Underestimation of meningococci in tonsillar tissue by nasopharyngeal swabbing

The relation between carriage of Neisseria meningitidis and progression to invasive disease is not fully understood. We assessed the rate of N meningitidis carriage by conventional swabbing and immunohistochemistry in patients undergoing tonsillectomy. Swabbing detected only a quarter of carriers, and bacteria were identified beneath the mucosal surface in tonsillar tissue by immunochemical testing. Our results indicate that N meningitidis is more widespread in the population than previously thought, and have broad implications for disease prevention and cure.