Microbiology in Patients Undergoing Stem Cell Transplantation in the First Year of a Tertiary Care Comprehensive Cancer Centre From India

INTRODUCTION: Infection remains a major challenge in patients undergoing stem cell transplants in developing countries. The Tata medical Center (TMC) is a new comprehensive cancer center in Eastern India started in May 2011. This abstract reviews the gut surveillance cultures for multi-drug resistant organisms (MDROs) in our transplant patients (SCT) in the first 10 months of operation.

MATERIALS AND METHODS: From Dec 2011 to early October 2012, information on patients undergoing SCT was reviewed. Indications for transplant included malignant [AML, MDS, NHL, Myeloma, Hodgkin Lymphoma] and non-malignant conditions [Thalassemia, Aplastic Anemia, Fanconi Anemia]. Fecal Surveillance cultures were taken prior to SCT and were carried out by a method based on Landman D et al (J Clin Microbiol 2005). All patients received anti-fungal (posaconazole in 12/21) and anti-viral prophylaxis (acyclovir 21/21). Patients were treated in HEPA filtered rooms and febrile episodes managed as per institutional policy, initiating therapy with amikacin and piperacillin-tazobactum.

RESULTS AND DISCUSSION: 21 patients [16 male and 5 female] underwent 22 hematopoietic stem cell transplant procedures [15 allogeneic and 7 autologous]. Allogeneic transplants included 11 matched related donor, 2 matched unrelated donor and 2 haploidentical transplants. Median age was 26yr [range: 6yr-60yr]. Surveillance culture was done in 19 patients and MDROs were detected all patients. Multiple MDRO strains were found in 11/19 patients. ESBL, MBL and AmpC producing organisms were found in 17/19, 4/19 and 5/19 patients respectively. Fever was documented in all transplant patients and 15 of 213 blood cultures drawn were positive with eight significant isolates among which was an MDRO Pseudomonas aeruginosa. Transplant related mortality in three patients was attributed to sepsis in two (pneumonia due to Aspergillus fumigatus, and Elizabethkingia meningoseptica)and GVHD in one patient. Antimicrobial therapy was escalated to Meropenem in 19/22, Colistin in 8/22, Teicoplanin in 10/22, Metronidazole in 9/22, Liposomal Amphotericin-B in 4/22, and Caspofungin in 5/22. In the 8 patients given colistin, carbapenamase positive organisms were documented in surveillance cultures of 4.   

CONCLUSIONS: The high level of antimicrobial resistance in the enteric flora of patients undergoing SCT in the developing world will have a significant impact on antibiotic usage and outcome.