Investigating the Prevalence and Intensity of Plasmodium falciparum Infection and Two Methods of Malaria Diagnosis in North-Western Nigeria

Aims: The study was undertaken to estimate the prevalence and intensity of Plasmodium falciparum infection, in randomly selected areas of north-western Nigeria and to evaluate the efficiency of microscopy and rapid diagnostic test (RDT) in detecting and determining intensity of P. falciparum infection.

Study Design: The study was conducted in public health facilities from five out of the seven states of north –western Nigeria between April and August, 2013.

The states are Kano, Kaduna, Katsina, Kebbi and Jigawa states, respectively.

Methodology: A total of one thousand four hundred and seventy (1,470) blood samples were collected. Patients were asked to sign consent form after which 2-5 ml of blood was drawn (venepuncture) into EDTA sample bottles. Rapid one step malaria HRP2 Rapid test was carried as described by (Cheesbrough, 2016), to determine presence of Plasmodium falciparum and stained in Giemsa and examined by thick and thin blood smears under light microscope (X 40 objective ) in oil immersion.

Results: A total of eight hundred and thirty four 834(56.5%) cases were positive microscopically while two hundred and eighty seven 287(19.52%) were positive with the RDT which showed high significance (P<0.05) in the efficiency of the diagnostic methods. Low intensity (+) was higher in 542 (36.87%) and different significantly within the states (P<0.05).The RDT showed high specificity of 68.21% while a higher sensitivity of47.68% was observed from the microscopy results which differed significantly (P<0.05) when the two methods were compared.

Conclusion: The results of the study established that P. falciparum malaria was endemic in the states evaluated with certain level of intensity. Microscopy was the most specific method of falciparum malaria diagnosis. However discordance between microscopy and RDT requires further investigations.