Mohamed MY., Abakar AD, Talha Albadawi A, Salah Eldin G. Elzaki, Mohammed YA, Mohamedahmed KA and Bakri Yousif M. Nour, Sudan
Plasmodium falciparum is a virulent species and causes most severe and pathogenic form of malaria, characterized by high parasitic burdens and vital organ dysfunctions. The diagnosis of falciparum malaria in Sudan depends on microscopy and Rapid diagnostic test (RDTs). Nested PCR targeted 18S rRNA gene provides an alternative technique for identification of parasite in thick and blood film.
The study aims to estimate the diagnostic performance of 18S rRNA gene analysis by nPCR for detection of P. falciparum versus microscopic detection.
This is a cross sectional hospital based study. Two hundred and twenty blood samples and relevant data were collected from patients with falciparum malaria attending Wad Medani Teaching Hospitals and 26 samples from healthy participants. Parasite count was counted using stained thick blood film. The DNA extraction was done using TE buffer. Moreover, Nested PCR for 18S rRNA gene was done using specific primers. Data were analyzed using MedCalc programs (V. 16).
The microscopic examination of blood films showed that all patients (220/100%) were positive for P. falciparum among patients. one sample (3.8%) was positive among healthy participants (1/26). When using nPCR for 18S rRNA gene 219 samples were positive (99.5%) form patients and one sample was positive (3.8%) among healthy participants. The area under curve (AUC), sensitivity, specificity, positive predictive value, negative predictive sensitivity and Weighted Kappa agreement for the nPCR were 0.935, 98.6%, 88.6%, 60.1%, 99.7% and 0.871(95% CI:0.770 - 0.972), respectively.
Nested PCR for 18S rRNA gene is sensitive, specific, reliable technique for diagnosis of Plasmodium falciparum in the endemic study area and can be introduced as a confirmatory diagnostic tool.