USEFULNESS AND LIMITATIONS OF 3 SEROLOGIC METHODS FOR DIAGNOSING OR EXCLUDING CHLAMYDIOSIS IN BIRDS

Diagnostic serology by use of elementary body agglutination is the mos t useful serologic method for diagnosis of chlamydiosis in birds, beca use it detects only IgM activity. A titer of 10 in budgerigars, cockat iels, and lovebirds and of greater than or equal to 20 in other types of birds is interpreted as being indicative of current infection. Late x agglutination, which detects IgM and IgG activity, may be useful in detecting large changes in titer. Direct complement fixation, detectin g only IgG activity, is usable to detect past infection whenever eleme ntary body agglutination and latex agglutination titers are <10. Limit ations of serologic results necessitating additional confirmatory test ing are lack of titers in the acute phase of disease and diagnostic ti ters in clinically normal birds with low-grade chronic infections and in birds with prolonged maintenance of titers. Additional suggested ex aminations are chlamydial culture by use of choanal/oropharyngeal swab samples. WBC count, determination of hepatic-associated enzyme activi ty, chlamydial ELISA by use of the aforementioned swab samples, and ad ditional serologic testing.