ABSTRACT
Malaria is a major health problem. The efficacy of treatment depends on its early diagnosis using rapid effective diagnostic tests. Correct diagnosis is urgently needed to reduce mortality and morbidity and also to reduce wastage of costly drugs. Comparison of microscopic blood smear examination, with the P. falciparum histidine rich protein 2 immunochromatographic test [HRP2-ICT] and the nested polymerase chain reaction [PCR] in detection of malarial infection in clinically suspected patients. A total of 91 patients attending Jazan General Hospital, Jazan KSA, complaining of a short febrile illness or prolonged undiagnosed pyrexia were investigated for harboring malaria parasites by microscopic Giemsa- stained blood smears, HRP2-ICT and nested PCR. The diagnostic performance of these methods was calculated. Out of the 91 clinically suspected malarial cases, 23 [25.3%] were positive for Plasmodium infection using microscopy, while HRP2-ICT and PCR detected 25 [27.5%] and 29 [31.9%] positive cases, respectively. Patients diagnosed by PCR proved to be 27 [93.1%] P. falciparum-infected and 2 [6.9%] P. vivax-infected. The differences in detection rates of these diagnostic tests were statistically significant [P<0.001]. Sensitivities of PCR, HRP2-ICT and blood smears were 97%, 83% and 77%, respectively. The three methods gave a specificity of 100%. Additionally, HRP2-ICT proved to be more in accord with PCR [K;= 0.8 versus 0.7] than the blood smear. Clinical diagnosis of malaria should not be relied on. Using antigen detection tests and PCR techniques in addition to microscopic blood examination will help to diagnose malaria cases accurately