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. 2020 Apr 1:15:Doc04.
doi: 10.3205/dgkh000339. eCollection 2020.

Test methods for surface disinfection: comparison of the Wiperator ASTM standard E2967-15 and the 4-field test EN 16615

Anja Jacobshagen  1 , Stefanie Gemein  1   2 , Martin Exner  1   2 , Jürgen Gebel  1   2
Affiliations

Test methods for surface disinfection: comparison of the Wiperator ASTM standard E2967-15 and the 4-field test EN 16615

Anja Jacobshagen et al. GMS Hyg Infect Control. .

Abstract
in English, German

Aim: Two test methods for surface disinfection (phase 2, step 2) - the Wiperator method (ASTM standard E2967-15) and the 4-field test (EN 16615) - were compared using a disinfectant solution based on quaternary ammonium compounds and a ready-to-use alcohol-based wipe. As test organisms, Staphylococcus aureus and Pseudomonas aeruginosa were used. Results: While the 4-field test is a manual method and better reflects the process in practice, with the Wiperator, the wiping process is better controlled because it is an automated procedure. A comparison of the effects of both methods on the target log10-reduction of S. aureus and P. aeruginosa indicates a statistically significant difference between the two test methods (Mann-Whitney U-Test. S. aureus: 0 (Umin)<4 (U crit ); n 1=8, n 2=8, p=0.001; 2-sided. P. aeruginosa: 24 (Umin)<26 (Ucrit); n 1=11, n 2=10, p=0.025, 2-sided). In addition, the results indicate that the wipe used has a major influence on the success of the disinfection process. Discussion: Both methods are suitable for efficacy studies of surface disinfectants, yet they differ in some aspects. Additionally our data indicate a statistically significant difference between the two test methods. Conclusion: Efficiency testing of surface disinfection is a complex process that depends on many different parameters. Since the 4-field test better reflects the practice, it makes sense to stick to this test procedure, taking into account that the EN 16615 was approved by CEN TC 216 in 2015 after method validation ring trials.

Ziel: Zwei praxisnahe Testmethoden (Phase 2, Stufe 2) für die Flächendesinfektion – die Wiperator-Methode (ASTM-Standard E2967-15) und der 4-Felder-Test (EN 16615) – wurden verglichen. Als Prüfprodukte wurden eine Desinfektionslösung auf Basis von quartären Ammoniumverbindungen und ein gebrauchsfertiges Desinfektionstuch auf Basis von Alkoholen verwendet. Ergebnisse: Während es sich beim 4-Felder-Test um eine manuelle Methode handelt, die die Praxis besser widerspiegelt, ist die Wiperator-Methode ein maschinelles Verfahren mit einem kontrollierteren Wischvorgang. Im Vergleich der Wirkungen beider Verfahren auf die Zielgröße log10-Reduktion von S. aureus und P. aeruginosa anhand zweier unabhängiger Stichproben ergab sich zwischen beiden Testverfahren ein statistisch signifikanter Unterschied (Mann-Whitney U-Test: S. aureus: 0 (Umin)<4 (Ukrit); n 1=8, n 2=8, p=0,001; 2-seitig. P. aeruginosa: 24 (Umin)<26 (Ukrit); n 1=11, n 2=10, p=0,025; 2-seitig. Die Ergebnisse zeigen ferner, dass das verwendete Tuch einen Einfluss auf den Erfolg des Desinfektionsprozesses hat. Diskussion: Der 4-Felder-Test und die Wiperator Methode sind standardisierte Verfahren und eignen sich für Wirksamkeitsuntersuchungen von Flächendesinfektionsmitteln, unterscheiden sich aber in einigen Aspekten: Verfahrensart (manuell – automatisiert), Wischvorgang (horizontal – punkförmig kreisend), Standardtuch (SCA-Wipe – J-cloth), Dauer des Wischvorgangs, Größe des Inokulums und Testfläche. Zusätzlich zeigen unsere Daten einen statistisch signifikanten Unterschied zwischen den beiden Testmethoden auf.Schlussfolgerung: Die Wirksamkeitsprüfung von Flächendesinfektionsmitteln ist ein komplexer Prozess, der von verschiedenen Parametern abhängt. Da der 4-Felder Test die Einflussfaktoren der praktischen Anwendung im Testdesign berücksichtigt, ist es sinnvoll, an diesem Prüfverfahren festzuhalten. Zudem wurde der 4-Felder Test vom CEN TC 216 im Jahr 2015 nach Ringversuchen zur Methodenvalidierung als EN 16615 genehmigt.

Keywords: 4-field test; Wiperator; disinfectant wipe; surface disinfection.

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Figures

Table 1
Table 1. Comparison of 4-field test and Wiperator method
Table 2
Table 2. Test suspension and recovery of CFU of S. aureus and P. aeruginosa (n=3)
Table 3
Table 3. Mean log10 reduction of S. aureus and P. aeruginosa by exposure to a disinfectant solution based on QAC at 2% with a SCA-wipe with both the 4-field test and Wiperator method at a contact time of 15 min (n=3)
Table 4
Table 4. Mean log10 reduction of S. aureus by exposure to a disinfectant solution, QAC at 1%, 15 min contact time using SCA-wipe and J-cloth in combination with 4-field test and Wiperator method (n=3)
Table 5
Table 5. Mean log10 reduction of S. aureus and P. aeruginosa by exposure to an alcohol-based rtu-wipe with the 4-field test and Wiperator method at 5 min contact time (n=3)
Table 6
Table 6. Test-statistics of Mann-Whitney-U-Test comparing log10 reduction of S. aureus and P. aeruginosa after exposition to WSH at 5 and 15 min with the 4-field test and Wiperator method
Table 7
Table 7. Volume output of J-cloth, SCA-wipe and rtu-wipe using the 4-field test and Wiperator method (n=3)
Figure 1
Figure 1. Diagram of the 4-field test [10] showing test surface (20x50 cm) with four test fields (5x5 cm) and stipulated wiping route of the wiping cloth. a=50 cm, b=20 cm, c=5 cm, d=10 cm, e=5 cm; the f and g dimensions of the unitary weight were at least 8.6 cmx12.1 cm, respectively, the block weighs 2.5 kg. The wiped area includes fields 1–4 with the turnaround at test field 4. Test field one is contaminated [10].
Figure 2
Figure 2. Wiperator [13]
See this image and copyright information in PMC

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References

    1. Dettenkofer M, Block C. Hospital disinfection: efficacy and safety issues. Curr Opin Infect Dis. 2005 Aug;18(4):320–325. doi: 10.1097/01.qco.0000172701.75278.60. - DOI - PubMed
    1. Boyce JM. Environmental contamination makes an important contribution to hospital infection. J Hosp Infect. 2007 Jun;65(Suppl 2):50–54. doi: 10.1016/S0195-6701(07)60015-2. - DOI - PubMed
    1. Gebel J, Exner M, French G, Chartier Y, Christiansen B, Gemein S, Goroncy-Bermes P, Hartemann P, Heudorf U, Kramer A, Maillard JY, Oltmanns P, Rotter M, Sonntag HG. The role of surface disinfection in infection prevention. GMS Hyg Infect Control. 2013;8(1):Doc10. doi: 10.3205/dgkh000210. - DOI - PMC - PubMed
    1. Russotto V, Cortegiani A, Raineri SM, Giarratano A. Bacterial contamination of inanimate surfaces and equipment in the intensive care unit. J Intensive Care. 2015;3:54. doi: 10.1186/s40560-015-0120-5. - DOI - PMC - PubMed
    1. Dancer SJ. Dos and don'ts for hospital cleaning. Curr Opin Infect Dis. 2016 Aug;29(4):415–423. doi: 10.1097/QCO.0000000000000289. - DOI - PubMed