Decentralisation of drug-resistant tuberculosis (DR-TB)
management and use of the Xpert MTB/RIF test improves the time from clinic presentation
to treatment from 50 days to 7 days in a population with a high burden of HIV and
TB co-infection, according to a study from Khayelitsha, South Africa, presented
at the 20th International AIDS Conference (AIDS 2014) on Monday.
Xpert MTB/RIF is a rapid test for identification of
TB and rifampicin-resistance. The test is being rolled out as a new diagnostic
for TB management in countries with a high burden of TB and HIV co-infection,
but there is limited evidence on the impact of the test in improving access to
Reducing the time between identification of
symptoms that suggest TB and the start of treatment is critically important. A
long delay between seeking health care and starting treatment increases the
risk of death from TB. People with TB may be lost from care and in the meantime pass on TB to their close contacts.
African study found that the decentralisation of treatment for drug-resistant TB reduced the time from diagnosis to treatment initiation from nine
weeks to less than four weeks. Xpert MTB/RIF further reduced the time to
treatment initiation to a median of seven days, with more than 90% of people living with HIV who had
rifampicin-resistant TB starting treatment.
More than 14,000 people are diagnosed with drug-resistant TB
in South Africa every year, with 65% estimated to be living with HIV (often referred to as HIV and TB co-infection). While case detection of drug-resistant TB is high, only 50% of people identified start second-line TB treatment, with
delays often up to several months. This leads to high mortality, particularly for people living with HIV, and ongoing transmission.
Khayelitsha is a large
township 40km outside Cape Town with a population of approximately 400,000
people. The antenatal HIV prevalence is 37% and there are currently 26,000
people on antiretroviral therapy (ART). Approximately 5100 TB cases are registered each year, with
approximately 200 rifampicin-resistant cases per year, 75% of both are in people living with HIV.
Between 2007 and 2013, decentralised management of drug-resistant TB was implemented progressively. Simultaneously, over 2007-2008,
first-line drug susceptibility testing (DST) moved from culture-based DST to
line probe assay (LPA).
The decentralised programme diagnosed 1368 people with drug-resistant TB (rifampicin-resistance), of whom 51% were female and 72% were living with HIV. Prior to
decentralisation (2003-2006), the median time to treatment was 71 days, using
culture DST (IQR 22-120 days), declining to 50 (IQR 12-88) with LPA and some decentralisation
during 2007-08 (p< 0.0001). Further decentralisation in 2009, 2010 and 2011
reduced the median delay to 39 days (IQR: 11-67), 32 (IQR 12-52), and 27 (IQR:
12-42) days respectively using LPA (p< 0.0001 for trend).
Xpert MTB/RIF was introduced in late 2011. This resulted in median delays of 13 (IQR: 7-19) and 7 (IQR: 3-11) days for
2012 and 2013 (p< 0.0001 when compared to the use of LPA). While HIV
infection was associated with longer delays across 2009 to 2011 using LPA
(p = 0.02), this significant difference disappeared in 2012-13 once Xpert MTB/RIF
was being used. Across 2009 to 2011, 94% of HIV-negative patients initiated
treatment, compared to 86% among people living with HIV (p = 0.001). Corresponding figures
for 2012-13 using Xpert MTB/RIF were 100% and 89% respectively (p = 0.001).