HIV related tuberculosis in the United Kingdom: epidemiology, practice and control

Background:

Latent tuberculosis infection (LTBI) reactivation amongst people living with HIV (PLWH) remains significant, despite HIV virological control.

Methods:

Four studies were undertaken. A UK survey of HIV clinicians determined current LTBI screening practice in PLWH. An evaluation of the Leicester HIV cohort defined overall risk of active TB amongst PLWH, and risk factors for incident TB. A patient questionnaire cohort study examined attitudes and planned behaviour towards LTBI screening/treatment amongst PLWH and correlated these with actual screening outcomes. Finally, systematic LTBI screening/treatment of the entire Leicester HIV cohort defined LTBI risk factors and assessed feasibility of programmatic screening.

Results:

National LTBI screening practices were heterogeneous and offered by 57.4% HIV centres; this was not congruent with local TB-HIV burden. 325/2158 (15.1%) of the Leicester HIV cohort had had active TB; 100/325 (30.8%) was incident TB occurring more than 3 months after HIV diagnosis, with incidence rate 4.47/1000 person years. Incident TB risk and the time taken to develop incident TB were significantly associated with TB incidence in the country of birth (p<0.0001). There was overwhelming support for LTBI screening amongst 444 PLWH answering Likert-scale questions; screening uptake 390/393 (99.2%); acceptance of LTBI chemoprophylaxis 36/37 (97.3%); treatment completion 34/36 (94.4%). Programmatic screening identified 142/1167 (12.2%) IGRA positive results; one had active TB and the remainder LTBI. LTBI diagnosis was significantly associated with TB incidence in the country of birth (p<0.0001). The greatest yield in terms of the proportion of LTBI positive cases/total screened occurred when PLWH from countries where TB incidence was >150/100,000, plus other sub-Saharan Africa countries, underwent screening. 120/141 (85.1%) commenced chemoprophylaxis; 114/120 (95%) completed.

Conclusions:

PLWH are still burdened by TB and more LTBI screening is required in the UK. It is supported by PLWH and is programmatically feasible. Cost-effectiveness analysis based on this data is planned.