Unexplained complaints in general practice: prevalence, patients' expectations, and professionals' test-ordering behavior.

OBJECTIVE: To gain insight into general practitioners' (GPs) test-ordering behavior for patients presenting with unexplained complaints. An unexplained complaint's symptoms are not alarming, and there is no plausible medical or psychosocial explanation for it. The Dutch College of General Practitioners (DCGP) recommends a watchful, waiting attitude for test ordering for unexplained complaints. METHODS: Observational, cross-sectional study of 567 doctor-patient consultations performed by 21 GPs. RESULTS: On average, 13% of consultations involved complaints considered unexplained by GPs. Unexplained complaints were positively related to test ordering (adjusted odds ratio [OR] = 2.4, 95% confidence interval [CI] 1.1-5.3), despite the DCGP's recommendation. Patients' expectations about testing influenced test ordering even more (adjusted OR = 4.1, 95% CI 2.2-7.6). DISCUSSION: Unexplained complaints happen daily in general practice. Besides the DCGP's recommendation, factors such as GPs' desire to understand complaints and patients' expectations seem to have impacts. Guideline development and quality improvement projects should respect, next to Bayesian rules, GP- and patient-related determinants of test ordering

Efficacy of vaccination in preventing giardiasis in calves

The objective of this study was to evaluate the efficacy of a vaccine in the prevention of Giardia duodenalis infection in calves. Six 2-week old calves were vaccinated subcutaneously with a sonicated G. duodenalis trophozoite vaccine. Six 2-week old control calves received a subcutaneous injection of sterile phosphate-buffered-saline mixed with adjuvant. Injections were repeated after 28 days. Eleven days after the second injection, calves were challenged orally with 1 × 10 5 purified G. duodenalis cysts from a naturally infected calf. Throughout the study, fecal samples were collected at regular intervals and examined for the presence of G. duodenalis cysts. Blood samples were collected weekly until G. duodenalis challenge and bi-weekly following challenge. Calves were euthanized 14 days after challenge and G. duodenalis trophozoites within the small intestines were enumerated. Serum antibody titers were significantly higher in vaccinated compared to non-vaccinated calves. Vaccinated calves tended to excrete more G. duodenalis cysts in their feces than non-vaccinated calves. The number of trophozoites in the small intestine was not different between vaccinated and non-vaccinated calves. Changes consistent of moderate enteritis were found in the intestines of one vaccinated and one non-vaccinated calf. Despite a serological immune response following vaccination, this vaccine was not efficacious in preventing giardiasis or reducing cyst shedding in calves