Trichomonads are small protozoan organisms which can be detected in many wildlife species and domestic animals. Usually, they are non-pathogenic commensals or cause relatively mild disease. A clinically significant representative of this group is the species Tritrichomonas (T.) foetus, the causative agent of bovine trichomoniasis. The pathogen is transmitted during breeding. While the infection normally remains asymptomatic in bulls, it can cause vaginitis, endometritis and abortion in cows. Bulls play an important role in the transmission of trichomonads, as they may remain lifelong parasite carriers and excretors. Diagnosis is established by direct microscopic detection of the pathogen in lavage samples or other samples suitable for investigation (e.g. aborted embryonal or fetal material, amnion, vaginal secretions). Another possibility for investigation is pathogen cultivation. As already indicated, the possibilities for a morphological differentiation of the pathogen T. foetus, which is relevant with regard to animal disease control legislation, from other trichomonads are limited. This is also true for Giemsa-stained smear preparations, as it has been shown that the number of flagella can vary within the same species. Therefore, molecular biological methods are more suitable for differentiation than morphological criteria. A PCR with specific primers enables the differentiation of T. foetus from contaminating trichomonads. This makes it possible to verify positive cultivation results and to avoid false-positive results. PCR can also be used directly without previous cultivation for investigation of sample material. Therefore, PCR should be included into animal disease control legislation as additional diagnostic tool and be used regularly for differentiation of Trichomonas isolates.
The tasks of the National Reference Laboratory for Trichomoniasis of Cattle include:
- Cooperation with national and international diagnostic institutions
- Research on improvement and standardization of T. foetus diagnostics and on questions relating to pathogenesis, immunization, and epidemiology
- Training in diagnostic methods
- Coordination of scientific studies with other laboratories
- Publication and spread of information