Though endemic in the southwestern United States and Mexico, travel to these areas has also increased the incidence in nonendemic areas. Frequently, serology offers the only evidence available to form a preliminary diagnosis. Serological evidence can then guide the selection of more definitive diagnostic techniques, such as culture or biopsy. While elevated single antibody titers may be diagnostic, paired samples are preferred. Negative fungal serology does not rule out the possibility of current infection.
Any titer suggests past or current infection.
CF serology alone should be ordered when following therapy. IgG antibody detected. Coccidioides IgG antibody detected. Repeat testing in 10-14 days may be helpful. Positive Presence of IgG antibody to Coccidioides detected, suggestive of current or past infection.