Over 50% of tuberculosis (TB) patients in London were not offered an HIV test, investigators reported at the Fifteenth Annual Conference of the British HIV Association (BHIVA). Even in groups with a high risk of HIV, the offer of a test for HIV was not universal, the conference was told.
An HIV test has been recommended for all adult patients diagnosed with active TB since the late 1990s. The importance of such screening is emphasised for patients with a high risk of HIV infection, including origin from a country with a high HIV prevalence.
Investigators from London wished to establish the proportion of TB patients offered HIV tests, and the factors affecting the offering of this test and its acceptance.
The records of all 1941 patients diagnosed with TB in London between 2003 and 2004 were reviewed. Researchers documented the demographic details of each patient, if an HIV test was offered, the results of such a test, and the factors associated with the offering and acceptance of an HIV test.
Overall HIV prevalence was 10% (193 of 1941 individuals). Just over half (52%) these patients were known to be HIV-positive before they were diagnosed with TB.
Of the 1840 patients who had not been tested for HIV before the development of TB, only 48% were offered an HIV test.
Overall HIV prevalence amongst TB patients tested for HIV (plus those already known to be HIV-positive) was 26%.
The investigators looked at the demographics of TB patients co-infected with HIV. They found that 93% were born outside the UK and that 80% came from sub-Saharan Africa.
TB patients who were female, aged between 20 and 49 years, were of black African origin and born outside the UK were significantly more likely to be co-infected with HIV.
Factors significantly associated with being offered an HIV test were: age between 20 and 49 years (p < 0.0001), being male (p < 0.0001), of black African origin (p < 0.0001), resident in the UK for less than twelve months (p < 0.001), having a good understanding of English (p = 0.04) and having sputum smear-positive TB (p < 0.006).
An HIV test was accepted by 73% of patients to whom it was offered. Factors associated with the refusal of a test were being female (p <0.001) and aged over 49 years (p < 0.001).
The proportion of patients being offered an HIV test varied considerably between clinics, from a low of 5% to a high of 94%. The highest rates of testing were at centres with integrated HIV and TB services.
Given the high proportion of patients who were untested, the investigators believe that the 10% prevalence of HIV and TB co-infection in London found in their survey is likely to be an underestimate. They emphasise that TB patients with a high risk of HIV were not always tested and conclude that the offering of an HIV test should be considered a key quality indicator for TB services.
Rodger A et al. HIV prevalence and testing practices among tuberculosis cases in London. Fifteenth Conference of the British HIV Association, abstract O25, Liverpool, 2009.