Diagnosis of Plasmodium falciparum malaria in children using the immuno-chromatographic diagnostic technique
AbstractBackground: Children under five years of age constitute the “at risk” population for fatal complications of P. falciparum malaria infection. Early diagnosis and prompt treatment are key features in the current Roll Back Malaria Programme.
Objective: To assess the diagnostic performance of the Immunochromatographic test (ICT) in the rapid diagnosis of falciparum malaria infection in children aged less than five years with a presumptive clinical diagnosis of malaria.
Method: This prospective study was conducted at the Children Emergency Room of the Lagos University Teaching Hospital between January and October 2001. Febrile children aged less than five years and were suspected to have malaria, were enrolled. Blood samples from all patients were tested using the ICT-Malaria P f Ò test kit as well as the conventional blood film microscopy after Giemsa staining.
Results: The results showed that the diagnosis of falciparum malaria was achieved within eight minutes using the ICT-Malaria P f Ò test kit. The sensitivity of the test kit was 69.6 percent while the specificity was 98.4 percent. However, among patients with severe malaria, the ICT had a sensitivity of 90.3 percent. The test kit was unable to detect antigenaemia at parasite density below 400/ml. An increase in body temperature was associated with higher rate of ICT test positivity.
Conclusion: The low sensitivity of the ICT technique obtained in this study makes it a poor screening tool for the routine diagnosis of falciparum malaria in children aged 0-5yrs. It may be useful in the rapid diagnosis of suspected severe malaria in febrile children. The high cost of the test kit is likely to prove a major limitation to its widespread use.
Nigerian Journal of Paediatrics Vol. 31(3) 2004: 71-78