Many people with HIV are not
disclosing their status when using sexual health clinics, according to the
results of a study conducted at a large London genitourinary medicine (GUM)
clinic and published in Sexually
Transmitted Infections. This could mean that current estimates of the
prevalence of undiagnosed HIV infections in the UK are too high. Moreover,
because of non-disclosure, people with HIV may not be receiving
appropriate care when using sexual health services.
It is estimated that approximately
one-quarter of all HIV infections in the UK are undiagnosed. This estimate is
derived from statistical modelling based on several surveillance- and
survey-based sources. One of the surveillance programmes is the anonymous HIV
testing of blood samples obtained from people attending GUM and sexual health
clinics. This involves testing small samples of blood left over from routine
syphilis screening for the presence of HIV antibodies. According to data
collected in 2009, an estimated 27% of previously undiagnosed patients left the
clinic unaware of their HIV infection.
However, there have been anecdotal reports
that some people with HIV do not disclose their status when attending GUM
clinics. If this was widespread, it could mean that the prevalence of
undiagnosed infections may have been overestimated.
Investigators at the John Hunter Clinic in
London wanted to establish a clearer understanding of the proportion of their
patients whose HIV was truly undiagnosed.
They therefore identified blood samples
obtained from people with apparently undiagnosed HIV infection. Viral load
monitoring and testing for the presence of anti-HIV drugs allowed the
investigators to see if patients were actually aware of their infection.
A total of 130 HIV-positive samples were
identified. Of these, 28 were from people not previously known to be
HIV positive. However, ten of these patients were excluded because survey data
showed they underwent an HIV test when attending the clinic. This left 18 people with apparently undiagnosed HIV infection.
Some 13 individuals (72%) had an
undetectable (n = 11) or very low (n = 2) viral load. It is extremely rare for someone to have such a low viral load unless they are taking HIV
A total of eight samples were viable for
testing for the presence of antiretroviral drugs. Results showed that all were
positive. In each case, drug levels were at therapeutic levels.
“This is the first published objective
evidence that non-disclosure of HIV status is a phenomenon is patients
attending GU clinics in the UK,” comment the investigators, who believe the
extent of non-disclosure should be examined in other clinics elsewhere in the
They conclude, “non disclosure affects the
estimate of the prevalence of HIV infection in attendees upon leaving the
clinic.” It can also have implications for the health of individual patients.
Some sexually transmitted infections require more intensive treatment in people with HIV, especially if they are not taking antiretroviral therapy. Rates
of certain infections – including sexually transmitted hepatitis C and LGV –
are much higher in people with HIV than other groups, and testing for these
infections may be more likely to occur if staff are aware that someone is
A previous study, presented to the British HIV Association conference in 2011, came to similar conclusions. You can read our news report on that study here: www.aidsmap.com/page/1756413