Effect Of Antibiotic Use Research Articles

Perils of quinolone exposure in cancer patients

The objective of this study was to determine the effect of antibiotic use (including prophylaxis) on the emergence of multidrug-resistant (MDR) breakthrough bacteremia in cancer patients. In this retrospective study, the authors identified all bacteremia episodes from July 2005 to December 2006 at their tertiary cancer center and compared the bacteria types and antimicrobial resistance in isolates from patients who had received antimicrobial agents as therapy or prophylaxis (breakthrough infections) with those from patients who had not received antimicrobial agents (nonbreakthrough bacteremia). Breakthrough bacteremia was more likely to be associated with MDR Escherichia coli (P = .002), MDR Pseudomonas aeruginosa (P = .02), and vancomycin-resistant enterococci (P = .01). Multivariate analysis revealed that breakthrough bacteremia was associated with hematologic malignancies and neutropenia (odds ratios, 9.9 and 3.0, respectively). Fluoroquinolone use was associated significantly with the emergence of methicillin-resistant Staphylococcus aureus (P = .04), MDR E. coli (P < .001), and MDR P. aeruginosa (P = .05). A strong association was observed between fluoroquinolone use and breakthrough bacteremia in multivariate analysis (odds ratio, 22; P < .001). Patients who had received vancomycin were more likely to have vancomycin-resistant enterococci bloodstream isolates than patients who had not received antibacterial agents (P < .001). Breakthrough infections were more common in neutropenic patients and in patients who had hematologic malignancies. The isolation of MDR organisms was associated strongly with the use of fluoroquinolones. The current findings demonstrated the importance of using a comprehensive approach to the prevention of MDR bacterial infections, including the initiation of antibiotic stewardship programs.

Regional consumption of antibiotics: A demand system approach

Through this paper, we have attempted to model the demand for different classes of antibiotics used for respiratory infections in outpatient care in Switzerland using a spatial version of the linear approximate Almost Ideal Demand System (AIDS) model. This model takes spatial dependency into account by means of spatial lags of antibiotic budget shares. We control for the health status of patients and the potential harmful effects of antibiotic use in terms of bacterial resistance. Elasticities to socioeconomic determinants of consumption and own- and cross-price elasticities between different groups of antibiotic have also been computed in this paper. Significant cross-price elasticities are found between newer or more expensive generations and older or less expensive generations of antibiotics.

Temporal effects of antibiotic use and Clostridium difficile infections

We tested a previously published model for the analysis of the temporal relationship between antibiotic use and the incidence of Clostridium difficile infection in a hospital with stable incidence of infection at >1 case per 1000 admissions per month. The study period was from April 2004 to June 2008 and used data from Infection Control and Hospital Pharmacy. We first described the monthly variation in C. difficile infection and then constructed a multivariate transfer function model that included lag time (cases of C. difficile infection in previous months and delays between changes in antibiotic use and changes in C. difficile infection). The average incidence of C. difficile infection was 1.5 cases per 1000 patients per month with no significant increase over 3 years. The number of cases of C. difficile infection in 1 month was dependent on the average number of cases of C. difficile infection in the previous 2 months. The models with data from the whole hospital showed a statistically significant relationship between the number of both hospital-acquired C. difficile infections and total C. difficile infections and consumption of piperacillin/tazobactam, ciprofloxacin and cefuroxime. The association between C. difficile infection and consumption of co-amoxiclav was only significant for hospital-acquired C. difficile infection. The model for hospital-acquired C. difficile infections explained 61% of the variance in C. difficile infections. These results provide support for antibiotic policies that minimize the use of broad-spectrum penicillins (co-amoxiclav and piperacillin/tazobactam), cephalosporins and fluoroquinolones.

Quasiexperimental Study of the Effects of Antibiotic Use, Gastric Acid-Suppressive Agents, and Infection Control Practices on the Incidence of Clostridium difficile -Associated Diarrhea in Hospitalized Patients

The objective of this study was to evaluate the effects of antimicrobial drug use, gastric acid-suppressive agent use, and infection control practices on the incidence of Clostridium difficile-associated diarrhea (CDAD) in a 426-bed general teaching hospital in Northern Ireland. The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (time-series analysis) model was built to relate CDAD incidence with antibiotic use, gastric acid-suppressive agent use, and infection control practices within the hospital over a 5-year period (February 2002 to March 2007). The findings of this study showed that temporal variation in CDAD incidence followed temporal variations in expanded-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.01/100 bed-days), broad-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.02/100 bed-days), fluoroquinolone use (average delay = 3 months; variation of CDAD incidence = 0.004/100 bed-days), amoxicillin-clavulanic acid use (average delay = 1 month; variation of CDAD incidence = 0.002/100 bed-days), and macrolide use (average delay = 5 months; variation of CDAD incidence = 0.002/100 bed-days). Temporal relationships were also observed between CDAD incidence and use of histamine-2 receptor antagonists (H2RAs; average delay = 1 month; variation of CDAD incidence = 0.001/100 bed-days). The model explained 78% of the variance in the monthly incidence of CDAD. The findings of this study highlight a temporal relationship between certain classes of antibiotics, H2RAs, and CDAD incidence. The results of this research can help hospitals to set priorities for restricting the use of specific antibiotic classes, based on the size-effect of each class and the delay necessary to observe an effect.

Antibiotic use in the first year of life and risk of atopic disease in early childhood

Reduced post-natal microbial stimulation resulting from improvements in public health measures, smaller family size, and through increased antibiotic use has been postulated to account for the increasing prevalence of atopic diseases seen predominantly in developed countries. To investigate use of antibiotics in the first year of life and subsequent development of atopic disease in early childhood. A prospective birth cohort of 198 children at high atopic risk was recruited prenatally and followed for 5 years. Illnesses and antibiotic use were ascertained through daily diaries, and diagnoses of asthma and hayfever were collected by questionnaire interviews. The children were examined regularly for eczema, and atopic status was defined by skin prick tests and serum total IgE. The effect of antibiotic use on subsequent atopic disease was examined using logistic regression with propensity score adjustment. 54.0% (107/198) of children received at least one course of antibiotics, mainly for acute respiratory illnesses (ARI). Thirty-three percent (329/984) of the ARI involved the lower respiratory tract (LRI). Twenty-three percent (222/984) of ARI were treated with antibiotics, with LRI significantly more likely to receive antibiotics. Antibiotic use was associated with asthma (unadjusted odds ratio 2.3; 95% confidence interval 1.2-4.5; P=0.01) but this association was reduced after propensity score adjustment. No associations were found between antibiotic use and eczema, current wheeze, current asthma, atopic asthma, allergic rhinoconjunctivitis or atopy. Although this was a small study, systematic and careful monitoring of ARI, antibiotic use, and asthma and atopic diseases did not indicate that receipt of antibiotics early in life led to subsequent asthma or atopy at 5 years.

The dynamic relationship between antibiotic use and the incidence of vancomycin-resistant Enterococcus: time-series modelling of 7-year surveillance data in a tertiary-care hospital

The role of antibiotics in the epidemiology of vancomycin-resistant Enterococcus (VRE) has been studied extensively, but controversies remain as to which, and to what extent, antibiotics facilitate the emergence and dissemination of VRE in hospitals. Aggregate data on the use of several antibiotic classes in terms of defined daily doses (DDD) per 100 patient-days (PD), and VRE incidence rates in terms of clinical isolates per 1000 PD, were evaluated during a 7-year period at a tertiary-care hospital. Time-series analysis (autoregressive integrated moving average (ARIMA) and transfer function models) was used to quantify the temporal effect of antibiotic use on VRE incidence and estimate effect-delays. The incidence rate of VRE observed in a specific bimester was found to be a function of its value during the preceding bimester and of prior changes in the volume of use of four antibiotic classes. In particular, an increase of one DDD/100 PD in the use of glycopeptides, fluoroquinolones, extended-spectrum cephalosporins and beta-lactam-beta-lactamase inhibitor combinations resulted, independently, in average changes of +0.024, +0.015, + 0.020 and -0.010 isolates per 1000 PD in the incidence of VRE, with average delays of 2, 4, 2 and 6 months, respectively, which explained 56% of the observed variation in VRE rates over time. Efforts to reduce VRE cross-transmission should be supplemented by targeted antibiotic control policies. The use of glycopeptides, broad-spectrum cephalosporins and fluoroquinolones in high amounts should be the targets of such policies. Penicillin-beta-lactamase inhibitor combinations might be suitable substitutes for extended-spectrum cephalosporins.

Temporal effects of antibiotic use and hand rub consumption on the incidence of MRSA and Clostridium difficile

The aim of this study was to determine the temporal relation between the use of antibiotics and alcohol-based hand rubs (ABHRs) and the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. An interventional time-series analysis was performed to evaluate the impact of two promotion campaigns on the consumption of ABHRs and to assess their effect on the incidence of non-duplicate clinical isolates of MRSA and C. difficile from February 2000 through September 2006. This analysis was combined with a transfer function model of aggregated data on antibiotic use. Consumption of ABHRs correlated with MRSA, but not with C. difficile. The final model demonstrated the immediate effect of the second hand hygiene promotion campaign and an additional temporal effect of fluoroquinolone (time lag, 1 month; i.e. antibiotic effect delayed for 1 month), macrolide (lag 1 and 4 months), broad-spectrum cephalosporins (lag 3, 4 and 5 months) and piperacillin/tazobactam (lag 3 months) use. The final model explained 57% of the MRSA variance over time. In contrast, the model for C. difficile showed only an effect for broad-spectrum cephalosporins (lag 1 month). We observed an aggregate-level relation between the monthly MRSA incidence and the use of different antibiotic classes and increased consumption of ABHR after a successful hand hygiene campaign, while no association with ABHR use was detected for C. difficile.

Emerging Insights into Antibiotic-Associated Diarrhea andClostridium difficileInfection through the Lens of Microbial Ecology

Antibiotics are the main, and often only, clinical intervention for prophylactic and active treatment of bacterial infections in humans. Perhaps it is not surprising that these drugs also shift the composition of commensal bacteria inside our bodies, especially those within the gut microbial community (microbiota). How these dynamics ultimately affect the function of the gut microbiota, however, is not fully appreciated. Likewise, how antibiotic induced changes facilitate the outgrowth and pathogenicity of certain bacterial strains remains largely enigmatic. Here, we discuss the merits of a microbial ecology approach toward understanding a common side effect of antibiotic use, antibiotic-associated diarrhea (AAD), and the opportunistic bacterial infections that sometimes underlie it. As an example, we discuss how this approach is being used to address complex disease dynamics during Clostridium difficile infection.

Effect of High Local Concentrations of Antibiotics on Early Bone Formation with Tooth Ash and Plaster of Paris in the Ovariectomized Rat

This studied determined the clinical effect of antibiotic use at the site of bone defect restoration in patients with osteoporosis, using tooth ash and plaster of Paris in ovariectomized rats. Forty-eight rats were assigned to four groups randomly and each group was further divided into 4 and 8 weeks after implantation. Histologic sections of the defects were obtained after surgery for histomorphometric analysis. Comparing each week, a significant difference was seen in bone formation by 4 weeks. Compared to controls, new bone formation increased significantly with tooth ash and saline, tooth ash and gentamicin, and tooth ash and gentamicin after ovariectomy. Tooth ash and saline resulted in the best bone formation. The degree of new bone formation was slightly lower when tooth ash and gentamicin were used compared to when tooth ash and saline were used. When tooth ash and gentamicin were compared according to ovariectomy, bone formation was significantly inhibited by ovariectomy at 4 weeks, while no significant difference was seen at 8 weeks.

Antibiotic Resistance in Long-Term Acute Care Hospitals The Perfect Storm

To examine bacterial antibiotic resistance and antibiotic use patterns in long-term acute care hospitals (LTACHs) and to evaluate effects of antibiotic use and other hospital-level variables on the prevalence of antibiotic resistance. Multihospital ecologic study. Antibiograms, antibiotic purchasing data, and demographic variables from 2002 and 2003 were obtained from 45 LTACHs. Multivariable regression models were constructed, controlling for other hospital-level variables, to evaluate the effects of antibiotic use on resistance for selected pathogens. Results of active surveillance in 2003 at one LTACH were available. Among LTACHs, median prevalences of resistance for several antimicrobial-organism pairs were greater than the 90th percentile value for National Nosocomial Infections Surveillance system (NNIS) medical intensive care units (ICUs). The median prevalence of methicillin resistance among Staphylococcus aureus isolates was 84%. More than 60% of patients in one LTACH were infected or colonized with methicillin-resistant S. aureus and/or vancomycin-resistant Enterococcus at the time of admission. Antibiotic consumption in LTACHs was comparable to consumption in NNIS medical ICUs. In multivariable logistic regression modeling, the only significant association between antibiotic use and the prevalence of antibiotic resistance was for carbapenems and imipenem resistance among Pseudomonas aeruginosa isolates (odds ratio, 11.88 [95% confidence interval, 1.42-99.13]; P=.02). The prevalence of antibiotic resistance among bacteria recovered from patients in LTACHs is extremely high. Although antibiotic use in LTACHs likely contributes to resistance prevalence for some antimicrobial-organism pairs, for the majority of such pairs, other variables, such as prior colonization with and horizontal transmission of antimicrobial-resistant pathogens, may be more important determinants. Further research on antibiotic resistance in LTACHs is needed, particularly with respect to determining optimal infection control practices in this environment.

Report looks into effects of antibiotic use in infancy on teeth

Report looks into effects of antibiotic use in infancy on teeth

Antibiotic use in shrimp farming and implications for environmental impacts and human health

Summary The use of antibiotics in aquaculture may cause development of antibiotic resistance among pathogens infecting cultured animals and humans. However, this is a recent issue and has not yet been thoroughly investigated. Furthermore, there is limited knowledge about the environmental effects of antibiotic use in aquaculture. It is well known that antibiotics are commonly used in shrimp farming to prevent or treat disease outbreaks, but there is little published documentation on details of usage patterns. This study, conducted in 2000, shows that a large proportion of shrimp farmers along the Thai coast used antibiotics in their farms. Of the seventy‐six farmers interviewed, 74% used antibiotics in shrimp pond management. Most farmers used them prophylactically, some on a daily basis, and at least thirteen different antibiotics were used. Many farmers were not well informed about efficient and safe application practices. A more restrictive use of antibiotics could have positive effects for the individual farmer and, simultaneously, decrease impacts on regional human medicine and adjacent coastal ecosystems. It is likely that dissemination of information could contribute to a decreased use of antibiotics, without decreasing the level of shrimp production.

Educational intervention for parents and healthcare providers leads to reduced antibiotic use in acute otitis media.

We used a controlled before-and-after design with the aims of reducing both the total consumption of antibiotics and the use of broad-spectrum antibiotics against acute otitis media (AOM), and to study to what extent prescriptions for antibiotics against AOM were dispensed. Information on evidence-based treatment of uncomplicated AOM was provided to doctors and nurses, and written guidelines were implemented. Pamphlets and oral information concerning symptomatic treatment and the limited effect of antibiotic use in AOM were given to parents. Eligible patients were 819 children aged 1-15 y. The proportion of patients receiving a prescription for antibiotics was reduced from 90% at baseline to 74% during the study period. The proportion of prescriptions for penicillin V increased from 72% at baseline to 85% during the study period. There were no significant changes at the control site. The proportion of dispensed prescriptions was 70% both at baseline and during the study period. Educational efforts reduced the total consumption of antibiotics and the use of broad-spectrum antibiotics for AOM in children aged 1-15 y at an emergency call service. Data on antibiotic use in AOM based only on prescribing overestimates the use of antibiotics.

How to evaluate and predict the ecologic impact of antibiotics: the pharmaceutical industry view from research and development

How to evaluate and predict the ecologic impact of antibiotics: the pharmaceutical industry view from research and development

Clinical and microbiological follow-up of an outbreak of Yersinia pseudotuberculosis serotype Ib.

Yersinia pseudotuberculosis, a food-borne pathogen, causes infection that commonly presents as gastroenteritis and mesenteric lymphadenitis. Post-infectious complications include erythema nodosum, reactive arthritis and, less commonly, uveitis and nephritis. Six serotypes of Y. pseudotuberculosis have been identified, and post-infectious complications have been identified following infection with some, but not all, serotypes. The first recognized outbreak of Y. pseudotuberculosis serotype lb occurred in British Columbia in November 1998. We documented the incidence of post-infectious complications and the effect of antibiotic use on the clinical course. Four months after the outbreak, a standardized questionnaire asking about symptoms and antibiotic use was administered by telephone to laboratory-confirmed cases. Stool samples were collected to examine for chronic carriage of Y. pseudotuberculosis and 59 of 74 eligible cases participated. The most common post-infectious symptoms were rash (8/59) and joint pain (7/59). Microbiological analysis, at follow-up, revealed 0/36 stools positive for Y. pseudotuberculosis. Seventy-eight percent of cases had taken antibiotics during their acute illness. There was no significant difference in the frequency of post-infectious symptoms between cases who had or had not taken antibiotics. The post-infectious pathogenicity of Y. pseudotuberculosis serotype lb is lower than that documented for other serotypes. Antibiotic use did not significantly alter the reported clinical course of illness.

The epidemiology of antibiotic resistance in hospitals: paradoxes and prescriptions.

A simple mathematical model of bacterial transmission within a hospital was used to study the effects of measures to control nosocomial transmission of bacteria and reduce antimicrobial resistance in nosocomial pathogens. The model predicts that: (i) Use of an antibiotic for which resistance is not yet present in a hospital will be positively associated at the individual level (odds ratio) with carriage of bacteria resistant to other antibiotics, but negatively associated at the population level (prevalence). Thus inferences from individual risk factors can yield misleading conclusions about the effect of antibiotic use on resistance to another antibiotic. (ii) Nonspecific interventions that reduce transmission of all bacteria within a hospital will disproportionately reduce the prevalence of colonization with resistant bacteria. (iii) Changes in the prevalence of resistance after a successful intervention will occur on a time scale of weeks to months, considerably faster than in community-acquired infections. Moreover, resistance can decline rapidly in a hospital even if it does not carry a fitness cost. The predictions of the model are compared with those of other models and published data. The implications for resistance control and study design are discussed, along with the limitations and assumptions of the model.

Antibiotic Prophylaxis in Acute Necrotizing Pancreatitis

Objective: To review the use of antibiotic prophylaxis in acute necrotizing pancreatitis. Background: Acute necrotizing pancreatitis is a complication that occurs in a minority of patients with acute pancreatitis, but has a high incidence of morbidity and mortality. Surgery and supportive care are important in the management of this disease. However, the role of antibiotic prophylaxis has been debated for decades. Data Sources: English-language clinical studies and review articles involving human subjects and appropriate in vitro data were located through a literature search (MEDLINE, January 1966-July 1998). Study Selection and Data Extraction: Relevant studies describing the use of antibiotic prophylaxis in acute necrotizing pancreatitis were reviewed. Data Synthesis: Earlier studies of antibiotic prophylaxis in patients with acute necrotizing pancreatitis did not show any benefit compared with placebo. Newer studies have shown a decrease in mortality and morbidity when antibiotic prophylaxis is given to patients with severe necrotizing pancreatitis. Conflicting results leave many questions unanswered, such as the effect of antibiotic use in resistance patterns, which antibiotic to use, duration of therapy, and cost-effectiveness of this strategy. Conclusions: With the available data, it is adequate to recommend that patients with at least 30% necrosis of the pancreas receive antibiotics to prevent infectious complications and to decrease potential mortality. Use of imipenem/cilastatin is supported by the largest prospective trial to date; however, the drug was compared with no treatment. Cefuroxime is the only drug shown to decrease mortality and should be considered an alternative that may be more cost-effective than therapy with imipenem/cilastatin. A comparison trial is needed before further recommendations are given.

Pneumonia in intubated patients: role of respiratory airway care.

In order to assess potential risk factors for pneumonia within the first 8 d of ventilation, we studied 83 consecutive intubated patients undergoing continuous aspiration of subglottic secretions (CASS). Multivariate analysis showed the protective effect of antibiotic use (relative risk [RR] = 0.10; 95% confidence interval [CI] = 0.01 to 0.71), whereas failure of the CASS technique (RR = 5.29; 95% CI = 1.24 to 22.64) was associated with a greater risk of pneumonia. In addition, there was a trend toward a higher risk of pneumonia (RR = 2.57; 95% CI = 0.78 to 8.03) among patients with persistent intracuff pressures below 20 cm H2O. The remaining factors analyzed were not significant. Failure of CASS did not influence the development of pneumonia among patients undergoing antibiotic treatment (33.0% versus 38.5%, p > 0.20), but was strongly associated with pneumonia (42.1% versus 8.3%, p < 0.01) among intubated patients not receiving antibiotics. When multivariate analysis was repeated in this subpopulation, failure of CASS (RR = 7.52, 95% CI = 1.48 to 38.07) and persistent intracuff pressure below 20 cm H2O (RR = 4.23, 95% CI = 1.12 to 15.92) were factors independently associated with the development of pneumonia. We conclude that leakage of colonized subglottic secretions around the cuff of the endotracheal tube is the most important risk factor for pneumonia within the first 8 d of intubation. This study confirms the importance of maintaining adequate intracuff pressure and effective aspiration of subglottic secretions in preventing pneumonia in intubated patients not receiving antibiotic treatment.

Cost effectiveness of antibiotic use

Cost effectiveness of antibiotic use

Effect of antibiotic use on the incidence of cephalosporin resistance in two Australian hospitals.

The incidence of resistance of Gram-negative bacteria to three generations of cephalosporins was surveyed in two large hospitals with widely differing rates of cephalosporin usage. Overall resistance (MIC greater than 5 mg/l) of Enterobacteriaceae to cefotaxime in the hospital using large amounts of cephalosporins was 4% compared with 0.7% in the other. Enterobacter species accounted for most resistant isolates and resistant Enterobacter cloacae replaced sensitive strains in four patients given cefotaxime in 1983. The distribution of species colonizing intensive care areas was similar in both hospitals with cephalosporin-resistant Pseudomonas aeruginosa and Acinetobacter calcoaceticus predominating.