A Comparative Study of the Efficiency of Knott's Concentration Technique and the Immunochromatographic Method in the Diagnosis of Wuchereria bancrofti
AbstractThis investigation was carried out in Afikpo North L.G.A. Ebonyi State, Nigeria, to compare the efficiency of the Immunochromatographic method (ICT) and the Knott's concentration techniques in detecting Wuchereria bancrofti in the blood of different humans, in Afikpo North L.G.A. Ebonyi State, Nigeria. Ethical approval was received from the Ebonyi State Ministry of Health. Consent forms were distributed to the subjects to indicate their willingness in giving out their blood for examination. Seven hundred and eight one (781) participants from thirty villages (30) consented to be examined and were parasitologically examined using the ICT and the Knott's concentration methods. From the study, the prevalence of the ICT and the Knott's concentration methods were 21.13% and 5.38% respectively. The sensitivity, specificity, positive predictive and negative predictive values were 100%, 83%, 25% and 100% respectively. Subjects within the age range of 58 – 62 years had the highest prevalence of 43.48% using the ICT method. Also, using the Knott's concentration technique, subjects within 58 – 62 years had the highest prevalence of 26.09%. Males were also more infected 24(6.16%) than females 18(4.59%). The ICT method detected more W. bancrofti antigens 85(21.85%) among males than 80(20.41%) among females. There was no statistically significant difference in the prevalence of infection among gender (P>0.05) at 2 tailed difference of .780. However, the ICT method is more sensitive than the Knott's concentration technique in detecting W. bancrofti antigen. Therefore, for adequate diagnosis of W. bancrofti and to achieve the elimination and proper control of lymphatic filariasis according to the goal of the National lymphatic filariasis/ Control Programme, the ICT method is the best since it can detect the onset of W. bancrofti in the blood unlike the Knott's concentration method which can only detect the worm when it has stayed for some years in the individual's body.
Keywords: Lymphatic filariasis, Immochromatographic method, Knott's concentration technique, Wuchereria bancrofti
Nigerian Journal of Parasitology, Vol. 33  September 2012, pp. 163-175