ABSTRACT
Significant advances were made in the diagnosis of filariasis in the 1990s with the emergence of three new alternative tools: ultrasound and tests to detect circulating antigen using two monoclonal antibodies, Og4C3 and AD12-ICT-card. This study aimed to identify which of these methods is the most sensitive for diagnosis of infection. A total of 256 individuals, all male and carrying microfilariae (1-15,679 MF/mL), diagnosed by nocturnal venous blood samples, were tested by all three techniques. The tests for circulating filarial antigen concurred 100 percent and correctly identified 246/256 (96.69 percent) of the positive individuals, while ultrasound detected only 186/256 (73.44 percent). Of the circulating antigen tests, ICT-card was the most convenient method for identification of Wuchereria bancrofti carriers. It was easy to perform, practical and quick.
Subject(s)
Adolescent , Adult , Aged , Animals , Child , Humans , Male , Middle Aged , Young Adult , Antibodies, Helminth , Antibodies, Monoclonal , Antigens, Helminth/blood , Elephantiasis, Filarial/diagnosis , Microfilariae/ultrastructure , Wuchereria bancrofti/immunology , Enzyme-Linked Immunosorbent Assay , Elephantiasis, Filarial/blood , Elephantiasis, Filarial , Sensitivity and Specificity , Young AdultABSTRACT
The surface structures of microfilaria and of the third stage larva of Wuchereria bancrofti were studied by scanning electron microscopy. Distinct features were observed that could be used for differentiating species of this parasite. Specifically, the sheath of microfilariae of W. bancrofti projected beyond the head. The head region of the microfilaria was composed of a cephalic cap with hook, mouth and amphidial opening, and its cuticle showed annulation. Spines were absent at the first transverse annulation, and the tail end showed a slight constriction. In the infective stage larva, characters which are used for differentiating species, such as the two bubble-like ventro-lateral papillae and one dorso-terminal papilla were rather similar to each other in size, but the grooves seen around the base were absent. A previously unreported feature of the third stage larva of W. bancrofti that was discovered in this study is a papilliform process on the left side of the posterior region, between the anus and the tail end.