The infusion of donor feces was significantly more effective for the treatment of recurrent C. difficile infection than the use of vancomycin. (Funded by the Netherlands Organization for Health Research and Development and the Netherlands Organization for Scientific Research; Netherlands Trial Register number, NTR1177.).

Highly sensitive techniques, such as PCR, have greatly improved the detection of respiratory viruses. However, the sensitivity of PCR tests also complicates clinical interpretation, as the presence of small amounts of viral targets may not necessarily have clinical relevance. We performed a prospective case-control study in asymptomatic and symptomatic young children. PCR detection of 14 respiratory viruses was performed in nasal washes, and results were quantified in copies per milliliter. A total of 141 cases and 157 controls were included. In 72% of the cases and 28% of the controls, at least one virus was identified. When stratified for age, at least one virus was identified in 47% of the controls younger than 1 year old. Rhinovirus (RV) was frequently detected in both symptomatic and asymptomatic individuals. Receiver operating characteristic analysis for quantitative rhinovirus detection showed that cutoff values for clinical relevance are feasible for RV. In contrast to rhinovirus, respiratory syncytial virus (RSV) was rarely detected in controls, suggesting that a positive RSV test result is almost always of clinical relevance, independent of viral quantity. In conclusion, our study shows that asymptomatic carriage of a respiratory virus occurs frequently in young children. However, significant differences in the amount of virus present were observed between cases and controls. This suggests that defining cutoff levels should be feasible and represents the next necessary step for diagnosing viral respiratory infections using molecular tests.

trialregister.nlIdentifier: NTR1780.

At a cut-off value 0.5 ODI in a population of 100 patients with a disease prevalence of 8% (overall median prevalence), 2 patients who have IA, will be missed (sensitivity 78%, 22% false negatives), and 17 patients will be treated or further referred unnecessarily (specificity of 81%, 19% false negatives). If we use the test at cut-off value 1.5 in the same population, that will mean that 3 IA patients will be missed (sensitivity 64%, 36% false negatives) and 5 patients will be treated or referred unnecessarily (specificity of 95%, 5% false negatives). These numbers should however be interpreted with caution, because the results were very heterogeneous.