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A new carrier method for assessing germicidal efficacy of disinfectants
Volume
21,
Number
2
A NEW CARRIER METHOD FOR ASSESSING GERMICIDAL EFFICACY OF DISINFECTANTS. M. Best, BSc, V.S. Springthorpe, MSc, S.A. Sattar, PhD.* University of Ottawa, Ottawa. Ontario, Canada. Lack of harmonization between efficacy tests for different classes of microorganisms has resulted in confusing information for disinfectant users. The available protocols also iack stringency. In our test, a hard surface carrier is contaminated with a standardized mixture of Mycobacwriuni hovis BCG, Sraphylococcus LIUI’~WS. Bacillus si~~rofhr,n~r~pl~,hilus spores, Trichophyton mentagrophyres spores and hepatitis A virus in 5 % fetal bovine serum. Each carrier is contaminated with 10 UL of the mixture and the moculum allowed to dry for90 minutes under ambient conditions. The dried inoculom is then covered with 60 uL of the disinfectant under test for a specitied contact time. Carriers are then placed in 2,940 uL of an eluent/neutralizer and the eiuates assayed separately for the five types of organisms. There was no interference between the organisms in the mixture. In tests with at least 10 products representing major classes of disinfectants, the mixture itself did not significantly mfliience their germicidal action; similar results were obtained by testing each organism individually. Three products (0.4% QAC with 23% HCI, 0.6% sodium hypochlorite and 2% alkaline glutaraldehyde) were consistently effective against all 5 challenge organisms. Povidone-iodme (I % iodine) was effective against all but bacterial spores; tive products were effective against S. (~ww.s only and 3 % hydrogen peroxide was ineffective against all of the test organisms. Our method, therefore, allows for concurrent evaluation of bactericidal, mycobactericidal, fungicidal, virucidal and sporicidal efficacy claims under more realistic conditions than can be obtained using a single organism. This rmethod permits a xmore reliable means of classifying germicides based on their spectrum of activity. The basic method IS also flexible enough to permit tests with either one type of organism or a lmixture different from that listed.
AbStTX2Ct.T
EARLY IDENTIFICATION OF CONTAMINATION PREVENTS OUTBREAK AMONG PATIENTS IN A DIALYSIS UNIT. D. Bingle, RN, BSN, CIC, N. Click, RN, MA, CIC,* L. Wollenberg, RN, BS, CNN, 1. Baird, MD, M. Mishkind, MD. Riverside Methodist Hospitals, Columbus, OH. Intradialytlc Parenteral Nutrition (I.D.P.N.), an intravenous lipid solution, is a nutritional supplement used for hemodialysis patienw 5 to IO percent of our dialysis population receive this supplement. Patients are eligible for this treatment only if they are malnourished and after ail other oral supplements have been unsuccessful. Two hemodialysis patients developed a febrile reaction during Infusion with increasing fever and symptoms after receiving I.D.P.N.. One required hospitalization for evaluation and the other was kept overnight in the Emergency Department observation unit. Blood cultures revealed Serratia marcescens in the first patienr. The second patient’s cultures were negative. Fourteen unused I.D.P.N. bags, all from the same lot number, were tested in our microbiologv-~ lab and grew Acinetobacter calcoaceticos, Serraba marcescens, and Xanthomonas maltouhilia. Further investigation determined that no other oatients had received I.D.P.N., nor was this product being used in other areas if the hospital. The supplier of the nutritional supplement was notitied and subsequently confirmed that the product was contaminated. The company contacted other users of their product after receiving our report and identified simultaneous patient problems in two other facilities which they felt could also have resulted from product contamination. The supplier has prowded no feedback as to the specific cause or quality asswance measures implemented as a result. Further investigatioil was instituted by the Food and Drug Administranon following our notification. Although lipids have previously been implicated in nosocomial bacteremia, this incident was unusual in Ihat it occurred in an outpatient setting. Recognition of symptoms and prompt action on the part of the staff involved to discontinue infusion of the product until contamination was ruled out prevented additional cases. The dialysis unit contracted independently with an outside supplier rather than with the main hospital pharmacy. We feel that when pharmaceutical products are being supplied by an outside vendor, It is important that infection Control be aware of this fact and to assure that quakty control lmeasures are adhered to by the supplier.
RISK OF INFECTION ASSOCIATED WITH INSUFFLATION DEVICES USED FOR LAPAROSCOPIC PROCEDURES. R Woodard, BSN,* J. Staszkiewicz, MPH, G. Bostic, MT, J. Band, MD. William Beaumont Hospital, Royal Oak, MI. Objective: Laparoscopic procedures require the installation of gas via an inrufflator to achieve pneumoperitoneum. Some investigators have suggested that a significant risk of nosocomial infection (NI) associated with insuftlation devices (ID) exists since organic and particulate debris has been found on examining these devices. As such. a microbial tilter in the circuit has been recommended to eliminate the potentlai for patient contamination. We assessed the risk of NI associated with laparoscopy and cultured IDS m use to determine if microbial filters should be routinely recommended. Methods: Review of nosocomial infection records for all inpatlents undergoing gynecologlc laparoscopy daring a 3 year period. Microbiologic cultures of IDS and tilters were performed both qualitatively and quantitatively. Results: Of 5 16 patients, only 3 (0.6%) developed a NI. Two patients had wound infections with expected flora (group G strep/E,: S. viridans/E. coli); one patient developed a pelvic abscess. No patient experienced peritonitis. None of the 7 cultured IDS OT filters revealed lnxrobial growth. Conclusion: We failed to demonstrate a link between gynecologic endascopy insuftlation using unfiltered gas and NI. The use of microbial filters for purposes of preventing mfection does no! appear warranted and is costly.
A COMPARISON OF SCRUBSUIT’S BACTERIAL COUNTS WITHiWITHOtiT THE USE OF A COVERGOWN WHEN LEAVING THE OPERATING ROOM (OPERATING ROOM). J. Bontrager, RN, MNA, M. Miller. RN, MS, CIC*. University of Phoenix, Phoenix. AZ. Many costly rituals are being practxed by Operating Room (OR) personnel. One lacking scientific support was the use of a protective, covergown, over the scrubsuit, when leaving the OR setting. The purpose of this descriptive study was to obtain data to either support, or not support, current dress code policies that mandate covergowns. Forty-three OR nursing personnel were ranoomiy selected from two 1a:ge coinInunity/teaching hospitals in Southwestern USA. Using Rodac plates, bacterial cultures were obtained from the right thigh and left shoulder of subjects’ scrubsuits. Used as their own control, subjects were cultured on two consecutive days: day one with a covergown; day two without a covergown. Cultures were obtained, on both days, at the beginnmg and end of the shift. Total bacterial counts were calculated using a pau t-Test for levels of significance. Results revealed that scrubsuits worn outside the OR, without the protection of a covergown, did not show a higher level of bacterial contamination than those using a covergown. Findings, from this study, lhas generated a probable change of dress code policies. AdditIonally, cost-saving for both hospitals 1s projected to be at least $5 - 10 thousand annually.
21,
Number
2
A NEW CARRIER METHOD FOR ASSESSING GERMICIDAL EFFICACY OF DISINFECTANTS. M. Best, BSc, V.S. Springthorpe, MSc, S.A. Sattar, PhD.* University of Ottawa, Ottawa. Ontario, Canada. Lack of harmonization between efficacy tests for different classes of microorganisms has resulted in confusing information for disinfectant users. The available protocols also iack stringency. In our test, a hard surface carrier is contaminated with a standardized mixture of Mycobacwriuni hovis BCG, Sraphylococcus LIUI’~WS. Bacillus si~~rofhr,n~r~pl~,hilus spores, Trichophyton mentagrophyres spores and hepatitis A virus in 5 % fetal bovine serum. Each carrier is contaminated with 10 UL of the mixture and the moculum allowed to dry for90 minutes under ambient conditions. The dried inoculom is then covered with 60 uL of the disinfectant under test for a specitied contact time. Carriers are then placed in 2,940 uL of an eluent/neutralizer and the eiuates assayed separately for the five types of organisms. There was no interference between the organisms in the mixture. In tests with at least 10 products representing major classes of disinfectants, the mixture itself did not significantly mfliience their germicidal action; similar results were obtained by testing each organism individually. Three products (0.4% QAC with 23% HCI, 0.6% sodium hypochlorite and 2% alkaline glutaraldehyde) were consistently effective against all 5 challenge organisms. Povidone-iodme (I % iodine) was effective against all but bacterial spores; tive products were effective against S. (~ww.s only and 3 % hydrogen peroxide was ineffective against all of the test organisms. Our method, therefore, allows for concurrent evaluation of bactericidal, mycobactericidal, fungicidal, virucidal and sporicidal efficacy claims under more realistic conditions than can be obtained using a single organism. This rmethod permits a xmore reliable means of classifying germicides based on their spectrum of activity. The basic method IS also flexible enough to permit tests with either one type of organism or a lmixture different from that listed.
AbStTX2Ct.T
EARLY IDENTIFICATION OF CONTAMINATION PREVENTS OUTBREAK AMONG PATIENTS IN A DIALYSIS UNIT. D. Bingle, RN, BSN, CIC, N. Click, RN, MA, CIC,* L. Wollenberg, RN, BS, CNN, 1. Baird, MD, M. Mishkind, MD. Riverside Methodist Hospitals, Columbus, OH. Intradialytlc Parenteral Nutrition (I.D.P.N.), an intravenous lipid solution, is a nutritional supplement used for hemodialysis patienw 5 to IO percent of our dialysis population receive this supplement. Patients are eligible for this treatment only if they are malnourished and after ail other oral supplements have been unsuccessful. Two hemodialysis patients developed a febrile reaction during Infusion with increasing fever and symptoms after receiving I.D.P.N.. One required hospitalization for evaluation and the other was kept overnight in the Emergency Department observation unit. Blood cultures revealed Serratia marcescens in the first patienr. The second patient’s cultures were negative. Fourteen unused I.D.P.N. bags, all from the same lot number, were tested in our microbiologv-~ lab and grew Acinetobacter calcoaceticos, Serraba marcescens, and Xanthomonas maltouhilia. Further investigation determined that no other oatients had received I.D.P.N., nor was this product being used in other areas if the hospital. The supplier of the nutritional supplement was notitied and subsequently confirmed that the product was contaminated. The company contacted other users of their product after receiving our report and identified simultaneous patient problems in two other facilities which they felt could also have resulted from product contamination. The supplier has prowded no feedback as to the specific cause or quality asswance measures implemented as a result. Further investigatioil was instituted by the Food and Drug Administranon following our notification. Although lipids have previously been implicated in nosocomial bacteremia, this incident was unusual in Ihat it occurred in an outpatient setting. Recognition of symptoms and prompt action on the part of the staff involved to discontinue infusion of the product until contamination was ruled out prevented additional cases. The dialysis unit contracted independently with an outside supplier rather than with the main hospital pharmacy. We feel that when pharmaceutical products are being supplied by an outside vendor, It is important that infection Control be aware of this fact and to assure that quakty control lmeasures are adhered to by the supplier.
RISK OF INFECTION ASSOCIATED WITH INSUFFLATION DEVICES USED FOR LAPAROSCOPIC PROCEDURES. R Woodard, BSN,* J. Staszkiewicz, MPH, G. Bostic, MT, J. Band, MD. William Beaumont Hospital, Royal Oak, MI. Objective: Laparoscopic procedures require the installation of gas via an inrufflator to achieve pneumoperitoneum. Some investigators have suggested that a significant risk of nosocomial infection (NI) associated with insuftlation devices (ID) exists since organic and particulate debris has been found on examining these devices. As such. a microbial tilter in the circuit has been recommended to eliminate the potentlai for patient contamination. We assessed the risk of NI associated with laparoscopy and cultured IDS m use to determine if microbial filters should be routinely recommended. Methods: Review of nosocomial infection records for all inpatlents undergoing gynecologlc laparoscopy daring a 3 year period. Microbiologic cultures of IDS and tilters were performed both qualitatively and quantitatively. Results: Of 5 16 patients, only 3 (0.6%) developed a NI. Two patients had wound infections with expected flora (group G strep/E,: S. viridans/E. coli); one patient developed a pelvic abscess. No patient experienced peritonitis. None of the 7 cultured IDS OT filters revealed lnxrobial growth. Conclusion: We failed to demonstrate a link between gynecologic endascopy insuftlation using unfiltered gas and NI. The use of microbial filters for purposes of preventing mfection does no! appear warranted and is costly.
A COMPARISON OF SCRUBSUIT’S BACTERIAL COUNTS WITHiWITHOtiT THE USE OF A COVERGOWN WHEN LEAVING THE OPERATING ROOM (OPERATING ROOM). J. Bontrager, RN, MNA, M. Miller. RN, MS, CIC*. University of Phoenix, Phoenix. AZ. Many costly rituals are being practxed by Operating Room (OR) personnel. One lacking scientific support was the use of a protective, covergown, over the scrubsuit, when leaving the OR setting. The purpose of this descriptive study was to obtain data to either support, or not support, current dress code policies that mandate covergowns. Forty-three OR nursing personnel were ranoomiy selected from two 1a:ge coinInunity/teaching hospitals in Southwestern USA. Using Rodac plates, bacterial cultures were obtained from the right thigh and left shoulder of subjects’ scrubsuits. Used as their own control, subjects were cultured on two consecutive days: day one with a covergown; day two without a covergown. Cultures were obtained, on both days, at the beginnmg and end of the shift. Total bacterial counts were calculated using a pau t-Test for levels of significance. Results revealed that scrubsuits worn outside the OR, without the protection of a covergown, did not show a higher level of bacterial contamination than those using a covergown. Findings, from this study, lhas generated a probable change of dress code policies. AdditIonally, cost-saving for both hospitals 1s projected to be at least $5 - 10 thousand annually.