scholarly journals Why sensitive bacteria are resistant to hospital infection control

2017 ◽  
Vol 2 ◽  
pp. 16 ◽  
Author(s):  
Esther van Kleef ◽  
Nantasit Luangasanatip ◽  
Marc J Bonten ◽  
Ben S. Cooper

Background: Large reductions in the incidence of antibiotic-resistant strains of Staphylococcus aureus and Clostridium difficile have been observed in response to multifaceted hospital-based interventions. Reductions in antibiotic-sensitive strains have been smaller or non-existent. It has been argued that since infection control measures, such as hand hygiene, should affect resistant and sensitive strains equally, observed changes must have largely resulted from other factors, including changes in antibiotic use. We used a mathematical model to test the validity of this reasoning. Methods: We developed a mechanistic model of resistant and sensitive strains in a hospital and its catchment area. We assumed the resistant strain had a competitive advantage in the hospital and the sensitive strain an advantage in the community. We simulated a hospital hand hygiene intervention that directly affected resistant and sensitive strains equally. The annual incidence rate ratio (IRR) associated with the intervention was calculated for hospital- and community-acquired infections of both strains. Results: For the resistant strain, there were large reductions in hospital-acquired infections (0.1 ≤ IRR ≤ 0.6) and smaller reductions in community-acquired infections (0.2 ≤ IRR ≤  0.9). These reductions increased in line with increasing importance of nosocomial transmission of the strain. For the sensitive strain, reductions in hospital acquisitions were much smaller (0.6 ≤ IRR ≤ 0.9), while communityacquisitions could increase or decrease (0.9 ≤ IRR ≤ 1.2). The greater the importance of the community environment for the transmission of the sensitive strain, the smaller the reductions. Conclusions: Counter-intuitively, infection control interventions, including hand hygiene, can have strikingly discordant effects on resistant and sensitive strains even though they target them equally, following differences in their adaptation to hospital and community-based transmission. Observed lack of effectiveness of control measures for sensitive strains does not provide evidence that infection control interventions have been ineffective in reducing resistant strains.

2017 ◽  
Vol 2 ◽  
pp. 16 ◽  
Author(s):  
Esther van Kleef ◽  
Nantasit Luangasanatip ◽  
Marc J Bonten ◽  
Ben S. Cooper

Background: Large reductions in the incidence of antibiotic-resistant strains of Staphylococcus aureus and Clostridium difficile have been observed in response to multifaceted hospital-based interventions. Reductions in antibiotic-sensitive strains have been smaller or non-existent. It has been argued that since infection control measures, such as hand hygiene, should affect resistant and sensitive strains equally, observed changes must have largely resulted from other factors, including changes in antibiotic use. We used a mathematical model to test the validity of this reasoning. Methods: We developed a mechanistic model of resistant and sensitive strains in a hospital and its catchment area. We assumed the resistant strain had a competitive advantage in the hospital and the sensitive strain an advantage in the community. We simulated a hospital hand hygiene intervention that directly affected resistant and sensitive strains equally. The annual incidence rate ratio (IRR) associated with the intervention was calculated for hospital- and community-acquired infections of both strains. Results: For the resistant strain, there were large reductions in hospital-acquired infections (0.1 ≤ IRR ≤ 0.6) and smaller reductions in community-acquired infections (0.2 ≤ IRR ≤ 0.9). These reductions increased in line with increasing importance of nosocomial transmission of the strain. For the sensitive strain, reductions in hospital acquisitions were much smaller (0.6 ≤ IRR ≤ 0.9), while community acquisitions could increase or decrease (0.9 ≤ IRR ≤ 1.2). The greater the importance of the community environment for the transmission of the sensitive strain, the smaller the reductions. Conclusions: Counter-intuitively, infection control interventions, including hand hygiene, can have strikingly discordant effects on resistant and sensitive strains even though they target them equally. This follows from differences in their adaptation to hospital- and community-based transmission. Observed lack of effectiveness of control measures for sensitive strains does not provide evidence that infection control interventions have been ineffective in reducing resistant strains.


1999 ◽  
Vol 20 (8) ◽  
pp. 565-567 ◽  
Author(s):  
Marie Eve Dy ◽  
Jill A. Nord ◽  
Vincent J. LaBombardi ◽  
Jay W. Kislak

AbstractA prospective study was undertaken to determine colonization rates, susceptibility profiles, and outcomes in patients with clinical isolates of Acinetobacter baumannii. Fifty percent of patients became colonized with A baumannii, and 29% of these patients had clinical and colonizing isolates with discordant susceptibility profiles, without apparent relation to antibiotic use. Barrier infection control measures are necessary to prevent nosocomial transmission.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jennifer A. Unger ◽  
Estella Whimbey ◽  
Michael G. Gravett ◽  
David A. Eschenbach

Objective. An outbreak of 20 peripartumClostridium difficileinfections (CDI) occurred on the obstetrical service at the University of Washington Medical Center (UWMC) between April 2006 and June 2007. In this report, we characterize the clinical manifestations, describe interventions that appeared to reduce CDI, and determine potential risk factors for peripartum CDI.Methods. An investigation was initiated after the first three peripartum CDI cases. Based on the findings, enhanced infection control measures and a modified antibiotic regimen were implemented. We conducted a case-control study of peripartum cases and unmatched controls.Results. During the outbreak, there was an overall incidence of 7.5 CDI cases per 1000 deliveries. Peripartum CDI infection compared to controls was significantly associated with cesarean delivery (70% versus 34%;P=0.03), antibiotic use (95% versus 56%;P=0.001), chorioamnionitis (35% versus 5%;P=0.001), and the use of the combination of ampicillin, gentamicin, and clindamycin (50% versus 3%;P<0.001). Use of combination antibiotics remained a significant independent risk factor for CDI in the multivariate analysis.Conclusions. The outbreak was reduced after the implementation of multiple infection control measures and modification of antibiotic use. However, sporadic CDI continued for 8 months after these measures slowed the outbreak. Peripartum women appear to be another population susceptible to CDI.


2007 ◽  
Vol 28 (8) ◽  
pp. 932-940 ◽  
Author(s):  
Denise Drudy ◽  
Norma Harnedy ◽  
Séamus Fanning ◽  
Margaret Hannan ◽  
Lorraine Kyne

Background.Clostridium difficileis a major cause of infectious diarrhea in hospitalized patients. Between August 2003 and January 2004, we experienced an increase in the incidence ofC. difficile–associated disease. We describe the investigation into and management of the outbreak in this article.Methods.A total of 73 consecutive patients with nosocomialC. difficile–associated diarrhea were identified.C. difficileisolates were characterized using toxin-specific enzyme immunoassays, a tissue-culture fibroblast cytotoxicity assay, polymerase chain reaction (PCR), and antimicrobial susceptibility tests. Rates of recurrence and ofC. difficilecolitis were recorded. Changes in antibiotic use and infection control policies were documented.Results.The incidence ofC. difficile–associated diarrhea peaked at 21 cases per 1,000 patient admissions. Of theC. difficileisolates recovered, 85 (95%) were identical toxin A–negative and toxin B-positive strains, corresponding to toxinotype VIII and PCR ribotype 017. All clonal isolates were resistant to multiple antibiotics, including ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin (minimum inhibitory concentrations [MICs] of greater than 32μg/mL) and erythromycin, clarithromycin, and clindamycin (MICs of greater than 256μg/mL). RecurrentC. difficile–associated disease occurred in 26 (36%) of the patients. At least 10 (14%) of the patients developedC. difficilecolitis. Additional infection control measures introduced included the use of ward memos, a hand-hygiene awareness campaign, increased environmental cleaning, attention to prescribing practices for antibiotics, increased awareness of diarrheal illness, and early isolation of affected patients. Total use of fluoroquinolones did not change throughout the study period. Despite persistence of this toxin-variant strain, the incidence ofC. difficile–associated disease in our institution decreased to fewer than 5 cases per 1,000 admissions.Conclusions.We report on the emergence of a fluoroquinolone- and clindamycin-resistant, toxin A–negative, and toxin B–positive strain ofC. difficileassociated with an outbreak ofC. difficile–associated disease in our institution during a 6-month period. We found that careful attention to improvement of infection control interventions was the most important means of controlling this nosocomial pathogen.


2020 ◽  
Vol 41 (S1) ◽  
pp. s116-s116
Author(s):  
Esther Paul ◽  
Ibrahim Alzaydani ◽  
Ahmed Hakami ◽  
Harish C. Chandramoorthy

Background: This study explores the perspectives of healthcare workers on the healthcare-associated infection (HAI) and infection control measures in a tertiary-care unit, through a self-administered questionnaire, semi-structured interviews, and reflexive sessions based on video-recorded sterile procedures performed in respondents’ work contexts. Video reflexive ethnography (VRE) is a method that provides feedback to medical practitioners through reflection analysis, whereby practitioners identify problems and find solutions. Methods: Quantitative questionnaire data were used to assess the knowledge of HAI among 50 healthcare workers and their attitude toward practice of infection control measures. Semistructured interviews based on an interview guide were used to collect qualitative data from 25 doctors and nurses. The interviews were audio recorded and transcribed verbatim immediately. Also, routine sterile procedures in the wards and intensive care unit were video recorded, and the footage was discussed by the infection control team and the personnel involved in the videos. This discussion was video recorded and transcribed. Both interview data and reflexive discussion of video-graph were analyzed using a thematic analysis. The quantitative data were analyzed using the Kruskal–Wallis test. Results: The quantitative data revealed no difference in the knowledge, attitude, and practice scores used to evaluate the infection control practices among the healthcare workers. We identified 4 themes from the qualitative data: (1) knowledge of HAI and infection control, (2) infection control measures in practice, (3) the shortfall in infection control measures and HAI, and (4) required implementation. Although the qualitative data indicated that the participants had excellent compliance with hand hygiene and personal protective equipment (PPE) use, the VRE and reflective sessions indicated otherwise. Some astounding lapses were revealed, like failure to engage in boundary maintenance between sterile and nonsterile areas, failure to observe proper hand hygiene measures, and use of traditional hijab face covers (used in an unsterile environment as well) instead of surgical masks. These findings demonstrate the advantage of combining VRE with qualitative and quantitative methodology to deduct the lapses in the practice of infection control among healthcare workers. Conclusions: Introduction of training programs focused on HAI and infection control measures in the educational system will help better inform medical and nursing students. Live video demonstrations of appropriate infection control practices during sterile procedures would be highly beneficial to educate the healthcare workers on correct infection control practices. Lapses in the use of PPE can be a possible reason for the outbreak of MERS-CoV, an endemic disease, in this part of Saudi Arabia.Disclosures: NoneFunding: None


Author(s):  
Basma A. Elawady ◽  
Mona S. Mohamed ◽  
Eman H. Elsebaie ◽  
Essraa A. Hegazy ◽  
Lamiaa A. Madkour

This study was carried out in the dental school of Ahram Canadian University in Egypt to investigate the knowledge and compliance of senior students and interns toward infection control practices. A self‑administered questionnaire was employed with questions pertinent to the participants’ knowledge of risks in the dental settings, the practice of hand hygiene, the use of protective equipment, and the management of sharp injuries, among others. Although the knowledge and practice of the 240 surveyed participants were good; they were not up to the coveted standards. Despite being an integral part of their curriculum, an alarming percentage (19.6%) of the participants denied receiving knowledge about infection control instructions. Meanwhile, only 72.5% were aware of being at risk in the dental settings, and 78.3% confirmed their practice of hand hygiene. On the other hand, 84.6% of the surveyed participants confirmed the availability of protective equipment and 94.2% of them expressed their willingness to apply infection control measures in the future. The defects in the knowledge and practice mandate corrective actions to promote and upgrade the students’ compliance. Meanwhile, other gaps can be rectified via developing state-of-the-art communicative strategies. Efforts are warranted to enhance the attitude and motivate the students to conform to the protective safety measures. With all the infection control procedures already established in dental schools, the challenge lies in improving the students’ compliance with these recommendations.


2009 ◽  
Vol 30 (3) ◽  
pp. 226-232 ◽  
Author(s):  
Mandy Wootton ◽  
Timothy R. Walsh ◽  
Eleri M. Davies ◽  
Robin A. Howe

Background.The presence of methicillin-resistantStaphylococcus aureus(MRSA) and glycopeptide-intermediateS. aureus(GISA) in hospitals poses a significant challenge to hospital infection control teams. The use of disinfectants for both surface and hand cleaning is an essential part of the infection control measures.Objective.To evaluate the effectiveness of common hospital hand disinfectants against MRSA, GISA, and heterogeneous GISA (hGISA).Methods.For methicillin-susceptible S.aureus(MSSA), MRSA, GISA, and hGISA, the levels of susceptibility to hand disinfectants and their active ingredients were determined. Suspension tests were performed on commercial handwashing products.Results.Minimum inhibitory concentrations (MICs) of 2-propanol, Chlorhexidine, and hexachlorophene were similar for all phenotypes. The MICs of cetrimide and triclosan were higher for the MRSA, GISA, and hGISA strains than for the MSSA strain. The MICs for the chlorhexidine-containing agents Hibisol and Hibiscrub (AstraZeneca) and for the propanol-containing agent Sterillium (Medline) were 1-2-fold lower for the MSSA strains than for the MRSA, GISA, and hGISA strains. Suspension tests showed that the GISA and hGISA strains were less susceptible to the triclosan-containing agent Aquasept (SSL) than were the MRSA and MSSA strains, with resistance increasing with glycopeptide resistance. Products containing Betadine (Purdue) were more effective against the GISA and hGISA strains than against the MRSA and MSSA strains, especially after the strain was exposed to the product for 30 seconds.Conclusions.Using the EN 1040 standard criteria for the performance of disinfectants, we determined that all agents, except 50% Aquasept for hGISA and 0.33% hexachlorophene for GISA, performed effectively. However, the GISA and hGISA strains were less susceptible to triclosan-containing products, compared with the MRSA stains, but were more susceptible to products containing Betadine.


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