the last decade there has been a resurgence in malaria infections throughout Africa due to drug resistance in the Plasmodium parasite and poor compliance with both non-drug preventative measures and chemoprophylaxis. In South Africa this resurgence has been aggravated by the ever increasing number of imported cases.
In the past, malaria parasites in South Africa were regarded as sensitive to chloroquine. Since 1988, invitro1,2 and in vivo3,4 studies
showed an appearance and increase in resistance to
chloroquine as well as the spreading of its distribution in the eastern parts of the country. These have necessitated continuing changes in chemoprophylaxis5 and treatment policies for South Africa.
This policy has been compiled utilising available information, but adaptation may sometimes be necessary to
suit local circumstances.
Information on the incidence, distribution and degree of drug resistance in South Africa is incomplete and there is an ongoing need for monitoring therapeutic response and reporting the observations to the Department of Health for future policy revision.
The objectives for the treatment of malaria are:
- the prevention of mortality
the prevention of complications
the rapid resolution of the illness
the elimination of parasitaemia to minimise transmission
to limit the development of drug resistance
PARASITES AND RISK GROUP
In sub-Saharan Africa, over 90% of human malaria infections are due to Plasmodium falciparum while the rest of the infections are due to P. vivax, P. ovale and P. malariae. Infections due to P. falciparum may be severe and complicated.A These complications occur almost invariably as a result of delay in treating an uncomplicated attack, but occasionally may develop rapidly. The vast majority of South Africans are non-immune,B including residents in seasonally endemic malaria areas. Non-immune travellers to malaria areas are particularly prone to the development of severe and complicated falciparum malaria.
A For extensive and in-depth clinical treatment guidelines of severe and complicated malaria, we recommend Severe and Complicated Malaria edited by Warrell et al.
B Immunity is contracted after continual long-term exposure to the Plasmodium parasite and repeated infection.
The most important element in the diagnosis of
malaria, in both endemic and non-endemic areas, is a high index of suspicion. Malaria areas in South Africa include low altitude areas in the Northern Province, Mpumalanga and north-eastern KwaZulu-Natal (Figure 1).5 Any person resident in, or returning from, a malaria area who presents with fever and flu-like symptoms should be tested for malaria. In the majority of cases, examination of blood smears will reveal malaria parasites.7 On initial examination malaria parasites may not be found. Further specimens should then be examined by an experienced laboratory before the infection is excluded.
The initial confirmation of parasitaemia may be simplified by the availability of two rapid identification
tests, the plasma reagent dipstick8 (Parasite-F®) and the rapid immunochromatographic test (ICT Malaria P.f.®). These tests are only suitable for P. falciparum diagnosis. Both tests have been used with great success by the provincial control personnel during the 1996 epidemic for active detection of malaria cases. Where the suspicion of malaria infection is high and laboratory confirmation is not obtained, treatment is still warranted.
Since these guidelines have been based on the limited drug sensitivity data available, it is essential that a
follow-up blood smear is taken 2-3 weeks after completion of treatment to confirm elimination of the Plasmodium parasites. Inadequate therapy may result in the increase of multiple drug resistant P.
falciparum infections, which are already prevalent in south-east Asia. Both the Parasite-F® and ICT Malaria P.f.® tests may remain positive for up to three weeks after successful therapy of P. falciparum and should therefore be not be used for follow-up for this period after treatment