Positive urine pneumococcal antigen test and vaccination

Abstract Introduction and objective Although urine pneumococcal antigen is an useful test, it has false positives such as pneumococcal vaccination. Material and methods Positive urine pneumococcal antigen in Hospital de Denia (January–February/2015). We studied epidemiological, radiological and microbiological variables as well as previous pneumococcal vaccination (Pneumo-23 and/or Pneumo-13). Results Urine pneumococcal antigen test was positive in 12.4% of 385 cases. Only 33.3% of positive cases had pneumonia in chest X-ray, and 35.4% of patients had previous pneumococcal vaccination. In most cases (87.5%), an antibiotic was prescribed. Conclusions Pneumococcal vaccination can produce a false positive result in the urine pneumococcal antigen test in clinical practice, leading to an unnecessary prescription of antibiotics.