[Risk factors and resistance patterns of invasive Acinetobacter Baumannii infection in Children]

Objective: To understand the risk factors and antibiotics-resistant patterns of invasive Acinetobacter baumannii infection in Children. Methods: This retrospective study was conducted in 6 tertiary hospitals from January 2016 to December 2018. The basic information, clinical data and the results of antimicrobial susceptibility testing were collected from the 98 pediatric inpatients with Acinetobacter baumannii isolated from blood or cerebrospinal fluid and analyzed. According to the susceptibility of the infected strains to carbapenems, they were divided into carbapenem-sensitive Acinetobacter baumannii (CSAB) group and carbapenem-resistant Acinetobacter baumannii (CRAB) group. According to the possible sources of infection, they were divided into nosocomial infection group and community infection group. Chi-square test or Fisher exact test were used to analyze categorical variables and rank sum test were used to analyze continuous variables. The risk factors of invasive CRAB infection in children were analyzed by Logistic regression. Result: There were 56 males and 42 females in 98 cases. The onset age of patients was 8 (2, 24) months. There were 62 cases (63%) from rural area. A total of 87 cases (89%) were confirmed with bloodstream infection, and 12 cases (12%) confirmed with meningitis (1 case was accompanied with bloodstream infection). In these patients, 66 cases (67%) received invasive medical procedures or surgery, 54 cases (55%) received carbapenems-containing therapy. Twenty-four cases were infected with CRAB, and 74 cases with CSAB. The onset age of cases in CRAB group was lower than that in CSAB group (4 (1, 9) vs. 10 (4, 24) months, Z=-2.16, P=0.031). The proportions of hospitalization in intensive care unit, carbapenem antibiotics using, pneumonia and adverse prognosis in CRAB group were higher than those in CSAB group (6 cases (25%) vs. 4 cases (5%), 18 cases (75%) vs. 36 cases (49%), 17 cases (71%) vs. 17 cases (23%), 6 cases (25%) vs. 4 cases (5%), χ²=5.61, 5.09, 18.32, 5.61, all P<0.05). Seventy-seven cases were nosocomial infection and 21 cases were hospital-acquired infection. The proportion of children hospitalized in high-risk wards for nosocomial infections, length of hospitalization, number of antimicrobial therapy received and duration of antimicrobial therapy were higher in the hospital associated infection group than those in the community acquired infection group (all P<0.05). Logistic regression analysis showed that children from rural area (OR=8.42, 95%CI 1.45-48.88), prior mechanical ventilation (OR=12.62, 95%CI 1.31-121.76), and prior antibiotic therapy (OR=4.90, 95%CI 1.35-17.72) were independent risk factors for CRAB infection. The resistance percentage of CSAB isolates to many classes of antibiotics was <6% except to gentamicin, which was as high as 20% (13/65). All CRAB isolates of resistant to ampicillin-sulbactam (20/20), cefepime (23/23), piperacillin (17/17), meropenem (23/23) and imipenem (24/24) were 100%. The resistance percentage to other antibiotics were up to 42%-96%. Conclusions: Most of invasive Acinetobacter baumannii infection in children in China are hospital-acquired. The outcome of invasive CRAB infection was poorer than that of CSAB infection. The drug resistance rate of CRAB strains isolated is high. Living in rural area, prior invasive mechanical ventilation and prior antibiotic therapy were independent risk factors for invasive CRAB infection. The prevention and control of nosocomial infection and appropriate use of antibiotics to reduce Acinetobacter baumannii infection.