Between January and April 2007, 424 calves under 22 days of age from 108 Dutch dairy herds were sampled to estimate the prevalence of non-normal faeces ('custard-like'-yellowish-coloured with custard consistency or diarrhoea: watery-like faeces) and the shedding of enteropathogens Escherichia coli K99 (E. coli), Coronavirus, Cryptosporidium parvum (C. parvum), Rotavirus and Clostridium perfringens (Cl. perfringens). In addition, information was collected on animal characteristics and herd-management practices. The probability of detecting each one of five enteropathogens given a calf with 'custard-like' faeces or diarrhoea was estimated using Bayes' rule and was based on the predicted probabilities from a multinominal model including each of five enteropathogens as independent variables. In addition, putative risk factors for the presence of each of five enteropathogens were analysed using logistic regression models with random herd effects. Fifty-seven percent of calves had faeces of normal colour (brownish) and consistency (firm), 23.8% (95%CI: 19.8-28.2%) had 'custard-like' faeces and 19.1% (95%CI: 15.5-23.2%) had diarrhoea. E. coli was the least detected enteropathogen (2.6% (95%CI: 1.3-4.6%) of calves, 9% (95%CI: 5-16%) of herds) and Cl. perfringens was most detected (54.0% (95%CI: 49.1-58.8%) of calves, 85% (95%CI: 77-91%) of herds). E. coli and Coronavirus were detected incidentally in only one or two calves per herd, whereas C. parvum and Cl. perfringens were frequently detected in up to four calves per herd. For calves with 'custard-like' faeces, the probability of detecting Rotavirus from a calf in its first week of age was 0.31 whereas for a calf in its second week, there was a 0.66 probability of detecting C. parvum. The probabilities of detecting E. coli, Rotavirus and C. parvum in calves with diarrhoea in their first week of age were 0.10, 0.20 and 0.43, respectively. In calves with diarrhoea between 1 and 2 weeks of age, the probability of detecting enteropathogens was 0.43 for C. parvum. None of the tested enteropathogens were related to 'custard-like' faeces or diarrhoea in the third week of age. Putative risk factors for E. coli, Coronavirus and C. parvum included the presence of peer-calves shedding Coronavirus, C. parvum or Rotavirus, respectively. Additionally, managerial risk factors such as non-optimal hygienic housing (for Coronavirus) and the routine use of antibiotics for diarrhoeic calves (for C. parvum) were found. No animal or managerial factors were associated with shedding of Cl. perfringens.

Since 2007, Q fever has become a major public health problem in the Netherlands and goats were the most likely source of the human outbreaks in 2007, 2008 and 2009. Little was known about the consequences of these outbreaks for those professional care providers directly involved. The aim of this survey was to estimate the seroprevalence of antibodies against C. burnetii among Dutch livestock veterinarians and to determine possible risk factors. Single blood samples from 189 veterinarians, including veterinary students in their final year, were collected at a veterinary conference and a questionnaire was filled in by each participant. The blood samples were screened for IgG antibodies against phase I and phase II antigen of C. burnetii using an indirect immunofluorescent assay, and for IgM antibodies using an ELISA. Antibodies against C. burnetii were detected in 123 (65.1%) out of 189 veterinarians. Independent risk factors associated with seropositivity were number of hours with animal contact per week, number of years graduated as veterinarian, rural or sub urban living area, being a practicing veterinarian, and occupational contact with swine. Livestock veterinarians should be aware of this risk to acquire an infection with C. burnetii. Physicians should consider potential infection with C. burnetii when treating occupational risk groups, bearing in mind that the burden of disease among veterinarians remains uncertain. Vaccination of occupational risk groups should be debated.

Infectious bronchitis virus (IBV) is, in spite of vaccination, still a major cause of respiratory problems in broilers and of poor egg production in breeders and layers in many parts of the world. A possible cause of the insufficient protection induced by vaccination is an inadequate application of the vaccine. This paper reports the results of two field studies. In the first, the results of the alpha-IBV IgM enzyme-linked immunosorbent assay (ELISA) on post-vaccination sera were compared with the efficacy of the IBV vaccination against homologous challenge of the same broilers. The results showed that groups with at least 50% positive sera in the IgM ELISA at 10 days post vaccination had a high level of protection against challenge. Most groups of broilers with a low level of IgM ELISA positives had a low or moderate level of protection against challenge. In a second field study, the IgM response to IBV vaccination was compared with detailed information of the vaccination process of 360 spray-vaccinated flocks of about 2-week-old broilers, layer pullets, broiler breeders and broiler grandparents. The information included parameters such as flock size, type of chicken, housing, age of the chicken, application route, vaccine, dose, water quantity and temperature, ventilation and light management, combination with other vaccines and temperature of the house. The aim was to identify factors that might be associated positively or negatively with the IgM response and thereby with the expected level of protection against homologous challenge under field conditions. Significant associations were detected between the level of IgM response and factors regarding type of bird, flock size, housing type, ventilation management, light management, age/interval of vaccination, interval between vaccination and blood sampling, and temperature of the water that was used to reconstitute the vaccine. This knowledge can be useful to improve the average efficacy of IBV vaccination in the field.

18This study was set up to get more insights in the severity and relevance of porcine circovirus type 2 (PCV2) infections in 27(pneumonia) at slaughter, and the 8 "low" herds had low percentages of pneumonia at slaughter.

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