Introduction: Part 1 of this two-part series describes the use of hydrogen peroxide as a fumigant and compares it with other fumigants on the market. Technical requirements are outlined while considering physical and biological limitations of the system. This second part focuses primarily on the use of process controls to verify and validate hydrogen peroxide fumigations. Finally, a model encompassing the entire fumigation process is presented. Methods: Part 2 of the series focuses on the authors' long-time personal experiences in room and filter fumigation using various fumigation systems and is supplemented with relevant literature searches. Results: The reader is introduced to the planning and implementation of fumigation process validations. Biological indicators help users develop safe and efficient processes. Chemical indicators can be used as process controls, while measuring physical parameters will help avoid condensation of hydrogen peroxide. How many biological and chemical indicators and what type should be applied for cycle development are additionally explained. Discussion: It is important to consider numerous technical requirements when planning to implement hydrogen peroxide fumigation at an institution. Also, considerable thought needs to go into the verification and validation of the fumigation process. Conclusions: Part 1 of this series presents an overview of different fumigation systems based on hydrogen peroxide on the market and their technical requirements. Part 2 focuses on validation and verification of hydrogen peroxide fumigation while considering the entire fumigation process. The two parts together will serve users as a guide to establishing hydrogen peroxide fumigations at their facilities.

Introduction: When working with pathogens in laboratories, animal or production facilities, and even hospitals, the potential need for room fumigation for decontamination purposes must be taken into consideration. Questions regarding the choice of fumigant, technical aspects of the room, its ventilation, the fumigation system to be used, and other issues will arise and will have to be addressed. Methods: This article is based on literature searches and was compiled using the authors' long-time personal experience in room and filter fumigation using various fumigation systems. Results: The article can be used as a guide to establish an effective fumigation system in a laboratory or an animal facility setting and may be adapted for use in hospitals. Different systems for hydrogen peroxide fumigation on the market are presented. Also, technical aspects are discussed. Discussion: Hydrogen peroxide is used in various forms for fumigation of rooms, equipment, and filters. Regardless of the individual limitations of these forms, hydrogen peroxide is a versatile fumigation method. However, it is important to consider numerous technical requirements when planning to implement hydrogen peroxide fumigation at an institution. Conclusions: Subsequent to the present overview of different fumigation systems based on hydrogen peroxide on the market and their technical requirements, part 2 of this article will focus on validation and verification of hydrogen peroxide fumigation while considering the entire fumigation process. The two parts together will serve users as a guide to establishing hydrogen peroxide fumigations at their facilities.

Introduction: Formaldehyde is still the method of choice for fumigation of rooms and HEPA filters at high- and maximum-containment facilities because of its proven track record and low cost. However, formaldehyde has been shown to be carcinogenic and should ideally be replaced by other, less hazardous methods. This change has in part been hampered by the relatively high cost of alternative methods. Methods: Here, we provide examples of room fumigations using aerosolized hydrogen peroxide showing not only that it can be used economically but also that it is a versatile method and may be used under circumstances not normally suited for fumigation. Results and Discussion: Four examples of fumigation setups are presented that illustrate the versatility, ease of use, and adaptability of aerosolized hydrogen peroxide as a fumigant. In addition, we demonstrate that aerosolized hydrogen peroxide passes through HEPA filters in biological safety cabinets and individually ventilated cage racks. Conclusions: Considering that the fumigation method presented here is simple and highly effective, we expect it to serve as a relatively cost-effective alternative to formaldehyde fumigation for disinfecting potentially contaminated rooms and surfaces.

Foot-and-mouth disease virus (FMDV) is a highly pathogenic and transmissible disease of cloven-hoofed animals with outbreaks having severe impact on livestock production. FMDV is generally studied in high- to maximum-containment laboratories to prohibit the virus from escaping into the environment. Formaldehyde is still the method of choice for fumigation of rooms and HEPA filters at FMDV facilities. However, formaldehyde, having been shown to be carcinogenic, should ideally be replaced by other, less hazardous methods. Here we show validation results for two different hydrogen peroxide fumigation methods and compare these to formaldehyde fumigation. The results identify hydrogen peroxide as a suitable alternative to formaldehyde fumigation.

Room fumigation has traditionally been performed using formaldehyde. However, recently new methods have been developed, including vaporized hydrogen peroxide (VHP). VHP offers a number of advantage...

International standards as well as national regulations often require the incorporation of HEPA filters in the exhaust of BSL-3 (unless work with non-airborne organisms is performed—Swiss Containment Ordinance [Federal Council, 2012]) and certainly BSL-4 laboratories (single HEPA filter on supply and double HEPA filter on exhaust). These may need to be decontaminated from time to time, for example prior to filter integrity testing (protection of the testing equipment in case filters or seals are damaged and thus leaking) or when exchanging filters (bag-in/bag-out may offer an alternative or an additional safety measure, respectively). However, HEPA filter housings are not generally equipped with sample ports that allow for placement of indicators to confirm a successful fumigation process. Additionally, a site-specific risk assessment concluded that since the filter boxes are situated in an area deemed to remain non-contaminated at all times (HEPA filter floor above laboratory suites), indicators may not be placed inside the filter housings as opening them prior to fumigation would open containment and thus pose a threat to the people working on the filter boxes as well as to the environment. In this article the authors describe the use of the IndicatorSafe, a simple and cheap solution to the above-mentioned problem. Placing the IndicatorSafe in the return line following the filter housing was shown to be an efficient alternative when fumigating filter housings with vaporized hydrogen peroxide (VHP), as shown during the validation of filter housing fumigation cycles, and may likely be adapted to other fumigation methods on the market.

Choosing the appropriate suit for a BSL-4 laboratory is of vital importance to create a safe work environment within such a facility. The suit has to provide protection for the wearer and be compat...

Human adenovirus vectors have been used widely as gene delivery vehicles. However, one major problem related to the use of these vectors is the presence of a preexisting immunity to human adenoviruses in a majority of the population. We (1–3) and others (4–6) are therefore developing nonhuman adenoviruses as gene therapy vectors. Among these, vectors derived from the ovine adenovirus isolate 287 (OAV) have been found to deliver genes with high efficiency to several mammals. This chapter introduces this novel vector system and describes the methodology of generating OAV vectors.KeywordsExpression CassetteRecombinant VirusHuman AdenovirusShuttle PlasmidGene Therapy VectorThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Within the last two decades, various vectors based on human viruses have been developed as gene transfer vehicles for gene therapy applications and vaccination. However, one yet unresolved problem connected to the use of viral vectors in humans is the pre-existing immunity to most of these vectors in the vast majority of the population which can result in impaired gene transfer efficiency and increased secondary toxicity. One approach to solve this problem is the development of recombinant viruses of non-human origin as vectors for gene transfer. The major rationale for using such vectors is the avoidance of vector neutralization by pre-existing antibodies directed against the virus on which the vector is based. Use of vectors based on non-human viruses may therefore allow the use of lower initial vector doses to achieve efficient gene transfer. Side-effects caused by interactions between vectors derived from human viruses with a primed immune system or with blood components could also be reduced. Furthermore, these vectors might show new cell type tropisms and could therefore infect tissue and organs that are not accessible to current viral vectors. This review outlines some of the problems inherent in the human origin of current viral vectors and describes features and progress with non-human adenovirus and baculovirus-derived vectors that may provide alternatives.