Second hand smoke exposure and the risk of invasive meningococcal disease in children: systematic review and meta-analysis

Jo Leonardi-Bee,Rachael L Murray,John Britton

doi:10.1186/1471-2458-12-1062

Abstract

BackgroundInvasive meningococcal disease remains an important cause of serious morbidity and mortality in children and young people. There is a growing body of literature to suggest that exposure to passive smoke may play a role in the development of the disease, therefore we have performed a systematic review to provide a comprehensive estimate of the magnitude of this effect for smoking by any household member, by individual family members, and of maternal smoking before and after birth.MethodsFour databases (Medline, Embase, PsychINFO and CAB s database) were searched to identify studies (to June 2012) and reference lists scanned for further studies. Titles, abstracts and full texts were checked for eligibility independently by two authors. Quality of included studies was assessed using the Newcastle-Ottawa Scale. Pooled odds ratios (OR) with 95% confidence intervals (CI) were estimated using random effect models, with heterogeneity quantified using I2.ResultsWe identified 18 studies which assessed the effects of SHS on the risk of invasive meningococcal disease in children. SHS in the home doubled the risk of invasive meningococcal disease (OR 2.18, 95% CI 1.63 to 2.92, I2 = 72%), with some evidence of an exposure-response gradient. The strongest effect was seen in children under 5 years (OR 2.48, 95% CI 1.51 to 4.09, I2 = 47%). Maternal smoking significantly increased the risk of invasive meningococcal disease by 3 times during pregnancy (OR 2.93, 95% CI 1.52-5.66) and by 2 times after birth (OR 2.26, 95% CI 1.54-3.31).ConclusionsSHS exposure, and particularly passive foetal exposure to maternal smoking during pregnancy, significantly increases the risk of childhood invasive meningococcal disease. It is likely that an extra 630 cases of invasive meningococcal disease annually in children under 16 are directly attributable to SHS exposure in UK homes.

Highlights

Invasive meningococcal disease remains an important cause of serious morbidity and mortality in children and young people
Another recent systematic review found exposure to second hand smoke (SHS) was associated with a two-fold increased risk of invasive meningococcal disease in those aged between 1 month and 19 years old [7], but this study did not explore the effects of smoking by different family members, or the effects of prenatal smoke exposure
Overview of included studies Of a total of 4534 papers identified from the searches, 193 titles were deemed to be potentially eligible for inclusion

Summary

Introduction

Invasive meningococcal disease remains an important cause of serious morbidity and mortality in children and young people. Invasive meningococcal disease is a catastrophic illness that can have devastating effects It is the most common cause of bacterial meningitis in the UK and Ireland, an important cause of serious morbidity and mortality in children and young adults [1] with nearly half of all cases of laboratory confirmed meningitis in England and. A recent metaanalysis limited to 16 large studies estimated this increase in risk at a relative odds of 2.30 (95% CI 1.74 to 3.06) among children with one or more parent who smoked [6] Another recent systematic review found exposure to SHS was associated with a two-fold increased risk of invasive meningococcal disease in those aged between 1 month and 19 years old [7], but this study did not explore the effects of smoking by different family members, or the effects of prenatal smoke exposure

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