Risk of Transmission of HPV from Vaginal Specula
How likely is it that you may transfer the human papillomavirus (HPV) from one woman to the next via vaginal specula? With over 33,000 cases of HPV-associated cancers occurring in the United States each year, according to the Centers for Disease Control and Prevention, it is critical that physicians and medical facilities understand how and where cross-contamination happens.
Even decades ago, researchers understood the possible connection between vaginal exams and HPV, leading to a joint study investigating the cross-contamination potential of the vaginal speculum.
Facts about Human Papillomavirus (HPV)
Even beyond the risk of cervical cancer, the different types of HPV can cause a variety of health problems for patients. The CDC estimates there are 360,000 people diagnosed with genital warts each year. HPV infections can lead to other types of cancer, as well. The virus is associated with cancer of the:
Infected women may remain asymptomatic for years, spreading the virus to their sexual partners and putting others at risk. It takes just one poorly thought out protocol to create a healthcare-associated infection.
The Joint Study
In 1986, researchers from Guy’s and St. Thomas’s Hospitals joined with scientists from Whittington and Royal Northern to investigate whether using one vaginal speculum on multiple patients might lead to transmission of HPV. They looked at whether HPV cells were found adhering to vaginal specula after colposcopy examinations. The patients all were diagnosed with premalignant cervical intraepithelial neoplasia. Several of the women also had HPV infections in other areas along their genital tracts.
After each use, the specula were rinsed in an aqueous solution of chlorhexidine to remove debris, and then washed in phosphate buffered saline to collect any cells from the surface. The researchers transferred the cells to a nitrocellulose filter to investigate them further.
Of the 29 vaginal specula examined, HPV16 DNA sequences were detected on four. Three additional types of HPV DNA were also discovered. The scientists tested an additional 16 vaginal specula and were able to recreate their findings.
This study proves that HPV infected cells survive basic cleaning and may be a source of HPV infection for patients. The researchers found HPV16 DNA on several of the sample devices. HPV16 is connected to premalignant and malignant disease of the cervix. The authors concluded that HPV is a stable virus that can transfer from patient to patient via medical instruments such as vaginal specula if not properly sterilized after each use.
The researchers recommend practitioners autoclaved these instruments between patients. If full sterilization is not possible, they must at least be washed and boiled for 10 minutes to reduce the risks. Plastic reusable instruments are poor choices because it is unclear whether disinfection is enough to eliminate the HPV DNA. It is difficult to test the effectiveness of current disinfection procedures, as well, since HPV will not propagate in vitro.
Using a disposable, single-use vaginal specula means there is no chance of HPV cross-contamination and no need to worry about expensive and possibly toxic disinfection solutions. Switching to single-use devices is the safer option.