A comparison of meningococcal carriage by pregnancy status

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.Neisseria meningitidis, simply known as meningococcus, is a gram negative bacterium and a leading cause of bacterial meningitis. Nasopharyngeal carriage is a prerequisite for invasive disease, and approximately 10-15% of healthy individuals are reported to carry the organism at any one time. Rates of carriage and transmission are known to increase in closed, or semi-closed living conditions such as military barracks, jails, and college dormitories[1,2] Additional factors shown to affect the carriage rate are: age, gender, social class, exposure to cigarette smoke, and vaccination[3,4].Recent information demonstrates that pediatric disease may correlate with a pregnant mother. For example, van Gils et al. evaluated 176 hospitalized children, half of whom were admitted for invasive meningococcus. Amongst the cases 19% of children were found to have a mother who was pregnant, compared to only 2% of controls. Multivariate analysis showed meningococcal disease was 11.7 times more likely to occur in a child whose mother was pregnant[5].One mechanism may be the immunologic changes of pregnancy predispose a woman to being an asymptomatic carrier. To test that hypothesis, we planned a cross-