Coronavirus as agent of neonatal calf diarrhea in southern Chile

Neonatal calf diarrhea is one of the most serious problems of cattle industry all over the world. Although the aetiology is complex, it is possible to assess that viruses play a very important role. During an investigation to study the importance of Rotavirus in enteric problems in calves and piglets, it was possible to demonstrate the presence, for the first time in southern Chile, of Coronavirus-like particles in a faecal sample of a 15 day old calf by means of electron microscopy. The importance of this diagnosis and some clinical characteristics of the disease are briefly discussed. Finally, the need for more research on this complex subject is recognized.     

Coronavirus as an agent of neonatal calf diarrhea in a Chinese dairy cattle farm.

Neonatal calf diarrhea is a significant health problem in dairy industry in the whole world. Although the aetiological agents of neonatal diarrhea are diverse, it is obvious that viruses play an important role. One of them is bovine coronavirus (BCV). Since BCV was discovered (MEBUS et al., 1969), there have been many published reports describing the virus and its importance in calves. In China, we first investigated the seroepidemiological status of BCV infections in cattle (YAO et al., 1990). The results showed that the incidence of infections with BCV in cattle in different chinese regions are high. Further work on direct diagnosis of BCV as a causative agent of diarrhea was therefore necessary. In the last years we have developed diagnostic methods including a monoclonal antibody-based ELISA to detect BCV and other diarrheal viruses. In this study, the diagnosis of an outbreak of BCV in chinese dairy cattle is described.     

Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

The bacteriological and serological prevalence of Campylobacter spp. and Yersinia enterocolitica in fattening pig herds in Lower Saxony

This article presents the results of a study on the occurrence of two bacteria that cause zoonoses, Campylobacter spp. and Yersinia enterocolitica. The study was carried out in 30 fattening herds in Lower Saxony, Germany, in 2004 and compares the results of bacteriological and serological methods of detection. Bacteriological findings of Campylobacter spp. in the faeces indicated that 69.7% of the fattening pigs were positive, but 81.2% tested positive serologically. All herds tested here were both bacteriologically and serologically positive for Campylobacter spp. Furthermore, only 8.4% tested positive for Yersinia enterocolitica in the faecal samples, but 66.8% of the animals were serologically positive for that bacterium. While bacteriological examination did not detect Yersinia enterocolitica in 56.7% of the herds tested, serological testing showed that only 16.7% of the units were without reacting animals. The great difference between the results of bacteriological and serological testing, especially in the case of Yersinia enterocolitica, can be explained by the intermittent intestinal excretion and predominance of this bacterium in the animals' tonsils. Low faecal excretion is also the reason for the low detection rate of 3.4% of Yersinia enterocolitica in the environmental samples, while that of Campylobacter spp. was 33.3%. These results indicate that the environment plays only a secondary role in the distribution of Yersinia enterocolitica in pig herds.     

Bovine viral diarrhea in a newborn calf

Bovine viral diarrhea virus was believed to be the cause of ill-thrift since birth, resulting in death of a Holstein calf. Bovine viral diarrhea virus was isolated from Peyer's patches and mesenteric lymph nodes, but serum neutralizing antibodies were not detected. The lymphoid depletion and myeloid suppression seen in this case may be a factor in the immune system dysfunction described for bovine viral diarrhea. Typical ulcerative lesions within the alimentary tract were not observed.     

The epidemiology of human enterohemorrhagic Escherichia coli infections in Lower Saxony

BACKGROUND: In the German federal state Lower Saxony, data on infections with enterohemorrhagic Escherichia coli (EHEC) and hemolytic uremic syndrome (HUS) are collected systematically since 1997 based on reports by physicians and laboratories. Initially the data were collected by means of a specific established surveillance system, since 2001 they are collected as part of the new infectious disease law. RESULTS: From 1997 to 2003, in Lower Saxony 880 EHEC-infections and 112 HUS-cases, 6 of whom died, were notified. This corresponds to an incidence of 1.6 EHEC-infections and 0.2 HUS-cases per 100000 person-years. No secular trend was observ-ed for the yearly number of HUS-cases, but raised numbers were observed for the years 1997 and 2002. There were strong regional differences of the EHEC/HUS-incidence from 0.7 in the district Braunschweig to 3.5 in the district Weser-Ems. For 56% of reported EHEC-cases, serotype information was available. The most frequent serogroup was O157, accounting for 30% of cases with serotype information. Of HUS-cases with known serotype, 86% were caused by O157, 20% by O157:H-. 52% of the EHEC-cases were less than 5 years old (HUS: 77%), and 68% less than 10 years (HUS: 92%). 23% of EHEC/HUS-cases could be identified as part of clusters with a mean number of 2.6 cases per cluster. These clusters almost exclusively affect-ed families. Though the data also contained information on possible sources or routes of infection, for none of the cases a microbiologically assured source was documented. CONCLUSIONS: The incidences of EHEC and HUS were higher in Lower-Saxony than in the whole of Germany. During the study period no significant trends concerning the number of HUS-cases or the distribution of serotypes were observed. More frequent serotyping and more complete information on sources or risks of infection should be achieved.     

BVD/MD and its control in Lower Saxony (after the support of the Lower Saxony animal epidemic fund)]

A report is given on the development of the subsidies granted by the "Nieders?chsische Tierseuchenkasse" für BVD/MD since 1973. The article shows the cyclic procedure and regional differences as well as the participation of vaccinations and embryo transfer at the frequent occurrence of persistent viraemic animals in single herds. According to the authors' opinion the struggle against BVD/MD must have two aims: 1. to search for and to cull out persistent viraemic animals 2. to prevent the arise of new persistent viraemic animals.