TechNet-21 - Forum

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  3. Wednesday, 12 January 2000
Post0216 INJECTION SAFETY 12 January 2000 CONTENTS 1. NEW SAN FRANCISCO CHRONICLE ARTICLE: REPLY TO COMMENTS 2. STERILITY TESTING - PROCESS CONTROL VERSUS PRODUCT CONTROL 3. INJECTION DEVICE ENVIRONMENTAL LIABILITY? Contributions to: [][/email] or use your reply button! ___________________________________________________________________________ 1. NEW SAN FRANCISCO CHRONICLE ARTICLE: REPLY TO COMMENTS In TECHNET Post0215, Injection Safety, on 11 January 2000, the New San Francisco Chronicle Article: "Global Push For Safe Needles: Agencies want to curb spread of deadly viruses" by William Carlsen was posted along with comments and corrections from Gordon Larsen, WHO/V&B. In todays posting, Bill Carlsen, SF Chronicle, replies. It is in all of our interests to get the correct and accurate story out. Action, comments and additions please: [][/email] or use your reply button ___________________________________________________________________________ From: William Carlsen To: "'Technet Moderator'" Subject: RE: Post0215 INJECTION SAFETY Date: Tue, 11 Jan 2000 11:18:37 -0800 Dear Allan: Thanks for posting our article "Global Push for Safe Needles" (Post 0215). I welcome any comments or corrections. I was a little perplexed, however, by the corrections from Gordon Larsen of WHO. He states that there is "no plan to phase out all sterilizables by the end of 2003." I went back to look at the Joint Statement of WHO/UNICEF/RED CROSS AND RED CRESCENT SOCIETES posted on Technet on November 8, 1999 (Post 203) and found a different statement. In that statement, it says under (4) that WHO and UNICEF "urge that by the end of 2001 all countries should use only auto-disable syringes or sterilisable syringes. Standard disposable syringes should no longer be used." That statement is followed by: "WHO and UNICEF urge by the end of 2003, all countries should use only auto-disable syringes for immunization." I'm confused by Mr. Larsen's statement that I have somehow reported this inaccurately. Maybe I'm missing something and I don't understand the joint statement. I thought I was giving it a straightforward interpretation. I welcome any comment from Mr. Larsen or any one else that could straighten this out for me. Clearly what Mr. Larsen says and what the joint statement says seem to be at odds. Meanwhile, I stand corrected on the number of A-Ds produced in 1999 at 150 million and not the 100 million figure that I reported, which was the estimate given me by both Beckton Dickenson and Univec. It is indeed encouraging that A-D manufacturing capacity will be 500 million in 2000. But that is capacity. What about actual production? Mr. Larsen notes that in 1999 the capacity was 300 million but only 150 million were produced. Again thanks for any comments and corrections. I strive to be as accurate as I can in my reports. Yours, Bill Carlsen, The San Francisco Chronicle ____________________________________*______________________________________ 2. STERILITY TESTING - PROCESS CONTROL VERSUS PRODUCT CONTROL Sterility testing for the processing of injection equipment was discussed in TECHNET Post0205, INJECTION SAFETY, 12 November 1999, in the context of the decision of the West Bengal, India, Government to stop using disposable injection equipment and return to sterilizables. In post0205, item 3. Sterility testing of disposable syringes & needles marketed in Calcutta, a long running discussion between Anthony Battersby, FBA Health Analysts, and Joel Schoenfeld, UNIVEC, a manufacturer of A-D syringes, the TECHNET Forum posted a 1998 paper by M Pal in the Indian Journal of Public Health: Sterility Testing of Disposable Syringes and Needles Marketed in Calcutta (IJPH, Vol:XXXXII, No.4, Oct-Dec 1999. Peter Hoffman, UK Public Health Laboratory Service, prepared this discussion of the thinking in the United Kingdom on the use of sterility testing in sterilization processing. Action, comments and additions please: [][/email] or use your reply button ___________________________________________________________________________ Date: Sat, 27 Nov 1999 08:50:54 -0500 From: Anthony Battersby Subject: STERILITY TESTING - PROCESS CONTROL VERSUS PRODUCT CONTROL To: [][/email] Dear Allan, Following the piece on "unsterile" disposables in Calcutta, I contacted Peter Hoffman at PHLS and asked him for his views on the merits of trying to carry out aseptic testing. He has written the following for Technet. Anthony ___________________________________________________________________________ STERILITY TESTING - PROCESS CONTROL VERSUS PRODUCT CONTROL There is an excellent analysis of this topic following an incident where inadequately sterilized infusion fluid was distributed throughout the UK. It is called "The myth of surgical sterility" Lancet 1972, December 16th, pages 1301 to 1303 and was written by the Deputy Director of the UK Public Health Laboratory Service of the time - Jos Kelsey. It has formed the UK thinking on sterilization quality assurance ever since. Briefly abstracted, the thinking is as follows: PRODUCT CONTROL Even with an experienced operator with good facilities, there is a definite false positive level when doing sterility tests. The paper gives examples as a 0.1% operator contamination rate with easy items like ampoules and a 5% rate with more difficult items like dressings (I can vouch for the latter from personal experience). Depending on the item, facilities and skill, I think operator contamination rates could well go up to 50% or beyond. All this makes detecting "real" contamination difficult and, if contamination is at a low rate, impossible. Using sterility testing for acceptance/rejection of "sterile" products, the situation is as follows: The paper gives the example that, statistically, if 20 random samples are taken from a batch that is 10% contaminated, there is a 1 in 8 chance that all samples (without operator contamination) will be sterile and the batch accepted. If 5% contamination, there would be a 1 in 3 chance of acceptance. As the sample size goes up, the testing gets more accurate, but the problem with false positives gets worse. There is the additional problem that several recovery media would be needed to grow most, but not all, bacterial contaminants. This would increase manipulation and consequent operator contamination. PROCESS CONTROL We know from laboratory work, what conditions are required to kill what levels of what contaminant. Microbes die straight-line semilogarithmically - i.e. exposed to something they don't like 9 out of 10 will die in a given unit of time - this means a 10-fold reduction. In a further unit of time exposed to the same conditions, a further 9 out of 10 will die. This is, under given conditions, "the decimal reduction time". Say 1,000,000 (10 to the power six) bacterial spores of a species that has a decimal reduction time of 1/2 a minute when exposed to steam at a certain temperature. In 30 seconds they will be reduced to 100,000; in one minute to 10,000; in three minutes to 1. In three and a half minutes to 0.1 - a tenth of a spore does not exist, but is also one tenth the chance of a spore surviving or one spore surviving in every ten batches put through the process. In this example, after six minutes, the spore level will be down to 0.000 001 (10 to the power minus six) - one millionth the chance of a spore surviving. This safety margin is not something that can be detected by culture. The conclusion from this argument is that sterility testing has a severely limited place in production or monitoring of sterile items. It is the process that needs monitoring. ____________________________________*______________________________________ 3. INJECTION DEVICE ENVIRONMENTAL LIABILITY? This is a follow-up to a discussion on potential for the extension of product liability legislation to injection devices - to cover their safe use eventual safe disposal. Comparisons were mad with the changing status of firearms and tobacco products in countries such as the USA. In Post0160 INJECTION SAFETY on 21 June 1999, Anthony Battersby, FBA, and Allan Bass, ACITHN, discussed issues of legal liability and negligence in relation to the unsafe use and the provision of of injection equipment. and asked: "Does anyone know what the legal position is?" In post0171, 2 August 1999, Janine Jagger, International Health Care Worker Safety Center at the University of Virginia Medical School, offered a few thoughts on the complexities of the legal environment. In today's posting, Anthony notes that regulations, requiring motor vehicle manufacturers liable for the ultimate disposal of their product. It should be noted that some countries (Switzerland) already requires the inclusion of cost of environmentally safe disposal in the purchase price of computer equipment. Action, comments and additions please: [][/email] or use your reply button ___________________________________________________________________________ Date: Thu, 16 Dec 1999 11:15:39 -0500 From: Anthony Battersby Subject: Injection safety To: [][/email] Dear Allan, The EU is in the process of passing legislation that will make motor manufacturers liable for the disposal and destruction of the motor vehicles which they manufacture. This will be fully implemented by 2006 and begins in 2001. So if car makers are to be liable for their products why not syringe manufacturers?? Ref: David Brown "Thousands of Cars left to rust by the roadside" Independent on Sunday pp 10 12 December 1999 Thanks, Anthony ____________________________________*______________________________________

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