Gram-negative bacteremia remains a severe complication of neutropenia with a high mortality rate. For high-risk patients prophylactic use of fluoroquinolones is recommended as a preventive strategy.
Aims: To study the effect of fluoroquinolone prophylaxis on Gram-negative bacteremia.
Methods: In the retrospective survey Gram-negative bacteremic episodes occurring in a centre for hematology and stem cell transplantation were studied. Data from the year before and after instituting prophylaxis were compared with regard to the incidence of blood stream infections, spectrum of pathogens, rate of fluoroquinolone resistance and all cause mortality of affected patient population.
Results: Only a slight decrease in the incidence of Gram-negative bacteremia was seen (ARR: 0.024) after the introduction of fluoroquinolone prophylaxis. Spectrum of pathogens remained unchanged. However, the proportion of fluoroquinolone resistant Gram-negative isolates increased markedly (from 24% to 59%, p = 0.001), especially fluoroquinolone resistant E. coli strains became more prevalent (from 16% to 75%, p<0.001). All cause mortality at 7 and 30 days remained the same or increased insignificantly.
Conclusions: With the current epidemiological background none of the expected benefits from the fluoroquinolone prophylaxis could be proven, whereas, the rate of fluoroquinolone resistance increased markedly. A reconsideration of present prophylactic strategies is suggested.