Giardiosis and other enteropathogenic infections: a study on diarrhoeic calves in Southern Germany.

BACKGROUND: Diarrhoea induces massive problems in the rearing of calves. The aim of the study was to obtain current data about the frequency of Giardia spp., Cryptosporidium spp. and Eimeria spp. in diarrhoeic calves in Southern Germany with the particular focus on giardiosis. RESULTS: 1564 samples were analysed for the three pathogens using microscopical methods. Giardia spp. was detectable in 112/1564 samples (7.2%). The mean age was 46.5 days and the odds of being infected with Giardia spp. increased slowly up to 8 times from about 12 days to 30 days of age. There appeared to be no seasonal influence on the frequency of Giardia spp. A mono-infection with Giardia spp. was diagnosed in 46 calves (2.9%) whereas 15 calves (1.0%) had a mixed-infection with Cryptosporidium spp. and 51 calves (3.3%) with Eimeria spp. Cryptosporidium spp. and Eimeria spp. could be detected in 646/1564 samples (41.3%) and 208/1564 samples (13.3%), respectively, with a mean age of 11.3 and 55.0 days, respectively. The odds of being infected with Cryptosporidium spp. increased up to 4.5 times until an age of 10 days. After that the odds decreased continuously and was approaching zero at about 30 days. The odds of being infected with Eimeria spp. increased continuously up to 30 times from about 20 days to 60 days of age. There appeared to be no significant seasonal influence on the frequency of Cryptosporidium spp.; but there was one for Eimeria spp.: the odds of being infected with Eimeria spp. in March and April decreased by about half and increased up to 2.3 times between July and September. Additionally, as requested by the veterinarians, 1282 of those samples were analysed for E. coli, Rota-, Coronavirus and Cryptosporidium spp. using an ELISA. Obtained frequencies for these pathogens were 0.9%, 37.8%, 3.4% and 45.3% with a mean age of 24.8 days, 12.1 days, 9.0 days and 12.1 days, respectively. CONCLUSIONS: The results indicate that in Southern Germany in addition to Eimeria spp., Giardia spp. seems to play a contributing role in diarrhoea in older calves, whereas Cryptosporidium spp. and Rotavirus are mostly relevant in young calves.

Molecular identification of zoonotic and livestock-specific Giardia-species in faecal samples of calves in Southern Germany.

BACKGROUND: Giardia-infection in cattle is often subclinical or asymptomatic, but it can also cause diarrhoea. The livestock-specific species Giardia bovis is the most frequently observed in cattle, however, the two zoonotic species Giardia duodenalis and Giardia enterica have also been found. Therefore calves are thought to be of public health significance. The aim of this study was to obtain current data about the frequency of the different Giardia-species in calves in Southern Germany. FINDINGS: Faecal samples of calves (diarrhoeic and healthy) in Southern Germany, diagnosed Giardia-positive by microscopy, were characterised by multi-locus PCR and sequencing.Of 152 microscopically Giardia-positive samples 110 (72.4%) were positive by PCR and successfully sequenced. G. bovis (Assemblage E) was detected in 101/110 (91.8%) PCR-positive samples, whilst G. duodenalis (Assemblage A) was detected in 8/110 (7.3%) samples and a mixed infection with G. duodenalis and G. bovis (Assemblage A+E) was identified in 1/110 (0.9%) samples. The sub-genotypes A1, E2 and E3 were identified with the ß-giardin and the glutamate dehydrogenase genes. In the majority of diarrhoeic faecal samples a co-infection with Cryptosporidium spp. or Eimeria spp. was present, however, there were some in which G. bovis was the only protozoan pathogen found. CONCLUSIONS: The results suggest that there is potentially a risk for animal handlers as calves in Southern Germany are, at a low percentage, infected with the zoonotic species G. duodenalis. In addition, it was found that G. bovis was the only pathogen identified in some samples of diarrhoeic calves, indicating that this parasite may be a contributing factor to diarrhoea in calves.