Pearls of Wisdom: Trich on a Liquid Pap Smear
A visiting OB-GYN resident presents you with the results of a recent liquid Pap smear that reported Trichomonas. The patient was a 27–year-old reportedly monogamous woman, who had been married for 3 years.
When the patient asks where this infection could have come from, how do you advise her?
A. It’s probably a false positive; repeat it in 6 months
B. It is an STD; hire CHEATERS Inc.
C. It is usually an STD, but determining its origin is problematic
D. It is probably a benign strain of Trichomonas
What is the correct answer?
(Answer and discussion on next page)
Louis Kuritzky, MD, has been involved in medical education since the 1970s. Drawing upon years of clinical experience, he has crafted each year for almost 3 decades a collection of items that are often underappreciated by clinicians, yet important for patients. His “Pearls of Wisdom” as we like to call them, have been shared with primary care physicians annually in an educational presentation entitled 5TIWIKLY (“5 Things I Wish I Knew Last Year”…. or the grammatically correct, “5 Things I Wish I’d Known Last Year”).
Now, for the first time, Dr Kuritzky is sharing with the Consultant360 audience. Sign up today to receive new advice each week.
We are always learning, right? Well this is a real case I encountered around October of 2003 in which a visiting resident physician changed my thinking.
The Conversation
OB: What’s your preferred treatment for this Trich on the Pap?
ME: Any symptoms?
OB: No, just the positive Pap.
ME: Well, then it’s most likely a false positive; let’s get a Trich culture.
OB: You know, at Louisville we always treat this.
ME: Let me share with you these articles that suggest otherwise.
OB: Our group just published an article specifically addressing this issue. Would you like to take a look?
ME: (Gulp) Sure!
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At this point, I am directed to the article authored by faculty at her institution.1 The article began with a historical position’ comment, “The conventional Pap smear has been previously shown to be ineffective in diagnosing or screening for Trichomoniasis in asymptomatic women.”
Well, so far so good.
However, they went on to prove their assertion that—in contrast to conventional Pap results—liquid Pap results positive for Trichomoniasis should be considered diagnostic.
Trich on Liquid Pap1
The Research
In their review of 203 consecutive asymptomatic patients the positive predictive value of a positive result on liquid based Pap testing was 100%. They comment, “The presence of T. vaginalis organisms, as stated by the liquid-based Pap smear pathology report, is accurate and warrants treatment without further testing.”
The identification of a potentially sexually transmitted infection can be explosive to a relationship, so clinicians should exercise great care and clarity before simply assuming extramarital activity. Trichomonas can remain as a silent pathogen in men or women for an indeterminate amount of time, so we don’t know whether the male partner has previously carried this asymptomatically and only recently transmitted it to his wife or if the patient had been infected from another partner prior to her spouse and remained asymptomatically infected.
Liquid-Based Pap and Trich1
Note: LB PAP = Liquid-based Pap Smear
The structure of my conversation with the patient when encountering this scenario goes something like this:
“Mary, your Pap test has identified Trichomonas infection. While this is most often a STI, it is possible that either you or your husband have been harboring the germ asymptomatically for a long time, possibly acquired from another partner prior to your marriage. It is not readily possible to determine exactly when you or your partner acquired the infection, or how long the infection has been present in either one of you. Our most important job, then, is to get you proper treatment. Because Trichomonas is most commonly a sexually transmitted infection, and such infections are sometimes accompanied by other sexually transmitted disorders, we do recommend screening at this time for other STIs.”
If Mary has reason to believe that there has been a breach in their relationship, she has been informed that Trichomonas is most commonly an STD. On the other hand, this may be recognition of an infection that has been asymptomatic for a long time.
The presence of Trichomonas on a liquid based Pap does not require further confirmation and should be treated. Ascertainment of the timing of acquisition of Trichomonas is problematic.
Reference:
1. Lara-Torre E, Pinkerton JS. Accuracy of detection of Trichomonas vaginalis organisms on a liquid-based Papanicolaou smear. American Journal of Obstetrics and Gynecology 2003;188:3354-6