Rate of undiagnosed HIV remains high among black African heterosexuals in London

The rate of undiagnosed HIV infection among heterosexual black Africans living in London remains unacceptably high, according to research published in JAMA Network Open. Oral testing showed that over 50% of men and 40% of women who reported they were HIV negative/untested were in fact HIV positive. There were also high levels of HIV risk behaviour, with a fifth of women and quarter of men reporting condomless last sex with a partner of different or unknown HIV status in the past year.

“Despite efforts to increase HIV testing, uptake in black African communities in London remains modest,” comment the investigators. “This study identified a large fraction of undiagnosed infection – greater than other at-risk populations – suggesting that the prevention and care needs of this group are not adequately met.”

In the UK, black African heterosexuals are one of the groups most affected by HIV. Surveillance data for 2016 suggests that 13% of new diagnoses and almost a quarter of all HIV infections are in this population. An estimated 12,300 black African heterosexuals were living with HIV in London. Public Health England estimated that the rates of undiagnosed HIV infection among black African men and women residing in London were 12% and 4%, respectively.



Refers to the mouth, for example a medicine taken by mouth.


Studies aim to give information that will be applicable to a large group of people (e.g. adults with diagnosed HIV in the UK). Because it is impractical to conduct a study with such a large group, only a sub-group (a sample) takes part in a study. This isn’t a problem as long as the characteristics of the sample are similar to those of the wider group (e.g. in terms of age, gender, CD4 count and years since diagnosis).


Having sex without condoms, which used to be called ‘unprotected’ or ‘unsafe’ sex. However, it is now recognised that PrEP and U=U are effective HIV prevention tools, without condoms being required. Nonethless, PrEP and U=U do not protect against other STIs. 

cross-sectional study

A ‘snapshot’ study in which information is collected on people at one point in time. See also ‘longitudinal’.

oral fluid

In HIV testing, refers to moisture obtained by swabbing an absorbent pad around the outer gums. Some tests require a sample of oral fluid, which in a person living with HIV is likely to contain HIV antibodies.

Dr Ibidun Fakoya of University College London and colleagues wanted to determine the proportion of black African men and women in London who had been tested for HIV in the past five years and to see what proportion of these were living with HIV – both diagnosed and undiagnosed.

They therefore designed a cross-sectional study using self-completed anonymous questionnaires that were distributed at social and commercial venues popular with black African communities across London in late 2016. Participants were asked about their HIV testing history over the past five years, HIV status, sexual behaviour, use of health services and knowledge of pre-exposure prophylaxis (PrEP). They were also asked to provide a saliva sample for anonymous HIV testing; the results were linked to the answers provided about HIV status in the self-completed questionnaire.

Similar surveys were conducted in 1999 and 2004, and one of the aims of the investigators was to see if rates of HIV testing and undiagnosed infections had changed in the intervening years.

The final study population consisted of 604 individuals – 292 women (median age 31 years) and 312 men (median age 35 years). A saliva sample for anonymous HIV testing was provided by 496 individuals, but in 33 instances (7%), testing was unsuccessful.

Ever testing for HIV was reported by 70% of women and 66% of men, with 33% of women and 24% of men reporting a test in the previous 12 months. The proportion testing in the previous five years increased among both men (40% to 51%) and women (51% to 53%) since the 2004 survey.

Factors associated with testing for HIV within the previous five years among women included shorter period of residence in the UK (less than five years vs more than 20 years), recent attendance at A&E, ever using a sexual health clinic and increasing number of sexual partners. Recent testing among men was associated with being in the 25-34 age group, higher education, being African born, using health services in the previous year, sexual health clinic attendance and a previous diagnosis with an STI.

Oral HIV testing showed that 93% of women and 90% of men were HIV negative. Tests were positive in 22 men (41% undiagnosed) and 16 women (56% undiagnosed). In the previous survey, over 70% of infections were undiagnosed in both men and women.

The investigators urge that the undiagnosed percentages revealed in the present analysis should be viewed with some caution – other surveillance data suggests that approximately 10% of HIV infections among black African heterosexuals in the UK are undiagnosed.

In other findings, sexual health clinics were the most popular location for HIV testing, followed by GP surgeries.

A fifth of women and a quarter of men said their most recent sexual experience had involved condomless sex with a partner of different or unknown HIV status. Only 72 women and 69 men said they had heard of PrEP and only a very small proportion said they would be interested in using it.

“Almost half of respondents who supplied an HIV-positive oral fluid specimen self-reported that they were HIV negative or untested,” conclude the authors. “Increasing access to initiated HIV testing initiated by health care professionals in primary care and other health care services, as well as access to HIV self-testing and self-sampling may bolster HIV testing rates so that they are similar to those in other populations disproportionately represented by the HIV epidemic in England.”


Fakoya I et al. HIV testing and sexual health among black African men and women in London, United Kingdom. JAMA Network Open, 2(3): e190864 doi:10.1001/jamanetworkopen.2019.0864.