RE: Autoclaving & needle sterilisation

[Guest guest]

Hi All, & Matt,

 

Matt Bauer wrote:

> When I replied to Attilio's message, I had no yet read Phil's. I

> also think we should be using single-use disposable needles. That

> is all that I use even though this is not required by my state

> (California). Phil is right about the difficulty in Prion

> eradication - they are scary phenomenon. I disagree though with

> his general claim that autoclaving will not render viruses

> non-infectious.

 

Matt, I accept that careful autoclaving with well maintained

equipment, destroys most, if not all, known viruses. However,

mistakes can occur and some autoclaves are not maintained / run

properly.

 

Also, see this: Espy MJ, Uhl JR, Sloan LM, Rosenblatt JE,

Cockerill FR 3rd, Smith TF. Detection of vaccinia virus, herpes

simplex virus, varicella-zoster virus, and Bacillus anthracis DNA by

LightCycler polymerase chain reaction after autoclaving:

implications for biosafety of bioterrorism agents. Mayo Clin Proc.

2002 Jul;77(7):624-8. Division of Clinical Microbiology, Mayo Clinic,

Rochester, MN 55905, USA. OBJECTIVE: To determine whether

autoclaving suspensions of vaccinia virus, herpes simplex virus

(HSV), varicella-zoster virus (VZV), and Bacillus anthracis

inactivate infectivity of these agents but allow detection of target

DNA by LightCycler polymerase chain reaction (PCR). MATERIAL

AND METHODS: Swabs were inserted into tubes containing serial

10-fold dilutions (10(-1) to 10(-5); 500 microL; 6 samples per

dilution) of vaccinia virus, HSV, VZV, or a single suspension of

10(8) colony-forming units of B anthracis (2 samples). One half of

the samples were autoclaved, and the remainder were not. An

aliquot of each not autoclaved sample served as a control for

infectivity. RESULTS: Autoclaving swabs saturated with

suspensions of vaccinia virus, HSV, or VZV eliminated the

infectivity of these agents; however, DNA was detectable in most

autoclaved samples in dilutions of 10(-1) to 10(-4) by LightCycler

PCR. All not autoclaved specimens were detected by culture

(infectivity) except for VZV and, in most dilutions of 10(-1) to 10(-3),

by assay of target DNA by LightCycler PCR. Similarly positive

results were obtained for PCR assessment of sporulated B

anthracis. CONCLUSIONS: Standard autoclaving procedures

eliminated the infectivity of viruses (and B anthracis), but target

DNA was often retained for detection by LightCycler PCR. Current

recommendations indicate that the laboratory diagnosis of

smallpox virus infection be performed only within Biosafety Level 4

facilities. We suggest that, in addition to the requirement for

immediate coordination with public health officials, the federal

government consider expanding the existing guidelines for

processing these specimens to encourage immediate collection,

autoclaving, and testing by LightCycler PCR to differentiate

smallpox virus from other dermal pathogens such as HSV and VZV

by specific qualified laboratories. PMID: 12108599 [PubMed -

indexed for MEDLINE]

 

My point is that AIDS, hepatitis and prion diseases are common.

Carriers may not be recognised if they present for acupuncture in

the pre- or sub- clinical stage. Therefore, the risk of cross-infecting

patients by needle re-use (sfter inadequate sterilisation) is very

REAL.

 

Why take the risk when cheap, disposable needles are available?

Why leave our profession open to public criticism on that score?

 

> While I support the concept of only using single-use

> pre-sterilized disposable needles, I think we should be careful

> not to overstate the danger that might come with properly

> sterilizing acupuncture needles. Acupuncture needles are likely

> the most easily sterilized type to medical equipment imaginable. A

> very thin, solid metal wire. The vast majority of problems

> (failures) historically associated with sterilization of medical

> equipment has been due to the desire of users to find the minimum

> time and temperature so as to not wear out the equipment too soon

> because of cost. The accepted time a! nd pressure standard for

> autoclaves is 15 pounds of pressure for 15 minutes. In California,

> we set a standard of 30 pounds for 30 minutes - essentially making

> it four times the accepted standard. The second most common

> problem with autoclaving failures has to do with the difficulties

> associated with the physical cleaning that should proceed the

> autoclaving process. Equipment that has complex, irregular

> surfaces (like dental drills) are difficult to clean before

> autoclaving. A solid acupuncture needle has no place for matter to

> accumulate except the region where the shaft meets the handle. The

> use of ultra-sonic cleaning devices (such as a jewelry cleaner)

> knocks trapped matter free so that autoclaving will then be quite

> effective. Of course, there are things that can go wrong with the

> autoclave or the manner in which it is used, but most all of these

> mistakes can be caught by using the right type to autoclaving

> testing device. The newer generations of these devices are remar!

> kably accurate. My bottom line here is that any properly

> autoclaved acupuncture needle poses much less of a health risk

> than virtually every bit of dental equipment and many other

> devices used in many fields of healthcare. While I agree

> acupuncturists should avoid all concerns by using single-use

> pre-sterilized disposable needles, we should also put our

> equipment into their proper perspective within the realm of

> medical devices. Matt Bauer

 

I accept that cleaning and re-sterilisation of AP needles are much

easier that for drapes and other hospital equipment. But we should

NOT simply follow " accepted hospital procedures " . Many medical

instruments are expensive and disposal after a single use is not a

practical option when hospital budgets are tight.

 

Some years ago, a confidential report to the UK Government from

the Expert Group on TSE recommended destruction after a single

use of all equipment that touched brain/nervous tissue of positive or

suspected cases harbouring TSEs (such as nvCJD.

 

However, when the COST of implementing that policy was

calculated, the recommendation was dropped because the cost

would have been millions per annum.

 

BOTTOM line: The UK Govmt ignored a recommendation from its

EXPERT GROUP on financial grounds! We should NOT follow their

example!

 

Best regards,

Phil

 

PS: Below are some other Medline Abstracts that confirm that best

practice procedure for autoclaving is a practical solution to reusing

medical equipment. However, they also confirm that best practice

is not always attained.

 

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Gurevich I, Dubin R, Cunha BA. Dental instrument and device

sterilization and disinfection practices. J Hosp Infect. 1996

Apr;32(4):295-304. Infection Control Section, Winthrop-University

Hospital, Mineola, New York, USA. Dental instruments and devices

require sterilization or high-level disinfection. An evaluation of the

implementation of such processes was undertaken. Eleven

thousand questionnaires on methods used to sterilize and disinfect

dental instruments were sent to dental practices and 1391 (13%)

were returned for evaluation. Sixty-eight percent of respondents

believed they were sterilizing their instruments, however, some of

the liquid chemical products used were not suitable for sterilizing

instruments, and 12% of respondents used incorrect contact

times. Forty-nine percent of respondents did not challenge

autoclaves with biological spores to check their function at an

acceptable frequency. There were similar product and timing

problems when a high-level liquid chemical disinfection was

attempted. Although the return sample was small, problems were

identified that can and should be corrected. This study

demonstrates that the potential for person-to-person transmission

of infectious agents such as the human immunodeficiency virus

(HIV) and hepatitis B and C viruses via inadequately sterilized

dental instrument exists depending on the prevalence of HIV in the

dental practice area. PMID: 8744514 [PubMed - indexed for

MEDLINE]

 

Hirose K, Tajima K, Fujihira N, Hasegawa S, Fujioka M. [AIDS/HIV

related knowledge, attitude and behavior of acupuncture therapists

in Aichi Prefecture - Article in Japanese] Nippon Koshu Eisei

Zasshi. 1995 Apr;42(4):269-79. Division of Epidemiology, Aichi

Cancer Center Research Institute. To promote AIDS prevention

measures in Japan, the actual state of knowledge, attitudes and

behaviors (KAB) of workers at risk for HIV infection requires

clarification. In the present study, acupuncture therapists in Aichi

Prefecture were evaluated for level of their KAB. By using a self-

administered questionnaire, the KAB condition of 500 acupuncture

therapists was surveyed from September-November in 1993.

Responses from 494 (98.8%) were available for analysis. Results

showed that knowledge level on general issues regarding HIV

epidemics was good. The main sources for information on

AIDS/HIV were TV, general lectures, public reports and magazines.

More than 80% of acupuncture therapists sterilize their needles by

autoclave or boiling and 60% of them use disposable needles.

Furthermore, 97% of the therapists reported utilizing one or the

other of these methods. More than a half of them have participated

in AIDS education programs. While about 30% of them responded

that they are able to accept HIV carriers as clients, 20% of them

expressed negative responses. There appears to be a discrepancy

between their level of knowledge of HIV transmission routes and

their practical attitude towards clients with AIDS and/or HIV

carriers. A more appropriate education program based on

behavioral science is desirable to lessen discrepancy distance

between general knowledge and preferable behavior regarding

AIDS/HIV. PMID: 7780170 [PubMed - indexed for MEDLINE]

 

Stinson MC, Green BL, Marquardt CJ, Ducatman AM. Autoclave

inactivation of infectious radioactive laboratory waste contained

within a charcoal filtration system. Health Phys. 1991 Jul;61(1):137-

42. Environmental Medical Service, Massachusetts Institute of

Technology, Cambridge 02139. A model system was developed

previously for disposal of solid laboratory waste that is both

radioactive and heat sensitive, e.g., HIV. A double polypropylene

bag with charcoal vent filter and absorbent was designed to meet

requirements for both steam sterilization and disposal as solid

radioactive waste. Earlier work demonstrated the effective

containment of radioactive gases by the filter and inactivation of

organisms as heat sensitive as HIV. We sought to broaden the

application of this model to ensure inactivation of microorganisms

that are more heat resistant than HIV. The efficacy of steam

sterilization using water or solutions of iodophor, hypochlorite, or

hydrogen peroxide was studied under constant temperature and

time conditions. The systems were monitored with internal probes,

physical, chemical, and biological indicators. Biological indicators

documented inactivation when bags containing hydrogen peroxide

(3%) were autoclaved for 60 min at 121 degrees C. Synergistic

activity between hydrogen peroxide and autoclave conditions

significantly reduced processing time. PMID: 2061040 [PubMed -

indexed for MEDLINE]

 

Carswell JW. Precautions against HIV transmission in hospitals.

Trop Doct. 1989 Jul;19(3):131-2. PIP: This article deals with the

precautions necessary for handling blood in a hospital environment.

It is known that most people who present to the hospital setting

may be unknowingly infected with HIV virus, and thus exposure to

blood should be handled with care. Routinely, anyone who is at

risk of coming in contact with contaminated blood should wear

gloves. The nature of the gloves should differ according to the

responsibility at hand. Thus plastic gloves should be used for

vaginal examinations, standard rubber gloves for deliveries and

surgical operations, and heavy duty gloves for scrubbing floors.

Soap and water should be readily available for personnel in the

event that presumed infected blood comes in contact with skin. A

concentration of 0.5% sodium hypochlorite should always be

available in the clinical setting, to treat unforseen blood spills.

Instruments contaminated with blood could be adequately handled

by using sterilization methods which are commonly in use. Boiling

the instrument for 20 minutes in hot water is adequate disinfection.

However, this method is not sufficient for fiber optic instruments;

instead manufacturer's instruction should be followed. Steam

sterilizers or autoclaves are more efficient for surgical instruments

such as artery forceps. Clearly, simple methods of disinfection are

adequate in killing HIV virus, and given that many people are

already infected with HIV, sterilization would be a useful routine to

practice in most hospitals in the developing countries. PMID:

2773053 [PubMed - indexed for MEDLINE]

 

Bradbeer C. Approaches to patients with HIV-related problems.

Entre Nous Cph Den. 1988 Oct(12):4-7. PIP: In the United

Kingdom, an increasing number of women with HIV infection are

found in family planning clinics. Of the 2 main groups of clients with

HIV problems, 1 is at low risk but is worried and has interest in

preventing exposure; the other is at high risk or is known to be

infected. Physicians must 1st determine to which group a patient

belongs. High risk group patients are recipients of blood and blood

products, intravenous drug users sharing needles, male

homosexuals, people from subSaharan Africa, and sexual partners

and offspring of any of these. For high risk patients, testing is done

in sexually transmitted disease clinics and repeated at 3 and 6

months. For known cases as well as high risk patients, counseling

includes information on safer sexual practices, such as use of

condoms, and on contraception and pregnancy, such as use of a

condom to prevent infection and a hormonal method to prevent

conception. The pill is not considered to be practical; IUDs carry an

increased risk of infection. Pregnancy is undesirable because of

the risk of infecting the baby, of having a malformed baby, or of

worsening the maternal prognosis. If an infected woman already is

pregnant, she is counselled about terminating the pregnancy. For

known cases, care also includes frequent cervical smears because

of the increased prevalence of cervical intraepithelial neoplasis. For

high risk cases, other tests should be done for hepatitis B and for

sexually transmitted diseases. Low risk cases are counselled on

the use of condoms and a spermicide; free condoms are provided

to men and women. For the clinic staff, general infection control

procedures are reinforced, including the use of autoclave, soap and

water, and household bleach. All staff wear gloves when dealing

with secretions and cover fresh skin abrasions with water-proof

plaster. Sharp instruments are placed in a study container and

incinerated with other disposable equipment. PMID: 12222330

[PubMed - indexed for MEDLINE]

 

Babb JR. Methods of reprocessing complex medical equipment. J

Hosp Infect. 1988 Feb;11 Suppl A:285-91. Hospital Infection

Research Laboratory, Dudley Road Hospital, Birmingham. The

choice as to which of the two gaseous processes is best suited to

individual hospital needs is a difficult one. Very few items are

unable to tolerate 73 degrees C (LTSF) and these few can

withstand 37 degrees C or 55 degrees C (EO). Unfortunately, LTSF

is a 'moist' process and sterilizers have a poor history of providing

sterilization without modification, and consequently few are used.

Ethylene oxide is more reliable, but environmental hazards are

greater and running costs high. Both processes are time-

consuming and the use of sporicidal disinfectants such as

glutaraldehyde is often the only practical alternative. Before

purchasing any gaseous sterilizer it is essential to consider

throughput and the availability of alternative processes. It may

prove sensible to share facilities or at least offer a regional facility.

It is certainly not worthwhile purchasing expensive gas sterilizers

for reprocessing inexpensive single-use items or for those that

require disinfection only. Low temperature steam is safe,

inexpensive and no special environmental provisions are

necessary. It is, however, not a sterilization process. Disinfectants,

hot water and steam will continue to be the only suitable methods

for reprocessing items outside the hospital sterile supply

department or disinfection unit. Concern over the decontamination

of blood-stained instruments following use on patients with

hepatitis B or HIV has led to an upsurge of interest in boilers and

inexpensive bench top ovens and autoclaves. Such processes are

likely to prove more effective than disinfectants but should heat

treatment prove impractical then 2% glutaraldehyde or 70% alcohol

may be used.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:

2896720 [PubMed - indexed for MEDLINE]

 

Anon. Controversial report warns of recycled glove use in Kenyan

hospital. AIDS Wkly Plus. 1997 Jul 21:19-20. PIP: Kibwage et al.

initiated a study into the microbial and physical quality of recycled

gloves at Kenyatta National Hospital after a laboratory assistant

wearing recycled gloves acquired HIV infection while taking a blood

sample from a patient. The worker died of AIDS in 1988. Kibwage

et al.'s findings were recently published in an article in the East

African Medical Journal. The researchers reported that Kenya

government hospitals autoclave used plastic gloves when there is a

shortage and autoclave new plastic gloves not meant for surgical

use for that purpose. Boiling the gloves in the autoclave at 125

degrees Celsius causes the gloves to stick to each other.

Separating them causes tiny tears and holes through which

microorganisms can pass. 41% of the recycled gloves used at

Kenyatta National Hospital are unsanitary and can transmit

disease. The hospital uses about 20,000 gloves each week.

Recycled gloves cost about one cent US each, compared to three

US cents each for presterilized gloves. Hospital officials dispute the

report's claims and counter that the gloves referred to in the study

were plastic ones used exclusively for examination. Kibwage et al.

recommend using gamma radiation and ethylene oxide to sterilize

gloves, surgical attire, and instruments. PMID: 12292413 [PubMed -

indexed for MEDLINE]

 

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Best regards,

 

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