Accurate Diagnosis of Camel Nasal Myiasis using Specific Second Instar Larval Fraction of Cephalopina titillator Extract

Cephalopina titillator (C. titillator) larvae are considered important nasal myiasis producing agent of camels, causing significant production losses in animals, and causing huge economic loss to the livestock industry all over the world. Myiasis is considered a zoonotic disease of global importance, some myiasis can be life-threatening for humans. The infestation was diagnosed only on post-mortem examination of the animal after slaughter. Therefore, the objective of the present research was to isolate and characterize a specific fraction extracted from C. titillator larval antigen, for the specific diagnosis of early infestation in living camels. Second larval instar extract of C. titillator showed higher diagnostic potency than first and third larval instars crude extracts. So that, an immunoaffinity larval fraction was isolated from the 2nd larval instar extract of C. titillator with the highest diagnostic potency than its crude extract and unbound fraction as proved by ELISA and western blot. The fraction has antigenic activity 87.67% of the initial activities, and with the 1719.6-fold increase in specific activity compared to its crude extract. It separated into two bands with molecular weight 52 kDa and 22 kDa by SDS-PAGE. The diagnostic potency of the isolated fraction was evaluated by indirect ELISA. The fraction recorded high specificity 96.88% and 100% sensitivity. Moreover, the fraction successfully achieved 94.12%, 100%, and 97.92 % positive predictive, negative predictive, and diagnostic efficacy values, respectively. Finally, the fraction recorded a prevalence of 65.95% of nasal myiasis in collected random blood samples of living camels by ELISA. Collectively, the current results present a promising diagnostic immunoaffinity fraction of the 2nd larval instar extract of C. titillator to detect specific antibodies of nasal myiasis in camels by ELISA.