One of the medical devices sometimes used by doctors is a pelvic ultrasound probe. In recent years, there’s been growing concern about whether these probes have the ability to transmit the HPV virus from one patient to another. But is there any truth to this idea? Let’s take a closer look to find out.
What Are Pelvic Ultrasounds and Ultrasound Probes?
Pelvic ultrasounds are scans used to see the organs near the pelvis. (1) They work kind of like echolocation by bouncing sound waves off of objects to determine information about their environment and surroundings.
An ultrasound transducer, also called an ultrasound probe, is the device that makes an ultrasound possible. By emitting and receiving the sound waves, the transducer is able to create images of the organs near the pelvis.
When Do You Use Pelvic Ultrasounds?
There are two main types of pelvic ultrasounds: transabdominal ultrasounds and transvaginal ultrasounds.
Transabdominal Ultrasounds
Transabdominal ultrasounds are the ones you’re probably most familiar with. During this procedure, an ultrasound technician will smear gel on the patient’s pelvic region, then glide the ultrasound transducer along the pelvis, allowing it to emit and receive sound waves thus creating images. These types of ultrasounds are typically used during pregnancy to view the fetus and listen to the fetal heartbeat.
Transvaginal Ultrasounds
Transvaginal ultrasounds are not nearly as well-known as transabdominal ultrasounds. During transvaginal ultrasounds, an ultrasound technician should place a condom on the transducer and cover it in gel before inserting it into the vagina. The probe can be used to produce images of the vagina, cervix, uterus, fallopian tubes, ovaries, and/or bladder. (2) These internal ultrasounds may be used during the first trimester of pregnancy, when diagnosing certain medical conditions (such as cysts, polyps, fibroids, or endometriosis), or if you’re just having general pelvic pain. Depending on the reason for the ultrasound, the procedure can take anywhere from a few minutes to nearly an hour. (3)
What Is the Risk of HPV Transmission?
Studies have shown that HPV is a stable virus, meaning it has the ability to survive on fomites (inanimate objects that have come into contact with an infection and can pass that infection onto others). HPV can also “survive an onslaught of chemical treatment[s] and still [be] able to be infectious.” (4)
HPV lives in the epithelial cells, which are found on the surface of the skin, vagina, cervix, anus, vulva, and penis head. (5) Given that a most people will get HPV at some point in their lifetime, a transvaginal ultrasound has a high risk of coming into contact with the HPV virus. Probes are not disposable, and are disinfected after each use with mild disinfectants to “avoid damaging the sensitive equipment.” (4)
However, the common disinfectants used on transvaginal probes are not strong enough to kill the HPV virus. Studies show that up to 7% of transvaginal probes remained contaminated with high-risk HPV DNA, even after low or intermediate level disinfection. Even high-level disinfectants don’t kill all remnants of high-risk HPV on ultrasound probes. (6)
What this means is that if a transvaginal probe comes into contact with the HPV virus, the virus can remain on the probe for weeks even after it’s been disinfected. Then, the probe can be inserted into another person, causing HPV transmission.
In addition to transvaginal probes, transabdominal probes also run the risk of transmitting HPV. HPV lives on the skin, and the transducer comes into direct contact with the skin on the pelvic region. Therefore, HPV could easily hop onto the transducer and stay on there until the next patient arrives.
How to Prevent HPV Transmission
Transducers are cleaned and covered between uses to disinfect and prevent them from coming into contact with environmental hazards. However, because most disinfectants don’t kill the virus, this seems to be a futile attempt to purify the probe.
During ultrasounds, the only way to prevent HPV transmission is to ensure that the transducer has been cleaned with a disinfectant that kills the HPV virus. So far, there is only one disinfectant that has been found to completely inactivate the HPV virus. This disinfectant is called Trophon ER. (7) You can ask your ultrasound technician before the procedure (or call ahead of time) to ensure that this is the disinfectant used on their transducers.
If you’re having a transvaginal ultrasound, you can also ensure that the technician uses an external condom on the probe. Though it is typically routine to do so, it’s always a good idea to ensure that your medical providers are following procedural recommendations.
Sources
- Pelvic Ultrasounds: University of Utah Health.
- What to Know about Transvaginal Ultrasounds: Medical News Daily, 2018.
- What is a Transvaginal Ultrasound?: Healthline, 2017.
- Eric J Ryndock & Craig Meyers (2014) A risk for non-sexual transmission of human papillomavirus?, Expert Review of Anti-infective Therapy, 12:10, 1165-1170, DOI: 10.1586/14787210.2014.959497
- What is HPV?: WebMD.
- Human Papillomavirus (HPV): Nanosonics, 2017.
- New Study Demonstrates Efficacy of Trophon EPR for Ultrasound Probe Disinfection: Imaging Technology News, 2016.
