Nosocomial and healthcare-associated infections

Transcription

1 Nosocomial and healthcare-associated infections David Lye FRACP, FAMS Senior consultant, Institute of Infectious Diseases and Epidemiology, Communicable Disease Centre, Tan Tock Seng Hospital Associate professor, Yong Loo Lin School of Medicine, National University of Singapore

2 Definitions Hospital-acquired or healthcare-associated? Centre for Disease Control/National Healthcare Safety Network, January 2014 Healthcare-associated infections (HAI) Localized or systemic condition resulting from an adverse reaction to presence of an infectious agent(s) or its toxin(s) not present on admission to the acute care facility

3 Healthcare risk factors

4 Prevalence of healthcareassociated infections

5 183 hospitals patients 93.2%

6 83%

7 Nosocomial pneumonia

8 Nosocomial pneumonia (VAP HAP HCAP) Increased hospital stay by 7-9 days Excess cost >USD$40,000 25% of ICU infections >50% antibiotic use Attributable mortality 33-50%

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10 HCAP vs.cap More MRSA (31%), Pseudomonas (26%), Non-fermenting GNB (10%), Other Enterobacteriaceae (9%) Less Pneumococcus, Haemophilus, Legionella

11 Risk factors and prevention General Hand hygiene and contact precaution to prevent crossinfection Mechanical ventilation Non-invasive ventilation, avoid intubation Continuous suction of subglottic secretions Endotrachel tube cuff pressure >20cm H20 Contaminated condensate emptied and prevented from entering ETT Sedation protocol to accelerate weaning Adequate ICU staffing Aspiration, body positioning, enteral feeding Semi-recumbent, degrees Enteral nutrition Colonisation Daily interruption of sedation and avoid paralytic agents Stress bleeding prophylaxis, transfusion and hyperglycaemia H2 antagonist or sucralfate Restricted transfusion trigger policy Insulin to maintain glucose mg/dl

12 Diagnosis CXR new or progressive Fever or leukocytosis Purulent sputum or desaturation CPIS 6 low probability of HAP

13 Culture-guided antibiotic therapy

14 Alternative diagnoses

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16 Catheter-associated urinary tract infection

17 Catheter-associated UTI (CAUTI) 40% of HAI s 15-25% in general hospitals had urinary catheters for 2-4 days 5-10% nursing home residents had urinary catheters, some for years Bacteraemia 1-4% with mortality ~13% Extended length of stay 2 days Cost CAUTI USD$676, bacteraemia USD$2836

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19 Extraluminal 66% GPC 79% GNB 54% Yeast 69%

20 Conditioning film of host urinary components Bacteria attach by hydrophobic and electrostatic interactions, and flagella Cell division, additional planktonic bacteria, extracellular matrix Loosely packed 3-D structure with fluid channels for nutrients and wastes Survival advantage: Resistance to sheer forces and phagocytosis Antimicrobial resistance

21 HICPAC 2009

22 Appropriate indications IDSA 2010

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24 Silver alloy catheters A Cochrane Review of short-term urethral catheters in hospitalized adults: Silver alloy catheters significantly reduced asymptomatic bacteriuria in catheters inserted for less than (RR:0.54; 95%CI: 0.43 to 0.67) and more than one week (RR:0.64, 95%CI: 0.51 to 0.80) [Cochrane Database Syst Rev. 2008;(2):CD004013] Confounding by comparators as benefit significantly reduced with different comparators In bacterial adherence study, no difference was found between silver alloy hydrogel urinary catheters and hydrogel catheters [Clin Infect Dis. 2010;51:550-60]

25 Antimicrobial-coated catheters Antimicrobial-coated urinary catheters including minocycline and rifampicin (RR:0.36; 95%CI: 0.18 to 0.73) and nitrofurazone (RR:0.52, 95%CI: 0.34 to 0.78) significantly reduced asymptomatic bacteriuria in catheters inserted for less than one week but not in those inserted for more than one week [Cochrane Database Syst Rev. 2008;(2):CD004013]

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27 Diagnostic criteria Urine culture or urinalysis was found to be nonspecific for CAUTI in 14 patients with long-term urinary catheters [Am J Infect Control. 1985;13: ] A study of 56 patients with spinal cord disorders: Cloudy urine had an accuracy of 83.1%, pyuria Sn 82.8%, and fever Sp 99% but Sn 6.9% for CAUTI [J Spinal Cord Med. 2009;32: ].

28 Urinalysis A study of 106 ICU patients: positive nitrite on urinalysis Sp 91.8% but Sn 29.5% Leukocyte esterase, white cells and presence of yeast or bacteria did not differentiate those with and without CAUTI [Intensive Care Med. 2006;32: ] A study of 144 ICU patients: combining leukocyte esterase and nitrite Sn 87.2%, Sp 61.6%, PPV 30.6% and NPV 96.1% [Intensive Care Med. 2001;27: ]

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31 Evidence base: treatment In a randomised study of 119 women with CAUTI, resolution occurred in 36% without antibiotic, 81% with single dose co-trimoxazole and 79% with 10 days of co-trimoxazole, after removal of urinary catheters [Ann Intern Med. 1991;114:713 9] Another randomised study of 619 patients with pyelonephritis and complicated UTI of whom 68 had urinary catheters, 5 days of levofloxacin versus 10 days of ciprofloxacin resulted in microbiological eradication of 79% versus 53% in the subgroup of catheterised patients [Urology. 2008;71:17 22] In another randomised study of 60 spinal cord patients with predominantly intermittent catheterisation comparing 3 versus 14 days of ciprofloxacin, microbiological cure was lower, and microbiological and clinical relapse higher in the 3-day group; however clinical cure was similar [Clin Infect Dis. 2004;39:658 64]. In a randomised study of 54 patients with LT-UC in nursing home with CAUTI comparing replacement and non-replacement of urinary catheters before antibiotic, 93% in the group with replaced urinary catheters became afebrile by 72 hours [J Urol. 2000;164: ].

32 Central line associated bloodstream infection

33 Central line associated bloodstream infections (CLABSI) CDC HICPAC prevention guideline 2011 Independently increased length of stay and hospital cost, but not mortality

34 Impact: death, length of stay and cost

35 Prevalence

36 Colonisation and bacteraemia

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38 Treatment Removal of catheter Duration of antibiotic Complicated vs. uncomplicated

39 Treatment Removal of catheter Duration of antibiotic Complicated vs. uncomplicated

40 Catheter salvage and antibiotic lock therapy

41 Clostridium difficile associated diarrhoea

42 Epidemiology Rising incidence since 2001 Severe and fatal CDAD Epidemic strain North American Pulse Field Type 1 (NAP1) or PCR ribotype 027 Increased toxins A and B, fluoroquinolone resistance, binary toxin Deletion tcdc which inhibits toxin production

43 Risk factors

44 Clinical features and epidemiology ICHE 1995; 16: 459 Definition: diarrhoea (6 watery stools 36 hours, 3 unformed stools 24 hours 2 days, 8 unformed stools 48 hours), pseudomembrane endoscopy, toxin A or B stool, +ve stool culture and no other cause +/- antibiotic use <1% ileus without diarrhoea Carriage common in infants, markedly decline by 1 year Adult carriage 2% Sweden to 15% Japan 10% hospital patients colonised Primary cause antibiotic-colitis, 15-25% antibiotic diarrhoea 30% hospital patients diarrhoea CD +ve Rehabilitation 25% Community <1/10000 antibiotic prescriptions

45 Clinical features and epidemiology ICHE 1995; 16: 459 Initial stool negative, test another (increased yield 10% for 3 stools) 20% initial culture-negative adults nosocomially acquire CDAD (high endemicity) 2/3 remain asymptomatic 8% per week 13% 1-2 weeks, 50% >4 weeks (CID 1998; 26: 1027) Median time from admission to CDAD 13 days (NEJM 2005; 353: 2442), 21 days (EID 2003; 9: 730)

46 3 or more unformed stools in last 24 hours Testing: Only on unformed stool Not on asymptomatic or test of cure or repeat in same episode of diarrhoea EIA sub-optimal sensitivity, 2-step GDH (with cell cytotoxin assay or culture) promising, PCR sensitive and specific

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48 Treatment

49 Cure higher with oral vancomycin for severe CDAD only Relapse similar (10%)

50 Fidaxomicin less relapse vs. vancomycin

51 AJG 2002;97:1769

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53 Surgical site infections

54 Surgical site infections (SSI) ICHE 1999;20:247 Third commonest HAI 14-16% of HAI s Among deaths in surgical patients with SSI, 77% related to SSI, 93% due to organ space SSI Increased length of stay by 10 days Increased cost by USD$2000

55 Diagnosis: SSI

56 ICHE 1999; 20: 247

57 ICHE 1999; 20: 247

58 SSI risk stratification and surveillance ICHE 1999; 20: 247 Within clean wound category, SSI risk % (SENIC) and % (NNIS) SENIC, 4 independent risk factors (abdominal operation, >2 hours, contaminated or dirty wound, >3 discharge diagnoses), each given 1 point if present, score 0-4 NNIS risk index 0-3, 1 point if present for (1) ASA >2 (2) contaminated or dirty wound (3) operating time >T hours [75 th percentile for specific operation] Inpatient, post-discharge and outpatient surveillance Direct and indirect detection 12 84% SSI detected after discharge Most SSI evident within 21 days

59 Risk index and SSI rates Wound category Clean Clean contaminated Contaminated SSI rate, % NNIS risk index SSI rate, % Dirty

60 Surgical site infections ICHE 1999;20:247 Patient factors Preoperative Skin preparation Hand and forearm antisepsis Intraoperative Operating room environment Surgical attire and drapes Asepsis and surgical techniques Postoperative Incision care

61 Pre-operative antibiotic prophylaxis ICHE 1999; 20: principles: Evidence of efficacy or effect of SSI catastrophic Antibiotic: safe, inexpensive, bactericidal, active against probable contaminants Time the infusion so bactericidal drug level in tissue and serum at skin incision Maintain therapeutic level until at most a few hours after incision is closed Indicated for all operations entering hollow viscus and clean operations where prosthetic material inserted or effect of SSI catastrophic Need for second dose depends on: tissue level by standard therapeutic dose, serum half life, MIC 90 of anticipated SSI pathogens Antibiotic given no more than 30 minutes before skin incision Vancomycin needs 1 hour infusion

62 Several good guidelines

63 Evidence: 1=meta-analysis, 2=RCT, 3=well-designed study, 4=opinion

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66 Surgical antibiotic prophylaxis

67 Antimicrobial prophylaxis in colorectal surgery: a systematic review of randomized controlled trials Br J Surg 1998;85:1232 Trials from 1984 to 1995, n=147 Effective for prevention of SSI in colorectal surgery No significant difference between many different regimens Not good: metronidazole OR doxycycline OR piperacillin alone, PO neomycin and erythromycin First-generation cephalosporins as good as newgeneration cephalosporins (OR 1.07, 95% CI )

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70 Visceral, trauma and vascular surgery IV cefuroxime 1.5G +/- metronidazole 500mg

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74 Right timing more important With right timing, re-dosing >2 T1/2 of prolonged surgery additional benefit

75 Duration of surgical antibiotic prophylaxis J Thorac Cardiovasc Surg 1977;73:470 Prospective double-blind study, 2 vs. 6 days of cephalothin, prosthetic valve surgery Sternal wound infection 2.1% vs. 2.8% Aust N Z J Surg 1998;68:388 Meta-analysis of prospective, randomised studies, same drug in both arms No advantage of multiple vs. single dose No difference: beta-lactam vs. others, >24 vs. 24 hours BMJ 1979;6165:707 Prospective, 3 doses of cephaloridine vs. 2 weeks flucloxacillin, THJR Overall deep infection 1.3%, no difference between 2 arms Br J Surg 1998;85:1232 Single dose pre-op as effective as long-term post-op (OR 1.17, 95% CI )

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79 Control blood sugar for DM

80 Normothermia for all but cardiac surgery

81 Pre-operative hair removal to reduce surgical site infections Cochrane Database Systematic Rev 2006;2:CD Assess RCT of hair removal vs. no hair removal, different methods and times N=11 3 RCT compared depilatory cream/razor vs. no hair removal no difference in SSI 3 RCT compared shaving with clipping more SSI with shaving (OR 2.02, 95% CI ) 7 RCT compared shaving with depilatory cream more SSI with shaving (OR 1.54, 95% CI ) 1 RCT compared each compared shaving OR clipping on day of surgery vs. day before surgery no difference in SSI Use clippers or depilatory cream, or do not shave

82 Questions?