Epidemiology and Infection

Original Papers

Bacterial infections

The risk of acquiring bacterial meningitis following surgery in Denmark, 1996–2009: a nationwide retrospective cohort study with emphasis on ear, nose and throat (ENT) and neurosurgery

M. F. HOWITZa1a2 c1 and P. HOMØEa1

a1 Department of Otolaryngology, Head & Neck Surgery, Rigshospitalet, University Hospital of Copenhagen, Denmark

a2 Department of Infectious Disease Epidemiology, Statens Serum Institut, Copenhagen, Denmark


This paper estimates the risk of bacterial meningitis following surgery between 1996 and 2009 in Denmark. We conducted two retrospective nationwide cohort studies; first by linking notified bacterial meningitis cases to the National Patient Registry to see how many had undergone a surgical procedure; second, we scrutinized notified bacterial meningitis cases to see if the clinician suspected a surgical procedure to be the aetiology. We found that ear, nose and throat surgery had an 11-fold, and neurosurgery a sevenfold, increased risk compared to the reference group in the first 10 days following surgery. Streptococcus pneumoniae was the pathogen most often involved. Operation procedures involving penetration of dura mater was associated with increased risk for post-operative bacterial meningitis. In absolute numbers we found few bacterial meningitis cases after surgery; however, patients undergoing certain surgical procedures are at-risk and should be considered when national vaccination guidelines are revised.

(Received November 10 2012)

(Revised June 15 2013)

(Accepted July 09 2013)

(Online publication August 09 2013)

Key words

  • Bacterial meningitis;
  • ENT;
  • epidemiology;
  • operation;
  • surgery


c1 Author for correspondence: Dr M. F. Howitz, Baunegårdsvej 36, DK-2820 Gentofte, Denmark. (Email: mfhowitz@gmail.com)