A case of false-positive pneumococcal urinary antigen test in a bacteremic Streptococcus agalactiae infection

Pneumonia due to Streptococcus pneumoniae is a major cause of disease requiring treatment and hospitalization (1,2). The standard procedure for confirming pneumococcal pneumonia is positive culture of S. pneumoniae from blood. However, it is estimated that only around 25% of cases are culture positive (1,2). Detection of pneumococcal antigens in urine is recommended as an alternative method, which is an rapid and easy test to perform (1). The most commonly used urinary pneumococcal antigen test in Denmark is ImmuView® (S. pneumoniae and L. pneumophila Urinary Antigen Test; SSI Diagnostica, Denmark) and BinaxNOW® (S. pneumoniae antigen card; Abott, Denmark).