What is the rate of positive NS1 in dengue?

The rate of positive NS1 results in dengue can vary depending on factors such as the timing of the test, the type of dengue virus strain, and the individual's immune response. During the early stages of infection, when the virus is actively replicating, the NS1 antigen is usually present in the blood, resulting in a higher rate of positive NS1 results. However, as the infection progresses and the immune system produces dengue antibodies, the NS1 antigen levels may decrease, leading to a higher rate of negative NS1 results. The overall rate of positive NS1 results can vary from 60% to 90% in the early phase of illness but tends to decrease as the infection progresses. Interpretation of test results should always be done in conjunction with other clinical findings.