FY2016 HPAI Response Using Heat Treatment For Virus .

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FY2016 HPAI ResponseUsing Heat Treatment for VirusEliminationFebruary 19, 2016BACKGROUNDTraditionally, cleaning with subsequent application of wet disinfectant has been used to eliminatehighly pathogenic avian influenza (HPAI) virus on Infected Premises. However, dry cleaning andheating of houses (also called heat treatment) is now an accepted method of disinfection/viruselimination where feasible. Heat treatment is not a “new” approach, but it has re-emerged as atested, cost-effective option.1Any disinfectant method(s) selected should consider the characteristics of the premises/housesand other factors which may impact the effectiveness of the virus elimination activities. Heattreatment may not be appropriate in all situations. The cleaning and disinfection options selectedand implemented must be included as part of the approved cleaning and disinfection plan andapproved by State Animal Health Officials and APHIS.DRY CLEANINGBefore the virus elimination/disinfection step, an Infected Premises must undergo dry cleaning.Dry cleaning must be conducted prior to heat treatment or other disinfection options. For moreinformation, see Cleaning and Disinfection Basics.By definition, dry cleaning involves the removal of any gross contamination and organic material(e.g., soil, manure, bedding, feed, eggs, feathers) from all production areas and equipment.Shovels, manure forks, brooms, and brushes should be used to sweep, scrape, and removeorganic material and debris from surfaces.While the removal of all organic material is ideal, this may not be a realistic objective for everyInfected Premises. The following steps provide general guidance for dry cleaning; if there are anyquestions regarding dry cleaning of premises, please contact Incident Command for furtherguidance.1. Minimize remaining organic material; in most cases the original surface should be visibleon floors, walls, and fans (e.g., wood or metal)2. No more than 0.25 inches of organic material should be present on any given surface thatwill come into contact with poultry when restocking occurs.3. No more than 0.25 to 0.5 inches of organic material should be present on any surface thatis not accessible to restocked poultry.4. Priority is to ensure all wet organic material is dry or removed. This is likely to be the mostrecent deposits to the site and thus, the most likely to have infectious material.5. Ensure all remaining organic material dries; i.e., if weather has made material damp orwet, allow to dry naturally or remove. Drying is an effective way to destroy/eliminate thevirus.6. The primary disposal method for poultry litter on the floor or ground is composting, withlandfill, burial, or other options.7. For situations with stored manure or manure pits, State and APHIS officials will make adisposal determination with the Incident Management Team.1Heat treatment was presented as an option for inactivating AI viruses in 1986; Halvorson, David A. “Avian Influenza-A MinnesotaCooperative Control Program.” Proceedings of the Second International Symposium on Avian Influenza, Georgia Center forContinuing Education, University of Georgia, Athens, Georgia. Sept 3–5, 1986. Symposium on Avian Influenza, US Animal HealthAssociation.1

Once dry cleaning is complete and the facility has been inspected and approved, as needed,disinfection can be performed by heat treatment of the barns/houses. This procedure involveswhole house heating, carefully balancing time, temperature, and environmental factors that mayimpact virus elimination.HEAT TREATMENTHeating barns/houses that have been dry cleaned is often the most efficient way to disinfectpoultry houses and destroy/eliminate HPAI virus. Current policy guidance (provided in Cleaningand Disinfection Basics) states that barns/houses must be heated to between 100 F and 120 Ffor a total of 7 days; with at least 3 consecutive days (of the 7 days) of heating continuously towithin this temperature range. USDA APHIS does not suggest that all methods of disinfection areequivalent in terms of destroying or eliminating living organisms; however, the scientific evidenceat this time demonstrates that heat treatment is effective at eliminating HPAI virus. To-date,application of heat treatment following this guidance has successfully eliminated HPAI virus. Ifnew scientific information becomes available, this guidance may be adapted. Temperaturesshould generally not exceed 120 F to avoid damage to fixtures and structures.100-120 F for a Total of7 days At least 3 consecutive days of drying and heatingmust be at this specified temperature (maintaininga temperature within this range).Examples of Heat TreatmentIn the first example, the premises is able to keep the barn at the specified temperature (between100 F and 120 F) for seven straight days. This fulfills the requirement for a total of 7 days attemperature as well as 3 consecutive days at temperature:Example 1. SuccessfulHeat TreatmentHeat Treatment Begins Day 1 – 100 F Day 2 – 100 F Day 3 – 110 F Day 4 – 105 F Day 5 – 110 F Day 6 – 115 F Day 7 – 115 FHeat Treatment EndsIn the second example, the premises experiences a severe cold wave at the same time as aheater breakdown. This premises is able to repair the heater quickly, but the barn temperatureslips below 100 F for 2 days. In this case, the premises must heat the barn for a longer period tofulfill the requirement of 7 total days at temperature and 3 consecutive days at temperature.2

However, the premises can count that first day at temperature towards the 7 total dayrequirement.Example 2. SuccessfulHeat TreatmentHeat Treatment Begins Day 1 – 100 F Day 2 – 95 F Day 3 – 95 F Day 4 – 100 F Day 5 – 110 F Day 6 – 115 F Day 7 – 110 F Day 8 – 105 F Day 9 – 100 FHeat Treatment EndsIf a premises cannot meet the 7 day total requirement (between 100 and 120 F) in addition to the3 consecutive day requirement at temperature for an extended period of time (greater than 2weeks or as recommended by Incident Command), the premises may need to consider analternative means of disinfection, in discussion with State and APHIS officials.USE & POSITIONING OF SENSORS/THERMOMETERSWhen heat treatment is used for virus elimination, temperature monitoring is required. At aminimum, there should be three thermometers placed in each barn (at each end and in thecenter). Additional sensors, particularly in larger facilities, are recommended. Preferably, sensorsshould transmit the temperature remotely and continuously to ease the burden of monitoring. In allcases, sensors/thermometers should be checked and in good working order prior to use. In turkeyhouses, sensors should be placed between 4 and 6 feet high. In layer houses, sensors should beplaced at the cage level. To avoid an artificially high temperature reading, do not place sensorsnear or directly on an individual heat source.DOCUMENTATIONIf heat treatment is used for virus elimination, it is critical to document the barns/houses reachingand maintaining appropriate temperatures. Incident Command can provide logs fordocumentation; records should indicate the temperature of the house at least two to four times perday for the seven day period. These logs should be uploaded in the Emergency ManagementResponse System (EMRS).ENVIRONMENTAL SAMPLINGIn addition to cleaning and disinfection steps, including heat treatment, environmental sampling isconducted at the completion of virus elimination activities. Taking environmental samples andtesting them for HPAI provides additional confidence that virus elimination activities have beensuccessful. Please see Post C&D Sampling Guide for more information.3

EVIDENCE SUPPORTING THE USE OF HEAT TREATMENTIt is well established that HPAI viruses can survive in cool and moist conditions, particularly whenorganic material is present.2 The World Organization for Animal Health (OIE)3 along with otherresearch4 has demonstrated that avian influenza (AI) viruses can live for extended periods inwater, liquid feces, and in soil at ambient temperatures (see Table 1). In particular, evidencesuggests that both dry and wet feces can harbor the virus for extended periods of time. One studyof H5N1 suggested that virus can remain infectious in both wet and dry feces for 18 hours, evenwhen the temperature is raised to 107.6 F.5Conversely, in the absence of moisture and at high temperatures, AI viruses can be quicklyinactivated. At 107.6 F, the virus was inactivated in both wet and dry feces after 24 hours; at98.6 F, virus was no longer infectious after 30 hours. HPAI virus also does not survive extendedperiods of time on surfaces that are not contaminated with organic matter.For heat treatment to be an effective virus elimination step, it remains critical to ensure 1) organicmaterial is removed as prescribed above and 2) barns are heated to the recommended time andtemperature, with adequate monitoring and documentation. Heat treatment is a valuable and costeffective option to eliminate virus from Infected Premises. 6Where Heat Treatment is Not EffectiveAs also seen in Table 1, heat treatment is not effective at deactivating HPAI virus in dried eggwhite, even at extremely high temperatures.7 Evidence from the 2014–2015 HPAI outbreakconfirms that HPAI viruses can live for extended periods in the presence of dried eggwhite/albumen, including on egg belts or elsewhere that this material may be found (e.g., on thefloor underneath an egg belt).For egg belts, two options are available: (1) the egg belt can be removed, disinfected with anapproved disinfectant, dried, and that belt may be replaced or (2) the egg belt can be disposed of,through approved mechanisms, and replaced with a new egg belt. The most cost effective optionshould be implemented.It is critical that where dried egg white (egg albumen) is present, these areas are disinfected withan approved disinfectant (if heat treatment is applied to the rest of the premises). In some cases,it may be necessary to consider other methods of disinfection for the entire barn/house.David E. Swayne, 2008. “Epidemiology of Avian Influenza in Agricultural and Other Man-Made Systems,” in David E Swayne, ed.,Avian Influenza. Ames, IA: Blackwell Publishing.3World Organization for Animal Health (OIE) 2009, OIE Technical Disease Card.4M. Ellin Doyle et al., 2007. “Destruction of H5N1 Avian Influenza Virus in Meat and Poultry Products.” UW -FRI Briefings.https://fri.wisc.edu/files/Briefs File/FRI Brief H5N1 Avian Influenza 8 07.pdf.5Baleshwari Kurmi et al., 2013. “Survivability of Highly Pathogenic Avian Influenza H5N1 Virus in Poultry Faeces at DifferentTemperatures.” Indian J. Virol. 24(2):272-277. DOI 10.1007/s13337-013-0135-2.6Heat treatment has been used effectively to eliminate other diseases, such as infectious laryngotracheitis in broiler houses,demonstrating some industry knowledge and familiarity with this approach: see Giambrone, J.J. et al., 2008. “ManagementPractices to Reduce Infectious Laryngotracheitis Virus in Poultry Littler.” J. Appl. Poult. Res. 17:64–68.7For more information, also see Swayne, D.E. & Beck, J.R. 2004. “Heat inactivation of avian influenza and Newcastle disease virusesin egg products.” Avian Pathology. 33(5):512-518. DOI 10.1080/03079450400003692.24

Table 1. Avian Influenza Viral PersistenceMaterial/SubstanceTemperature ( F)Duration (Days unless otherwise noted)82.426-3062.694-15839.230-35WateraLiquid Fecesa68.0777.0-89.64N/A14107.618 hours152.620 hours129.9513 hours (21.4 days)68.015Room Temp.15Refrigeration Temp.24341.036571.649N/A3bDry FecesadWet & Dry FecesDried Egg WhitefeFeathersCulture MediacSoilcSurfaces (e.g., steel, tiles, tire,plastic, etc.)caWorld Organization for Animal Health (OIE), 2009, OIE Technical Disease Card.These temperatures were taken in the shade.cM. Ellin Doyle et al., 2007. “Destruction of H5N1 Avian Influenza Virus in Meat and Poultry Products.” UW -FRI Briefings.https://fri.wisc.edu/files/Briefs File/FRI Brief H5N1 Avian Influenza 8 07.pdf.dBaleshwari Kurmi et al., 2013. “Survivability of Highly Pathogenic Avian Influenza H5N1 Virus in Poultry Faeces at DifferentbTemperatures.” Indian J. Virol. 24(2):272-277. DOI 10.1007/s13337-013-0135-2.eUSDA, 2015. “Reduction of Infectious HPAI in Animal Agricultural Settings.”https://www.aphis.usda.gov/animal health/downloads/animal diseases/ai/hpai-reduction-of-infectious.pdf.fOIE, 2014, Terrestrial Animal Health Code. Chapter 10.4: Infection with Avian Influenza Viruses.OTHER FACTORS AFFECTING VIRUS ELIMINATIONMany factors impact the survivability of HPAI viruses. Changing any one factor may influence thevirus’s ability to survive in the environment. These factors include: Relative Humidity Weather Type of Surface Material (e.g. wood,concrete, etc.) pH Salinity TimeTemperatureLight (UV)Virus StrainMatrix (the makeup of any remainingorganic material).The current policy guidance for heat treatment (between 100 F and 120 F for 7 days; with at least3 consecutive days continuously maintaining a temperature in this range) takes into account thatmany of these factors are difficult or impossible to control. In the future, there may be additionalrecommendations reflecting the role that these factors can play in the effectiveness of viruselimination activities.5