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SOLVing the swab dilemma

OK, I have a confession to make.  I am a truly appalling gynaecologist!  I know, I claim to be a generalist – one who loves it all – but when it comes to the non-pregnant women I admit that I am sometimes less than enthusiastic.

Now this is not such a dilemma as I work in an ED, and there are not a lot of non-pregnant Gynae emergencies that I cannot sort out with a quick US and examination.  But here is my dilemma [maybe you share this one?]:  I have trouble finding the cervix on spec exam.  I know if I practiced more and got good at it I would be an ace cervix-locator. But….  I do i so infrequently and poorly that I just never really got there.

So, why worry?  Well I work in an area where STIs are rampant – we need to get good Micro samples and sort out who has go what.  And my training was to get an endocervical swab to prove (or disprove) these diagnoses.  I have always been told that clinican-obtained swabs were the gold-standard.  Accept no less.  In the last few years there has been a trend towards SOLVS (self-obtained lower vaginal swabs) for STI testing.  And I have been of the belief that they were the poor cousin to my fumbling attempts to swab the cervical canal.

BUT, wait!  News just in….  SOLVS might actually be better than my swabbing samples.  2 recent papers that I have seen looking at the diagnosis of Chlamydia and Gonorrhea indicate that the patients are better than me at getting a diagnostic sample.

This Paper from Stewart et al in BMJ Dec 2012 compared SOLVS to clinician-endocervical swabs for the screening of asymptomatic women for chlamydia.  In summary the SOLVS had a sensitivity of 97%, compared to the endocervical swabs 88% (P – significant) with narrow CI.

So I think it is fair to say that SOLVS is at least non-inferior to clinician-obtained swabs.  And I would go further to state that SOLVS is definitely superior to Doc-swabs when the Doc happens to be me!

Now, one last word of caution.  This does NOT mean that clinical examination is useless.  It would be tempting to say that we can manage a PV discharge or pain without having to get the patient undressed and have a look.  This is not the case.

I can recall countless cases where I have seen women either self-diagnose or be “diagnosed” blindly and empirically treated for what was thought to be thrush or bacterial vaginosis.  They eventually get a proper examination and it is clear that the culprit is something else – herpes, trichomonas etc.

So by all means get the patient to do a SOLVS – but you still need to have a look, to ensure you are not missing anything.  Although I think when we are prely screening for STI or other micro in an asymptomatic woman, then a SOLVS alone should suffice.

Now – not sure if this is news to anyone else?  BUt would love to hear your comments.  More Women’s health coming all month.

Casey

 

Comments

  1. I do these quite commonly – if I’m doing an asymptomatic STI screen, I always do a SOLVS + a urine PCR for Chlam (+/- Gon). I’ll usually do an external genital exam esp if there’s vulval symptoms – but there’s plenty of young women < 18 who'll refuse this. We've done SOLVS for Group B Strep carriage in pregnancy for a long time – why shouldn't all LV swabs be done like this?

    Of course, it doesn't replace a Spec, endocervical swab or PV exam if you are working up for PID or something else where you have a clinical algorithm to work through. But a useful tool in many other settings!

  2. Yes SOLVS are pretty handy for chlamydia screening. I pretty much never collect my own swabs for asymptomatic patients. But I certainly agree with the comments that if there are any symptoms including rash, discharge, pelvic pain or dyspareunia then it’s important to do a proper exam which includes external inspection, spec, swabs and often bimanual palpation. It’s amazing how many times patients think they have thrush / herpes / warts / whatever when it’s in fact something completely different. And remembering of course that for the investigation of vaginal discharge, in most cases a HVS for MC&S and ECS for chalmydia +/- gonorrhoea PCR is sufficient, but if there is a purulent cervical discharge then they also need an endocervical MC&S. This, of course, requires you to locate the cervix… hahaha.

    • Dear Penny, Maybe I am a little Irish (apologies to the really smart Islanders out there).
      But how would I know that they had a cervical discharge, unless I had seen their cervix?
      Of course then I would find it easier to swab! Answered.

      On a seroius note. IF I am really struggling to find the cervix in a woman with a PV discharge / other suggestive Sx. Can I just look, ensure I am not missing anything obvious (ulcers, tumours, FBs…) and then fall back on a LVS or HVS which seem to actually have a better pick up rate for STIs than an actual doctorly Endocervical swab?
      Talk soon
      C

      • Sarah Davies says

        Had a thought about this Casey-
        this is for PCRs but what about for M/C/S’s?
        It’s thought rates of resistant gonorrhoea are increasing in the Kimberley, but if we just do PCRs we won’t get sensitivities.
        But for asymptomatic screening it seems like very good news.

  3. lucy britto says

    Hi Casey, it can be hard to find the elusive cervix but I agree that in the Kimberley you need to swab the pus and if you can’t see the cervix you don’t know ther’s pus.
    There are a few tricks in cervix hunding. could you ask a colleague to watch what you are doing/
    otherwise
    try a different position to change the angle of the pelvis, ( sit on fists)lie pt on their side , use the longest speculum or do a bimanual before the spec so you know exactly where the cervix is.

  4. Stuart Garrow says

    I came across your blog. Just for the record the term SOLVS (the problem) was coined in my original paper describing our research project conducted in the Kimberley in 2000 and published in 2002. (i was the director of Kimberley Public health at the time) Our study showed that simple instructions in a cross cultural setting could produce reliable results. Further we published an actual technique with pictures which was validated. No need to rely on a study from Leeds in England when you have study years before from your back yard.
    see
    http://sti.bmj.com/content/78/4/278?ijkey=74d7e7fd8a0e281951c704af61884c2167f2a2ff&keytype2=tf_ipsecsha

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