Biological Agents And Factors Affecting Decontamination. Bruce R. Cords, Ph.D. Ecolab Inc.

Transcription

1 Biological Agents And Factors Affecting Decontamination Bruce R. Cords, Ph.D. Ecolab Inc.

2 Biological Agents of Concern B. anthracis Anthrax Variola major Smallpox Yersinia pestis Plague Vibrio cholera Cholera Filovirdia Ebola Aphthovirus Foot & Mouth Disease Botulinum Toxin Botulism

3 Resistance to Biocides PRIONS BACTERIAL SPORES PROTOZOA CYST/OOCYSTS (e.g. Crytosporidium) MYCOBACTERIUM NON-ENVELOPED VIRUSES FUNGI VEGETATIVE BACTERIA LIPID-ENVELOPED VIRUSES

4 Relative Biocidal Activity Bacterial Spores Mycobacterium Non-enveloped Viruses Peroxyacids, glutaraldehyde, formaldehyde, chlorine dioxide, ethylene oxide Mycobacterium Non-enveloped Viruses Fungi Phenolics, Iodophors, Hypochlorites Vegetative Bacteria Enveloped Viruses Quaternary Ammonium Compounds, Organic Acids * There Are Exceptions!

5 Antimicrobial Tests (Required for EPA Registration) Product Test Required Organisms General disinfectant AOAC Use Dilution S. cholerasuis ATCC S. aureus ATCC 6538 Hospital disinfectant AOAC Use Dilution S. cholerasuis ATCC S. aureus ATCC 6538 P. aeruginosa ATCC 1542 Sporicidal AOAC Sporicidal B. subtilis ATOC Cl. sporogenes ATCC 3584

6 Food Contact Surface Sanitizer AOAC Germicidal Detergent Sanitizer Test 99 ml Sanitizer Use-Solution 25ºC Add 1 ml of E.coli or S.aureus (minimum of 7.5 x 10 7 CFU/ml) 30 second Contact Time Required Efficacy: % Kill in 30 seconds at 25ºC Enumerate Survivors Neutralize 1 ml

7 Suggested Surrogates Agent Variola major (Smallpox) Yersinia pestis (Plague) Vaccinia virus Surrogate Yersinia pseudotuberculosis Bacillus anthracis (Anthrax) B. subtilis B. cereus B. globigii Foot-and-Mouth Disease Virus? Norwalk Virus Feline calicivirus

8 Regulatory Hurdle EPA does not allow real or implied claims for any infectious agent that is not stated on the product label. Very few commercial products have been tested against the candidate biological agents.

9 Legal Issues 1) It is a violation of Federal law to use an EPA registered product in a manner inconsistent with its labeling. Solution strength must be according to label Applications must be on the label 2) It is a violation of Federal law for a manufacturer to make real or implied claims for efficacy against organisms which are not on the label. Creates problems when we encounter: FMDV Anthrax Norwalk SARS Avian Influenza H5N1

10 Anthrax/Bacillus anthracis No products carry label claims (some have crisis exemption) Cutaneous, pulmonary, and gastrointestinal transmitted by aerosols and on environmental surfaces Infectious dose ,000 spores (inhaled) Effective agents (published literature).25%-.50% ( ppm) Peroxyacetic Acid 2% (20,000 ppm) Glutaraldehyde 4% (40,000 ppm) Formaldehyde 1% (10,000 ppm) Sodium Hypochlorite

11 Smallpox/Variola Major Complex Coat No products carry label claims Transmitted through aerosols, contact with infected person, and environmental surfaces Low infectious dose - a few virons Effective agents (published literature) 1% (10,000 ppm) Sodium Hypochlorite 2% (20,000 ppm) Glutaraldehyde 2% (20,000 ppm) Formaldehyde

12 Levels of Decontamination Somewhat Dependent on Infectious Dose Smallpox Anthrax A few virons can induce disease. Infectious dose (inhaled) may be 10,000 spores Smallpox decontamination to 100 virons/m 2 not acceptable Anthrax decontamination to 100 spores/m 2 probably a safe level

13 Plague/Yersinia pestis No products carry label claims Transmitted as an aerosol through respiratory droplets or plague-infected fleas. Organism does not survive more than a few hours outside the host. Infectious dose Effective agents (published literature) 1% (10,000 ppm) Sodium Hypochlorite 70% Ethanol 2% (20,000 ppm) Glutaraldehyde Many general disinfectants

14 Cholera/Vibrio cholera No products carry label claims Transmitted by contact and in water and food contaminated with excreta from infection individuals Infectious dose 10 6 Effective agents General disinfectants

15 Ebola/Filovirida Enveloped RNA Virus No products carry label claims Transmitted by contact with infected individuals or their blood/secretions. Environmental? Low infectious dose Effective agents (published literature) 2% (20,000 ppm) Sodium Hypochlorite 2% (20,000 ppm) Glutaraldehyde.5% (5,000 ppm) Peracetic Acid 1% (10,000 ppm) Formaldehyde

16 Foot & Mouth Disease/ Apthovirus Non Enveloped RNA Virus Some products carry Label Claims Transmitted by aerosols, environmental surfaces and direct contact between animals Low infectious dose Effective agents (published literature and product approvals).03% (300 ppm) Peracetic Acid.1% (10,000 ppm) Peroxymonosulphate.05% (500 ppm) Sodium Hypochlorite Other products (Ministry of Agriculture Fisheries and Food; U.K.)

17 Is SARS a Potential Bioterrorism Agent? 1. Available? Yes 2. Culturable? Yes 3. Infective? Highly 4. Deliverable? Unknown 5. Decontamination? Likely to be susceptible to common disinfectants

18 Lessons Learned from the Anthrax Case 1. We were not prepared for decontamination (e.g. Hart Building). 2) It took three treatments with ClO 2 to achieve adequate results. 3) Many items were destroyed as opposed to decontaminated. 4) Ambulance chasers with cure-alls were abundant (e.g. spores vs. vegetative).

19 Bacillus anthracis Spores vs. Vegetative Cells Peracetic Acid 5-log reduction Spores Vegatative 2,500 ppm for 30 min. 150 ppm for 30 sec.

20 Factors Contributing to Failure of Decontamination Disinfectant/Biocide: Selection of biocide not effective against infectious agent Biocide too dilute Insufficient contact time Temperature too low* Relative humidity too low (gaseous disinfectants)

21 Factors Contributing To Failure of Decontamination Environmental Factors: Presence of organic matter* Inactivation of QAC s by residual soaps and detergents Incorrect application/coverage Inadequate treatment of water supply Wettability of surface

22 All Sanitizers Are NOT Created Equal Reduced Temperature Sanitizer Efficacy 70 o F. Well Water (250 ppm) 30 Seconds L o g 6 5 R 4 e d 3 u 2 c t 1 i 0 o 0.20% 0.35% 0.13% 0.26% Acid n Peracetic Acid Organic Acid Anionic Quat Iodophor Chlorine S. aureus E. coli

23 All Sanitizers Are NOT Created Equal Reduced Temperature Sanitizer Efficacy 55 o F. Well Water (250 ppm) 30 Seconds L o g 6 5 R 4 e d 3 u 2 c t 1 i 0 o 0.20% 0.35% 0.13% 0.26% Acid n Peracetic Acid Organic Acid Anionic Quat Iodophor Chlorine S. aureus E. coli

24 L o g R e d u c t i o n All Sanitizers Are NOT Created Equal Reduced Temperature Sanitizer Efficacy 40 o F. Well Water (250 ppm) 30 Seconds 0.20% 0.35% 0.13% 0.26% Acid Peracetic Acid Organic Acid Anionic S. aureus E. coli Quat Iodophor Chlorine

25 All Sanitizers Are NOT Created Equal Reduced Temperature Sanitizer Efficacy 40 o F. Well Water (250 ppm) 2 Minutes L o g 6 R e d u c t i o n % 0.35% 0.13% 0.26% Acid Peracetic Acid Organic Acid Anionic Quat Iodophor Chlorine S. aureus E. coli

26 Effect of Temperature Organic Load and Concentration on Disinfectant Activity Quaternary Disinfectant: (Log Reduction for P. aeruginosa) QUAT 1000 ppm 5 minutes 20 C 10 C x0.5 x1.0 x2.0 x0.5 x1.0 x2.0.03% F P P F F P BSA.3% F P P F F F BSA Taylor et al 1999 P (Pass) = > 5 log reduction F (Fail) = < 5 log reduction

27 Effect of Temperature Organic Load and Concentration on Disinfectant Activity Peracetic Acid Disinfectant: (Log Reduction for P. aeruginosa) Peracetic Acid 300 ppm 5 minutes 20 C 10 C x0.5 x1.0 x2.0 x0.5% x1.0 x2.0.03% P P P P P P BSA.3% F P P F P P BSA Taylor et al 1999 P (Pass) = > 5 log reduction F (Fail) = < 5 log reduction

28 Treatment of a 48 Hour Biofilm of Pseudomonas aeruginosa* Minute Contact Time ppm 160 ppm 320 ppm Peracetic/Organic Acid Peracetic Acid Chlorine *Fatemi and Frank Journal of Food Protection. Vol. 62 ( )

29 Effect of Relative Humidity on Sporicidal Activity (B. globigii) of Formaldehyde Log Concentration RH Temp Reduction Time 400 mg/m 3 30% 25 C mg/m 3 98% 25 C 1 9 Ref: Emerging Infectious Disease Vol 9 No 6 p. 625

30 Effect of Relative Humidity on Sporicidal Activity (B. subtilis v niger) of Peracetic Acid Vapor Log Concentration RH Temp Reduction Time 1mg/L 80% RT >5 log 10 1mg/L 60% RT >4 log 10 1mg/L 40% RT >3 log 10 Ref: Emerging Infectious Disease Vol 9 No 6 p. 626

31 Inactivation Of Bacillus spp. By Boiling In Tap Water Initial log CFU/ml After 5 Boiling C UNC C UNC B. anthracis (sterne) B. cereus (commercial) B. cereus ATCC 9592 B. thuringensis ATCC C = Covered UNC = Uncovered Temp above surface: C = 98.9 C UNC = 77.3 C Ref: Emerging Infectious Disease Vol 10 No

32 National Center for Food Protection and Defense Study No: 910F Ecolab Development of Time/Temperature Concentration Matrix for Inactivation of Infectious Bioterrorism Agents by Chemical Biocides Student: Hilgren Ecolab Co-Advisors: Swanson Ecolab Diez University of Minnesota

33 Bacillus Spores General Method Food Soil Egg Yolk Emulsion Whole Milk Flour Slurry 8.8% protein 3.5% fat 7.6% starch Spore/soil mixture dried on stainless steel carrier Carrier immersed in candidate biocide for 10 minutes

34 Impact of Food Soil on Inactivation of B. cereus spores by Peroxyacetic Acid (Preliminary Results) Conditions = 10 minute exposure 20 C B. cereus ATCC Log Reduction 5,000 ppm 10,000 ppm No Soil >7.0 >7.0 Whole Milk Egg Yolk Flour Ref: Ecolab, NCFPD Project

35 Impact of Food Soil and Temperature on Inactivation of B. cereus Spores by Peroxyacetic Acid (Preliminary Results) Conditions = 10 minute exposure 10,000 ppm Peroxyacetic acid B. cereus ATCC #10987 Log Reduction 10 C 20 C 30 C No Soil 6.0 >7.0 >7.0 Whole Milk >7.0 Egg Yolk Flour Ref: Ecolab, NCFPD Project

36 Impact of Food Soil on Inactivation of B. cereus spores by Sodium Hypochlorite (Preliminary Results) Conditions = 10 minute exposure 20 C B. cereus ATCC Log 50,000 ppm No Soil >7.0 Whole Milk 1.2 Egg Yolk 1.9 Flour >7.0 Note: 1,000 ppm - >7.0 log reduction Ref: Ecolab, NCFPD Project

37 Other Results to Date: Quarternary Ammonium Chloride Not effective at 75,000 ppm (7.5%), 20 C Normal disinfection level = ppm Iodophor Not effective at 19,000 ppm (1.9%), 20 C Normal disinfection level = 25 ppm Acidified Sodium Chlorite Somewhat effective Egg yolk and milk results not as good as flour Hydrogen Peroxide Effective at 25-30%; 20 C Not effective at 10 C Mixed Peroxyacid System Results similar to peroxyacetic acid

38 Future Testing to Include: B. anthracis (nonvirulent strain) Yersinia Pestis