Nosocomial Acinetobacter baumannii infections: microbiological and clinical epidemiology.

BACKGROUND: Acinetobacter baumannii is an important opportunistic pathogen that is rapidly evolving toward multidrug resistance and is involved in various nosocomial infections that are often severe. It is difficult to prevent A. baumannii infection because A. baumannii is ubiquitous and the epidemiology of the infections it causes is complex. OBJECTIVE: To study the epidemiology of A. baumannii infections and assess the relation between fluoroquinolone use and the persistence of multidrug-resistant clones. DESIGN: Three case-control studies and a retrospective cohort study. SETTING: A 20-bed medical and surgical intensive care unit. PATIENTS: Acinetobacter baumannii was isolated from 45 patients in urine (31%), the lower respiratory tract (26.7%), wounds (17.8%), blood (11.1%), skin (6.7%), cerebrospinal fluid (4.4%), and sinus specimens (2.2%). One death was due to A. baumannii infection. MEASUREMENTS: Antimicrobial resistance pattern and molecular typing were used to characterize isolates. The incidence of A. baumannii infection and the use of fluoroquinolones were calculated annually. RESULTS: Initially, 28 patients developed A. baumannii infection. Eleven isolates had the same antimicrobial susceptibility profile, genotypic profile, or both (epidemic cases), and 17 were heterogeneous (endemic cases). A surgical procedure done in an emergency operating room was the main risk factor for epidemic cases, whereas previous receipt of a fluoroquinolone was the only risk factor for endemic cases. The opening of a new operating room combined with the restriction of fluoroquinolone use contributed to a transitory reduction in the incidence of infection. When a third epidemiologic study was done, previous receipt of a fluoroquinolone was again an independent risk factor and a parallel was seen between the amount of intravenous fluoroquinolones prescribed and the incidence of endemic infection. CONCLUSION: Epidemic infections coexisted with endemic infections favored by the selection pressure of intravenous fluoroquinolones.

[Venous thrombosis of the legs and cancer. Evaluation of risk factors of venous thrombosis in the medical environment]. / Thromboses veineuses des membres inférieurs et cancer. Evaluation des facteurs de risque de thrombose veineuse en milieu médical.

In medical patients, risk factors of leg venous thrombosis are not well evaluated. Cancer is considered as an important one. The aim of this study was to evaluate the role of intrinsic thrombotic risk (tumor hypercoagulable state) and external thrombotic risk (associate factors). We have made a prospective analysis of thrombotic venous risk factors in two medical populations with leg venous thrombosis: patients with cancer and patients without cancer. Risk of thrombosis depends on the thrombogenic importance of the risk factor and its chronicity or not. We assessed cancer and thromboembolic disease at the time of diagnosis and during a median follow up of 125.2 days. We included 31 consecutive cases of cancer (21 men, 10 women, mean age 63.8 years), and 50 consecutive cases of non cancer patients (32 men, 18 women, mean age 65.5 years), these two populations were not different. The classic risk factors of venous thrombosis were not frequent in cancer patient. Analysis of thrombotic risk showed that 61% of cancer patient group had venous thrombosis without classic thrombotic risk, as compared to 32% in non cancer patient group, showing the direct role of cancer in thrombosis (p < 0.01). The cancer was often aggressive and metastatic adenocarcinoma of various origins. The effect of chemotherapy is not clear, only hormonotherapy seemed to be responsible in two cases. Cancer hypercoagulability, defined by clinical characteristics, is a real risk factor of venous thrombosis but of low frequency. Indeed, the incidence of venous thrombosis in oncologic unit is rare (0.4%). Finally, thromboembolic disease in cancer patients is not different than in no cancer patients, Trousseau's syndrome is unfrequent. Prognosis is poor (40% death with 44.5 days of median survival), and antithrombotic therapy complications are frequent (bleeding 16%, oral anticoagulants resistance 20%).