FEBRIL NEUTROPENIA ETIOLOGY IN A HEMATOLOGY DEPARTMENT

Aim: Chemotherapy-induced febrile neutropenia (FN) predisposes patients to life-threatening infections and typically requires hospitalization. Patients with profound neutropenia have increased risk of septicemia associated with significant morbidity. To provide the appropriate broad-spectrum antimicrobial cover, documentation of causative agents and their antimicrobial susceptibilities should be established in each hospital. Methods: The goal of the present study was to investigate the causative microorganisms in 27 febrile neutropenic patients between January 2006 and December 2007. Results: ln our hematology unit, among 122 febrile neutropenic episodes 57 isolates from cultures of febrile neutropenic patients, gram-negative bacteria was prevalent (45.6%). Among the gram-positives (%42.1% of isolates) coagulase-negative staphylococci (CNS) were the predominant bacteria (13/23) followed by Staphylococcus aureus (7/23). Escherichia coli (14/26) and Klebsiella spp. (7/26) were the most common species among 26 gram-negative bacteria. Conclusion: The most important issue in febrile neutropenia is still a mortal situation in immunocompromised patients. So documentation of the flora in each unit would help to decide appropriate empirical therapy which is life saving.

should be started immediately. The etiological agents and their antibiotic susceptibilities differ by time and by hospitals as a result of therapeutic and medical manipulations. As immediate administration of antibiotic therapy is crucial for successful management of infections, at least yearly documentation of causative microorganisms is mandatory in each center (3).
In this study we report the microorganisms isolated from cultures of neutropenic patients in GATA Haydarpasa Hospital department of hematology between January 2006 and December 2007.

MATERIAL AND METHODS
The selected patients were adults hospitalized in the hematology department, whose cultures were obtained at the time they had fever and neutropenia (PMNL<500/mm³ or expected neutropenia within few days due to chemotherapy). Twenty seven patients (five of them with catheter) were included in this study. All the patients in this retrospective study were with hematological malignancies and had neutropenia duration of average 16±2 days.
At least one set of cultures were taken before the initiation of antibiotic therapy. Cultures were observed by BACTEC 9240 continuous monitoring system (BD Biosciences).
Microbiological investigation of positive cultures were performed by classical microbiological methods and by miniAPI identification system. For commensal skin flora members at least two consequent isolates either from peripheral vein or one from catheter was considered to be positive. If catheter site was positive, the clinical sign and symptoms of septicemia were sought for significant positivity (4).

RESULTS
During the two year period, twenty seven febrile neutropenic cases were hospitalized. One hundred twenty two febrile neutropenic episodes were observed. In 57 episodes positive cultures were obtained. Thirty eight (67%) isolates were from hemocultures, 12 (20.8%) were from urine cultures and 7 (12.2%) were from catheter, abscess and wound. Twenty six (45.6%) isolates were gram negative bacteria, whereas 23 (42.1%) isolates were gram positive bacteria. The predominant bacteria were E.coli and coagulase-negative staphylococci. The isolated microorganisms are shown in Table 1.

DISCUSSION
The benefit of immediate use of appropriate antimicrobiological therapy has been implied years ago (5). It is easier to define the infection and to take cultures in cases with apparent site of infection. It is not usually possible in cases with febrile neutropenia due to difficult localization of infection (6). Approximately in 80% of cases the causative microorganism is from the endogenous flora (7).
In our study documented infections are 47% which is comparable to the results of mentioned studies.
Early studies show that gram-negative microorganisms were the most frequently isolated pathogens during the neutropenic episodes (13). After transplantation procedures and use of long term intravascular catheters in clinical practice, gram-positive isolates have become more frequent in febrile neutropenic patients (9,(14)(15)(16).
In our country, in two large studies by the year 1996 blood isolates were grampositive microorganisms, whereas in 1998 both gram-positive and gram-negative bacteria were found to be equal (17,18).  There are different reports from different centers in all around the world. The difference may be due to used chemotherapy protocols or due to antimicrobial therapy. Among gramnegative microorganisms, the most common isolate is E.coli whereas in grampositive microorganisms the most common one is coagulase-negative staphylococci (6,21). In our report we detected similar results.
In this study we report the data of isolated microorganisms in our unit. Forty six percent of isolates were gram negative bacteria, whereas 42% of isolates were gram positive bacteria. There is a slight predominance of gram-negative microorganisms in our unit which can be explained by lack of transplantation and no long term use of intravascular catheters.
The most important issue in febrile neutropenia is still a mortal situation in immunocompromised patients. So documentation of the flora in each unit would help to decide appropriate empirical therapy which is life saving.