OCCUPATIONAL SAFETY AND HEALTH Case study Multi-Drug resistant TB treatment at AngloGold Ashanti
In recent months, media articles have raised the issue of multi-drug resistant (MDRTB) and
Extensively Drug Resistant Tuberculosis (XDRTB) in Southern Africa and internationally. This
follows both a drive to highlight an international awareness campaign and the detection of an
XDRTB strain in KwaZulu-Natal, which is a new mutant virulent strain that had not previously been
MDRTB refers to Multi Drug Resistant TB where the TB organism demonstrates resistance to at
least Isoniazid (H) and Rifampicin (R), two of the most effective first line anti-TB drugs available.
XDRTB stands for Extensively (or Extremely) Drug Resistant TB, where the TB organism
demonstrates resistance to one of the second line injectable drugs (Kanamycin (Km), Amikacin
(Am), or Capreomycin (Cm)) and to the Fluoroquinolones. A global perspective
According to the World Health Organization (WHO), 8.9 million new cases of TB were reported in
2005, with 80% of these in 22 highest-burden countries. South Africa is placed at fifth highest in
burden of disease and seventh highest in disease incidence. Further, of the 1.7 million TB related
deaths in 2004, 98% were in the developing world. MDRTB is present in 102 of 109 countries
which report TB statistics to the WHO.
The WHO estimates suggest that 424,203 MDRTB cases were detected in 2004, representing
4.3% of all new and previously treated TB cases. More than half of these were in China and India,
while the highest estimated prevalence was in countries of the former Soviet Union and certain
provinces of China. This represents a 55% increase over the estimates for 2000.
The first global survey of TB culture and drug sensitivity testing showed that 10% of global
MDRTB bacterial isolates fulfilled the criteria for XDRTB. Of MDRTB isolates detected in Africa,
less than 1% were XDRTB. This may not be a true reflection of the situation and might reflect the
lack of cultures (TB bacterial samples) being tested in Africa (owing to lack of infrastructure and
TB in South Africa
Not only is South Africa experiencing a high burden of TB cases, this is negatively influenced by
the high rates of HIV infection in the country. The South African mining industry has seen a steady
rise in the incidence of TB over the past 20 years, fuelled by the HIV epidemic and, to a lesser
Identifying the outbreak of XDRTB in KwaZulu-Natal has been facilitated by the application of DNA
technology. The organism – named the KZN strain – demonstrated particular virulence, causing
52 deaths in 53 patients in the initial case finding report whilst demonstrating resistance to all
available treatment. Further investigation identified the strain in patients in 28 hospitals in
KwaZulu-Natal, but not necessarily in the severely resistant form. The KZN strain has not been
identified among AngloGold Ashanti employees.
TB in AngloGold Ashanti
Currently the TB incidence within AngloGold Ashanti’s South African operations is estimated at a
rate of 3,000 per 100,000 individuals. AngloGold Ashanti Health’s TB Control Programme is
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OCCUPATIONAL SAFETY AND HEALTH Case study
robust, incorporating and exceeding the criteria stipulated by the South African National TB
Control Programme Guidelines, and the Department of Mineral and Energy Guidelines for the
Recent TB case finding reports indicate that between 85% and 90% of the current TB cohort
(employees with TB) are also infected with HIV. Despite the TB Control Programme (with outcomes
which exceed the WHO objectives of 85% successful treatment outcomes for new TB cases), the
MDRTB-infected patients were first identified at AngloGold Ashanti in 1987. Following a noted
increase in the number of patients presenting with MDRTB in 2003, a combined research project was
initiated at AngloGold Ashanti’s request with the Department of Biomedical Tuberculosis Research at
the University of Stellenbosch using DNA fingerprinting technology to evaluate the epidemiology and
identify the possible causes. Within the cohort of MDRTB, the health service currently has three
patients who meet the criteria for XDRTB, where the disease is not responding to the available
medication. These patients obviously pose a threat to other patients, health care workers and visitors.
Two of the six classes of second line alternative drugs used for the treatment of MDRTB were
previously not available in South Africa. The health service has since remedied this situation via
the intervention of the Medicines Control Council (MCC), in the event that any cases of the virulent
strain of XDRTB (as identified in KwaZulu-Natal) manifest within AngloGold Ashanti.
A particular area of concern is that, with increased exposure, health care workers naturally have
a higher incidence of TB than lay people and consequently a higher incidence of MDRTB. Since
1999, four health care workers in service are known to have contracted MDRTB; one has
The MDRTB risk to health care workers has prompted even greater infection control effort in our health
facilities including; provision of special respiratory protective equipment for staff, ward ventilation
control measures, installation of UV lights and a six monthly medical surveillance programme. AngloGold Ashanti’s response to MDRTB and XDRTB
The average incidence of MDRTB in the West Vaal hospital in the Vaal River operations over the
last four years (2002 to 2006) is 5.3% of all TB cases. The WHO defines an MDRTB ‘hot spot’ as
an area with rates of 7% and above. States in the former Soviet Union and Eastern Europe, for
example, have MDRTB rates of 10 to 14% and higher.
Mortality as a result of MDRTB is much higher than that associated with normal TB. Strongly
influencing that mortality rate is the presence of HIV infection in the patient.
Of the total cohort of 140 patients being followed:
32% died, although not necessarily from the MDRTB
7.1% were transferred out to other appropriate facilities
7.9% of patients who had laboratory evidence resistance but without clinical evidence of
disease are being followed up (with negative subsequent laboratory tests)
The drug cost for treating normal TB is approximately R4 per day and R155 per day for MDRTB.
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OCCUPATIONAL SAFETY AND HEALTH Case study
In response to the presence of and increase in MDRTB patients, AngloGold Ashanti Health has
set up an Isolation MDRTB ward at the West Vaal Hospital where patients with confirmed MDRTB
are treated. This is the only facility of its kind outside of the state facilities in South Africa.
A comprehensive strategy has been developed in the face of rising MDRTB and the detection of
a few XDRTB cases. Elements of the strategy include:
Transmission and environmental controls to limit the spread of the disease, including early
identification and limiting the spread in the clinical environment;
Patient-centred controls, which include the promotion of cough education and etiquette,
identifying and fast tracking coughing patients through clinic and hospital waiting areas and
Staff-centred controls, including ensuring that staff wear personal protective equipment (PPE)
More efficient treatment follow-up, particularly for treatment defaulters;
Monitoring and surveillance of statistics; and
Information, education and communication.
All of the above are normal elements of well run ‘drug sensitive’ TB control programmes and strict
application will do much to reduce the incidence of MDRTB and XDRTB
Despite having a sophisticated TB laboratory on site (that makes use of up to date and current best
practice microscopy and culture technology) it may still take from two to eight weeks to confirm the
diagnosis of normal TB or MDRTB. This prolongs the potential infectious period before isolation of
patients in the MDRTB ward can be justified. The possibility of transmission of normal sensitive TB or
MDRTB strains in the setting of a high HIV prevalence in the population is therefore a significant reality.
Rapid identification of MDRTB strains using DNA technology such as that used at the University of
Stellenbosch has the potential to confirm diagnosis within 48 hours on a single sputum sample. At
present this is however still a research tool and as such is expensive and available in only a few
specialised laboratories. It requires development into a form that can be performed at any laboratory.
The health service is currently investigating the introduction of rapid techniques to identify
resistance to Rifampicin (Rifampicin resistance is a surrogate marker of MDRTB as nearly all cases
of Rifampicin resistance are associated with Isoniazid resistance, which fulfills the diagnostic
criteria for MDRTB), with plans to have this diagnostic regimen up and running for routine use at
the West Vaal Hospital TB Laboratory in the first quarter of 2007. This could result in the current
delay in identification of possible MDRTB patients being shortened to 48 hours, making it possible
to institute appropriate isolation infection control measures for the suspects much earlier, thus
According to Dr Alistair Calver, senior specialist physician at AHS, “The biggest challenge to
achieving higher successful outcome percentages is the fact that our mortality rates from other
AIDS-defining conditions within our TB cohort is high. This reflects a need to get more of our HIV
infected employees onto our Wellness Program and Anti-Retroviral Therapy (ART) at an earlier
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ENVIS Bulletin Vol7(2) : Himalayan Ecology Summary of completed/ongoing projects DEMOGRAPHIC, BIOLOGICAL AND CULTURAL PROXIMATES OF HEALTH AND DISEASE IN ARUNACHAL PRADESH R.K. Pathak Department of Anthropology, North-Eastern Hill University, Shillong 793022, Meghalaya The present study has been undertaken to find out the demographic, biological and cultural proximates
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