The burden of tuberculosis in South Africa
Dr Bernard Fourie
MRC National Tuberculosis Research Programme, South Africa

Africa and southern Africa
In their 1997 reports on the tuberculosis epidemic and on anti-tuberculosis drug resistance in the world, the WHO paints a bleak picture of the global failure of health service providers to deal with the burden of tuberculosis. In the 216 reporting member countries of the WHO, representing a total population of 5,72 billion, there were an estimated 7,4 million new cases of tuberculosis in 1995. This represents a rate of 130 cases among every 100 000 persons.

In Africa the case rate is 216 per 100 000. The 11 countries of the Southern Africa subregion contribute approximately 275 000 cases every year to the total case load in Africa. Almost half of these come from South Africa. In an analysis of tuberculosis trends and the impact of HIV infection on the situation in the subregion, it is estimated that by 2001 the smear positive case rate would have increased from 198 per 100 000 population for the region as a whole, to 681 per 100 000 if tuberculosis control efforts are not optimised. To aggravate the situation, 69% of these cases would be directly attributable to HIV infection.1

A serious complication of the tuberculosis problem in Southern Africa has been the emergence of multi-drug resistant (MDR) strains of the organism causing the disease. Patients infected with MDR require prolonged chemotherapy with very expensive medication which will at best cure only half of them. Such treatments cost at least 100 times as much as the cost of curing an ordinary tuberculosis patient infected with drug-sensitive bacteria. Very few countries can afford this additional burden.

In order to determine the magnitude of the MDR problem in Southern Africa, and the implication for National Tuberculosis Programmes (NTP's), surveys are being conducted in various countries as part of the activities of the WHO/IUATLD Global Working Group on Tuberculosis Drug Resistance Surveillance. So far, information is available for four countries in southern Africa: Botswana, Lesotho, South Africa, and Swaziland.

Results confirmed that initial resistance to first-line drugs is relatively low in southern Africa compared to some other regions in Africa and Asia where the problem is up to 5 times more common. Resistance rates range between 4% and 12% for isoniazid, and between 4% and 7% for streptomycin. For rifampicin it is 1% and for ethambutol 1%; MDR is fortunately still low at 1%, indicating that resistance strains are not commonly transmitted from person to person. On the other hand, rates for acquired resistance, that is resistance which has arisen in patients previously inadequately treated for tuberculosis, are at least three times higher than in patients not previously exposed to anti-TB medications. The high rates of acquired resistance point to a failure of control programmes to effectively manage case-holding and treatment adherence.

South Africa
South Africa is burdened by one of the worst tuberculosis epidemics in the world, with disease rates more than double those observed in other developing countries and up to 60 times higher than those currently seen in the USA or Western Europe. The MRC estimated that the country had an estimated 180 507 cases (55% reported) in 1997, or 419 per 100 000 of the total population.Of these, 32,8% (73 679 cases) were probably infected with HIV. Although South Africa has lagged behind other African countries in terms of HIV incidence (probably because of geographical, social and political barriers), the HIV epidemic has increased rapidly and exponentially during the last 6 years.

The tuberculosis problem in South Africa is largely a result of historical neglect and poor management systems, compounded by the legacy of fragmented health services. Prior to the introduction of the Tuberculosis Register in 1995 cure rates were unknown, and consequently control efforts could not challenge poor performance. The implication of this failure is evident from the fact that in 1997 a cure rate of only 54% could be recorded, with the consequence of continued high rates of transmission in the country.

The impact of TB/HIV-coinfection in provinces such as KwaZulu-Natal, Mpumalanga and Gauteng, is leading to sharp increases in tuberculosis rates in these areas. Over the next 5 years the epidemiological profile of tuberculosis in South Africa is likely to change dramatically. Increasing rates are likely to continue, and will be more pronounced in provinces with fast-growing HIV infection rates. Optimal tuberculosis control efforts with high cure rates and a significant decline of more than 20% in the transmission of HIV infection will be required before stabilisation and eventually a downward turn in tuberculosis rates in the country might only become visible towards the end of this period.

Estimates by the MRC National Tuberculosis Programme indicate that current trends in the epidemic will continue unless effective control is achieved, resulting in 3,5 million new cases of tuberculosis over the next decade and at least 90 000 patients dying.1 The financial implications are staggering: Given that more than US$100 million are spent annually on tuberculosis in South Africa, in excess of US$3 billion would be required over the next 10 years if current increases in tuberculosis rates are allowed to continue unabated. On the other hand, significant reductions in transmission of HIV infection together with effective tuberculosis control would mean a turn-around in the tuberculosis epidemic by the year 2003. At least 1,7 million tuberculosis cases will be prevented and more than US$400 million would be saved.

On the positive side, however, tuberculosis was declared a top health priority by the Department of Health in November 1996 and National Health Minister Zuma committed her Department to implementing a new control programme based on the DOTS strategy of the World Health Organisation. The pace and extent of implementation of the programme is, however, slow in most provinces. Since 1996, a system of case registration based on strict criteria for case definition was implemented in South Africa. These registrations, based on standardised criteria, are now beginning to present a clearer picture of disease rates in the country than what was available before. Some progress is being made in certain provinces in South Africa. Mpumalanga (despite relatively high HIV rates) and the Western Cape are already showing dramatic improvements in cure rates, because of disciplined implementation of the DOTS strategy of the WHO in these provinces. Other provinces are at various stages of implementation of the process .

In comparison with the MRC estimates based on epidemiological modelling as mentioned above, actual registration reports to the National Department of Health indicated smear positive rates per province (per 100 000 of the total population) of 285 for the Western Cape, 300 for the Eastern Cape and 328 for the Northern Cape. All other provinces had rates below 200. The overall rate for South Africa was 163 for smear positive and 310 for all pulmonary tuberculosis cases.2 It suggests that the country might be in a slightly better situation than what had been estimated as the worst scenario. Also, it appears that the epi-centre of tuberculosis in South Africa is shifting away from the Western Cape, which had until recently been regarded as one of the regions with the highest tuberculosis rates in the world. Several factors might be responsible for this shift, including improved case-finding in the Eastern and Northern Cape, and/or more effective control procedures in the Western Cape.

Although the overall situation in South Africa still seems to be far less than optimal, these early signs of improvement could signal the beginning of better times for tuberculosis control in the country.

References

  1. Fourie PB, Weyer K. Epidemiology. In: WHO review of the tuberculosis situation in South Africa. Geneva: WHO, July 1996.
  2. Fourie PB, Donald PR. Epidemiology of tuberculosis. In: Donald PR, Fourie PB, Grange JM (eds). Tuberculosis in Childhood. Pretoria: Van Schaik's Publishers, 1999.

SADC Countries

CONTACTS:

Dr Martie van der Walt
E-mail: vdwalt@mrc.ac.za

Dr Roxanna Rustomjee
E-mail: roxanna.rustomjee@
mrc.ac.za

Prof Valerie Mizrahi
E-mail: mizrahiv@
pathology.wits.ac.za

Prof. Paul van Helden
E-mail: pvh@sun.ac.za

 

Last updated:
22-Jun-2011

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