Factors Influencing the Genesis and Development ofInvasive Meningococcal Disease and Carriership of Neisseria meningitidis – Resultsof Nationwide Prospective Questionnaire Survey of Cases and Controls

Summary

The nationwide prospective questionnaire study of cases and controls was implemented during theperiod from October 1996 till May 1998. Thirty-nine districts participated (=54.2% of district hygienestations) and 107 invasive meningococcal diseases were included in the study (=76.9% of diseasesrecorded during the given period in the Czech Republic by active surveillance). A total of 390subjects were included in the study – 107 with invasive meningococcal diseases, 211 healthy controlsand 72 healthy carriers of Neisseria meningitidis. This is the first study in the Czech Republic whichanalyzes comprehensively socioeconomic, health and stress factors in relation to the genesis anddevelopment of invasive meningococcal disease or carriership of N. meningitidis. The relationshipbetween these factors and meningococcal disease or carriership was evaluated by the chi squaretest: odds ratio (OR) and statistical significance (p for chi square – Yates correction or Fischer’sexact test). For the development of invasive meningococcal disease in particular, risk factors aresignificant (p < 0.05) which at the time weaken the overall resistance of the organism: febrilediseases, respiratory diseases, other diseases, exertion, exposure to cold, mental stress, other stress,injury, staying in places outside the home on brigades, training courses, stay in crowded premises.As to long-term factors the development of the disease is influenced by a contaminated environment,passive smoking and lower education of the mother which indicates a different lifestyle. Conversely,factors negatively correlated with the development of the disease are active participation in sportsand favourable economic conditions. For death: significant risk factors (p < 0.05) are also factorswhich weaken the resistance of the organism: exertion, mental stress, other stress (= alcoholconsumption), staying outside the home on brigades, training courses etc. For carriership riskfactors are significant (p < 0.05) when the mucosal membranes of the upper airways are impaired(staying in a dusty environment, in smoke-filled rooms, contaminated atmosphere, active smoking,passive smoking) and factors where contact with other people is frequent (overcrowded rooms,multi-generation housing, use of public transport, staying outside the home on brigades, trainingcourses etc.). A risk factor is also lower education of parents which indicates a different lifestyle.Conversely, factors negatively correlated with carriership are favourable economic conditions,frequent outdoor stay and active participation in sports. By comparison of factors significantlyassociated with the development of invasive meningococcal disease or carriership data are assem-bled for the implementation of effective preventive measures.

Key words:
invasive meningococcal disease – carriership of Neisseria meningitidis – risk factors.