Study shows trophon EPR effective in inactivating high-risk, cancer-causing HPV

May 20 2015

A new study presented at the Society for Healthcare Epidemiology of America (SHEA) has demonstrated that the trophon^® EPR is the only high level disinfection system proven to kill natural, infectious, high-risk human papilloma virus (HPV) under normal use conditions.

High-risk HPV accounts for 5% of all cancers worldwide and is responsible for almost all cases of cervical cancer and is a leading cause of oral, throat, anal and genital cancers.

Studies have already demonstrated the HPV transmission risk from ultrasound probes, where between 3% and 7% of probes used in transvaginal examination are contaminated with HPV, despite the use of probe covers and routine disinfection with wipes. Until now however, there has not been a good mechanism to test the effectiveness of various disinfectants against real, infectious HPV.

Researchers from Penn State College of Medicine and Brigham Young University in the United States have developed a method to grow sufficient infectious HPV particles that can be used to determine the effectiveness of various disinfectants.

They carried out a study, which was published last year, looking at the effectiveness of the disinfectants glutaraldehyde and ortho-phthalaldehyde (OPA) which are commonly used on ultrasound probes and found both disinfectants failed to inactivate natural, infectious, high-risk HPV16 – even after 24 hours of contact time. These results led to this most recent study where ortho-phthalaldehyde (OPA), hypochlorite and the trophon EPR device were tested against HPV16 and HPV18, the major cancer-causing types of HPV. The results, which were presented at the Society for Healthcare Epidemiology of America spring conference over the weekend, showed that the trophon EPR was the only disinfectant to completely inactivate HPV.

“Disinfectant efficacy testing was not previously possible until we developed a method to grow sufficient infectious HPV particles for research,” said Craig Meyers, Distinguished Professor of Microbiology and Immunology, Penn State College of Medicine. “Without a means to test the natural, infectious form of HPV, the susceptibility of disinfectants has remained unknown.

“Our first study showed that neither glutaraldehyde nor ortho-phthalaldehyde (OPA) were effective against HPV while this new study found that trophon EPR was completely effective. The concern is that these other liquid chemical disinfectants are commonly used in medical and healthcare facilities. Where this is happening, HPV is not being killed, posing a risk for transmission.”

The new study concluded that healthcare professionals should consider these results when selecting appropriate disinfection methods and that a review of disinfection standards as related to high level disinfection may be warranted.

“The results of this latest study are clinically very significant and emphasise the importance of effective reprocessing of ultrasound probes to minimise the risk of cross contamination,” said Michael Kavanagh, Nanosonics Chief Executive Officer and President. “It is clear from a number of published studies that the risk of cross contamination with HPV is real and this new study clearly demonstrates the unique effectiveness of trophon EPR in inactivating high-risk, cancer causing HPV.

“The outcomes of this study along with ongoing clinical work we are conducting further supports our objective of establishing trophon EPR as the new standard of care for the high level disinfection of ultrasound probes. This clinical outcome also informs other healthcare settings where our platform technology may be highly relevant. We will now work with the various regulatory and society bodies to provide the necessary awareness and education on this important topic.”