Management of an outbreak of multiresistant Acinetobacter baumanii infection in a surgical intensive care unit

The first report of multiresistant Acinetobacter baumanii (MRAB) was published in 1994. We report about an outbreak sensitive to Polimyxin only. In June 2006 a German holidaymaker (male, 70 years old; patient 1) in Greece felt dyspnea, thoracic pain and fever. He went to a hospital in Crete. CT indicated left-sided pleural empyema, mediastinal emphysema, pericardial effusion and pneumonia. Rapid deterioration lead to septic shock with need for mechanical ventilation. He came to our ICU (15 beds and six IMC beds) via air transport. Endoscopy showed esophagus perforation with need for operation and endoscopic stenting. Several BALs and a central venous catheter from the beginning showed MRAB with intermediate susceptibility to meropenem/aminoglycosides only. The patient received meropenem and gentamycin at first.

Despite isolation, MRAB spread over and infected eight more patients in separate rooms and different sections of the ICU 32 days later. Further transmission occurred within a few days: three male patients with multiple trauma (42, 20, and 62 years old; patients 2, 3, and 4), cardia carcinoma (female, 66 years old; patient 5), necrotizing pancreatitis (female, 78 years old; patient 6), splenomegaly owing to polycythaemia vera (male, 74 years old; patient 7 – MRAB diagnosis postmortem), rectal carcinoma (female, 76 years old; patient 8 – isolation because of MRSA infection even before) and respiratory failure after gastric banding (female, 41 years; patient 9). All patients suffered from septic shock with high fever, needed high volume replacement and catecholamines several times and prolonged mechanical ventilation. MRAB was isolated in the tracheal secretion or BAL in all patients, in abdominal drainage (patient 6), and in central venous catheter (patient 5). Environmental investigations showed no problematic circumstances. Colistin i.v. is not available in Germany so it had to be procured from the USA, which caused a delay of treatment for a few days. Another delay occurred because of the rapid growing number of patients who needed Colistin. Patients were treated with an adjusted dosage for 16 days.

All patients of the ICU were isolated to avoid new infections as a precaution. After convalescence of two patients, all MRAB patients were moved to the IMC, which was converted to an ICU for this period, to isolate infected patients from uninfected. Three out of nine patients died.

All these laborious measures with a great expenditure of logistics worked well; no further transmissions were observed.