Changing pattern of pathogens causing broviac catheter-related bacteraemias in children with cancer

Central line-associated blood stream infections: characteristics and risk factors for mortality over a 5.5-year period

BACKGROUND/AIM

Central line-associated bloodstream infections (CLABSIs) are associated with substantial morbidity and mortality and the infection rates vary in a wide range1397645907(high: 62.5%; low: 20%) in developing countries. We aimed to investigate the characteristics and the risk factors for mortality in patients with CLABSIs in intensive care units (ICUs) and provide the relevant data.

MATERIALS AND METHODS

The electronic medical records database and file records obtained through active surveillance by an infection control committee of a hospital were screened to identify patients with CLABSIs hospitalized from January 2008 through July 2013.

RESULTS

A total of 166 CLABSI episodes in 158 patients out of 17,553 on 38,562 catheter and 94,512 hospitalization days were evaluated. The infection developed in catheterized patients at a median of 14 days (range 2-88), and the highest infection rate with 13.4% (n = 20) was the femoral region among the places where the catheter was inserted. Of the patients catheterized, 54.4% survived whereas 45.6% died. In patients having Candida infection, the mortality was significantly higher. High APACHE II scores and Candida infections were found to be significant risk factors associated with mortality.

CONCLUSION

APACHE II scores and bloodstream infection with Candida species were the most powerful predictors of mortality. In ICU practice, health-care givers must consider the emerging role of Candida for both invasiveness and mortality.

Port type is a possible risk factor for implantable venous access port-related bloodstream infections and no sign of local infection predicts the growth of gram-negative bacilli

BACKGROUND

Implantable venous access port (IVAP)-related blood stream infections (BSIs) are one of the most common complications of implantable venous ports. The risk factors and pathogens for IVAP-related BSIs are still controversial.

METHODS

We retrospectively reviewed all patients who received IVAPs at a Hospital in Taiwan from January 1, 2011 to June 31, 2014. Two types of venous port, BardPort® 6.6 fr (Bard port) and Autosuture Chemosite® 7.5 fr (TYCO port) were used. All patients with clinically proven venous port-related BSIs were enrolled.

RESULTS

A total of 552 patients were enrolled. There were 34 episodes of IVAP-related BSIs during the study period for a total incidence of 0.177 events/1000 catheter days. Port type (TYCO vs. Bard, HR = 7.105 (95% confidence interval (CI), 1.688-29.904), p = 0.0075), age > 65 years (HR = 2.320 (95 % CI, 1.179-4.564), p = 0.0148), and lung cancer (HR = 5.807 (95% CI, 2.946-11.447), p < 0.001) were risk factors for port infections. We also found that no local sign of infection was significantly associated with the growth of gram-negative bacilli (p = 0.031).

CONCLUSIONS

TYCO venous ports, age > 65 years, and lung cancer were all significant risk factors for IVAP-related BSIs, and no sign of infection was significantly associated with the growth of gram-negative bacilli.

Invasive bacterial and fungal infections in paediatric patients with cancer: incidence, risk factors, aetiology and outcomes in a UK regional cohort 2009-2011

BACKGROUND

Cancer is the second most common cause of childhood deaths in the United Kingdom and infection contributes to a quarter of all cancer-related deaths. This study aimed to estimate the risk, aetiology and outcome of bloodstream bacterial and fungal infections in children with cancer within a geographically defined region in South-West London over a 3-year period.

METHODS

Web-based questionnaires were completed using case records of children with positive blood cultures admitted to five London hospitals during 2009-2011.

RESULTS

A total of 112 children with a median age of 5.4 (IQR 3.6-11.2) years had 266 significant blood cultures during 149 infection episodes. Haematological malignancy affected 68 patients (60.7%) and solid tumours 44 (39.3%). The overall bloodstream infection rate was 1.5 episodes per 1,000 days-at-risk (95% CI, 1.2-1.8) and was similar for those with haematological malignancies and solid tumours. Most episodes were attributed to central venous catheter infection (120/149, 80.5%). Coagulase-negative staphylococci were isolated in almost half the bloodstream infections (127/266; 47.7%), while Gram-negative organisms accounted for a further quarter (64/266; 24.1%). Fungal isolates from blood were uncommon (8/112 children, 7.1%) but significantly associated with neutropenia (18/149 [12.1%] vs. 1/114 [0.9%], P = 0.0004). Six children (5.4%) died, including three (2.7%; 95% CI, 0.6-7.6%) whose deaths were infection-related.

CONCLUSIONS

This study provides an updated risk estimate for bloodstream infections in children with cancer and adds to the framework for developing evidence-based guidance for management of suspected infections in this highly vulnerable group.

Catheter-associated bloodstream infections in pediatric hematology-oncology patients

Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.

Routine surveillance for bloodstream infections in a pediatric hematopoietic stem cell transplant cohort: Do patients benefit?

BACKGROUND

Hematopoietic stem cell transplant (HSCT) recipients are at a high risk for late bloodstream infection (BSI). Controversy exists regarding the benefit of surveillance blood cultures in this immunosuppressed population. Despite the common use of this practice, the practical value is not well established in non-neutropenic children following HSCT.

METHODS

At the IWK Health Centre (Halifax, Nova Scotia), weekly surveillance blood cultures from central lines are drawn from children following HSCT until the line is removed. A retrospective chart review was performed to determine the utility and cost of this practice. Eligible participants were non-neutropenic HSCT recipients with central venous access lines. The cost of laboratory investigations, nursing time, hospital stay and interventions for positive surveillance cultures was calculated.

RESULTS

Forty-three HSCTs were performed in 41 children. Donors were allogenic in 33 cases (77%) and autologous in 10 cases (23%). There were 316 patient contacts for surveillance cultures (mean seven per patient) and 577 central line lumens sampled. Three of 43 patients (7%) had clinically significant positive surveillance blood cultures. Bacteria isolated were Klebsiella pneumoniae (n=2) and Corynebacterium jeikeium (n=1). All follow-up cultures before initiation of antimicrobial therapy were sterile. All three patients were admitted for antimicrobial therapy if they were not already hospitalized and/or had an uncomplicated course. The estimated total cost of BSI surveillance and management of asymptomatic infection over six years was $27,989.

CONCLUSION

The present study suggests that BSI surveillance in children following HSCT engraftment has a very low yield and significant cost. It is unclear whether it contributes to improved patient outcomes.

Symptoms and signs of port-related infections in oncology patients related to the offending pathogens

AIM

There is limited information about symptoms and signs of port-related infections linking to their offending pathogens.

METHODS

Oncology patients proven to have port-related infections were retrospectively analysed. We divided them into two subgroups according to their symptoms and signs. Onset of fever and chills with or without hypotension following the port flush was classified as 'port flush form infection'. Presence of local inflammatory signs, including erythema, warmth, tenderness and pus formation and systemic infection signs, including fever, chills with or without hypotension was classified as 'local inflammatory form infection'.

RESULTS

There were 29 episodes of port-related infection among 28 patients, with port flush form 22 episodes and local inflammatory form seven episodes. Of 22 episodes of port flush form infections, 20 (91%) were nosocomial glucose non-fermenting gram-negative bacilli, with Acinetobacter baumannii (11 episodes, 50%) and Enterobacter cloacae (four episodes, 18%) the most common. Polymicrobial infections occurred in four episodes (18%). Candida infection occurred in two episodes (9%). Of seven episodes of local inflammatory form infections, six (86%) were gram-positive cocci, with Staphylococcus aureus (five episodes, 71%) the most common. The time from port implantation to its infection was 272 +/- 255 days (30-993 days) for the port flush form infections and 82 +/- 87 days (22-265 days) for the local inflammatory form infections. This difference was not significant difference (p = 0.068).

CONCLUSIONS

The differences between infection of patients with port flush form and local inflammatory form in incidence and offending microorganism suggest that the aetiology of infection were different.

Bloodstream infection caused by Stenotrophomonas maltophilia in children

BACKGROUND

Stenotrophomonas maltophilia, a multidrug resistant Gram-negative pathogen, has become a more frequent cause of bloodstream infections (BSI). Little is known about development of S. maltophilia bacteremia in children. The objective of this study was to define risk factors and outcomes associated with S. maltophilia BSI in children.

METHODS

This was a retrospective case-control study conducted at The Children's Hospital of Philadelphia between January 1, 2000 and July 31, 2005. All patients with S. maltophilia BSI were compared with a random sample of patients with non-Stenotrophomonas Gram-negative rod BSI.

RESULTS

Fifty-one cases and 103 control subjects were included in the study. The median patient age was 2 years (interquartile range: 1 day-8.5 years). Patients with S. maltophilia BSI were significantly more likely to have a malignancy and be coinfected with other organisms than those with other Gram-negative rod infections. On multivariate analysis, patients with S. maltophilia BSI were more likely to develop their infection in the home setting (adjusted OR, 4.18; 95% CI: 1.44-12.16; P = 0.009). Additionally, prior exposure to trimethoprim-sulfamethoxazole, receipt of steroids or other immunosuppressive medication in the 30 days preceding infection and black race were associated with the development of S. maltophilia BSI.

CONCLUSIONS

Patients with Stenotrophomonas maltophilia BSI are more likely to have a polymicrobial infection and develop their infection in the home setting compared with patients with BSI caused by other Gram-negative rods.

Central venous catheter-related Stenotrophomonas maltophilia bacteraemia and associated relapsing bacteraemia in haematology and oncology patients

This retrospective study investigated the clinical significance and impact of Stenotrophomonas maltophilia bacteraemia in 49 haematology and oncology patients at a tertiary referral medical centre in Taipei between July 1999 and December 2003. Sixteen patients had 24 episodes of central venous catheter (CVC)-related bacteraemia, with the main clinical characteristics being a nosocomial bacteraemia (100%), preceding antibiotic therapy (94%), bacteraemia developed in a general ward (87%), immunosuppressive therapy (75%), in-situ CVC-related bacteraemia (75%), and neutropenia (63%). Only four (25%) patients had inflammatory signs at the CVC site following diagnosis of bacteraemia. Five patients had recurrent bacteraemia, with risk-factors being long-lasting (>10 days) neutropenia (p 0.036) and an initial failure to remove the CVC (p 0.001). These cases did not involve re-infection, as the same S. maltophilia strain was identified following random amplified polymorphic DNA (RAPD) analysis of the initial and subsequent isolates. However, relapses could occur after long latency periods (maximum, 200 days). Most patients were cured after removal of the CVC, even without appropriate antibiotic treatment. Physicians should have a high index of suspicion for CVC-related bacteraemia with haematology and oncology patients with CVCs and S. maltophilia bacteraemia. In addition to appropriate antibiotic therapy, removal of the CVC is crucial for successful treatment of CVC-related S. maltophilia bacteraemia and prevention of relapses.

Diagnosis of catheter-related bloodstream infections among pediatric oncology patients lacking a peripheral culture, using differential time to detection

BACKGROUND

Current methods for in situ diagnosis of catheter-related bloodstream infections require concurrent collection of central venous catheter (CVC) and peripheral vein (PV) blood cultures. Both the pain and inconvenience of PV cultures are undesirable.

METHODS

A prospective study was conducted (August 2002 to March 2004) to assess the accuracy of diagnosing catheter-related bloodstream infections based on the difference in time to detection of blood cultures drawn concurrently from 2 lumens of a multilumen CVC. This difference in time to detection between 2 lumens was compared with results of the standard criterion with paired CVC and PV blood cultures.

RESULTS

Twenty-one infectious episodes were categorized as catheter-related bloodstream infections and 38 as non-catheter-related bloodstream infections. With a cutoff in difference in time to detection between 2 lumens of > or =180 minutes, the sensitivity of this test to diagnose a catheter-related bloodstream infection was 61% (95% confidence interval, 39-80%) and the specificity was 94% (95% confidence interval, 82-99%). In 4 of 7 episodes with false-negative results, the colony counts in cultures from both lumens were >400 colony-forming units/mL (maximal value reported), indicating the limitation of this method when both lumens of the catheter are colonized. With the pretest probability of catheter-related bloodstream infections ranging from 28% to 54%, the positive predictive value of a difference in time to detection between 2 lumens of > or =180 minutes for diagnosis of catheter-related bloodstream infections ranged from 81% to 93% and the negative predictive value ranged from 67% to 86%.

CONCLUSION

Within the context of its limitations, this novel method provides an alternative for diagnosing catheter-related bloodstream infections among patients with a CVC, without PV cultures.

[Catheter-related infections: microbiology]

Coagulase negative staphylococci, Staphylococcus aureus and Pseudomonas sp. are the most frequent microorganisms responsible for catheter-related infections. A relative frequency of microorganisms varies according to the countries, microenvironment and outbreaks of multiresistant bacterias. Infections due to fungi, S. aureus and Pseudomonas sp. are associated with the more severe complications. Recent data suggest that chlorhexidine, either used for cutaneous antisepsis or for catheter impregnation decreases infections due to gram positive cocci. Ecological data should be taken into account when deciding a probabilistic treatment in case of suspicion of catheter-related infection.

Catheter-related bloodstream infection in adult haematology patients: catheter removal practice and outcome

The aim of the present study was to describe the practice of central venous catheter (CVC) removal and outcomes of catheter-related bloodstream infection (CR-BSI) in adult haematology patients. Patients were identified retrospectively according to diagnosis coding of inpatient episodes and evaluated when, on examination of medical records, there had been evidence of sepsis with strong clinical suspicion that the source was the CVC. Demographic and bacteriological data, as well as therapeutic measures and clinical outcomes, were recorded. One hundred and three patient episodes were evaluated. The most frequent type of CVC was the Hickman catheter and the most frequently isolated pathogen was coagulase-negative staphylococci. Twenty-five percent of episodes were managed with catheter removal. Treatment failure, defined as recurrence of infection within 90 days or mortality attributed to sepsis within 30 days, occurred significantly more frequently in the group managed without catheter removal (52.5% versus 4%, P < 0.05). Specifically, 90-day recurrence was more common when the catheter was retained (46% versus 0%). However the difference in 30-day attributable mortality (7% versus 4%) was not significantly different. Notably, no significant difference between the two groups emerged in respect of other measured characteristics that had been considered as potential determinants of outcome. More frequent CVC removal for CR-BSI, in this population, should be considered. Management of CR-BSI without catheter removal is associated with treatment failure, morbidity and carries significant resource implications.

Bacteremia after hematopoietic stem cell transplantation: incidence and predictive value of surveillance cultures

We studied 622 transplants undertaken between 1982 and 2001 to: (1) determine the incidence, timing and etiology of bacteremias, and (2) examine the ability of routine surveillance cultures to predict bacteremias. A total of 404 episodes (0.65 episode per patient) occurred in 248 patients, due to coagulase-negative staphylococci (n=171, 42%), Gram-negative bacteria (n=129, 32%), streptococci (n=48, 12%), other Gram-positive bacteria (n=33, 8%), anaerobes (n=9, 2%) and fungi (n=14, 3%). Bacteremias were more frequent in allogeneic (0.96 episode/patient) compared to autologous (0.44) transplants (P<0.0001). The overall incidence decreased from 0.92 episode/patient until 1990 to 0.66 in 1991-1996 and 0.55 in 1997-2001 (P<0.0001), but this was only observed in autologous transplants. Among them, 212 (53%) occurred before hospital discharge and 192 (47%) thereafter. This proportion was lower for coagulase-negative staphylococci, other Gram-positive bacteria and Gram-negative bacteria compared to other agents (P=0.001). In 50% of the cases, the agent responsible for the bacteremic episode was present in routine surveillance cultures previously.

IN CONCLUSION

(1) bacteremias remain a frequent complication, particularly in allogeneic transplantation, even long after hospital discharge; (2) routine surveillance cultures can predict bacteremias in 50% of the cases, but the practical impact of this observation is limited in view of the costs.

Difference in time to detection: a simple method to differentiate catheter-related from non-catheter-related bloodstream infection in immunocompromised pediatric patients

Current methods for diagnosis of catheter-related infection (CRI) are cumbersome and may require removal of the central venous catheter (CVC). A prospective study was conducted to validate the difference in time to detection (DTD) of cultures of blood samples obtained simultaneously from a peripheral vein (PV) and from the CVC for differentiation of CRI and non-CRI. During a 15-month period, 9 episodes were categorized as CRI and 24 as non-CRI. The median DTD for patients with CRI was significantly higher than that for patients with non-CRI (457 vs. -4 min; P<.001). The optimum cutoff point for diagnosis of CRI was a DTD of > or =120 min (sensitivity, 88.9%; specificity, 100%). With pretest probability of CRI ranging from 28% to 54%, the positive predictive value of a DTD of > or =120 min for the diagnosis of CRI was 100%; the negative predictive value was 89%-96%. On the basis of findings from this study, which is the largest, to date, to involve pediatric patients with tunneled CVCs and the first to use paired quantitative blood cultures as a "criterion standard," DTD was found to be a simple, reliable tool for diagnosis of CRI in hospitals that use continuously read blood culture systems.

Prospective study of indwelling central venous catheter-related complications in children with broviac or clampless valved catheters

PURPOSE

To compare two types of central venous catheters (Broviac and valved clampless) for the incidence and severity of catheter-related complications in children.

PATIENTS AND METHODS

The authors report data on the mechanical and infectious complications collected in a prospective analysis of 92 catheters inserted in 82 children from January 2000 to March 2001.

RESULTS

Two different devices were inserted: 51 Broviac and 41 clampless valved catheters. During the follow-up of 17,803 catheter-days 52 complications were observed: 40 mechanical episodes and 12 infectious events. In the Broviac group the median follow-up was 179 days and the total number of catheter-days was 10,911. A total of 29 complications were observed, occurring in 22 catheters (43%), with an overall incidence of 0.27/100 catheter-days. In the clampless group the median follow-up was 134 days and the total number of catheter days was 6893. A total of 23 complications were observed, occurring in 19 devices (46%), with an incidence of 0.32/100 catheter days.

CONCLUSIONS

There were no major differences in the incidence of mechanical or infectious complications between the two devices. Malfunction was more frequent in Broviac catheters, whereas catheter displacement occurred more frequently in clampless valved catheters. These results show the importance of central venous catheter-related mechanical complications in the management of children with hematologic or oncologic malignancies.

Catheter-related infections: diagnosis and intravascular treatment

The diagnosis of catheter-related infections relies on the presence of clinical manifestations of infection and the evidence of colonization of the catheter tip by bacteria, mycobacteria, or fungi. The reference method to confirm the latter requires the withdrawal of the catheter for culturing, which frequently turns out to be inconvenient, unnecessary and costly. New methods try to avoid these drawbacks and to assess the presence of tip colonization without withdrawal. Comparative quantitative blood cultures with a marked increase (> or = 5) in colony counts between blood obtained from the catheter lumen and from a peripheral vein simultaneously is one of those methods. It has a high sensitivity (>80%) and specificity (94-100%) but it is cumbersome and requires both an easy backflow of blood in the catheter and the existence of bacteremia. Cytocentrifugation and acridine orange staining of blood withdrawn from an infected catheter lumen has a sensitivity and a specificity of over 90% for the diagnosis of tip colonization. 'Superficial cultures' comprise the semiquantitative culture of the hub, of the skin surrounding the catheter entrance and of the first subcutaneous portion (1 cm) of the catheter after swabbing. The sensitivity of this method is >90%, specificity is >80%, and positive and negative predictive values for catheters (considering together those with and without clinical data of infection) are 66 and 97%, respectively. Endoluminal brushing has proved to be an impractical and unreliable procedure, at least in our experience. New methods based on the speed of bacterial growth to detectable levels of micro-organisms in conventional blood cultures are a new and interesting way of assessing catheter-related infections. Moreover, as the use of antimicrobial-coated catheters becomes more prevalent, the existing definitions of catheter colonization and catheter-related infection may need to be modified, because such coatings may lead to false-negative culture results. Many catheter infections, diagnosed without catheter withdrawal, can be handled nowadays with the so-called 'antibiotic lock-in technique', which consists in 'locking' the infected catheter lumen with a solution containing antibiotics. A high proportion of infected catheters, mainly those with coagulase-negative staphylococci, can be maintained in place and sterilized with this technique, including catheters in patients with therapeutic failure after receiving conventional intravenous antibiotic therapy. New diagnostic and therapeutic techniques may avoid the unnecessary withdrawal of thousands of efficient, difficult to replace and expensive intravascular lines.

Incidence of septicaemias and invasive mycoses in children undergoing treatment for solid tumours: a 12-year experience at a single Italian institution

We carried out a retrospective study on the infection rate--in episodes per 100 person months at risk (p/m/r)--of septicaemia and invasive mycoses in children with solid tumours treated at a single institution between 1985 and 1996. Among 982 patients, accounting for 8108 p/m/r, 257 infectious episodes were documented, for an infection rate of 3.2. The infection rate for "intensive" treatment was greater than that for "less intensive" treatments, 3.7 compared with 0.5, respectively; P<0.001. 58% of infectious episodes were associated with neutropenia, 22% were megatherapy-related, and 39% were related to central venous catheter (CVC), while in 13% of the episodes no risk factor was identified. Of the episodes, single organism Gram-positive bacteraemias accounted for 62%, single organism Gram-negative for 23%, multiple organism bacteraemias for 7%, invasive mycoses for 4%, and isolated fungaemias for 4%. The infection rate for Gram-positive organisms decreased significantly over time (-5.9% per year; P<0.01), but increased for the Gram-negative organisms (+3.4% per year; P=0.4). This study demonstrates that the risk of bacteraemia increases in parallel with the treatment intensity, and that a considerable number of children with solid tumours develop bacteraemia in the absence of an identifiable risk factor.

Catheter-related infections: diagnosis and intravascular treatment

The diagnosis of catheter-related infections relies on the presence of clinical manifestations of infection and the evidence of colonization of the catheter tip by bacteria, mycobacteria or fungi. The reference method to confirm the latter requires the withdrawal of the catheter for culturing, which frequently turns out to be inconvenient, unnecessary and costly. New methods try to avoid these inconveniences and to assess the presence of tip colonization without withdrawal. One of these methods uses quantitative blood cultures with a jump (> or = 5) in colony counts between blood obtained from the catheter lumen and simultaneously from a peripheral vein. It has a high sensitivity (>80%) and specificity (94%-100%) but is cumbersome and requires both an easy backflow of blood in the catheter and the existence of bacteremia. Cytocentrifugation and acridine orange staining of blood withdrawn from an infected catheter lumen has a sensitivity and a specificity of over 90% for the diagnosis of tip colonization. "Superficial cultures" consist in the semiquantitative culture of the hub, of the skin surrounding the catheter entrance and of the first (1 cm) subcutaneous portion of the catheter after swabbing. Sensitivity of this method is >90% and specificity is >80%, and positive and negative predictive values for catheters (considering together those with and without clinical data of infection) are 66% and 97%, respectively. Endoluminal brushing has turned out to be an impractical and unreliable procedure, at least in our experience. New methods based on the speed of bacterial growth to detectable levels of microorganisms in conventional blood cultures are a new and interesting way of assessing catheter-related infections. Besides, as use of antimicrobial-coated catheters becomes more prevalent, the existing definitions of catheter colonization and catheter-related infection may need to be modified, because such coatings may lead to false-negative culture results. Many catheter infections, diagnosed without catheter withdrawal, can be handled nowadays with the so-called "antibiotic lock-in technique", which consists in locking the infected catheter lumen with a solution containing antibiotics. A high proportion of infected catheters, mainly those with coagulase-negative staphylococci, can be maintained in place and sterilized with this technique, including catheters in patients with therapeutic failure after receiving conventional intravenous antibiotic therapy. New diagnostic and therapeutic techniques may avoid the unnecessary withdrawal of thousands of efficient, difficult to replace and expensive intravascular lines.

Mechanical complications related to indwelling central venous catheter in pediatric hematology/oncology patients

Indwelling central venous catheters (CVC) are essential devices in the management of children with oncologic/hematologic diseases or following bone marrow transplantation. The authors report data on the mechanical complications observed in pediatric hematology/oncology patients, collected by a retrospective analysis of clinical records of 482 patients in whom 567 indwelling central venous catheters had been inserted from January 1992 to December 1998 at the G. Gaslini Institute. During the study period, 52 episodes of mechanical complications (9%) were observed: mechanical obstruction (24 episodes), catheter dislocation (13), problems related to catheter material (12), and accidental removal (3). In 25 cases removal and replacement of CVC was necessary for the treatment of complications, while medical treatment (thrombolytic-antithrombotic) was successful and well tolerated in 8. The study shows the importance of mechanical complications in children with indwelling CVC for hematologic or oncologic diseases. Moreover, the experience of administering a systemic low-dosage thrombolytic therapy demonstrates new prospects of reducing CVC replacement by restoring CVC viability.

Bacillus sphaericus bacteraemia in children with cancer: case reports and literature review

In the period 1989-1999, Bacillus sphaericus was demonstrated to cause 12 out of 469 (2%) episodes of bacteraemia in children with cancer or receiving bone marrow transplant at G. Gaslini Children's Hospital, Genoa, Italy. Neutropenia was present in five episodes, six episodes, (all without neutropenia) were related to the presence of a central venous catheter, and one episode occurred in a patient with intestinal graft vs. host disease and gut colonization. All patients survived. Ciprofloxacin was the only drug active against all the isolated strains.Bacillus sphaericus represents a new cause of infection in the immunocompromised host, with low aggressiveness, but a peculiar pattern of antibiotic susceptibility.

Bloodstream infections in children with cancer: a multicentre surveillance study of the Italian Association of Paediatric Haematology and Oncology. Supportive Therapy Group-Infectious Diseases Section

A one-year prospective, multicentre surveillance study on aetiology, main clinical features and outcome of bloodstream infections in children with cancer was conducted in 18 paediatric haematology centres belonging to the Italian Association for Paediatric Haematology and Oncology. A total of 191 bloodstream infections were reported during the study period. Of them, 123 (64%) occurred in neutropenic and 68 (36%) in non-neutropenic patients. Gram-positive cocci caused 45% (85/191) of the episodes, gram-negative rods 41% (78/191), and fungi 9% (18/191). The remaining 5% (10/191) of the episodes were poly-microbial infections. A total of 204 pathogens were isolated (46% gram-positive cocci; 44% gram-negative rods; and 10% fungi). The aetiologic distribution was similar among neutropenic and non-neutropenic patients. A correlation between the infection and the presence of an indwelling central venous catheter was found in 20% (23/114) of the episodes among neutropenic patients and in 55% (23/62) among non-neutropenic patients. Gram-negative micro-organisms were isolated in an unusually high proportion of catheter-related infections (48%). The overall mortality rate from any cause within 30 days from the first positive blood culture was 11%, and was higher among patients who were neutropenic at the onset of the infection than among those who were not neutropenic (15 versus 4%, P = 0.03). In addition, the mortality was significantly higher in recipients of bone marrow transplantation than in patients with acute leukaemia or solid tumour (21, 11 and 6%, respectively) and was also higher in fungaemias and poly-microbial infections (22 and 30%) than in single gram-positive and gram-negative bacteraemias (11 and 6%).

Nosocomial colonization, septicemia, and Hickman/Broviac catheter-related infections in bone marrow transplant recipients. A 5-year prospective study

In this 5-year prospective study of 242 bone marrow transplantation (BMT) recipients from whom daily blood cultures via the indwelling Broviac/Hickman catheter were obtained, there was a median of 35 catheter-days during hospitalization, mean of 40 days, and total of 9,667 catheter-days which were divided almost equally between neutropenic (4,771) and non-neutropenic (4,896) days. One hundred twenty (50%) patients had a total of 161 episodes of nosocomial bacterial or candidal infections. Overall, 81 (33%) patients experienced 100 episodes of catheter-related infections and 90 (37%) patients experienced 112 episodes of septicemia, including 51 episodes of catheter-related septicemia. There was an incidence of 11.59 septicemia episodes, including 5.28 catheter-related septicemia episodes, 2.48 colonization only (without subsequent septicemia), and 2.59 exit site infections only, per 1,000 catheter-days. Over a period of a total of 6,593 afebrile days, 34 (14%) patients developed 40 episodes of colonization, a rate of 6.07 per 1,000 afebrile days, of which 16 developed into septicemia. Twenty-five patients had 1 episode each of exit site infection without bacteremia. There were 10 (4%) septicemia-related deaths, 4 of which were catheter-related; 50% of all deaths involved Pseudomonas aeruginosa. The mortality due to catheter-related septicemic episodes was not greater than that of the non-catheter-related episodes. Neutropenia was found to be a significant risk factor in our study: 76% of the septicemia episodes (85/112) and 65% of the catheter-related infectious episodes (65/100) occurred during neutropenia. There was a higher incidence of septicemic episodes during neutropenia than during non-neutropenic periods, 17.82 versus 5.51 per 1,000 days (p < 0.0001), and a higher rate of catheter-related infections during the neutropenic period, 13.62 versus 7.15 during non-neutropenic days per 1,000 days (0.001). Fourteen of 16 colonization episodes developed into septicemia during neutropenia versus 2/24 during non-neutropenic periods, a rate of 5.47 versus 0.47 per 1,000 afebrile days, respectively (p < 0.0001), and 9/10 deaths occurred during neutropenia.

Broviac catheter-related bacteraemias due to unusual pathogens in children with cancer: case reports with literature review

Among 102 episodes of intravenous catheter related bacteraemias documented between January 1989 and July 1996 in children receiving antineoplastic chemotherapy or bone marrow transplantation at G. Gaslini Children's Hospital, Genoa, Italy, were identified seven episodes due to unusual pathogens: Bacillus circulans, Bacillus licheniformis, Brevibacterium casei, Flavimonas oryzihabitans, Porphyromonas asaccharolytica, Comamonas acidovorans and Agrobacterium radiobacter. Susceptibility to different antibiotics of all strains are reported. In all cases catheter removal was required for culture negativization. All episodes were diagnosed in absence of granulocytopenia.

Central venous catheter-related septicaemia in paediatric cancer patients

A prospective study of septicaemia, with special reference to central venous catheter (CVC)-related septicaemia, was performed over a nine-month period in paediatric cancer patients undergoing anti-neoplastic therapy. A total of 142 patients with 153 CVCs were included in the study. Seventy-two episodes of septicaemia were detected in 66 patients; overall, 46% of patients developed one or more episodes of septicaemia. Thirty-nine (54%) of these episodes occurring in 34 patients were CVC-related. Twenty-one (29%) of the episodes occurring in twenty patients were probably unrelated to CVCs and 12 (17%) episodes in 12 patients were of uncertain source. A total of 22932 CVC days were studied. The rate of CVC-related septicaemia was 1.7 episodes/1000 catheter days. Gram-positive organisms were commonest, causing 34 (87%) episodes of CVC-related septicaemia. Twenty-five (71%) of 35 evaluable episodes were successfully treated with antibiotics without CVC removal. Two patients died, CVC related sepsis probably contributing to death, and one patient suffered prolonged morbidity associated with CVC sepsis. Gram-negative organisms were the commonest cause of CVC-unrelated septicaemia, being implicated in 13 (62%) episodes.