Asymptomatic malaria parasitaemia in sickle-cell disease patients: how effective is chemoprophylaxis?

BACKGROUND & OBJECTIVES Sickle-cell trait confers protection against malaria while homozygote sickle-cell disease (SCD) patients are at greater risk of malaria infection, hence the use of malaria chemoprophylaxis in SCD patients. The use of malaria chemoprophylaxis and asymptomatic parasitaemia were studied in SCD and non-SCD patients. STUDY DESIGN A semi-structured questionnaire was administered to both patients and controls; a thick blood film was also examined in both the groups. RESULTS Sixty-nine percent of patients use proguanil, 22% do not use any form of chemoprophylaxis, while 9% use pyrimethamine. There was no significant difference between level of parasitaemia in patients and controls (p = 0.1), a positive smear was found in equal numbers of patients on chemoprophylaxis and those not on chemoprophylaxis (p = 0.3). In the month preceding the study, 31% of patients vs 18% of controls had received treatment for malaria. There were no significant differences between patients and controls in frequency of malaria attacks (p = 0.06), last episode of malaria (p = 0.2). Ten percent of patients and 2% of controls use bednets. CONCLUSION This study did not find any advantage in the use of malaria chemoprophylaxis in SCD patients over controls or SCD patients not on chemoprophylaxis. Vector control should also be considered in the fight against malaria. There is a need to look into why both patients and controls fail to use bednets in a malaria endemic country.