Epidemiological investigation after hospitalising a case with pandrug-resistant Acinetobacter baumannii infection

Pandrug-resistant Acinetobacter baumannii (PDRAB) emerged in Taiwan in the early 2000s but was not identified in the Children's Hospital (Hospital A) until March 2005 when a patient was transferred from a respiratory care hospital (Hospital B). PDRAB was recovered from an eye swab taken on admission; once aware of the culture result, in addition to implementing infection control precautions, an epidemiological investigation was conducted in both hospitals. A total of 212 specimens were taken from 30 hospital inpatients (seven in Hospital A, 23 in Hospital B), clinical equipment and ward environment. Thirteen (15.5%) of 84 specimens obtained from Hospital A and 23 (18%) of 128 specimens obtained from Hospital B were positive for A. baumannii; of these, six isolates from two patients and clinical equipment in Hospital A and five from three patients in Hospital B were PDRAB. One patient stayed in both hospitals, and had one PDRAB isolate detected at each. Of the 36 A. baumannii isolates, there were nine IRS-PCR (infrequent restriction site-polymerase chain reaction) patterns, 12 PFGE (pulsed-field gel electrophoresis) patterns and six antibiogram patterns identified. Twenty-five isolates belonged to a major IRS-PCR type (four PFGE patterns) and presented with either pandrug resistance (all 11 PDRAB isolates clustered in this type) or multidrug resistance (only susceptible to imipenem). A. baumannii is an ubiquitous organism that can be isolated from patients and their equipment. A clone of A. baumannii with multi- or pandrug resistance was circulating in both hospitals.