Research
A comparison of meningococcal carriage by pregnancy status
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* Corresponding author: Eric J Knudtson eknudtso@ouhsc.edu
1 Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, The University of Oklahoma Health Sciences Center, PO Box 26901, WP 2470, Oklahoma City, OK, 73160 USA
2 Oklahoma State Department of Health, 1000 NE 10th, Oklahoma City, OK 73117 USA
3 The University of Oklahoma Health Sciences Center College of Public Health, 801 N.E. 13th St. Oklahoma City, OK 73104 USA
Journal of Negative Results in BioMedicine 2010, 9:6 doi:10.1186/1477-5751-9-6
Published: 11 August 2010Abstract
Neisseria meningitidis is the second leading cause of invasive meningitis. A prerequisite for infection is colonization of the nasopharynx, and asymptomatic carrier rates are widely reported in the range of 10-15%. Recent reports have indicated an increased likelihood that a pediatric admission for Neisseria meningitidis will have a mother who is pregnant in the home. We hypothesized that this association may relate to immunologic changes in pregnancy leading to higher carrier rates.
We compared the carrier status by performing nasopharyngeal swabs for Neisseria meningitidis in 100 pregnant and 99 non-pregnant women.
Average age of the participants was 28.9 +/- 6.7 years. The average gestational age at specimen collection was 27.5 +/- 9.4 weeks. Non pregnant women were significantly more likely to use tobacco (38% vs 24%, p < 0.0001). In the entire 199 patients, only one pregnant patient tested positive for Neisseria meningitidis (0.5%; 95% CI: 0.01%-2.8%).
The meningococcal carrier rate in our population is well below what is widely reported in the literature. Assuming a 1% carrier rate in the pregnant group and a 0.5% carrier rate in the non pregnant group, 4,763 patients would be required to detect a difference of this magnitude, given 80% power and an alpha of 0.05.