7%; specificity, 97.4%/99.1%; positive predictive value, 76.3%/94.4%; negative predictive value, 92.6%/96.8%; and accuracy, 90.8%/96.5%.When compared with conventional culture, 16S PCR plus sequencing substantially improves the etiologic diagnosis of infectious pleural effusion. In our opinion, this technique should be added to the routine diagnostic armamentarium of clinical microbiology laboratories.

Ventilator-associated pneumonia due to meticillin-resistant Staphylococcus aureus: risk factors and outcome in a large general hospital

BACKGROUND

Data about risk factors and impact on outcome of methicillin-resistant S. aureus (MRSA) in unselected patients with ventilator-associated pneumonia (VAP) are limited.

AIM

To assess predisposing factors and outcome of VAP due to MRSA in a large teaching institution.

METHODS

Prospective study carried out over four years in the three adult ICUs of our hospital. Patients with MRSA-VAP were compared with those with bacterial VAP due to other microorganisms.

FINDINGS

Overall, 474 episodes of bacterial VAP were collected. Significant differences between MRSA-VAP (111) and VAP due to other microorganisms (363) were found for median age (68 vs. 62 years), median APACHE II score (12 vs. 11), neurosurgery (5.4% vs. 13.8%), abdominal surgery (35% vs. 19%), prior treatment with any antibiotic (82.9% vs. 64.5%) and with imipenem (24% vs. 11%) at present admission before VAP, and pleural effusion (12% vs. 5%). Multivariate analysis adjusted for confounding factors showed that higher APACHE II score, prior treatment with any antibiotic and pleural effusion were independent risk factors for MRSA. As for treatment and outcome, the differences between MRSA-VAP and other VAP were inadequate empiric treatment (70% vs. 53%), median cost of antibiotics per episode (€974 vs. €726), and in-hospital mortality (60% vs. 47%). At multivariate analysis, however, MRSA was not found to be an independent risk factor for mortality.

CONCLUSION

MRSA is a common cause of VAP. Underlying conditions predispose to its high mortality.

Prospective, randomised study of selective versus routine culture of vascular catheter tips: patient outcome, antibiotic use and laboratory workload

In order to assess the value of vascular catheter tip culture in patients with negative blood cultures, all tip samples from hospitalised patients were prospectively randomised (1:1) to two different routines for processing catheters: culture of all tips (routine A) vs culture only of tips from patients with concomitant bacteraemia or fungaemia (routine B). Over a nine-month period, 426 catheters from 318 patients were randomly assigned to routine A and 429 catheters from 322 patients to routine B (n=40 [corrected] patients). We compared the outcome and costs from both groups. No statistically significant differences were found with respect to demographic data, mortality, hospital stay or antimicrobial use. In non-bacteraemic/fungaemic cases (N=517), days on antimicrobial therapy after catheter withdrawal were significantly higher in patients from group A [10.0 days (interquartile range, IQR): 6.0-14.0] vs 8.0 days (IQR: 4.7-12.2), P=0.03], as was the number of daily defined doses (DDDs) of antimicrobials [10.8 DDDs (IQR: 2.4-26.9) vs 7.5 DDDs (IQR: 1.5-20.0), P=0.03]. Median antimicrobial cost per treated patient was significantly higher in group A: €222.30 (IQR: €20.30-€1,030.60) vs €109.10 (IQR: €10.90-€653.20), P=0.05. If all vascular catheter tips were processed according to routine B, the microbiology laboratory workload would decrease by 77% for the total number of catheters processed. Microbiology laboratories should not routinely culture catheter tips in patients without bacteraemia or fungaemia.

Application of real-time PCR for the differentiation of Entamoeba histolytica and E. dispar in cyst-positive faecal samples from 130 immigrants living in Spain

In an effort to improve the diagnosis of intestinal amoebiasis, a real-time PCR has been used for the detection and differentiation of Entamoeba histolytica and E. dispar infections in African or South American immigrants who live in Spain. Faecal samples from all of the 130 subjects had apparently been found to contain E. histolytica/E. dispar cysts by microscopical examination. Using the real-time PCR, E. histolytica DNA was detected in faecal samples from only 10 (7.7%) of the immigrants, with E. dispar DNA detected in the samples from another 117 (90.0%) of the subjects. The use of such PCR in the routine investigation of patients found positive for E. histolytica/E. dispar cysts (by microscopy) is recommended, especially in non-endemic areas.

How many lumens should be cultured in the conservative diagnosis of catheter-related bloodstream infections?

BACKGROUND

Recent practice guidelines for the diagnosis of catheter-related bloodstream infection (CRBSI) describe as an "unresolved issue" the number of lumens from which blood culture specimens should be drawn to make a conservative diagnosis of CRBSI. Our objective was to determine how many CRBSI episodes would be missed if not all catheter lumens were sampled.

METHODS

We performed a retrospective study (1 January 2003-31 May 2009) in patients with microbiologically proven CRBSI in which all available catheter lumens (those that did not contain clots) were used to draw blood culture samples. We calculated the number of episodes that would have been missed in double- and triple-lumen catheters if the culture of samples obtained from 1 lumens had been eliminated.

RESULTS

We studied 171 episodes of proven CRBSI in 154 patients. Overall, if 1 lumen-associated culture had been eliminated for both double-lumen and triple-lumen catheters, we would have missed 27.2% and 15.8% of episodes of CRBSI, respectively. If we had eliminated 2 cultures for triple-lumen catheters, 37.3% of episodes would have been missed.

CONCLUSIONS

Samples for blood culture should be obtained through all catheter lumens to establish a diagnosis of CRBSI.

[Autochthonous amebic liver abscess in Spain: an emerging disease? Case report and description of a PCR-based diagnostic test]

INTRODUCTION

In Spain an increase in cases of amebiasis has been detected in patients with no history of traveling to, or immigration from, endemic areas.

MATERIAL AND METHODS

This study describes two new cases of amebic hepatic abscess due to native protozoa and reviews 21 more cases of amebic hepatic abscess reported in Spanish patients who had never left the Iberian Peninsula. In addition, a new PCR-based technique for diagnosing Entamoeba histolytica is described.

RESULTS

Twenty cases (87%) occurred in men. The age range of the affected patients was 26 to 77 years. Two of the 3 women with extraintestinal amebiasis were HIV-positive. There was no history of exposure to the parasite in 17 cases. In the remaining 6 cases, direct contact with patients affected with amebiasis or with individuals or foods from endemic areas was recorded.

CONCLUSION

Entamoeba histolytica infection is becoming an emerging disease in our country. Amebiasis should be included in the differential diagnosis of consistent clinical entities even when there is no background of traveling or immigration. New molecular diagnostic tools can help to characterize this infection and should be considered reference techniques in combination with serological methods.

Comparison of phenotypic with genotypic procedures for confirmation of coagulase-negative Staphylococcus catheter-related bloodstream infections

We sought here to review the present definition of catheter-related bloodstream infections (CR-BSI) due to coagulase-negative staphylococci (CNS) by comparing the routine phenotypic methods with a genotypic procedure that considers different morphotypes. Our phenotypic characterization of CNS isolates included routine identification with biotype and antibiotype. The genotypic diagnosis was based on longer incubation periods with the consideration of all morphotypes and molecular typing by pulsed-field gel electrophoresis techniques. We prospectively selected 61 episodes of suspected CR-BSI by CNS occurring during 1 year, based on the presence of a compatible clinical setting and the isolation of one or more CNS from blood and catheter tip. Of these episodes, 47 (77%) were identified as true episodes of CR-BSI based on the presence of microorganisms of the same genotype in the blood and on the catheter tip. The sensitivity, specificity, positive predictive, negative predictive, accuracy, positive likelihood ratio, and negative likelihood ratio values obtained by different phenotypic microbiological approaches to establish the diagnosis of CR-BSI were as follows: identity at species level (78.7%, 85.7%, 94.9%, 54.5%, 80.3%, 5.51, and 0.25, respectively); identity of species and biotype (59.6%, 92.9%, 96.6%, 40.6%, 67.2%, 8.34, and 0.44, respectively); identity of species and antibiotype (61.7%, 92.9%, 96.7%, 41.9%, 68.8%, 8.64, and 0.41, respectively); and identity of species, biotype, and antibiotype (48.9%, 92.9%, 95.8%, 35.1%, 59%, 6.85, and 0.55, respectively). Our study demonstrates the inaccuracy of the diagnosis of CNS CR-BSI when the current definition based on conventional routine microbiological practice is followed. A new definition of CNS CR-BSI is necessary, at least as an epidemiological and research tool.

A prospective, randomized, and comparative study of 3 different methods for the diagnosis of intravascular catheter colonization

BACKGROUND

Demonstration of catheter tip colonization is usually performed by use of Maki's semiquantitative technique, although the superiority of quantitative techniques has been claimed on the basis of their purported ability to detect both endoluminal and exoluminal microorganisms.

METHODS

We prospectively compared Maki's semiquantitative technique and the quantitative methods of sonication and vortexing for the detection of colonization of intravascular catheter tips and catheter-related bloodstream infections. All 3 techniques were performed on the tip of each catheter, and the order in which each technique was performed was randomly assigned.

RESULTS

Of the 1000 catheter tips that were processed, 329 (32.9%) had positive results for at least 1 of the 3 techniques when a breakpoint of >or=100 colony-forming units (cfu)/catheter segment was used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique. Eighty-two of the catheter tips for which results were positive were from patients with catheter-related bloodstream infections. For each technique, the likelihood of detection decreased progressively depending on the order in which the technique was performed (i.e., second vs. first and third vs. second). The likelihood of detection of catheter colonization for each technique, when the technique was performed first and when 2 breakpoints (>or=100 cfu/catheter segment [criterion B] and >or=1000 cfu/catheter segment [criterion A]) were used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique, was as follows: 99.1% and 100% for Maki's technique, 95.1% and 92.9% for sonication, and 93.1% and 72.8% for vortexing (for criteria B and A, respectively). No inferiority of Maki's technique could be demonstrated when results were compared according to whether catheter placement was short term (i.e., <7 days) or long term (i.e., >or=7 days), either for the detection of colonization or for the detection of catheter-related bloodstream infections.

CONCLUSIONS

According to data from the present study, the quantitative techniques of sonication and vortexing were not superior to Maki's technique under the test conditions used. The greater simplicity of Maki's semiquantitative technique makes it the procedure of choice for routine work in the microbiology laboratory.