I rarely use the Talk Clean To Me blog as a means to vent, but I just can’t keep quiet any longer on this topic. Over the last several months there has been increasing chatter about the need to find a product that carries an HPV claim as a result of a published study looking at the efficacy of some disinfectants against HPV. I can certainly understand the interest in reading such a study; however, like any published work we need to understand the limitations of the study and how that can be applied to your infection prevention practice.
My intent is not to disparage the study. However, as I have expertise in the requirements for registering disinfectants with the EPA, the FDA and Health Canada, I hope I can shed a bit of light on the topic so that you do not waste your time trying to find a disinfectant with an HPV claim. The following are the questions I ask when reading a study and determining its relevance:
1) Question: Were the disinfectants used representative of commonly used products for disinfection of environmental surfaces or medical devices?
Answer: The study did not include many of the more commonly used disinfectant actives such as QUATs or the up and coming Improved Hydrogen Peroxide products.
2) Question: Would the testing methodology used in the study allow for the product(s) to be registered by the appropriate regulatory body?
Answer: The efficacy method used in the study was not equivalent to what a disinfectant manufacturer would have to conduct and submit to EPA, FDA or Health Canada in order to make a claim of efficacy against HPV.
3) Question: Are there any labs accredited by the EPA, the FDA or Health Canada that can conduct testing against HPV to allow for registration of a claim?
Answer: No. An investigation of EPA, FDA and Health Canada accredited labs confirmed that there are currently no labs that can grow HPV in a lab setting to a sufficient enough titre that would allow for submission of such a claim.
Like HPV, there are a number of pathogens that cannot be cultured in a lab and therefore cannot be tested for efficacy. Generally, regulatory bodies recommend that when testing for efficacy against these kinds of pathogens, surrogate organisms with similar characteristics are used. For example, Human Norovirus, like HPV, cannot be cultured in a lab; however, regulatory bodies have instead identified Feline Calicivirus (FCV) as the surrogate that has similar qualities to Norovirus. Therefore, if products can prove effectiveness against FCV, a Norovirus efficacy claim can be made. This same concept cannot be used for HPV however; regulatory bodies have not yet identified an appropriate surrogate as there is no Health Canada, EPA or FDA approved test method for HPV. Therefore, disinfectant companies cannot make an HPV efficacy claim on their product labels.
Although this study appears to have compelling evidence, one must take into consideration the science behind disinfectant claims and what current guidelines allow. Although there are no approved test methods for HPV and there are no current disinfectants on the market that have claims for HPV, it is logical to assume that disinfectants with multiple claims against non-enveloped viruses could be effective against HPV.
Climbing down from my soapbox....thanks for reading!