A 12-year-old male came to clinic and had a plantar wart treated by cryotherapy. As part of the patient instructions, the attending physician mentioned that the patient should wear clean socks to help prevent footwear contamination, and that the family could also try Lysol® brand spray disinfectant. The attending clearly stated that he did not have laboratory evidence that this worked, but that he felt he had seen a decrease in spread of the warts to the same foot and cross contamination of the other. The resident and attending seeing the patient later decided to look up this question and see if there was any evidence which might support this other than experience. They found that the disinfectant had alcohol that can be used to treat human papilloma virus but at a lower concentration than should be effective. The attending remarked that after this he might recommend to disinfect with isopropyl alcohol but that this commonly still had a lower concentration than necessary to disinfect.
There are differences between cleaning, disinfecting and sanitizing.
- Cleaning removes dirt, germs, and other foreign material from objects and surfaces. Germs are not necessarily killed but cleaning lowers their numbers. Cleaning usually involves soap, water or variations of these.
- Disinfecting kills germs on surfaces or objects using chemicals. This does not necessarily clean the objects and surfaces of dirt and other foreign material.
- Sanitizing lowers the number of germs on surfaces or objects to a safe level using a variety of cleaning and disinfecting methods, as judged by public health standards or requirements.
Lysol® is a commercially-available disinfectant for home use. The manufacturer claims it has disinfecting activity against a variety of germs including bacteria (e.g. Staphylococcus aureus including MRSA, Streptococcus pyogenes, Escherichia coli 0157:H7, etc.), fungi (e.g. Trichophyton mentagrophytes, mildew, etc.) and viruses (e.g. Influenza A, B, Respiratory Syncytial Virus, Rhinovirus and Rotavirus). The manufacturer does not claim that Lysol has activity against HPV and is not unique in not claiming this. Another widely used hospital disinfectant, Virex®, also does not claim disinfecting against HPV, but does work for other difficult pathogens such as Hepatitis B, HIV, and tuberculosis. Lysol’s manufacturer has specific recommendations on how the product should be used on various non-porous surfaces for disinfecting activity. The manufacturer does says it can also be used on soft surfaces such as pillows, cushions, upholstery, backpacks, etc. but does not make recommendations specifically for non-porous surfaces.
Human papilloma virus (HPV) “…can be transmitted through direct virus-cell contact, such as skin-skin contact, sexual activity, and prolonged exposure to contaminated clothing as the virus may be carried on fomites…” It is resistant to drying and heat and able to survive on clothing and laboratory equipment although exact survival time is unknown. HPV is susceptible to a variety of disinfectants including “… 90% ethanol for at least 1 minute, 2% glutaraldehyde, 30% Savlon [chlorhexidine gluconate and cetrimide], and/or 1% sodium hypochlorite can disinfect the pathogen….”
Footwear potentially can be difficult to prevent contamination because of difficulty in cleaning of the contact surface materials (i.e. leather, suede), deters general cleaning and/or disinfecting. People also often do not wash footwear as often as other garments. Shoes are moist, warm environments which facilitates viability of the virus.
Prevention of warts includes keeping feet clean and dry, using flip-flops/sandals in public pools and locker rooms or other moist wet areas, avoiding contact with other warts including not picking at the wart, not using the same file, pumice stone or nail clipper that are used on health skin and nails, and washing hands after touching warts. Frequent washing of potentially contaminated objects such as socks is also appropriate.
Lysol® disinfecting spray contains 40-60% alcohol and 0.1-1% quaternary ammonium compounds, benzyl-C12-18-alkyldimethyl, and salts with 1,2-benzisothiazol-3(2H)-one 1,1-dioxide. This alcohol concentration is too low to disinfect for HPV using the information above. A 2014 study of the susceptibility of HPV type 16 to clinical disinfectants found that HPV were susceptible to isopropanol, phenol and peracetic acid-silver disinfectant and hypochlorite after 45 minutes of exposure. Concentrations and viral types tested (native or quasivirions) showed different patterns of susceptibility. Overall, the study found HPV is highly resistant to commonly used clinical disinfectants.
Questions for Further Discussion
1. Would you recommend any disinfection methods for the contact surfaces for plantar warts? If yes, what methods?
2. What is the scientific basis that home treatments such as using potatoes or vinegar could work to treat warts?
Preventive Medicine and Health Maintenance
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for this topic: Human Papilloma Virus
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
Virex® Tb. Johnson Wax Professional. Available from the Internet at http://www.johnsondiversey.com/wcmt/ProductAttachments/en-US/PIS/SPC214.pdf (rev. 2003, cited 12/5/2011).
LYSOL® Disinfectant Spray. Reckitt Benckiser. Available from the Internet at http://www.lysol.com/cleaning-products/disinfecting-sprays/disinfectant-spray (rev. 2010, cited 12/5/2011).
Material Safety Data Sheet. LYSOL® Disinfectant Spray. Reckitt Benckiser. Available from the Internet at http://www.rbnainfo.com/MSDS/US/Lysol-Brand-III-Disinfectant-Spray-US-English.pdf (rev. 7/9/2010, cited 12/5/2011).
Centers For Disease Control. How to Clean and Disinfect Schools to Help Slow the Spread of Flu.
Available from the Internet at http://www.cdc.gov/flu/pdf/school/cleaning_disinfecting_schools.pdf (rev. 10/2011, cited 12/5/2011).
Public Health Agency of Canada. Human Papilloma Virus Pathogen Safety Data Sheet.
Available from the Internet at http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/papillome-eng.php (rev. 4/19/2011, cited 12/5/2011).
Meyers J, Ryndock E, Conway MJ, Meyers C, Robison R. Susceptibility of high-risk human papillomavirus type 16 to clinical disinfectants. J Antimicrob Chemother. 2014 Jun;69(6):1546-50.
ACGME Competencies Highlighted by Case
- Patient Care
3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
4. Patient management plans are developed and carried out.
5. Patients and their families are counseled and educated.
6. Information technology to support patient care decisions and patient education is used.
7. All medical and invasive procedures considered essential for the area of practice are competently performed.
8. Health care services aimed at preventing health problems or maintaining health are provided.
- Medical Knowledge
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.
- Practice Based Learning and Improvement
12. Evidence from scientific studies related to the patients’ health problems is located, appraised and assimilated.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
14. Knowledge of study designs and statistical methods to appraisal clinical studies and other information on diagnostic and therapeutic effectiveness is applied.
15. Information technology to manage information, access on-line medical information and support the healthcare professional’s own education is used.
16. Learning of students and other health care professionals is facilitated.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital