New Guidance for T. Vaginalis Screening and Diagnosis

Transcription

1 Transcript Details This is a transcript of an educational program accessible on the ReachMD network. Details about the program and additional media formats for the program are accessible by visiting: ReachMD info@reachmd.com (866) New Guidance for T. Vaginalis Screening and Diagnosis Narrator: Welcome to ReachMD. This is a special edition of Advances in Women s Health, sponsored by Hologic. Your host is Dr. Jennifer Caudle who is a Family Medicine physician and Assistant Professor in the department of Family Medicine at Rowan University-School of Osteopathic Medicine. Joining me today is Dr. Paul Nyirjesy who is a Professor in the Departments of Obstetrics and Gynecology and Medicine and also Director of the Drexel Vaginitis Center at Drexel University College of Medicine in Philadelphia, Pennsylvania. He and I are going to discuss how the CDC regularly updates their STD treatment recommendations. Then we ll focus on trichomonas infections which are very common and also the fact that there are now new testing methods that are available. Dr. Nyirjesy, welcome to the program ReachMD Page 1 of 6

2 Thanks for having me. So, could you please comment on what the CDC STD treatment guidelines are and how they are developed? Sure, so the CDC STD Treatment Guidelines have actually been around since 1982.Initially, the CDC gathered a group of experts in the room and just asked them how they treated various sexually transmitted infections. In 1993, it evolved to an evidence-based approach and gradually they have gotten more and more extramural participation from subject matter experts, professional organizations, and so now, basically, every 3 to 4 years they enlist subject matter experts to do a full literature review, answer what they think are the pressing questions about diagnosis and treatment of various STDs and then they gather this all together to come up with updates on the recommendations. And this has now become the most common source of STD treatment information in the United States. My understanding is that it is one of the most accessed links on the CDC website and it is considered to be an authoritative document on how to treat sexually transmitted infections. Could you now discuss for us the prevalence of T. vaginalis infections in the United States, and can you also discuss what the sequelae are associated with untreated or undertreated infections, and who are most at risk? So, trichomonas infections are one of the most common, STDs and just to give you a sense of things, it is estimated that there are about 3.7 million persons infected every year in the United States and that probably more than gonorrhea and chlamydia combined. And in a way, it s been the ignored pathogen. If you look at the Federal Government goals for controlling STDs in the healthy people 20/20 document it is not even mentioned. And I think part of the reason why it has been ignored in the past is that it s thought to be just a vaginal infection in women that causes some very fairly minor symptoms, in men fairly minor symptoms as well, as urethritis or prostatitis, but now there has also been a concern that it may have other health implications. So, just as an example, it has been associated with 2 to 3-fold increase risk of HIV acquisition. It has been associated for a long time with pre-term birth and other adverse pregnancy outcomes and in women who are HIV-positive, it is associated with an increased risk of pelvic inflammatory disease. So there is a growing amount of data 2017 ReachMD Page 2 of 6

3 to show that this is more than just a minor nuisance infection. Could you please discuss who is most at risk? So, the people who are most at risk, in general, are people who are most at risk for sexually transmitted infections. So there are relatively high prevalences in STD clinics and in correctional facilities. Persons who have multiple sex partners are more at risk; those who exchange sex for payment; those who are using illicit drugs; those who have a history of STD. Interestingly, if you look at the epidemiology of it, though, it tends to occur in a somewhat older population than things like gonorrhea and chlamydia, so a fairly significant number of cases happen in women who are over the age of 25, whereas gonorrhea and chlamydia tends to happen in younger women. So the age group that is affected is somewhat broader. Both culture and wet mount microscopy have historically been employed to detect the presence of T. vaginalis. Could you discuss their respective disadvantages as screening or diagnostic methods for detecting T. vaginalis? Everybody loves to do a wet mount. It is really satisfying when you get a swab from the patient s secretions, you put it under the microscope and then you see these trichomonas floating around and you know that the patient has a trichomonas infection. This is what people have relied on for decades. It turns out that a wet mount is a fairly lousy test and the sensitivity of the wet mount is only about 50%. And so, if somebody is relying on a wet mount for diagnosis they are missing trichomoniasis all the time. The culture has been the gold standard for diagnosis in the past and it is much more sensitive. The problem with culture is that you can t just do a culture swab and send it to the lab. You have to have the culture medium that is sitting there in your office. You have to inoculatethe medium immediately and then send it off to the lab and so, unless you have a program where you see a lot of women where you are going to be doing cultures, which is not an easy test to have around. It may also be less sensitive than your technology. The one advantage of culture, though, is that if the culture is positive then you know that the patient really does have trichomoniasis ReachMD Page 3 of 6

4 As a follow-up, what are the comparative advantages of NAATs over other means of detecting T. vaginalis? The main advantage is that it s now considered the gold standard. It is considered the most sensitive test. It s also got a very good specificity as well, so you have a very accurate test. From my point of view, the big advantage is that on the very same swab that you are sending off for gonorrhea and a chlamydia test, you can just add the word trichomonas to the requisitions list and they can do trichomonas testing as well. Sometimes it can also be done off a Pap specimen, so there is also the convenience factor of being able to use that sample, and so, it is an easy test and it is more sensitive than culture and this is why it is now the gold standard in the current STDTreatment Guidelines. Once T. vaginalis infection has been confirmed, you know, what treatment approaches are available, and are there side effects to these therapies that might impact adherence? Is antimicrobial resistance a problem in this situation? The mainstay of therapy are the nitroimidazoles; either metronidazole which can be given as a single 2 gram dose or tinidazole which can also be given as a single 2 gram dose. Keep in mind that for people who are HIV positive, it is now recommended that they get the alternative regimen, which is metronidazole 500 mg twice a day for 7 days. Are there side effects to these therapies that might impact adherence? The main side effect is going to GI intolerance and with a single 2 gram dose of either metronidazole or tinidazole they are fairly well tolerated, so unless the patient throws up the dose, it is something that they should be able to manage. The other when it is a little bit of a nuisance is that there is the possibility of a disulfiram-like reaction, so the patients need to be sure to abstain from alcohol use for 24 hours after completion of metronidazole. Tinidazole, by the way, has a longer half-life. If they use tinidazole, they should be sure to abstain from alcohol for 3 days after taking the medication. Other than that, tinidazole is generally more expensive. So I think that that is really why metronidazole is the 2017 ReachMD Page 4 of 6

5 drug that people use the most. Is antimicrobial resistance a problem? It is hard to tell because there is not ongoing active surveillance of trichomonas infections. There is some concern that resistance is getting to be more of an issue. In vitro there seems to be some growing issues with resistance and there are more and more isolated cases, and so the estimates are that metronidazole resistance may happen in as many as 4 to 10% of cases of vaginal trichomoniasis; probably less with tinidazole, maybe 1%. If you are just tuning in, you are listening to Advances in Women s Health sponsored by Hologic on ReachMD. I am your host, Dr. Jennifer Caudle, and I am joined by Dr. Paul Nyirjesy and we are discussing the CDC guideline updates on trichomonas. So, how do you ensure a woman has responded to antimicrobial therapy? So, the overall approach is very much similar to the approach that is now recommended for gonorrhea and chlamydia testing. So, for gonorrhea and chlamydia testing resistance is a concern, but the much bigger concern is reinfection. And so instead of bringing somebody back for a test of cure visit right after treatment, what is recommended is that you bring her back 3 months later. And so, it is kind of a test of cure evaluation, but also an evaluation that is meant to assess whether reinfection from a partner has occurred. And so, similar recommendations are in place for patients who are treated for trichomoniasis. As a follow-up, the 2015 Guidelines cited a 2006 study by Peterman and colleagues that state that reinfection with T. vaginalis is high in women; in that study 17% within 3 months of therapy, hence the rationale for partner therapy. Could you describe how partner therapy is accomplished, and are partners routinely tested for T. vaginalis? And if not, should they be? If I may, let me kind of go backward on this, so with male testing it is important to realize that you can t 2017 ReachMD Page 5 of 6

6 just do a single swab from one location, get a positive or negative and determine whether the partner has a trichomonas infection. Sometimes it might be the urine that has the infection; sometimes it might be the coronal sulcus; sometimes it might be semen and to tell a man that he does not have trichomoniasis, you really need to have 3 swabs done which nobody is doing routinely. And so what I tell my female patients, and keep in mind I am a gynecologist and so I am just seeing the women, is that no matter what the partner says or no matter what the partner s doctor says, the partner needs to be treated. So, the recommendations now are to try to do partner-expedited therapy where you give the patient a prescription for her and for her partner. That way her partner can be treated. The catch is that in certain states in the United States it is actually illegal to do that unless you have a relationship with the partner as your patient, and so the CDC has a really helpful map and if you just go to the CDC.gov site you will be able to find the map which will tell you which states permit partner-expedited therapy and which states do not permit it. Well, Dr. Nyirjesy, we focused a lot of trichomonas today, but is there anything else you wanted to mention regarding the updated CDC guidelines? Sure, they have gone through a lot of changes. Sometimes there are updates that come out later that might change those recommendations, and so, for those of you who are interested, there is a PDF that is available for free download at CDC.gov, and if you really want to see your tax dollars at work, you can download a free app, it is called STD PX Guide and it has abbreviated recommendations in there and then it also has links to the full text document if there is a specific area where you want to see everything that is written about the condition. Dr. Nyirjesy, thank you so much for sharing this information with our ReachMD listeners. My pleasure. Narrator: You ve been listening to ReachMD. The preceding program was sponsored by Hologic If you have missed any part of this discussion and to find others in this special series of Advances in Women s Health, visit ReachMD.com/womenshealth. Thank you ReachMD Page 6 of 6