Risk Factors For Multidrug Resistance Research Articles

Explaining risk factors for drug-resistant tuberculosis in England and Wales: contribution of primary and secondary drug resistance

Drug-resistant tuberculosis can be transmitted (primary) or develop during the course of treatment (secondary). We investigated risk factors for each type of resistance. We compared all patients in England and Wales with isoniazid- and multidrug-resistant tuberculosis in two time-periods (1993-1994 and 1998-2000) with patients with fully sensitive tuberculosis, examining separately patients without and with previous tuberculosis (a proxy for primary and secondary drug-resistant tuberculosis). Patients with previous tuberculosis smear positivity and arrival in the United Kingdom <5 years were strongly associated with multidrug resistance and isoniazid resistance. In patients with no previous tuberculosis HIV infection, residence in London and foreign birth were risk factors for multidrug resistance, and non-white ethnicity, residence in London and HIV infection for isoniazid resistance. Risk factors for each type of resistance differ. Elevated risks associated with London residence, HIV positivity, and ethnicity were mainly seen in those without previous tuberculosis (presumed transmission).

Nosocomial multi-drug resistant Acinetobacter baumannii bloodstream infection: risk factors and outcome with ampicillin-sulbactam treatment

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii poses a therapeutic problem. The aim of this study was to assess the risk factors for nosocomial MDR- A. baumannii bloodstream infection (BSI) and the efficacy of ampicillin-sulbactam (A/S) in its treatment. Of 94 nosocomial A. baumannii BSI during the year 2000, 54% involved MDR strains, 81% of which were genetically related. Various risk factors for MDR- A. baumannii were found, of which intensive-care unit admission and prior aminoglycoside therapy were independently associated with MDR- A. baumannii acquisition on multivariate analysis. Of MDR- A. baumannii BSI cases, 65% received A/S and 35% inadequate antibiotic therapy, whereas of 43 non-MDR cases, 86% were treated according to susceptibility and 14% inappropriately with antibiotics to which these organisms were resistant. Crude mortality was comparable in the adequately treated groups. Respective mortalities among patients treated adequately and inadequately were 41.4 and 91.7% ( p<0.001). Among severely ill patients, A/S therapy significantly decreased the risk of death ( P=0.02 OR=7.64). MDR- A. baumannii has become highly endemic in our institution. A/S appears to be one of the last effective and safe empirical resorts for treatment of MDR A. baumannii BSI.

Drug-resistant tuberculosis in Taipei, 1996-1999

Objectives: To determine the trends, patterns, and risk factors associated with drug-resistant tuberculosis, we conducted a hospital-based retrospective study in Taipei. Methods: Clinical and bacteriologic data were routinely collected from 453 patients with a diagnosis of tuberculosis who were treated at Taipei Municipal Chronic Disease Hospital from January 1996 through December 1999 for whom drug-susceptibility testing was done. Results: Resistance to at least one drug was identified in 154 (34%) out of the 453 patients, and 34 (7.5%) patients were resistant to at least isoniazid and rifampin. Among the 199 patients with recurrent tuberculosis, 98 (49.2%) had isolates that showed resistance to at least one drug. Among the 254 new patients, 56 (22.0%) had isolates that were drug resistant. For all 453 patients, resistance to rifampin was most common (17.4%), followed by resistance to isoniazid (13.9%), streptomycin (13.7%), ethambutol (8.2%), and kanamycin (3.5%). A history of previous tuberculosis therapy (odds ratio = 9.4; 95% CI, 2.9-28) and being born outside of Taiwan (odds ratio 3.3; 95% CI, 1.1-34) were significant risk factors for multidrug resistance. Conclusions: Our data suggest that the Taipei tuberculosis control program should be rapidly strengthened by expanded use of directly observed therapy and more careful bacteriologic and clinical follow-up, particularly in cases of recurrence and in persons born outside of Taiwan in tuberculosis endemic areas. Our results also indicate that the regular measuring of rates of drug resistance and the monitoring and guiding of tuberculosis treatment programs could increase the therapeutic response rate and prevent the appearance of newly acquired resistance in patients with tuberculosis. In addition, with high rifampin resistance (17.4%), the regulated market for rifampin is essential in Taiwan. (AJIC Am J Infect Control 2001;29:41-7)

Prevalence and risk factors for multidrug resistant uropathogens in ED patients

The purpose of this study was to describe resistance patterns of infecting organisms and determine risk factors for multidrug resistance in patients with urinary tract infections. Retrospective case series of 435 patients age ≥16 with urinary tract infection. Multidrug resistance was defined as resistance to ≥two classes of antibiotics. Demographic, historical, and microbiological data were collected. Univariate analysis and multivariate logistic regression were used to determine risk factors for multidrug resistance. Multidrug resistance was seen in 37% of isolates. Univariate analysis revealed numerous associations with resistance. Multivariate analysis found three independent factors associated with multidrug resistance: urinary catheter use (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4 to 4.8), age ≥65 years (OR 3.0, 95% CI 1.7 to 5.4) and antibiotic use (OR 4.6, 95% CI 2.8 to 7.5). Diabetes was also a risk factor when patients with urinary catheters were excluded (OR 2.4, 95% CI 1.1 to 5.3). Resistance was seen in all groups of patients, but was particularly common in older patients and those who used a urinary catheter. Antibiotic use was highly associated with multidrug resistance.