Mortality risk from A. baumannii infection in lung transplant patients highlighted
MedWire News: Infection with the gram-negative bacterium Acinetobacter baumannii is associated with significantly increased mortality in lung transplantation (LTX) patients, results from a US study show.
Writing in the journal Lung, Davis Nunley (The Ohio State University College of Medicine, Columbus) and colleagues explain that "LTX requires continual systemic immunosuppression, which can result in infections that may compromise recipient survival."
To investigate survival rates among LTX patients after infection with A. baumannii, the team reviewed data on 20 patients at their hospital who had evidence of the bacterium in blood, respiratory, or other secretions during an 8-month period and who were followed-up 1 year later. Of these, six were immunosuppressed LTX patients and 14 were non-LTX, nonimmunosuppressed patients.
All of the LTX recipients and 11 of the non-LTX group acquired pneumonia, the researchers note.
Although the A. baumannii strain was identified as multidrug-resistant, the patients were treated with a variety of antibiotics, including tigecycline, colistimethate, and imipenem, and immunosuppression treatment was reduced in all the LTX patients.
LTX patients required a significantly greater mean number of days of total antibiotic therapy (76 days) compared with non-LTX patients (16 days).
Nevertheless, A. baumannii was persistently recovered from bronchoalveolar lavage fluid and respiratory secretions from four (66.7%) of the six LTX recipients during the treatment period compared with just one (7.1%) of the 14 non-LTX patients.
Furthermore, all four of the LTX patients with persistent A. baumannii infection died as a consequence of their infection compared with one of the non-LTX patients.
Nunley and team conclude: "Despite receiving more antibiotic therapy, LTX recipients infected with A. baumannii were less likely to clear their infection and consequently experienced greater mortality compared with non-LTX immunocompetent patients."
They add: "Because multidrug-resistant A. baumannii clearly affected the outcomes of these LTX recipients, vigilant techniques for minimizing the spread of this organism in the immunosuppressed population require strict adherence."
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By Mark Cowen