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. DIAGNOSIS
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.
FOLLOW-UP SMEAR
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 The guidelines are endorsed by the Medical Association of South Africa. |
