人畜共患病-鼠疫2010.ppt

Diagnosis of C. psittaci infection can indeed be difficult and is usually accomplished through testing paired sera, or only one serum sample, using the micro-immunofluorescence (MIF) test, which is more sensitive and specific than the complement fixation test. Highly sensitive nucleic acid amplification assays can be used to specifically detect C. psittaci. Culture is also possible, but technically rather difficult for requiring biosafety level 3 laboratories. Like in birds, tetracyclines are the drugs of choice for treating human psittacosis. Doxycycline or tetracycline is usually administered, unless contraindicated, like in the case of pregnant women and children under 9 years, where erythromycin can be used. The length of treatment will vary with the drug, but should be continued for at least 14 days for tetracycline. Antigen detection Smears For C. psittaci infectionin birds,smears can be prepared from faeces, cloacal swabs, conjunctival scrapings, although pharyngeal or nasal swabs are preferred Impression smears can also be prepared from tissue samples obtained from liver, spleen, kidney, lung and pericardium. In cats and koalas, organisms may be detectedfrom conjunctival, urogenital or genital swabs. Prepared smears can be stained for detection of chlamydiae using one of several staining procedures, for example, modified Machiavello, modified Gimenez, Giemsa, or modified Ziehl-Neelsen (MZN) Fluorescent antibody tests using Chlamydiaceae-specific anti-LPS antibodies or species-specific mAbs to MOMP, Pathological specimens Following the submission of tissue samples to the diagnostic laboratory for analysis, chlamydiae can be demonstrated in histological preparations using a variety of staining procedures. Immunohistochemical staining procedures that utilise mAbs directed against chlamydial surface antigens, such as LPS or MOMP, are more sensitive and produce more striking results in comparison to histochemical staining. Immunoassays Most of the c