In vivo fitness of carbapenem-resistant Acinetobacter baumannii strains in murine infection is associated with treatment failure in human infections.

OBJECTIVES: Mortality among patients with carbapenem-resistant Acinetobacter baumannii (CRAB) infections varies between studies. We examined whether in vivo fitness of CRAB strains is associated with clinical outcomes in patients with CRAB infections. METHODS: Isolates were collected from patients enrolled in the AIDA trial with hospital-acquired pneumonia, bloodstream infections and/or urinary tract infections caused by CRAB. The primary outcome was 14-day clinical failure, defined as failure to meet all criteria: alive; haemodynamically stable; improved or stable Sequential Organ Failure Assessment (SOFA) score; improved or stable oxygenation; and microbiological cure of bacteraemia. The secondary outcome was 14-day mortality. We tested in vivo growth using a neutropenic murine thigh infection model. Fitness was defined based on the CFU count 24 hours after injection of an inoculum of 105 CFU. We used mixed-effects logistic regression to test the association between fitness and the two outcomes. RESULTS: The sample included 266 patients; 215 (80.8%) experienced clinical failure. CRAB fitness ranged from 5.23 to 10.08 log CFU/g. The odds of clinical failure increased by 62% for every 1-log CFU/g increase in fitness (OR 1.62, 95% CI 1.04-2.52). After adjusting for age, Charlson score, SOFA score and acquisition in the intensive care unit, fitness remained significant (adjusted OR 1.63, 95% CI 1.03-2.59). CRAB fitness had a similar effect on 14-day mortailty, although the association was not statistically significant (OR 1.56, 95% CI 0.95-2.57). It became significant after adjusting for age, Charlson score, SOFA score and recent surgery (adjusted OR 1.88, 95% CI 1.09-3.25). CONCLUSIONS: In vivo CRAB fitness was associated with clinical failure in patients with CRAB infection.

Health indicators and social gradient in adolescent immigrants' health risk and healthcare experiences.

Few studies have assessed healthcare experiences in apparently healthy adolescents, or whether healthcare attitudes are linked to the two leading adolescent health indicators, smoking and obesity. Even fewer have examined these relationships in adolescent immigrant groups or made comparisons to adolescent non-immigrants. Using a cross-sectional study, healthcare experiences were compared among three groups of adolescents (n = 589) including Russian immigrants (n = 154), Ethiopian immigrants (n = 54), and non-immigrants (n = 381). Bootstrap estimates indicated positive healthcare experiences were less common among Russian adolescent immigrants (OR = 0.38, CI = 0.17, 0.86) compared to non-immigrants, unless the Russian adolescent immigrants reported above average socioeconomic status, in which case they were more likely than non-immigrant adolescents to report positive healthcare experiences (OR = 3.22, CI = 1.05, 9.85). Positive healthcare experiences were less likely among adolescents who were smokers (OR = 0.50, CI = 0.27, 0.91), and more likely for adolescents with a normal or low BMI (OR = 3.16, CI = 1.56, 6.40) and for those relying on parents for health information (OR = 1.97, CI = 1.05, 3.70). CONCLUSION: Findings suggest a social gradient in which positive healthcare experiences were more common among adolescence with higher socioeconomic status for some immigrants (Russian adolescents) but not for others. The two leading health indicators were related to healthcare experiences, but as adolescent smokers were less likely to have positive healthcare experiences, proactive efforts are needed to engage this group. What is Known: • Health indicators (such as obesity) and healthcare attitudes are linked to healthcare service use among adolescents sampled from outpatient and inpatient populations. What is New: • A social gradient involving socioeconomic status and being an adolescent immigrant was found regarding risky health indicators (i.e., smoking, use of internet as the primary source of health information). • Problematic health indicators, such as smoking, is linked to less positive healthcare attitudes in apparently healthy adolescents (both immigrants and non-immigrants).

Adolescent immigrants, the impact of gender on health status.

Background: : Although studies have described the 'healthy immigrant effect' in adults, far fewer have examined the 'healthy immigrant effect' for adolescents living in immigrant families. Those few studies that did, noted conflicting results, and also differed on whether gender confounds the results. : This cross-sectional study was informed by the community-based participatory research (CBPR) approach in which researchers obtained the expertise and guidance on instrument design and study implementation. Data collection of self-administered surveys was completed between May 2015 and December 2015 on adolescents. Comparisons were made among six groups based on gender and immigrant status. : Of the total sample ( n = 618), more than a third were first or second generation immigrant adolescents ( n = 239). Comparisons among six groups, categorized by gender and immigrant status (i.e. first generation immigrants, second generation immigrants, native born), indicated many differences. However, when the differences were taken into account using logistic regression models, excellent health status was least likely to be reported by second generation immigrant males (versus native born adolescent females) ( P < 0.01), even after adjusting for the independent associations found for psychological symptoms ( P < 0.0001), not smoking ( P < 0.05) and having normal BMI ( P < 0.05). : This study demonstrates the relative disadvantage of second generation immigrant boys, but not first generation boys or first and second generation immigrant girls relative to their native counterparts. Reasons for the gap may be differences in support services and/or parental expectations; however further studies are needed to confirm these possibilities.