RESUMO
The study aimed to investigate the underlying causes of recurrent malaria infection in Khartoum State. This study was conducted in El Haj Yousif a pen-urban area in the northeast border of Khartoum state in the period August 1998 -December 2000, it was a prospective, clinically based study. Three hundred patients presenting with recurrent malaria were studied. Eighty three percent of the patients were found to have P. falciparum, 10% have mixed infection [P. falciparum and P. vivax], 5% have P. vivax only and 2% of cases have P. ovale. Unlike what is generally believed not all recurrent malaria in Khartoum State was due to recrudescence of the primary infection, [incomplete treatment or drug resistance or re-infection]. A significant proportion was due to relapse from persistent hypnozoites [P. vivax and P. ovale] in the liver, relapses of which can be prevented by eradication of the liver hypnozoites by primaquine therapy. This was confirmed by the malaria parasite identification and count which was done on the blood samples