0 showing a positive result of a blood test for a particular antibody (= a substance in the blood that fights a disease):
patients who are seropositive for HIV antibodies
Mean concentrations of only those defined as seropositive (as above).
All the individuals tested who had microfilariae-positive skin snips were seropositive, giving a sensitivity of 100%.
The final explanation for apparent seroconversion within the population is the immigration of seropositive individuals.
In this study, if 25 % or more of the growers tested seropositive, the next sampling round would yield seropositive finishers.
Table 3 compares the households with only the index case infected to the households with two or more seropositive members (including the index case).
Overall, of 2331 sera tested, 305 (13 %) were seropositive.
The inset graph depicts the changing value of the skewness of the distribution used to estimate the cut-off for seropositive samples.
Most of these patients had been in contact with seropositive animals or have been professionally associated with animals or animal products.
