Interpretive Criteria:
<1:8 Antibody Not Detected
> or =1:8 Antibody Detected
Single titers of > or =1:64 are indicative of recent or current
infection. Titers of 1:8-1:32 may be indicative of either past or
recent infection, since CF antibody levels persist for only a few
months. A four-fold or greater increase in titer between acute and
convalescent specimens confirms the diagnosis.