Saturday 20 July 2013

When a positive isn't really a positive

When is a positive not really a positive? Sounds like the start of a bad riddle. Alas, this is not the case. I am referring to HIV testing and the fact that 2 and a 1/2 months ago I had routine booking in bloods taken at the hospital. Having no tattoos, never taken drugs, no blood transfusions, no donated organs, not in a job at risk of needle-stick and my husband is a regular blood donor (and so HIV negative) the HIV part of the booking in bloods didn't even cross my mind. When two weeks later I received a phone message telling me not to worry but there had been a problem with one of my bloods and it needed re-doing I simply assumed a vial had been lost or contaminated.

Nothing could have prepared me for the phone call telling me I had tested positive for HIV. I had to get it repeated three times because I simply could not take it in. My head was spinning, I was told I had to come in for further blood tests to confirm and check my levels. At no point was it being raised that perhaps the test was flawed. The first (and perhaps stupidest thing) I did was rush to search online. I wanted to know everything about HIV and the tests themself. So I also dug out my booking in bloods booklet to see what they said. The booklet which can be downloaded here talks about the tests. On the first page it mentions that tests will need to be repeated to 'check the results' and then on the 3rd page it begins to talk about HIV. It does not mention the risk of false positives or even seem to acknowledge that they exist. This is what has angered me the most as I went through hell, and I am sure I am not alone in this, whilst I waited for the results of my next round of tests. A hell that I was put through unnecessarily because:
  • I was not (I believe) adequately informed about the tests before having them, as that booklet does not, in my opinion give the full picture
  • Information at the time on the NHS site for example made no mention of false positives
  • The very high accuracy and sensitivity figures given. For example here suggests a sensitivity of 99.3-99.7%.

At the follow up appointment I went fully prepared with what must have seemed like a million questions. The midwife was wonderful and did understand my anger and upset, as well as fear and I can not fault her for her professionalism and care. However, I had to have the ELISA repeated, I asked why the confirmatory Western Blot was not being used as this is what I had read online was the standard method to confirm a result. As the Western Blot separates out the sample and looks for three specific aspects of HIV rather than simply looking for antibodies. I had lost faith in the ELISA test as I knew I did not have HIV but feared that the test would once again falsely say I did. I also had to have a viral load taken to confirm my levels of the virus.

A viral load is simply that, there is no positive or negative. It looks for the amount of the virus in your blood. You can not get a negative you can simply get a 'load undetected' which a lab will not accept as being negative but will simply respond by saying it means your viral load is too low to detect. Now you will get a 'load undetected' even if you are HIV negative, but it does not mean they will sign you off as such. So, now the fear set in again that I would never get this diagnosis out of my blue maternity notes and that it would affect the rest of the pregnancy. I'm one of those people who finds themself swinging between fear, upset and then anger! It was this anger that fuelled my first complaint to the NHS about their 'receiving a positive test' page. They have since responded to say that they would look into the matter, and then that they would change the page and add my suggested reference to false positives. You can find the new page here, although I am disappointed that it does not list the potential causes of a false positive. I think this might help reassure people.

Anyway to cut a very long story shortish the ELISA came back negative and the viral load, as expected, 'load not detected'. I thought this might finally be the end of it. No! At my 20 weeks scan I had to have a 4th HIV test, when I asked why as I could not find any information to say why a negative was now not being accepted as negative I was told that it was needed to sign me off. Anyway, this one also came back negative and my fantastic midwife has signed me off and told them no more tests! Can not fault her or her determination, she has been wonderful. Whilst I am thanking people, the following are two amazing charities that deserve my thanks and support:

Apologies that this is more diary like than normal blog post but I wanted to share this to try and help other people who might find themselves in my situation or who are worrying about test results for them or a loved one. Normal service will resume shortly!