Post on 26-Dec-2015
transcript
Validation and Monitoring of Non-burn Health Care Risk
Waste Treatment Facilities in Gauteng
Linda Godfrey, Dave Baldwin, Martella du Preez, Pauline Coubrough
Overview
Introduction Sterilization versus Disinfection Approaches and Standards Case Studies Testing Standards and Protocols Evaluation of Efficacy Monitoring
Requirements Conclusions and Recommendations
Introduction
South Africa traditionally utilised incineration
Minimum Requirements (DWAF, 1998), infectious waste must be incinerated or otherwise sterilised prior to disposal
Ash disposed of to an H:H or H:h landfill Presents the approach adopted by
GDACEL for validation and monitoring
Sterilization versus Disinfection
Introduction of new non-burn treatment technologies
- Heat treatment - microwaving, electro-thermal de-activation (ETD), autoclaving
- Chemical Treatment – chlorine, ozone Non-burn treatment facilities are not
typically required to disinfect health care risk waste
Distinguish between sterilization and disinfection
Sterilization versus Disinfection Sterilisation reduction in microorganisms by one
million (106 or more than 99.9999% are killed) Low Level Disinfection - most bacteria, some
viruses and some fungi are killed, complete absence of resistant microorganisms e.g. tubercle bacilli or bacterial spores cannot be relied on.
Intermediate Level Disinfection - Myocardium tuberculosis, most viruses and fungi are killed, but not necessarily bacterial spores.
High-level Disinfection - all microorganisms, with the exception of small numbers of bacterial spores are killed.
BACTERIAL SPORES (e.g. Bacillus Subtilis, Clostridium sporogenes)
↓MYCOBACTERIA
(e.g. Mycobacterium tuberculosis var. bovis)↓
NON-LIPID OR SMALL VIRUSES (e.g. Poliovirus, Coxsackie virus, Rhinovirus)
↓FUNGI
(e.g. Trichophyton spp, Crytococcus spp, Candida spp)↓
VEGETATIVE BACTERIA (e.g. Pseudomonas Aeruginosa, Staphylococcus Aureus, Salmonella
spp)↓
LIPID OR MEDIUM SIZED VIRUSES (e.g. Herpes Simplex Virus, Cytomegalovirus, Respiratory syncytical
virus, Hepatitis B Virus, Human Immunodeficiency Virus)
Incr
easi
ng r
esi
stance
to t
reatm
ent
Approaches and Standards
State and Territorial Association on Alternative Treatment Technologies (STAATT, 1994)
STAATT 1 recommended Level III microbial inactivation
- inactivation of vegetative bacteria, fungi, lipophilic/hydrophilic viruses, parasites and mycobacteria at ≥ 6 Log10 reduction; and
- inactivation of B. stearothermophilus or B. subtilis spores at ≥ 4 Log10 reduction.
Vegetative Bacteria:Staphylococcus aureus (ATCC 6538)Pseudomonas aeruginosa (ATCC 15442)
Fungi:Candida albicans (ATCC 18804)Penicillum chrysogenum (ATCC 24791)Aspergillus niger
Viruses:MS-2 Bacteriophage (ATCC 15597 – B1)
Parasites:Cryptosporidium spp. oocysts Giardia spp. cysts
Mycobacteria:Mycobacterium terraeMycobacterium phleiMycobacterium bovis (BCG) (ATCC 35743)
Spores:Bacillus stearothermophilus (ATCC 7953)Bacillus subtilis (ATCC 19659)
Approaches and Standards STAATT2 (1998) - “the use of additional
biological indicators to demonstrate the efficiency of treatment systems provides no additional safeguards to public health and safety”.
The list of test organisms was reduced to Mycobacteria and Bacillus spores only,
- inactivation of mycobacteria at ≥6 Log10 reduction, and
- inactivation of B. stearothermophilus or B. subtilis spores at ≥4 Log10 reduction
International Standards
Efficacy and monitoring in US States varies:
- STAATT1
- Relaxed STAATT1 (exclusion of parasites)
- STAATT2
- Relaxed STAATT2 (exclusion of mycobacteria)
Emphasis on parametric monitoring Varying monitoring frequency and intervals
South African Standards
South Africa currently only has draft guidelines for the validation and efficacy testing of non-burn treatment facilities
Limited guidance to establishment of non-burn treatment facilities
Reliance on international standards and approaches for efficacy testing and monitoring
Case Study 1
Evertrade Medical Waste, Johannesburg First non-burn treatment facility in SA,
2002 No SA guidelines for efficacy testing
and monitoring Gauteng DACEL adopted the
conservative STAATT requirements, i.e. STAATT1
CSIR and National Health Laboratories
Case Study 1
Minimum, Level III microbial inactivation
One or more biological indicator from each microbial group:Fungi Vegetative Bacteria
• Candida albicans• Staphylococcus aureus Viruses Mycobacteria• MS-2 Bacteriophage • Mycobacterium phleiParasites• CryptosporidiumSpores• Bacillus subtilis
Problems Experienced
Availability of organisms in SA Availability of correct ATCC cultures
- closest ATCC culture- B. subtilis indicator vials- importation of viable Cryptosporidium
oocysts Method of introduction of samples into
treatment process Medium for sample introduction Concentrations required for samples
Problems Experienced
Lack of animal testing facilities for Cryptosporidium animal infectivity tests
- Percentage viability instead of log reduction Laboratory techniques
- Streak Plate Method vs Membrane Filtration Method for Candida albicans
Transport methods – B. subtilis Time frame for validation testing
Results
All test organisms showed the Stericycle ETDTM treatment process employed by EMW Operations to meet the Level III requirements set by GDACEL of:
- a ≥ 6 Log10 inactivation for vegetative
bacteria, fungi, lipophilic/hydrophilic viruses, parasites and mycobacteria, and
- a ≥ 4 Log10 reduction for spores.
Case Study 2
Evertrade Medical Waste, Cape Town Relaxed standards by Western Cape
Department of Environmental and Cultural Affairs and Sport, i.e. relaxed STAATT 2
AllkilTM Bacillus subtilis indicators Reduced testing requirements resulted in
- cost savings for the company and - reduced the time required for testing by weeks- without compromising the validity of results
Results
Testing programme showed 100% inactivation of Bacillus subtilis spores, i.e. Level III inactivation required Western Cape
a ≥ 4 Log10 reduction for spores.
Calibrated parametric monitoring, e.g. temperature, pressure, throughput, residence time, etc to support monitoring.
Testing Standards and Protocols
Problems and challenges encountered Development of Guidelines for Testing
Standards and Protocols for Non-burn Health Care Risk Waste Treatment Technologies
Identifies 4 testing phases:- Performance Testing- Regular Testing Programme- Reduced/Routine Testing Programme- Investigative Testing
Testing Standards and Protocols Level III inactivation, as a minimum, for all
non-burn technologies, all sizes:- inactivation of vegetative bacteria, fungi,
lipophilic/hydrophilic viruses, parasites and mycobacteria at ≥ 6 Log10 reduction; and
- inactivation of B. stearothermophilus or B. subtilis spores at ≥ 4 Log10 reduction.
Performance testing programme weekly for a one month period, i.e. at least 4 times, on “normal” infectious waste.
The plant must also demonstrate that it can meet the programme on a challenge load.
Testing Standards and Protocols Evaluation of Gauteng draft validation
guidelines- Proposed monitoring programme: general
assessment- Performance testing- Regular testing- Analytical procedures for efficacy testing- Availability of analytical facilities in
South Africa- Availability of microbiological organisms in
South Africa
Testing Standards and Protocols
Cost of implementation- Testing costs for Large Commercial
Facilities
- Testing costs for Small on-site Facilities Alternative validation programmes
- Proposed requirements- Estimated costs
Comparative costs of various validation programmes
Testing Programme
Cost [R]
Commercial Facilities
Small on-site
FacilitiesSTAATT1: Performance Testing (1) R260 800 R125 800
STAATT1: Performance Testing (2) R190 800 R77 800
STAATT2: Performance Testing R37 750 R15 100
Daily Monitoring (a) R400 /m R400 /m
Daily Monitoring (b) R3 200 /m R7 200 /m
Monthly Monitoring R17 000 R7 000
Performance testing scenarios:(1) Complete STAATT 1 testing(2) Reduced STAATT 1, excluding parasites
Daily monitoring scenarios:(a) Suggested Guidelines, i.e. once per day.(b) Draft Gauteng Guidelines, i.e. every 2
hours of operation.
Challenges
The limited availability of required ATCC organisms in South Africa
The requirements for the importation of viable Cryptosporidium oocysts for every validation test
The limited availability of accredited laboratories in South Africa
The limited availability of qualified individuals to supervise validation programmes
Challenges
Interpretation of requirements from authorities
Interpretation of results by laboratories, the proponent and authorities
Lack of consistency between Provincial Authorities in their approach to the validation of non-burn treatment technologies
Lack of national guidelines for validation and monitoring
Conclusions
Need for capacity to implement and assess testing programmes
Library of required organisms established at an accredited laboratory(s)
Relaxation of STAATT 1 As a minimum the exclusion of parasites Reduction in frequency of regular testing
to once per day Role of parametric monitoring
The development, implementation and enforcement of guidelines to support validation
and monitoring of non-burn health care risk waste treatment facilities, will ensure that these
treatment facilities do not give rise to environmental and human health risks now or
in the future.