Incidence Of Resistant Infections Research Articles

Estimated Incidence of Antimicrobial Drug-Resistant Nontyphoidal Salmonella Infections, United States, 2004-2012.

Salmonella infections are a major cause of illness in the United States. The antimicrobial agents used to treat severe infections include ceftriaxone, ciprofloxacin, and ampicillin. Antimicrobial drug resistance has been associated with adverse clinical outcomes. To estimate the incidence of resistant culture-confirmed nontyphoidal Salmonella infections, we used Bayesian hierarchical models of 2004–2012 data from the Centers for Disease Control and Prevention National Antimicrobial Resistance Monitoring System and Laboratory-based Enteric Disease Surveillance. We based 3 mutually exclusive resistance categories on susceptibility testing: ceftriaxone and ampicillin resistant, ciprofloxacin nonsusceptible but ceftriaxone susceptible, and ampicillin resistant but ceftriaxone and ciprofloxacin susceptible. We estimated the overall incidence of resistant infections as 1.07/100,000 person-years for ampicillin-only resistance, 0.51/100,000 person-years for ceftriaxone and ampicillin resistance, and 0.35/100,000 person-years for ciprofloxacin nonsusceptibility, or ≈6,200 resistant culture-confirmed infections annually. These national estimates help define the magnitude of the resistance problem so that control measures can be appropriately targeted.

Program and AbstractsThirty-third Annual Meeting of the Surgical Infection SocietyLas Vegas, NevadaApril 12–15, 2013

Program and AbstractsThirty-third Annual Meeting of the Surgical Infection SocietyLas Vegas, NevadaApril 12–15, 2013

A national evaluation of antibiotic expenditures by healthcare setting in the United States, 2009

Promoting appropriate antibiotic use has the potential to decrease healthcare costs by reducing unnecessary prescriptions and the incidence of resistant infections. However, little is known about where antibiotic costs are incurred in the US healthcare system. We evaluated antibiotic expenditures by healthcare setting and antibiotic class in the USA. Systemic antibiotic expenditures in 2009 were extracted from the IMS Health(©) National Sales Perspectives database. These data represent a statistically valid projection of all medication purchases in the USA from 1 January 2009 to 31 December 2009. Antibiotic expenditures totalled $10.7 billion. The majority (61.5%) of expenditures were associated with the outpatient setting, especially from community pharmacies. Inpatient and long-term care settings accounted for 33.6% and 4.9% of expenditures, respectively. The class of antibiotics that accounted for the most antibiotic expenditure overall was the quinolones, followed by the penicillins. Over $10.7 billion was spent in 2009 on antibiotic therapy in the USA. Differences were observed in antibiotic expenditures by healthcare setting, with the majority in the outpatient setting, 87% of which was in community pharmacies.

Fluoroquinolone Prophylaxis in Acute Myeloid Leukemia (AML) Patients Undergoing Post-Remission Chemotherapy Reduces Hospital Admission Rates

Abstract 2570 Background:High-dose cytarabine (HIDAC) is a standard treatment for younger AML patients (pts) receiving post-remission chemotherapy. The risk for febrile neutropenia (FN) is high among these pts and considered a medical emergency, requiring prompt hospital admission and treatment. In 2004 our institution adopted the use of fluoroquinolones (FQ) for bacterial prophylaxis in AML pts receiving HIDAC. We compared rates of hospital admission due to FN before and after the initiation of bacterial prophylaxis with FQ. We also evaluated the incidence of blood stream infections (BSI) and the incidence of resistant infections among the two groups. Methods:We identified AML (excluding acute promyelocytic leukemia) pts receiving cytarabine-based remission induction chemotherapy at Cleveland Clinic who achieved a complete remission and then were treated with HIDAC post-remission chemotherapy (cytarabine dose of 3000mg/m2 × 6) from 1997–2008. Pts receiving FQ prophylaxis with ciprofloxacin 500mg twice daily or levofloxacin 500mg once daily comprised the treatment group, while AML patients with no prophylaxis served as controls. Pts were excluded if they developed an episode of FN during hospital admission for HIDAC or received non-FQ bacterial prophylaxis. Categorical data and continuous variables were analyzed per chemotherapy cycle using Fishers exact test and independent-sample t-tests, respectively. Results:80 pts received HIDAC post-remission chemotherapy during the study period; 52 received FQ prophylaxis; 28 did not. A total of 198 chemotherapy cycles were administered, 148 in the FQ group and 50 in the control group. The mean age (+/−SD) of the entire cohort was 44.8 (11.4) years; 53% were female. Despite the decreased use of granulocyte-colony stimulating factor in the FQ group (12% vs. 50%, p<0.001), the duration of neutropenia was the same (24.6 days vs. 23.8 days, p=0.5) between groups. All other baseline characteristics were similar. FQ treated pts had a 33% absolute reduction in hospital admissions due to FN (50.7% vs. 84%, p<0.001) and when admitted, hospital LOS for FN was shorter for the FQ group (7.9 days vs. 10.5 days, p=0.007). The incidence of BSI was also reduced in the FQ group (23% vs. 42%, p=0.009); however there was an increase in resistant gram-negative (5/17 vs. 0/14, p=0.04) and resistant gram-positive (15/19 vs. 3/9, p=0.03) infections among pts treated with FQ. Conclusion:AML pts treated with HIDAC chemotherapy followed by FQ prophylaxis had fewer and shorter hospital admissions due to FN compared to pts with no prophylaxis. FQ treated patients were at increased risk of developing antibiotic-resistant bacterial BSI. Disclosures:No relevant conflicts of interest to declare.

Primary Tuberculosis in Children

Resistant strains of Mycobacterium tuberculosis were recovered from cultures of gastric washings of children who had received no prior drug therapy and in whom demonstrable tuberculous disease was present. The incidence of primary strains resistant to streptomycin and PAS was of a low order (3 per cent) and comparable to that reported in adults. Combined-drug resistance was found in only 2 out of 101 strains. The incidence of primary isoniazid drug resistance, when analyzed by the United States Public Health Service criterion, was 16.3 per cent as compared to 6.3 per cent by the Veterans Administration criteria for resistance. Reasons are given for suggesting that the Veterans Administration criteria for isoniazid drug resistance may be more suitable than those of the United States Public Health Service for analysis of primary drug-resistant strains isolated from gastric washings in children. With the use of similar criteria for drug resistance the incidence of 6.3 per cent reported here for isoniazid was greater than that of 2.6 per cent for adults reported in New York City in 1961, the most suitable population group for comparison. The lower incidence of primary resistant disease in the adult group may be in part a reflection of disease due to endogenous reinfection by sensitive organisms acquired during childhood before the use of isoniazid. Since the factor of endogenous reinfection is eliminated in the present study the incidence of primary resistant disease reported here probably represents transmission of infection by individuals in the community whose organisms had become resistant during treatment. Another factor contributing to the higher incidence of resistant infection in the present group may be that the patients in the present study were drawn from a limited geographic area and one of high risk for tuberculosis. Since the incidence of primary drug-resistant disease represents, in a measure, the level of tuberculosis control in a given community, continuing studies are necessary to determine its rate of increase or decrease. Such studies are now in progress.