Performance of the Ov-16 lateral flow test and ELISA on a panel of sera samples against <i>Onchocerca volvulus</i> (Ov) status and Ov-16 enzyme immunoassay (ELISA).

<p>Performance of the Ov-16 lateral flow test and ELISA on a panel of sera samples against <i>Onchocerca volvulus</i> (Ov) status and Ov-16 enzyme immunoassay (ELISA).</p

Example soft cassette tests run with standard wick (Ahlstrom 243) or compressed cellulose wick.

<p>All tests were run with positive-spiked blood samples. Vivid samples shown below were run with 5 µl of blood and Cytosep samples shown were run with 30 µl of blood.</p

Signal strength of test and control line as a result of location of sample application.

<p>Diluted Ov-16-positive plasma samples were applied to either the conjugate pad upstream of the dried conjugate (BC), directly onto the conjugate (OC) or on the nitrocellulose upstream of the test and control lines (NC). Line scans show average pixel intensity across the width of the nitrocellulose strip.</p

Fraction of tests that failed due to blood on membrane after dry.

<p>Tests that had blood on the membranes after the test was dry were counted as failed tests. This failure rate is shown as a function of the volume, blood filter, and wick material. A minimum of 10 tests were run for each condition shown.</p

Performance of assay-actuated lateral flow test on spiked whole-blood samples compared to ELISA and the lateral flow test with sera.

<p>Sensitivity and specificity values are calculated against microfilaria status. The 95% confidence intervals are indicated in parentheses for the sensitivities and specificities and were calculated using the normal approximation interval.</p

Sensitivity and specificity of the lateral flow test at different read times.

<p>Four different people read the test results over these time points. At days 30 and 70 the tests were read by two readers indicated by superscripts 1 and 2. For this sample size (n = 100), a change of 0.02 in sensitivity or specificity represents a discordance in 1 test result. For test development results throughout drying, the correlation coefficients for 1 hour and 24 hours were calculated relative to the 20 minutes test results(*). The remaining time points give the correlation coefficients calculated relative to the 24-hour dry reads.</p

Inventory of specimens used to evaluate the Ov-16 lateral flow test.

<p>Inventory of specimens used to evaluate the Ov-16 lateral flow test.</p

Thickness over time of three compressed hydrophilic materials.

<p>Sample thicknesses were measured after exposure to 37°C and 80% relative humidity over time.</p

Schematic and pictures of Ov-16 soft cassette test.

<p>A) top view schematic of the basic Ov-16 lateral flow strip components, with compressed cellulose at the wick end noted (although Ahlstrom 243 absorbent material was also used when specified as standard wick material). B) Side view schematic of the test as assembled in the soft cassette housing, before fluid actuation. C) Side view schematic of a running test shown, with expansion of cellulose resulting in lift of overlay material and blood sample filter. D) Top and side views of the soft cassette housing, with test components labeled on top view.</p

Additional file 1: Table S1. of Analysis of age-dependent trends in Ov16 IgG4 seroprevalence to onchocerciasis

Village name, number of study participants, Ov16 prevalence and MF prevalence values used to generate Fig. 4b. (DOCX 15 kb