SAHR 2007 - Health Systems Trust

Health and Related Indicators 15
Tuberculosis (TB)
Considerable prominence has been given to tuberculosis in
South Africa, particularly because of the high-profile outbreak
of extensively-resistant TB in Tugela Ferry. The latest World
Health Organization report on the global TB picture [Global
TB Control 2007], noted that globally the 2005 targets for
DOTS programme of 70% case detection and 85% cure were
“narrowly missed”. It did acknowledge, though, that all of the
Millennium Development Goals in this regard were unlikely
to be met by 2015. Globally, TB prevalence and death rates
have been falling. The total number of new cases is, however,
“rising slowly” as the case-load in Africa, South-East Asia and
the Eastern Mediterranean regions grows. The report gave
prominence to 22 “high burden countries”, including South
Africa, that together account for approximately 80% of all
new cases each year. South Africa was ranked 7th, based on
the number of incident cases. Those countries ranked higher
all have considerably larger populations (India, China,
Indonesia, Nigeria, Bangladesh and Pakistan). The following
key findings are taken from that report, as provided to the
WHO by the national and provincial TB programmes.
In 2005, South Africa reported 270 178 new and relapse
cases. Of the 241 879 new cases, 39 379 (16.4%) were
extrapulmonary. Critically, given the way in which cure rates
are calculated, only 51.9% of the new cases were smearpositive.
There were 125 460 new smear-positive and
76 680 new smear-negative / unknown cases. South Africa
had almost the highest incidence (all forms) per 100 000
population per year of all the high-burden countries (600,
only exceeded by Zimbabwe with 601 and Kenya with 641).
The incidence of smear-positive TB was reported as 245 per
100 000 population. The locally reported figure is comparable
(Table 15). However, updated data from NDoH show a
continued increase in the overall incidence of TB, which was
reported as 722 cases per 100 000 population for 2006.
Some of this increase may be due to improved data quality,
since the Electronic TB register was introduced fully in 2004.
Of the 15 countries with the highest estimated TB incidence
(all ages, all forms) in 2005, South Africa and its immediate
neighbours (Namibia, Botswana, Zimbabwe, Mozambique,
Lesotho, Swaziland) provided 7 countries, and a further 2
(Zambia, Malawi) were members of the Southern African
Development Community (SADC). The overlap with the global
epicentre of the HIV pandemic is striking.
The prevalence (all forms) for South Africa was recorded by the
WHO as 511 and the mortality (all forms) as 71 per 100 000
Health Status – Infectious Disease
population. This last figure is markedly different from that
calculated from the StatsSA Causes of death 2005 report.
The WHO report notes approximately 34 000 deaths from
TB in 2005. The StatsSA data included 73 903 deaths due to
TB (ICD-10 codes A15-A19) as the underlying cause of death
in the same year, without adjusting for under-reporting. Using
the StatsSA mid-year population estimate yields a mortality
of 158 per 100 000 population. It is possible that a number
of TB cases are being seen outside of the provincial treatment
programmes, or that a number present in extremis and are
thus not registered with the programme before succumbing
to the disease.
The WHO figures are based on a standard data collection
form distributed to national treatment programmes.
Outcomes for the 2005 figures were based on the TB
patients registered in 2004 and MDR-TB patients registered
in 2002. The WHO report makes the important statement
that “[t]he specific effects on TB epidemiology of HIV infection,
drug resistance, the impact of DOTS and other phenomena
cannot easily be disentangled in routinely collected data”.
Nonetheless, a key feature of the report is the apparent
mismatch between the improvement in DOTS coverage
over time and the treatment success rates achieved in South
Africa. Despite the claimed improvement in DOTS coverage,
the percentage of new smear-positive cases considered to
be treatment successes (the sum of those cured and those
completing treatment) has not changed over the last 9 years
(Figure 4). In 2005, South Africa reported that 94% of the
population was covered by DOTS, compared with none in
1996 and 13% in 1997. Despite this, the cure rate for the
2004 cohort was only 54%. In addition, 15% of the cohort
completed treatment, 7.4% died, 1.5% failed treatment, 11%
defaulted, 6.2% transferred to another facility (and the treatment
outcome was unknown) and a further 4.5% were not
evaluated. For the 2004 cohort, only two high-burden countries
reported worse treatment success (Russian Federation,
at 59%, and Zimbabwe, at 54%) and one (Uganda) reported
the same value (70%). Outcomes for smear-positive retreatment
cases were predictably poorer. Of the 2004 cohort,
27% were cured, 29% completed treatment, 12% died,
2.4% failed treatment, 17% defaulted, 6.8% transferred and
6.2% were not evaluated. Treatment success was thus 56%.
The 2006 national targets for TB control (a cure rate for new
smear-positive pulmonary TB cases of 60% and an interruption
rate for new smear-positive TB cases of 10%) thus seem
reasonable, if depressingly modest. Actual outcomes for
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