Evaluation of liquor analysis and PCR for diagnosis of encephalitozoonosis in the rabbit

The purpose of the present study was the evaluation of the clinical utility of CSF analysis and PCR for the diagnosis of the neurological type of encephalitozoonosis in rabbits. A total of 46 rabbits with neurological symptoms due to encephalitozoonosis were included in the study. CSF was examined in 21 rabbits with encephalitozoonosis and 20 healthy laboratory rabbits. In all rabbits collection of CSF was easy to perform. Few rabbits with vestibular disease showed short-term deterioration of neurological symptoms which were completely reversed after eight hours. CSF analysis of laboratory rabbits revealed WBC counts from 0 to 4 cells/mu l (median 1.5 cells /mu l). The protein level ranged from 0.13 to 0.31 g/l (median 0.24 g/l). In contrast to this, pet rabbits with the neurological type of encephalitozoonosis showed distinct monocytic-lymphocytic pleocytosis with WBC counts from 5 to 78 cells/mu l (median 15.3 cells/mu l) and increased protein levels from 0.31 to 1.54 g/l (median 0.69 g/l). Compared to healthy rabbits, distinction for both parameters was highly significant (p < 0.001). It was concluded that mononuclear pleocytosis and elevated protein is a regular feature of rabbit encephalitozoonosis. PCR for detection of E. cuniculi-DNA as used in this study was based on an established protocol (Katzwinkel-Wladarsch et al. 1996). PCR-testing of CSF revealed positive results only in two of 19 samples (10.5%), while for urine 15 of 38 samples (39.5%) tested positive for E. cuniculi-DNA. With microscopy after trichrome stain, however, E. cuniculi spores were detected only in four out of 38 urine samples (10.5%). All results of trichrome stain correlated with those of PCR. In conclusion, PCR of CSF is no help for diagnosis of encephalitozoonosis in rabbits. PCR for detection of E. cuniculi in urine on the other hand, was found to be far more sensitive than trichrome stain. To determine sensitivity and specificity of this PCR in urine, future studies should include larger numbers of rabbits and those with clinical renal disease.