Increased attack rate of meningococcal disease in children with a pregnant mother

Objective. To investigate the relationship between meningococcal disease and family composition, especially pregnancy in mothers. Methods. This was a retrospective matched case-control study. Case patients were children ( aged 0 - 18 years) who had meningococcal disease and were admitted to our hospital from 1990 to 2002. Children who were admitted to 1 of the general pediatric wards of the hospital during the same period and did not have meningococcal disease served as control subjects. One control subject ( matched according to gender, age, and yea, and season of admission) was enrolled for each case patient. Parents of case patients and control subjects were asked to fill out a questionnaire on family composition, birth dates of siblings, and pregnancy at the time of hospital admission. Results. A total of 88 matched case-control pairs were included. In the case group, 17 ( 19%) mothers reported having been pregnant at the time of hospitalization of their child, compared with 2 (2%) in the control group. Other family characteristics were not different. After adjustment for confounding factors, pregnancy of mothers remained a significant risk factor for meningococcal disease in children ( odds ratio: 11.7; 95% confidence interval: 2.6 - 53.9). Conclusions. Meningococcal disease in children was highly associated with pregnancy of the patient's mother during hospitalization. Mechanisms by which the presence of a pregnant mother in a family affects the attack rate of meningococcal disease in her children need additional investigation