CHICAGOFifteen to 20 years ago, treatment of patients infected with
Pseudomonas aeruginosa infection after stem cell transplantation was limited to
certain beta-lactam and aminoglycoside antibiotics that were active against the
Because newer antibiotics, such as the fluoroquinolones and the
cephalosporins cefotaxime (Claforan) and cefepime (Maxipime), have greater
activity against P aeruginosa and less toxicity than previously prescribed
antibiotics, there has been every reason to believe that treatment has improved
and mortality has declined.
According to a study from Fred Hutchinson Cancer Research Center, Seattle, P
aeruginosa infections occur only rarely after stem cell transplantation, but
overall mortality exceeds 30%. More than 35% of patients relapse after
antibiotic treatment, and for these individuals, mortality is 90%.
"Even though the incidence of these infections is only about 1%, when
these people get infected, they have a very poor prognosis for the initial
infection. Once the initial infection appears to be treated successfully, there
is still a fairly high risk of relapse, and when patients do relapse, the
prognosis is terrible," said Morgan Hakki, MD, a senior fellow in the
Program in Infectious Diseases at Fred Hutchinson.
46 Cases of Invasive P aeruginosa
The study, presented in a poster session at the Interscience Conference on
Antimicrobial Agents and Chemotherapy (ICAAC abstract 780), was a retrospective
review of 46 cases of invasive P aeruginosa infection in individuals who
underwent hematopoietic stem cell transplantation between 1990 and 2000.
Although patients were treated with combination antibiotics for an average
of 16.8 days, the mortality rate attributable to P aeruginosa was 31.4%. Ten of
28 survivors (35.7%) relapsed with P aeruginosa infection a median of 9 days
after the cessation of antibiotic therapy, and 90% of these individuals died
within 36 days.