Pediatr Transplantation 2014: 18: 87–93
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Pediatric Transplantation DOI: 10.1111/petr.12177
Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation Simojoki S-T, Kirjavainen V, Rahiala J, Kanerva J. Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation.
Suvi-Tuuli Simojoki1, Vesa Kirjavainen2, Jaana Rahiala1,3 and Jukka Kanerva1 1
Abstract: The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo-SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI-based in 87% and 54% developed GVHD (21% grade III-IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first-line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost-effective.
Infections and GVHD account for the most treatment-related deaths in patients treated with allo-SCT. Approximately 20–25% of the patients with febrile neutropenia have a microbiologically defined septicemia, majority of which are caused by bacteria (1–5). At present, gram-positive bacteria are the most common causes of the infections in immunocompromised patients (5–8). However, gram-negative bacteria, especially Pseudomonas aeruginosa,
Abbreviations: allo-SCT, allogeneic stem cell transplantation; BMT, bone marrow transplantation; BSI, bloodstream infections; CCFA, cycloserine–cefoxitin–fructose agar; CDAB, Clostridium difficile A&B; CLSI, Clinical and Laboratory Standards Institute; CRP, C-reactive protein; ELFA, enzyme–linked fluorescence assay; ESBL, extendedspectrum beta-lactamase; FUO, fever of unknown origin; GVHD, graft-versus-host disease; HEPA, high-efficiency particulate air; MIC, minimal inhibitory concentration; p.o., per oral; RPMI, Roswell Park Memorial Institute medium; SCT, stem cell transplantation; SG, Sabouraud’s glucose; TBI, total body irradiation; VRE, vancomycinresistant enterococci.
Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Children’s Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland, 2Finnish Red Cross Blood Service, Helsinki, Finland, 3Department of Pediatrics, Porvoo Hospital, Porvoo, Finland
Key words: surveillance cultures – allogeneic hematopoietic stem cell transplantation – pediatric Jukka Kanerva, Children’s Hospital, Helsinki University Central Hospital, P.O. Box 281, FIN-00029 Helsinki, Finland Tel.: +358 50 427 9167 Fax: +358 94 717 4707 E-mail: [email protected] Accepted for publication 16 September 2013
cause greatest mortality in SCT patients (8). Antibacterial prophylaxis is not recommended for pediatric SCT patients owing to lack of research data (9). Fungi cause a significant amount of infections to pediatric patients suffering from hematological malignancy especially during severe neutropenia (10–13). Fungal colonization, neutropenia, mucosal damage of the intestine, bacterial infections, and the administration of antibacterial agents are considerable risk factors for the development of fungal infections (10, 14, 15). Pathogens have been found to colonize the gastrointestinal tract prior to infection. Surveillance cultures have thus been considered to predict systemic infection (3, 16). However, there is a scarcity of studies on surveillance cultures, notably on pediatric allo-SCT patients. The majority of surveillance culture studies have been performed in the 1980s and 1990s, and the benefit from routine cultures in identifying infections of immunosuppressed patients has remained controversial (3, 17–21). 87
Simojoki et al.
The aim of this study was to determine whether the surveillance cultures are useful for predicting subsequent systemic infection. In addition, we studied whether the cultures aid in targeting the antibiotic treatment of infections. Patients and methods We retrospectively reviewed the medical records of all pediatric patients undergoing allo-SCT in our hospital from January 2007 to December 2009. Table 1 summarizes the characteristics of the 52 patients. A total of 57 transplantations were performed, because three patients received two transplants and one patient received three transplants. Most of the patients (87%) were conditioned with TBI-based (10–12 Gray) regimen. In 41 (72%) transplantations, cyclosporine was given as prophylaxis against GVHD. Additional methotrexate was given in 31 (76%) of the cases. Antilymphocyte globulin was administered to 21 (37%) in transplants to enhance engraftment and to prevent GVHD. Additional GVHD prophylaxis consisted of mycophenolate mofetil, sirolimus, and prednisolone given in different combinations to single patients. GVHD developed in 31 (54%) transplants and severe grade III-IV in 21%. Fourteen percent had severe stage 3-4 gastrointestinal GVHD.
Patient management Patients received p.o. trimethoprim–sulfadiazine (trimethoprim 5 mg/kg/day) as prophylaxis against Pneumocystis jiroveci from pretransplant period until day +7. The prophylaxis was resumed at neutrophil engraftment >1.0 9 109/L (median 18 days). The antifungal prophylaxis regimen consisted of p.o. or i.v. fluconazole (5 mg/kg once daily) and p.o. nystatin (100 000 IU three times daily). Patient rooms were equipped with HEPA filtration and a possibility of positive pressure.
Table 1. The general characteristics of allo-SCT patients Characteristics
Patients n = 52 (57 transplants)
Age, median (range) Sex (female/male) Diagnosis ALL CR1 ALL relapse AML CR1 AML relapse CML SAA Others Transplant type URD SIB UCB
9 yrs (7 months–17 yrs) 17/35 21 13 3 2 1 4 8 29 18 10
ALL CR1, acute lymphoblastic leukemia at first remission; AML CR1, acute myeloid leukemia at first remission; CML, chronic myeloid leukemia; SAA, severe aplastic anemia; Others, myelodysplastic syndrome, non-Hodgkin lymphoma, severe combined immunodeficiency, interferon-gamma receptor-2 deficiency, and congenital hypoplastic anemia. URD, unrelated donor; SIB, sibling donor; UCB, umbilical cord blood.
88
The patients had routine surveillance cultures obtained weekly from the stool (bacterial, fungal and Clostridium difficile cultures, and C. difficile toxin assay) and from the throat (bacterial and fungal cultures). Symptoms and findings of infection and GVHD were examined daily. The body temperature was measured four times a day. When patients developed a fever of ≥38 °C, had an increase in the CRP level, or had other symptoms of infection, blood cultures were drawn from both central venous catheters or from both lumens of the two-lumen catheters. Subsequently, they received ceftazidime and cloxacillin combination as the first-line empiric antibacterial regimen. Patients with persistent fever despite administration of antibiotics usually received glycopeptide and carbapenem (usually meropenem) as a second-line treatment. During antimicrobial treatment, blood cultures were obtained daily for approximately three days or until the infection clinically resolved. Systemic antifungal treatment was started if fever persisted despite broad-spectrum antibacterial medication.
Culture methodology and susceptibility tests The bacterial specimens from stool and throat were cultured on blood agar plates. Biochemical methods were used to identify one or two main species in the flora and possible findings deviating from normal flora of the region. The beta-hemolytic streptococci (groups A, C, G) and major growth of the upper airway pathogens were identified in bacterial throat cultures. The commercial VIDASâ CDAB test (bioMerieux SA, Marcy l’Etoile, France) based on the ELFA fluorescence technique was used to detect toxins A and B produced by C. difficile directly from stool. In addition, the specimens were cultured on selective CCFA media. The fungal stool and fungal throat specimens were cultured on SG agar plates and incubated at +28 and +37 °C. The stool yeast specimens were cultured on selective chromogenic media (CHROMagar Candida, CHROMagar, Paris, France). Candida albicans was identified based on the color reaction of the colony on the media, and other yeast species were named “yeast, non-C. albicans.” The antimicrobial susceptibility testing conformed to the susceptibility standards of CLSI. The bacterial susceptibility testing was performed on the Mueller–Hinton agar by the disk diffusion method. The fluconazole susceptibility of C. albicans was determined with fluconazole disk or Etest strip (bioMerieux SA) on RPMI plate. For other yeasts and antimicrobial agents, the MIC was determined with Etest strips on RPMI agar plate.
Material The bacterial and fungal colonization data were registered from the week prior to transplantation through 100 days post-transplant. All the data concerning the patients’ episodes of infection from the pretransplant week to 100 days post-transplant were acquired from the medical records. These data included the antimicrobial therapy used, the symptoms of infection, CRP, changes in the neutrophil count, identified infectious agents, and the possible utilization of surveillance cultures to determine successful therapy. All episodes, that included antimicrobial therapy based on either fever (≥38.0 °C) and other clinical findings, CRP elevation or a positive blood culture, were registered as an infection episode.
Surveillance cultures in transplantation Statistics The sensitivity, specificity, and the positive and negative predictive values were calculated. The evolution of stool colonization over time was analyzed using the Pearson’s chi-square test. A p-Value of
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Pediatric Transplantation DOI: 10.1111/petr.12177
Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation Simojoki S-T, Kirjavainen V, Rahiala J, Kanerva J. Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation.
Suvi-Tuuli Simojoki1, Vesa Kirjavainen2, Jaana Rahiala1,3 and Jukka Kanerva1 1
Abstract: The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo-SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI-based in 87% and 54% developed GVHD (21% grade III-IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first-line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost-effective.
Infections and GVHD account for the most treatment-related deaths in patients treated with allo-SCT. Approximately 20–25% of the patients with febrile neutropenia have a microbiologically defined septicemia, majority of which are caused by bacteria (1–5). At present, gram-positive bacteria are the most common causes of the infections in immunocompromised patients (5–8). However, gram-negative bacteria, especially Pseudomonas aeruginosa,
Abbreviations: allo-SCT, allogeneic stem cell transplantation; BMT, bone marrow transplantation; BSI, bloodstream infections; CCFA, cycloserine–cefoxitin–fructose agar; CDAB, Clostridium difficile A&B; CLSI, Clinical and Laboratory Standards Institute; CRP, C-reactive protein; ELFA, enzyme–linked fluorescence assay; ESBL, extendedspectrum beta-lactamase; FUO, fever of unknown origin; GVHD, graft-versus-host disease; HEPA, high-efficiency particulate air; MIC, minimal inhibitory concentration; p.o., per oral; RPMI, Roswell Park Memorial Institute medium; SCT, stem cell transplantation; SG, Sabouraud’s glucose; TBI, total body irradiation; VRE, vancomycinresistant enterococci.
Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Children’s Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland, 2Finnish Red Cross Blood Service, Helsinki, Finland, 3Department of Pediatrics, Porvoo Hospital, Porvoo, Finland
Key words: surveillance cultures – allogeneic hematopoietic stem cell transplantation – pediatric Jukka Kanerva, Children’s Hospital, Helsinki University Central Hospital, P.O. Box 281, FIN-00029 Helsinki, Finland Tel.: +358 50 427 9167 Fax: +358 94 717 4707 E-mail: [email protected] Accepted for publication 16 September 2013
cause greatest mortality in SCT patients (8). Antibacterial prophylaxis is not recommended for pediatric SCT patients owing to lack of research data (9). Fungi cause a significant amount of infections to pediatric patients suffering from hematological malignancy especially during severe neutropenia (10–13). Fungal colonization, neutropenia, mucosal damage of the intestine, bacterial infections, and the administration of antibacterial agents are considerable risk factors for the development of fungal infections (10, 14, 15). Pathogens have been found to colonize the gastrointestinal tract prior to infection. Surveillance cultures have thus been considered to predict systemic infection (3, 16). However, there is a scarcity of studies on surveillance cultures, notably on pediatric allo-SCT patients. The majority of surveillance culture studies have been performed in the 1980s and 1990s, and the benefit from routine cultures in identifying infections of immunosuppressed patients has remained controversial (3, 17–21). 87
Simojoki et al.
The aim of this study was to determine whether the surveillance cultures are useful for predicting subsequent systemic infection. In addition, we studied whether the cultures aid in targeting the antibiotic treatment of infections. Patients and methods We retrospectively reviewed the medical records of all pediatric patients undergoing allo-SCT in our hospital from January 2007 to December 2009. Table 1 summarizes the characteristics of the 52 patients. A total of 57 transplantations were performed, because three patients received two transplants and one patient received three transplants. Most of the patients (87%) were conditioned with TBI-based (10–12 Gray) regimen. In 41 (72%) transplantations, cyclosporine was given as prophylaxis against GVHD. Additional methotrexate was given in 31 (76%) of the cases. Antilymphocyte globulin was administered to 21 (37%) in transplants to enhance engraftment and to prevent GVHD. Additional GVHD prophylaxis consisted of mycophenolate mofetil, sirolimus, and prednisolone given in different combinations to single patients. GVHD developed in 31 (54%) transplants and severe grade III-IV in 21%. Fourteen percent had severe stage 3-4 gastrointestinal GVHD.
Patient management Patients received p.o. trimethoprim–sulfadiazine (trimethoprim 5 mg/kg/day) as prophylaxis against Pneumocystis jiroveci from pretransplant period until day +7. The prophylaxis was resumed at neutrophil engraftment >1.0 9 109/L (median 18 days). The antifungal prophylaxis regimen consisted of p.o. or i.v. fluconazole (5 mg/kg once daily) and p.o. nystatin (100 000 IU three times daily). Patient rooms were equipped with HEPA filtration and a possibility of positive pressure.
Table 1. The general characteristics of allo-SCT patients Characteristics
Patients n = 52 (57 transplants)
Age, median (range) Sex (female/male) Diagnosis ALL CR1 ALL relapse AML CR1 AML relapse CML SAA Others Transplant type URD SIB UCB
9 yrs (7 months–17 yrs) 17/35 21 13 3 2 1 4 8 29 18 10
ALL CR1, acute lymphoblastic leukemia at first remission; AML CR1, acute myeloid leukemia at first remission; CML, chronic myeloid leukemia; SAA, severe aplastic anemia; Others, myelodysplastic syndrome, non-Hodgkin lymphoma, severe combined immunodeficiency, interferon-gamma receptor-2 deficiency, and congenital hypoplastic anemia. URD, unrelated donor; SIB, sibling donor; UCB, umbilical cord blood.
88
The patients had routine surveillance cultures obtained weekly from the stool (bacterial, fungal and Clostridium difficile cultures, and C. difficile toxin assay) and from the throat (bacterial and fungal cultures). Symptoms and findings of infection and GVHD were examined daily. The body temperature was measured four times a day. When patients developed a fever of ≥38 °C, had an increase in the CRP level, or had other symptoms of infection, blood cultures were drawn from both central venous catheters or from both lumens of the two-lumen catheters. Subsequently, they received ceftazidime and cloxacillin combination as the first-line empiric antibacterial regimen. Patients with persistent fever despite administration of antibiotics usually received glycopeptide and carbapenem (usually meropenem) as a second-line treatment. During antimicrobial treatment, blood cultures were obtained daily for approximately three days or until the infection clinically resolved. Systemic antifungal treatment was started if fever persisted despite broad-spectrum antibacterial medication.
Culture methodology and susceptibility tests The bacterial specimens from stool and throat were cultured on blood agar plates. Biochemical methods were used to identify one or two main species in the flora and possible findings deviating from normal flora of the region. The beta-hemolytic streptococci (groups A, C, G) and major growth of the upper airway pathogens were identified in bacterial throat cultures. The commercial VIDASâ CDAB test (bioMerieux SA, Marcy l’Etoile, France) based on the ELFA fluorescence technique was used to detect toxins A and B produced by C. difficile directly from stool. In addition, the specimens were cultured on selective CCFA media. The fungal stool and fungal throat specimens were cultured on SG agar plates and incubated at +28 and +37 °C. The stool yeast specimens were cultured on selective chromogenic media (CHROMagar Candida, CHROMagar, Paris, France). Candida albicans was identified based on the color reaction of the colony on the media, and other yeast species were named “yeast, non-C. albicans.” The antimicrobial susceptibility testing conformed to the susceptibility standards of CLSI. The bacterial susceptibility testing was performed on the Mueller–Hinton agar by the disk diffusion method. The fluconazole susceptibility of C. albicans was determined with fluconazole disk or Etest strip (bioMerieux SA) on RPMI plate. For other yeasts and antimicrobial agents, the MIC was determined with Etest strips on RPMI agar plate.
Material The bacterial and fungal colonization data were registered from the week prior to transplantation through 100 days post-transplant. All the data concerning the patients’ episodes of infection from the pretransplant week to 100 days post-transplant were acquired from the medical records. These data included the antimicrobial therapy used, the symptoms of infection, CRP, changes in the neutrophil count, identified infectious agents, and the possible utilization of surveillance cultures to determine successful therapy. All episodes, that included antimicrobial therapy based on either fever (≥38.0 °C) and other clinical findings, CRP elevation or a positive blood culture, were registered as an infection episode.
Surveillance cultures in transplantation Statistics The sensitivity, specificity, and the positive and negative predictive values were calculated. The evolution of stool colonization over time was analyzed using the Pearson’s chi-square test. A p-Value of
