Prevalence of multidrug resistant bloodstream infections in febrile neutropenic patients with hematolymphoid malignancies: A retrospective observational study from a newly established tertiary oncology center in India

Background: Bloodstream infections are the major cause of life-threatening complications in febrile neutropenic patients with hematolymphoid malignancies. The prevalence of these bloodstream infections is 20-30%. The bacteria that are most frequently isolated belong to Enterobacterales and Pseudomonas species. The overall infection attributable mortality rate is 21.5%. Objective: The main objective of this study was to evaluate the prevalence of bloodstream infections with multidrug-resistant (MDR) organisms in adult patients with hematolymphoid malignancies and febrile neutropenia at our newly established tertiary cancer center. Materials and Methods: This was a retrospective observational study conducted between June 2018 and April 2020 in the Departments of Microbiology and Medical Oncology at the Homi Bhabha Cancer Hospital/Mahamana Pandit Madan Mohan Malviya Cancer Center (under the aegis of the Tata Memorial Hospital, Mumbai), a tertiary oncology cancer center in Varanasi, Uttar Pradesh. We analyzed the data of all adult febrile neutropenic patients with hematolymphoid malignancies, specifically the blood culture positivity, isolated bacterial organisms, their antimicrobial resistance spectrum and the overall mortality. Results: There were 1670 adult patients with hematolymphoid malignancies who visited the outpatient and inpatient departments over a period of 2 years; of them, 307 patients had febrile neutropenia and their blood cultures were sent to the microbiology laboratory. The mean age was 41.8 ± 16.7 (range, 15-82) years, with a male predominance (186, 61%). The most common clinical diagnosis was acute lymphoid leukemia (80, 26.1%), followed by non-Hodgkin's lymphoma (76, 24.8%). Microbiologically confirmed bloodstream infections were present in 74 (24.1%) patients. Forty-seven (64.0%) patients had healthcare-associated infections, whereas 27 (36.4%) had community-acquired infections. Common organisms isolated were Escherichia coli (28, 36.4%), Klebsiella pneumoniae (12, 15.6%), Pseudomonas species (8, 10.8%), coagulase-negative Staphylococcus species (7, 9.4%), Staphylococcus aureus (5, 6.5%), Streptococcus species (4, 5.2%), Enterococcus species (3, 3.9%), Citrobacter koseri (3, 3.9%), Acinetobacter baumannii (2, 2.6%), Aeromonas species, and Shewanella putrefaciens (1, 1.3%). Of the 55 Gram-negative bloodstream infections, 21 (38.2%) were carbapenem-resistant. Of the 19 Gram-positive bloodstream infections, there were a significant proportion of resistant organisms noted as well, including methicillin-resistant Staphylococcus aureus in 15.8% (3/19; 60% [3/5] of the Staphylococcus aureus infections) and vancomycin-resistant Enterococcus (VRE) in 5.3% (1/19; 33.3% [1/3] of all enterococcal infections). Overall, the mortality rate was 32.6% (100/307). The mortality rate was greater in patients with MDR bloodstream infections (20/47, 42.5%) compared to that in patients with non-MDR bloodstream infections (3/27, 11.2%; P = 0.004). Conclusion: The high prevalence of MDR Gram-negative and MRSA bloodstream infections in our patients is an alarming situation in a newly established tertiary cancer center. Rigorous infection control policies, patient education, and doctor and support staff education are important components of antibiotic stewardship and constitute important steps to prevent MDR bloodstream infections and reduce sepsis-related mortality.