gms | German Medical Science

GMS Hygiene and Infection Control

Deutsche Gesellschaft für Krankenhaushygiene (DGKH)

ISSN 2196-5226

Zum Stand der Viruzidie-Prüfung in Deutschland

Testing virucidal activity in Germany: an update

Original Contribution

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GMS Krankenhaushyg Interdiszip 2007;2(1):Doc04

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/journals/dgkh/2007-2/dgkh000037.shtml

Published: September 13, 2007

© 2007 Steinmann et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Abstract

Several chemical disinfectants have been tested in a quantitative suspension test for virucidal activity as per the test method devised by the German Society for Control of Viral Diseases (DVV) and the former German Federal Health Office (BGA, now the Robert Koch-Institute, RKI) drafted in 1982. The introduction of the term “limited virucidal activity” (effective against enveloped viruses) in addition to the existing term “virucidal activity” (effective against non-enveloped and enveloped viruses) by the Robert Koch Institute has led to enormous expansion of these tests. However, there are no definitions to determine when a disinfectant with virucidal activity as apposed to a disinfectant with limited virucidal activity is to be used. The 1982 guideline was recently revised, while bringing it into line to reflect the latest insights. The BSA challenge has been omitted, while other controls such as verification of the sustained effect and interference control with which cell susceptibility is verified have been incorporated. A new requirement is that all tests be conducted in at least two independent batches, followed by biometric evaluation of the test results with calculation of the 95% confidence interval. The new guideline differs from DIN EN 14476, which in the meantime has been published in Europe, in that it does not feature the statistics now required. This guideline has introduced the parvovirus for chemothermal inactivation as well as the Bovine Viral Diarrhea Virus (BVDV) as test virus for the limited virucidal activity (in addition to vaccinia virus which serves as a surrogate virus for hepatitis C virus – HCV). A second important example is Feline Calicivirus (FCV), which serves as a surrogate for noroviruses. In the USA efficacy testing of surface disinfectants against noroviruses is conducted with FCV in a carrier test (practice-related test). The third surrogate virus is the Duck Hepatitis B Virus (DHBV), used as a surrogate for hepatitis B virus (HBV).

Today evaluation of the virus-inactivating properties is often conducted in parallel with bacteriological evaluation, so as to avoid any subsequent surprises in respect of viral efficacy. The DVV has failed over the past 24 years to formulate guidelines for practice-oriented tests. The future challenge is to define these as quickly as possible. Here similar approaches should be used for e.g. process challenge devices, challenge, exposure time as for bacteriological evaluation, so that the resultant application recommendations have equivalent status. The term “limited virucidal activity” should be expanded to disinfectant efficacy at European level.

Zusammenfassung

Viele chemische Desinfektionsmittel sind in einem quantitativen Suspensionsversuch auf Virus-Wirksamkeit nach der Prüfmethode der Deutschen Vereinigung zur Bekämpfung der Viruskrankheiten e.V (DVV) und des Bundesgesundheitsamtes (BGA, heute Robert Koch-Institut, RKI) von 1982 untersucht worden Die Einführung des Begriffes „begrenzt viruzid“ (wirksam gegenüber behüllten Viren) zusätzlich zu dem bereits bestehenden Begriff „viruzid“ (wirksam gegen unbehüllte und behüllte Viren) durch das Robert Koch-Institut hat diese Prüfungen enorm ausgeweitet. Es fehlen allerdings die Definitionen, nach denen ein viruzides bzw. begrenzt viruzides Desinfektionsmittel eingesetzt werden soll. Die Richtlinie von 1982 ist kürzlich überarbeitet und neuen Erkenntnissen angepasst worden. Weggefallen ist die BSA-Belastung, aufgenommen wurden weitere Kontrollen wie die Nachwirkungs- und die Interferenzkontrolle, mit der die Zellsuszeptibilität überprüft wird. Neu ist die Forderung, alle Versuche in mindestens zwei unabhängigen Ansätzen durchzuführen und die sich anschließende biometrische Auswertung der Untersuchungsergebnisse mit Berechnung des 95% Konfidenz-Intervalls. Die jetzt notwendige Statistik unterscheidet die neue Leitlinie von der mittlerweile in Europa veröffentlichten DIN EN 14476. In dieser Leitlinie ist das Parvovirus für die chemothermische Inaktivierung eingeführt worden, sowie auch das Bovine Viral Diarrhea Virus (BVDV) als Prüfvirus für die begrenzte Viruzidie (neben Vakziniavirus als Surrogatvirus für Hepatitis C Virus (HCV). Ein zweites wichtiges Beispiel ist das Feline Calicivirus (FCV), als Surrogat für die Noroviren. Flächendesinfektionsmittel können in den USA mit dem FCV auf Wirksamkeit gegenüber den Noroviren in einem Carrier-Versuch (praxisnaher Versuch) überprüft werden Das dritte Surrogatvirus ist das Duck Hepatitis B Virus (DHBV), als Ersatz für das Hepatitis B Virus (HBV).

Heute geschieht in vielen Fällen die Evaluierung der virusinaktivierenden Eigenschaften parallel zu den bakteriologischen Prüfungen, um später Überraschungen hinsichtlich der Virus-Wirksamkeit zu vermeiden. Die DVV hat es in den letzten 24 Jahren versäumt, Prüfrichtlinien für praxisnahe Untersuchungen zu entwickeln. Sie möglichst rasch zu definieren, stellt die Herausforderung für die Zukunft dar. Dabei sollte in Punkten wie Prüfkörper, Belastung, Einwirkzeiten möglichst parallel zur bakteriologischen Evaluierung gearbeitet werden, damit die resultierenden Anwendungempfehlungen gleichberechtigt nebeneinander stehen. Der Begriff „begrenzt viruzid“ für die Desinfektionsmittel-Wirksamkeit sollte nach Europa getragen werden.


Text

In addition to vaccinations, isolation and cohort formation, disinfection measures play a pivotal role in the hospital setting and in medical practice in the interruption of viral chains of infection. For that reason chemical disinfectants must be endowed with virus-inactivating properties, and this must be demonstrated in corresponding tests.

Several of the chemical disinfectants presently available on the German market have been tested in a quantitative suspension test for virucidial activity as per the test method devised by the German Society for Control of Viral Diseases (DVV) and the former German Federal Health Office (BGA, now the Robert Koch-Institut, RKI) drafted in 1982 [1], [2].The test viruses used are the Elstree vaccinia strain, poliovirus vaccination strain type I, LSc-2ab strain, adenovirus type 5 and polyomavirus (formerly, papovavirus) SV 40 strain 777. The introduction of the term “limited virucidal activity” (effective against enveloped viruses; test viruses: Elstree vaccinia strain and Bovine Viral Diarrhea Virus strain NADL) in addition to the existing term “virucidal activity” (effective against non-enveloped and enveloped viruses) by the Robert Koch Institute [3] has led to enormous expansion of these tests in the past year and a half. However, at present there are no definitions to determine when a disinfectant with virucidal activity as apposed to a disinfectant with limited virucidal activity is to be used.

The 1982 guideline was recently revised by the specialist committee “Viral Disinfection” at the DVV under the direction of Prof. Rabenau, while bringing it into line to reflect the latest insights [4]. The version of the newly named guideline (name changed for legal reasons) first published in December 2005 by the DVV and RKI dates back to 15 June 2005.

The most important differences relate to the omission of the BSA load as well as the incorporation of other controls such as verification of the sustained effect and interference control with which cell susceptibility is verified. A new requirement is that all tests be conducted in at least two independent batches, followed by biometric evaluation of the test results with calculation of the 95% confidence interval. The new guideline differs from DIN EN 14476, which in the meantime has been published in Europe and does not call for biometric evaluation, in particular in respect of the statistical calculations now specified [5]. This guideline has introduced parvovirus for chemothermal inactivation. For the first time this guideline also cites Bovine Viral Diarrhea Virus (BVDV) as test virus for the limited virucidal activity (in addition to vaccinia virus), which serves as a surrogate virus for hepatitis C virus (HCV). The approach taken here is to introduce a virus that is pathogenic to animals for testing products intended for use in human medicine since at present no corresponding human-pathogenic test viruses can be adequately grown in cell culture. In the USA, too, BVDV is also being used in the meantime in everyday tests by the Environmental Protection Agency (EPA) as a surrogate for HCV (http://www.epa.gov/oppad001/pdf_files/hepcbvdvpcol.pdf). A second important example is Feline Calicivirus (FCV), which serves as a surrogate for noroviruses. In the USA efficacy testing of surface disinfectants against noroviruses is conducted with FCV in a carrier test (practice-related test; http://www.epa.gov/oppad001/pdf_files/fcv2_confirm_surf_pcol.pdf). Even evaluation of swabs for efficacy against noroviruses is carried out on the basis of an EPA protocol (http://www.epa.gov/oppad001/pdf_files/fcv3_towel_ini_pcol.pdf). The third very important surrogate virus is the Duck Hepatitis B Virus (DHBV), used as a surrogate for hepatitis B virus (HBV). The committee “Viral Disinfection” at the DVV in Germany is planning to appoint DHBV as test virus, once a multicenter trial has been successfully completed at a later date. Here, too, the USA is ahead of us. There investigation results obtained with DHBV (http://www.epa.gov/oppad001/pdf_files/hbvprotocol.pdf) can already be extrapolated to HBV.

Often today, evaluation of virus-inactivating properties is already a component of development activities in parallel to bacteriological tasks following a situation whereby in the past many chemical disinfectants were optimized only for efficacy against bacteria and fungi, giving rise to later surprises in respect of viral efficacy when testing the products available on the market. However, over the past 24 years the DVV has failed to formulate guidelines for practice-oriented tests since in the last analysis quantitative suspension tests have merely an orientational character and the application recommendations must be tailored to the results of practical tests.

Here it should be borne in mind that in many respects, e.g. process challenge devices, challenge, exposure times, similar approaches are used as for bacteriological evaluation so that the resultant application recommendations have equivalent status.

Top priority for the time being must be accorded to the formulation of practice-oriented test guidelines, and attempts must be made to achieve this as soon as possible. This will give the user of chemical disinfectants a greater sense of security in his efforts to interrupt viral infection chains in the hospital and medical practice and to provide better protection to patients and staff. Surrogate viruses can play an important role in testing and be integrated into test guidelines. Once the corresponding indications have been defined, the term “limited virucidal activity” should be expanded to disinfectant efficacy at European level.


Curriculum Vitae

Dr. Jochen Steinmann

Figure 1 [Fig. 1]

Associate and technical-scientific head of MikroLab GmbH (Laboratory for Applied Microbiology) in Bremen.

Jochen Steinmann was reading Microbiology at the Christian-Albrecht University, Kiel (CAU), and started out after his dissertation as scientific assistant at the Institute for Hygiene (later: Department for Medicinal Microbiology) of the CAU in 1974. Main focus of his research at that time is improvements of the virological diagnostics.

After changing to head of the Clinical Virology at that Federal Institute for Hygiene Bremen in 1981 he was engaged in nosocomial virus infections, especially of rota- and enterovirus infections in pediatrics. The identification and prevention of virus infections in hospitals are henceforth his scientific main interest. A publication on hygienical hand disinfection has been rewarded with the Düsseldorf Hygiene Award in 1996. At the beginning of 2002 he left the civil service and founded the MikroLab GmH in Bremen. MicroLab GmbH understands itself as a service organisation for the chemical-pharmaceutical industry on all issues of applied virology.

Jochen Steinmann is a member of numerous scientific associations and German and international committees dealing with questions of virus inactivation.

Prof. Dr. rer. nat. habil. Manfred H. Wolff

Figure 2 [Fig. 2]

Director of the Chair for Microbiology and Virology, University Witten/Herdecke.

Manfred H. Wolff was reading biology at the Rheinische Friedrich-Wilhelm University Bonn, but wrote his dissertation at the Institute for Medical Microbiology and Immunology (Virus Department) of the University Bonn and gets his doctors degree for Dr. rer. nat. Here he staid as Scientific Assistant. In 1975 he moved to USA for one year (Department of Microbiology, Committee on Virology, University of Chicago) but moved back to Bonn, where he finally decided for Virology. In 1981 he habilitated at the Medicinal Faculty of the Bonn University and was appointed professor in 1982. He received the call to the Chair of Microbioloy and Virology of the University Witten/Herdecke in 1986.

His scientific focus is on the Varicella-Zoster-Virus, its pathogenesis and molecular-scientific tests for transcription-regulation. Besides that, he deals with problems of virus infections. He is a member of numerous scientific associations and boards.


References

1.
Richtlinien des Bundesgesundheitsamtes und der Deutschen Vereinigung zur Bekämpfung der Viruskrankheiten e.V. zur Prüfung von chemischen Desinfektionsmitteln auf Wirksamkeit gegen Viren. Bundesgesundheitsblatt. 1982;25:397-8.
2.
Kommentar zur Richtlinie des Bundesgesundheitsamtes und der Deutschen Vereinigung zur Bekämpfung der Viruskrankheiten e.V. zur Prüfung von chemischen Desinfektionsmitteln auf Wirksamkeit gegen Viren. Bundesgesundheitsblatt. 1983;26:413-4.
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Anonym. Prüfung und Deklaration der Wirksamkeit von Desinfektionsmitteln gegen Viren. Stellungnahme des Arbeitskreises Viruzidie beim Robert Koch-Institut (RKI) sowie des Fachausschusses Virusdesinfektion der Deutschen Gesellschaft zur Bekämpfung der Viruskrankheiten (DVV) und der Desinfektionsmittelkommission der Deutschen Gesellschaft für Hygiene und Mikrobiologie (DGHM). Bundesgesundheitsblatt. 2004;47(1):62-6.
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Anonym. Leitlinie der Deutschen Vereinigung zur Bekämpfung der Viruskrankheiten (DVV) e. V. und des Robert Koch-Instituts zur Prüfung von chemischen Desinfektionsmitteln auf Wirksamkeit gegen Viren in der Humanmedizin (Fassung vom 15. Juni 2005). Hyg Med. 2005;30:460-7.
5.
E DIN EN 14476. Chemische Desinfektionsmittel und Antiseptika - Quantitativer Suspensionsversuch Viruzidie für in der Humanmedizin verwendete Desinfektionsmittel und Antiseptika - Prüfverfahren und Anforderungen (Phase2/Stufe1). Berlin, Wien, Zürich: Beuth Verlag; 2005.