Incidence of tuberculosis (TB) among
HIV-positive heterosexual people in England and Wales declined significantly between
2002 and 2010, investigators report in the online edition of AIDS. The fall is attributed to changes
in the epidemiology of HIV in the UK and increased uptake of antiretroviral
therapy. The vast majority of TB diagnoses – 84% – involved people from
However, the authors caution that their
results leave no room for complacency and point to the need to adhere to HIV
and TB testing guidelines. “Our findings reinforce the need for stricter
implementation of existing testing guidelines in the HIV and tuberculosis
clinic setting, and support the recommendation for primary care practitioners
to consider the risk of both diseases in migrant patients from high prevalence
Most cases of heterosexual HIV in the UK
involve people born in sub-Saharan Africa. There is a high prevalence of TB
in this region. As a result, a substantial number of HIV-positive, heterosexual people
in the UK are likely to have been exposed to TB.
It is recommended that all HIV-positive
people in the UK should be screened for TB. Despite this recommendation, the
incidence of active TB in this population is unknown.
A team of investigators examined
three national databases to establish the incidence of TB among HIV-positive
heterosexuals living in England and Wales between 2002 and 2010. Their analysis
also allowed the investigators to establish the risk factors associated with a
A total of 45,322 heterosexual people received
HIV care in England and Wales during the period of the study. Active TB was
diagnosed in 4266 individuals (9.4%).
Over half (54%) received a
simultaneous diagnosis of HIV and TB; 8% were diagnosed with TB more than three
months before their HIV diagnosis; and 38% were diagnosed with TB more than
three months after their HIV infection was detected.
“Active tuberculosis may have been prevented
in some cases had testing and treatment for latent tuberculosis been a routine
part of the initial assessment at the time of HIV diagnosis,” suggest the
Almost all (92%) of the people who
received a simultaneous diagnosis had their HIV diagnosed late, and 53% had a
CD4 cell count below 100 cells/mm3.
Some 84% of TB diagnoses involved black
African people. Factors associated with TB co-infection included sex (male vs female, AOR = 1.29, 95% CI, 1.15-1.44); ethnicity (black African, AOR
= 3.41, 95% CI, 2.45-4.76; Indian, Pakistani or Bangladeshi, AOR = 4.37, 95%
CI, 2.63-7.26), and acquiring HIV infection abroad (AOR = 2.31, 95% CI,
Between 2002 and 2010, incidence of TB
among HIV-positive heterosexuals fell from 30 per 100 to 8.8 per 1000. This
fall was highly significant (p < 0.01).
“This decline is due to a modest fall in
the absolute number of incident tuberculosis diagnosis…and a large increase in
the total number of heterosexual adults living with diagnosed HIV,” explain the
They believe patients are becoming less
susceptible to TB. “Firstly, the fall in TB diagnoses has coincided with a
decline in the overall number of heterosexuals in the UK acquiring their HIV
infection in sub-Saharan Africa, where there is a high prevalence of
tuberculosis. Secondly, in recent years, the uptake of ART [antiretroviral
therapy] among persons with a CD4-cell count < 350 cells/mm3 has
increased in line with national HIV treatment guidelines.”
Nevertheless, TB incidence among
HIV-positive heterosexual people was still significantly higher than that seen in the
general UK population (0.14 per 1000). The incidence of TB reported among
HIV-positive black Africans (11 per 1000) was approximately four times higher
than the UK rate for HIV-negative Africans born abroad (2.7 per 1000) and
25 times higher than the rate among HIV-negative black Africans born in the UK
(0.43 per 1000).
The incidence of TB among people not
taking antiretroviral treatment was over 14 times higher than that seen in
people taking anti-HIV drugs (56 per 1000 vs 3.9 per 1000; p < 0.01). The highest TB incidence
throughout the period of the study was among people not taking HIV
therapy who had a CD4 cell count below 200 cells/mm3.
“We have reported a significant decline
between 2002 and 2010 in the annual tuberculosis incidence rate among
heterosexual adults living with diagnosed HIV in England and Wales. However,
the tuberculosis incidence rate in 2010…greatly exceeds that in the general
population,” conclude the investigators.