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Elimination programs for Wuchereria bancrofti and Onchocerca volvulus are in critical need of sensitive, specific, and point-of-contact (POC) tools that can be used for surveillance years beyond cessation of mass drug administration when infection intensities are low. Previously, Wb123 and Ov16 were identified individually as potential filarial antigens for an antibody-based POC test. The present study compares single-antigen Wb123- and Ov16-based POC tests with an integrated configuration to detect antibodies to Wb123 and Ov16 simultaneously. Wb123 and Ov16 isolates were striped onto lateral flow strips containing anti-IgG4. Sera from W. bancrofti-, O. volvulus-, and other helminth-infected or -uninfected individuals were added to the strips with buffer. Strips were read for the appearance of a positive or negative test line for both antigens at 20 min and following drying. Sensitivity, specificity, and predictive values were calculated for the single-antigen and biplex strips. Single and biplex lateral flow strips showed nearly identical results, with >90% sensitivity for Ov16 and >92% sensitivity for Wb123. Overall specificities for the single and biplex tests were 98% and 96% for Ov16 and Wb123, respectively. Biplex tests performed as well as the single-antigen tests regardless of the intensity of patient IgG4 response. The high sensitivity and specificity make these new biplex tests extremely useful for POC long-term surveillance following mass drug administration in Africa that should reduce time and cost in areas where bancroftian filariasis and onchocerciasis are coendemic., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Improved methods are needed for field diagnosis of onchocerciasis, to support efforts aimed at elimination of the disease. A rapid-format card test was evaluated that detects IgG4 antibodies to recombinant Onchocerca volvulus antigen Ov16 with serum samples from patients with onchocerciasis and with various types of control serum samples. The sensitivity of the test with serum samples from 106 microfilariae-positive subjects was 90.6%. The test was equally sensitive with serum samples obtained from patients in Africa and Latin America. Specificity was excellent; positive tests were observed for 2 of 38 serum samples from patients with other filarial infections and for 1 of 23 serum samples from patients with nonfilarial helminth infections. The 3 "false-positive" serum samples were from West Africans who could have been coinfected with onchocerciasis. No positive tests were observed with nonendemic serum samples from normal adults, patients with autoimmune disorders, or patients with the hyper-IgE syndrome. This new test holds great promise as a simple tool for diagnosis of onchocerciasis.