HIV screening

Some clinical circumstances should trigger an offer of an HIV test as a matter of routine, for example as part of antenatal care.


In high prevalence areas, there is a good case for even more extensive testing, including strategies for population screening.

Screening by clinical circumstance

Screening offers the potential to detect HIV in people without HIV-related symptoms. Testing asymptomatic people should increase early diagnosis and so improve outcomes for patients. There are several clinical situations that are associated with higher risk of HIV and when an HIV test should be offered as a matter of routine:

 

All patients with a diagnosis of a sexually transmitted infection OR a viral hepatitis

Any patient with an STI is, almost by definition, also at risk of HIV. A substantial proportion of those with Hepatitis B or C may also have been at risk of HIV infection. Therefore anyone diagnosed with any of these conditions should be offered an HIV test. This includes any patient diagnosed with chlamydia, genital warts, genital herpes or Trichomonas as well as gonorrhoea or syphilis. Those with pubic lice may or may not have had unprotected sex.

I saw a patient in her mid 50s and from Egypt. She presented with a single genital wart. She had had one on and off sexual partner for 9 years. I was actually most interested in the opportunity to test her for viral hepatitis, because we had never done this for her despite the high prevalence of Hepatitis C in Egypt. Because of the genital wart I also offered a test for HIV. To my surprise she was HIV positive. She has taken the diagnosis incredibly well and her blood results are so good she doesn’t need treatment yet. She disclosed that she was raped 9 years ago; we don’t yet know her on-off partner’s HIV status. That’s the second time I have diagnosed HIV on the basis of a ‘minor’ STI. Thank heavens I did”.

Women undergoing an abortion

There is evidence that women undergoing abortions have a relatively higher prevalence of HIV (1). All women who have been referred for an abortion or undergone one should be offered an HIV test.

We work in an area with a very high prevalence of HIV. We did an audit of all those patients who were coded as having an abortion in the last year to check if they had been offered tests for chlamydia and HIV. We found our local services were good at notifying us of chlamydia tests taken and the results. However they did not appear to be offering HIV tests. As a team we agreed we would raise this with women presenting for an abortion, so we added it to our template. We also decided to add to the template a reminder to check contact details at presentation and ask each woman if we can call her a week after the procedure. Our nurse then calls and checks the woman is OK and has her contraception plan in place; she also makes sure she has had her HIV test and result. Finally we have emailed our CCG suggesting that the local services commissioned to provide abortions should be expected to offer HIV tests as a matter of routine”.
 
(1) HIV testing in abortion clinics, Bates SM J Fam Plann Reprod Health Care 2011;37:198–200. doi:10.1136/jfprhc-2011-100136

Pregnant women in antenatal care

In the UK, all pregnant women will be offered an HIV test because medical interventions such as antiretroviral therapy and avoidance of breast feeding cut the risk of transmission from mother to baby to below 1%  (from perhaps 20% if untreated, although risks vary widely). NB management advice differs in resource-poor settings, where breast-feeding is recommended.

Some women become infected during the course of their pregnancy and so, especially in high prevalence areas, provision of repeat testing in late pregnancy and/or testing of partners at booking is being considered.

Two of my patients found out about their HIV status in the antenatal clinic. I must admit that seeing what they have been through has made me much more active in offering HIV tests to women before they conceive – it is especially hard getting the diagnosis antenatally. Nevertheless they are both doing fine, as are the babies (all three of them!)"

High prevalence area: women seeking contraception

Because of the routine offer of HIV tests to women antenatally, many practices in higher prevalence areas consider it ideal to discuss HIV testing with women seeking contraception:

All women are offered an HIV test when they are pregnant, but we think it is much better to know if you have HIV BEFORE you get pregnant”.

All patients having an acute medical admission

As has been discussed in The case for HIV testing late diagnosis – especially very late diagnosis – can be dangerous for patients. Some of these patients have been missed by both primary and secondary services. Therefore there have been pilots of HIV testing in patients being admitted to acute medicine and this has resulted in new diagnoses being made.

 

Population screening

Many of the clinical circumstances that should trigger an HIV test target women (eg those having abortions or contraception advice). Heterosexual men with HIV are at higher risk of being diagnosed in late stage illness than other groups. Practices need to promote awareness of this issue and strategies to address it. The aim of population screening is to diagnose HIV early, ie to avoid waiting for symptomatic presentations.
  
Screening of newly registering patients in high prevalence areas

It was proposed in the 2008 UK HIV Testing Guidelines that screening for HIV should be piloted in areas of high prevalence (where >2 / 1000 population aged 15-55 are diagnosed with HIV). In the general practice context the focus has been on offering HIV tests to newly registering patients. It is thought that cost-effectiveness is likely to be achieved at positivity rates above 1/1000. You can find out the prevalence of HIV in your area when you come to do our audit (see the box on the left). If you can't wait, you can also find it here.

NICE guidance on HIV testing for Africans, and for men who have sex with men also endorsed this.

HIV screening projects in high prevalence areas have used both point of care tests and also normal venous samples.

Point of care tests are quick and easy to use and give instant results, helping to ensure patients are not lost to testing or follow up. Positive results need to be confirmed. Practices commissioned to provide HIV screening will be supplied with such tests.

Venous samples enable other relevant tests to be offered as appropriate (such as haemoglobinopathy screens, Hepatitis B or C, rubella immunity tests or lipids). Some practices find this helps normalise HIV testing within the context of general healthcare.

You can find out more about the evaluation of the screening pilots here.

  Kalyna, 26 - a patient's view
I came to London from the Ukraine just under a year ago, and quite quickly found work in a bar. I needed to sort out contraception, so I registered with a doctor. When I first visited the practice I was seen by a nursing assistant and had my blood pressure checked and so on. To my surprise the assistant then offered me an HIV test – she explained they were being offered to all new patients. She explained that HIV was very treatable and that was why they wanted people to get the finger prick test.

I agreed and I think we were both fairly shocked with the positive result. She very quickly arranged for me to meet a nurse in a local clinic to have another test to double check – they found I was indeed infected. Things have been a bit of a whirlwind since then. I think an old boyfriend of mine in the Ukraine had used drugs before I knew him – I am trying to track him down so I can be sure he gets a test. This will not be an easy conversation, but I have had good advice from my clinic.

My immunity is good so apparently I don’t need treatment yet – I can see now that it is good that the infection was detected early, whatever my regrets.

[translated from Ukrainian; not her real name].




Did you know...

Antiretrovirals were initially used singly however it quickly became apparent that this led to resistance and so now they are used in combinations of 3 or more.

The first HIV antibody test became widely available in 1985, current venous sample tests are for HIV1 and 2; both antibody and antigen.

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