Recent Developments

*  2002: Malaria Cases in KwaZulu-Natal for 2001 have decreased by over 75% from the previous year. ( Data from South African Department of Health ) This is thought to be partly a result of the re-introduction of DDT spraying and the change of the first-line treatment to co-artemether in some areas, as well as a regional approach to malaria control in the Lubombo SDI. ( See vector control, parasite control and malaria transmission below as well as Lubombo SDI Malaria Control )

Update on Malaria in Southern Africa
Jan 2001

 "Malaria has slowed economic growth in African countries", to the extent that some countries are experiencing negative growth rates, and that since the 1960's the continent as a whole has sacrificed a third of its economic output (as GDP), for a loss now reaching $100 billion annually (Heads of State Meeting, African Summit on Roll Back Malaria, Abuja, Nigeria, 2000).

Historical malaria situation in South Africa

South Africa is not exempt from the potential ravages of malaria with its debilitating effects on communities and development. The areas affected can be seen from the continental distribution of the disease  (Box 1).

Box 1: Continental distribution of malaria. Since no continental atlas of malaria distribution, intensity and seasonality is available, the MARA/ARMA project is collecting and analysing all relevant published and unpublished malaria data from across Africa  ( http://www.mara.org.za ). An early product of this collaboration is a theoretical model of distribution of endemic malaria, based on continental long-term climate data . Red areas are those where climate is suitable and malaria probably endemic; blue and white areas have unsuitable climate and probably rarely epidemic or no malaria. This model agrees well with the few available country-level malaria maps.

Due to local climate, malaria transmission follows a distinctly seasonal pattern, and experiences marked inter-annual fluctuations leading to periodic epidemics.

Prior to its control from the late 1940's, malaria was endemic in the provinces of KwaZulu-Natal, Mpumalanga and Northern Province with recorded epidemics as far south as Durban and Pretoria on the highveld (Figure 1). Malaria mortality estimates by magistrates in KwaZulu-Natal from November 1931 to June 1932 totalled 22 132 (population at risk = 985 000), an exceptionally high mortality rate of 2.2%. In 1932, all the districts of KwaZulu-Natal Province, bar one, reported cases of malaria.

Figure 1: Malaria risk in South Africa in 1938, prior to the introduction of disease control.

Malaria is controlled in South Africa through mosquito vector control by intra-domiciliary spraying with a residual insecticide and parasite control by definitive diagnosis and treatment towards parasitological cure. Additional control measures include the use of focal larviciding and more recently insecticide impregnated bed nets as subsidiary control measures in specific areas.

Vector control

DDT was the insecticide used for indoor malaria mosquito control from the 1940's until 1996 when synthetic pyrethroids were introduced. The change was instituted due to mounting international pressure to have DDT banned, high levels of DDT in the breast milk of primiparous mothers and social resistance (re-plastering over DDT and refusing household access) due to the increased incidence of bedbugs, associated with the use of DDT. An increasing number of donor agencies would not fund malaria control programmes using DDT, even though the World Health Organisation still supports its use in public health.

Parasite control

Malaria in South Africa is based on definitive diagnosis by microscope or more recently by rapid diagnostic kit, followed by appropriate treatment. First line treatment policy in South Africa has varied provincially since KwaZulu-Natal changed from the use of chloroquine to sulphadoxine / pyrimethamine due to resistance by the malaria parasite Plasmodium falciparum. Policy has just changed again due to resistance, to combination therapy co-artemether

Malaria Transmission

Malaria transmission is distinctly seasonal in South Africa with notifications generally increasing from November onwards (Figure 2). Peak rates in health facility malaria outpatients usually occur in April and decline by June.

Figure 2. Seasonal profile of malaria cases for the 1998/99 malaria season (Source Department of Health, South Africa)

There has been a marked increase in malaria transmission in South Africa since 1996 (Figure 3) with the situation being most pronounced in KwaZulu-Natal Province (Figure 4). 

Figure 3: Malaria case totals for South Africa aggregated by season (July to June) for July 1971 to June 2000. The line is an exponential curve modelled on the season totals.

The underlying reasons for the increase are difficult to quantify, but two proven factors are the rediscovery of Anopheles funestus in sprayed houses in the malaria areas, which have been shown to be resistant to synthetic pyrethroids ( the insecticide used to spray the houses) and the high levels of resistance to first line malaria treatment in KwaZulu-Natal (sulphadoxine / pyrimethamine) by the malaria parasite Plasmodium falciparum .

Figure 4. Notified malaria cases from the 3 malarious Provinces in South Africa.

The problem of insecticide resistance has been addressed in KwaZulu-Natal by a prompt reversion to the use of DDT for intra-domiciliary spraying during the winter of 2000. This action should, as was the case in the past, eradicate Anopheles funestus from the targeted areas with a resultant decrease in transmission.

The situation in regard to parasite control is more complex. The community based in vivo studies (drug efficacy) conducted in KwaZulu-Natal during the current malaria season, show parasitological resistance levels greater than 62% to sulphadoxine / pyrimethamine. A more effective treatment is essential to reduce morbidity, mortality and transmission. There is a global consensus that using a single drug (sequential monotherapy) should be replaced by combination therapy including an artemisinin derivative towards delaying the emergence and spread of drug resistance but also towards improved clinical cure rates and reduced transmission.  Based on these facts, the first line therapeutic drug for malaria had to be revised in KwaZulu-Natal and the decision has been taken to change from monotherapy to a drug combination of artemisinin and lumafantrene (co-artemether), which will be introduced in mid-February 2001.

A regional approach to malaria control

A regional malaria collaborative project between South Africa, Swaziland and Mozambique, part of the Lubombo Spatial Development Initiative and funded by the Business Trust, aims to control malaria in southern Mozambique. The study showed infection rates as high as 90% in children aged 2 to <15 years of age in the Mozambique sector and in close proximity to the highest risk areas in Ingwavuma district (Figure 5, 6).

The highest risk malaria areas in South Africa are border areas, specifically Ingwavuma, and these areas will benefit positively from reductions in malaria transmission in southern Mozambique (Figure 5, 6).

Figure 5. Malaria incidence at magisterial district level in South Africa during the 1988/89 and 1998/99 malaria seasons.

A house spraying programme is in place in both KwaZulu-Natal and Swaziland; a vector control programme based on house spraying commenced in southern Mozambique in November 2000. Both Swaziland and KwaZulu-Natal are using DDT, and Mozambique, a Carbamate insecticide. Malaria control cannot be viewed as a country specific problem, but is best viewed in a regional context as both mosquitoes and infected persons move across borders from non-controlled areas, thus limiting the effectiveness of control in South Africa. There is a high level of support for this regional approach to malaria control and the positive benefits this should have for tourism development in the areas of Northern KwaZulu-Natal, Eastern Swaziland and southern Mozambique. Sub-district malaria distribution maps are being developed towards dispensing appropriate malaria risk information to the tourism sector right down to the facility level.

Figure 6. Plasmodium falciparum infections.

In conclusion: Given the commitment by government there is no reason to believe that malaria in South Africa cannot again be reduced to low levels by the effective use of appropriate insecticides and effective drugs, and sustained in the longer term through a regional approach to control. The latter is a first for the African continent and is timely in view of the World Health Organisation's "Roll Back Malaria" Initiative.