Background: This systematic literature review of the epidemiology of Guillain-Barré syndrome (GBS) identifies trends in incidence rates by age, study method and cause of disease. It is important to have a reliable estimate of incidence to determine and investigate any changes: no previous systematic reviews of GBS have been found. Methods: After critical assessment of the reliability of the reported data, incidence rates were extracted from all relevant papers published between 1980 and 2008, identified through searches of Medline, Embase and Science Direct. Results: Sixty-three papers were included in this review; these studies were prospective, retrospective reviews of medical records or retrospective database studies. Ten studies reported on the incidence in children (0–15 years old), and found the annual incidence to be between 0.34 and 1.34/100,000. Most studies investigated populations in Europe and North America and reported similar annual incidence rates, i.e. between 0.84 and 1.91/100,000. A decrease in incidence over the time between the 1980s and 1990s was found. Up to 70% of cases of GBS were caused by antecedent infections. Conclusions: Our best estimate of the overall incidence of GBS was between 1.1/100,000/year and 1.8/100,000/year. The incidence of GBS increased with age after 50 years from 1.7/100,000/year to 3.3/100,000/year.

This study found that incidence rates of primary GN vary between 0.2/100,000/year and 2.5/100,000/year. The incidence of IgA nephropathy is at least 2.5/100,000/year in adults; this disease can exist subclinically and is therefore only detected by chance in some patients. In addition, referral policies for diagnostic biopsy vary between countries. This will affect the incidence rates found.

Background: A systematic review of literature published between 1980 and 2007, on the incidence of myasthenia gravis, was undertaken. Methods: All relevant papers found through searches of Medline, Embase and Science Direct were critically appraised and an assessment was made of the reliability of the reported incidence data. Results: Thirty-one studies were included in the review, the majority of which investigated populations in Europe. The incidence rates reported were between 3.0 and 30.0/1,000,000/year. However, it is thought that the rates at the upper end of this range, reported by the prospective studies, provided the most accurate estimates. Overall, incidence rates have increased over time owing to a greater awareness of the disease and improved methods of diagnosis. Conclusions: The most accurate estimate of incidence of myasthenia gravis was around 30/ 1,000,000/year. The incidence in children and adolescents aged 0–19 years was found to be between 1.0 and 5.0/ 1,000,000/year. The rates presented in this review are likely to be an underestimate of the true incidence rates, as mild cases will have been missed and cases in the elderly will have been misdiagnosed.

SummaryObjective To undertake a systematic review of literature published between 1980 and 2008 on the incidence of autoimmune thyroid disease. Design All relevant papers found through searches of Medline, EMBASE and ScienceDirect were critically appraised and an assessment was made of the reliability of the reported incidence data. Results The reported incidence of autoimmune hypothyroidism varied between 2·2/100 000/year (males) and 498·4/100 000/year (females) and for autoimmune hyperthyroidism, incidence ranged from 0·70/100 000/year (Black males) to 99/100 000/year (Caucasian females). Higher incidence rates were found in women compared to men for all types of autoimmune thyroid disease. The majority of studies included in the review investigated Caucasian populations mainly from Scandinavia, Spain, the UK and the USA. It is possible that nonautoimmune cases were included in the incidence rates reported here, which would give an overestimation in the incidence rates of autoimmune disease presented. Conclusion To our knowledge this is the most comprehensive systematic review of autoimmune thyroid disease conducted in the past two decades. Studies of incidence of autoimmune thyroid disease have only been conducted in a small number of mainly western countries. Our best estimates of the incidence of hypothyroidism is 350/100 000/year in women and 80/100 000/year in men; the incidence of hyperthyroidism is 80/100 000/year in women and 8/100 000/year in men.

BackgroundTo evaluate the risk of foetal loss associated with pandemic influenza vaccination in pregnancy. Retrospective cohort study. UK General Practice Research Database Pregnancies ending in delivery or spontaneous foetal death after 21 October 2009 and starting before 01 January 2010.Methodology/Principal FindingsHazard ratios of foetal death for vaccinated compared to unvaccinated pregnancies were estimated for gestational weeks 9 to 12, 13 to 24 and 25 to 43 using discrete-time survival analysis. Separate models were specified to evaluate whether the potential effect of vaccination on foetal loss might be transient (for ∼4 weeks post vaccination only) or more permanent (for the duration of the pregnancy). 39,863 pregnancies meeting our inclusion criteria contributed a total of 969,322 gestational weeks during the study period. 9,445 of the women were vaccinated before or during pregnancy. When the potential effect of vaccination was assumed to be transient, the hazard of foetal death during gestational weeks 9 through 12 (HRunadj 0.56; CI95 0.43 to 0.73) and 13 through 24 (HRunadj 0.45; CI95 0.28 to 0.73) was lower in the 4 weeks after vaccination than in other weeks. Where the more permanent exposure definition was specified, vaccinated pregnancies also had a lower hazard of foetal loss than unvaccinated pregnancies in gestational weeks 9 through 12 (HRunadj 0.74; CI95 0.62 to 0.88) and 13 through 24 (HRunadj 0.59; CI95 0.45 to 0.77). There was no difference in the hazard of foetal loss during weeks 25 to 43 in either model. Sensitivity analyses suggest the strong protective associations observed may be due in part to unmeasured confounding.Conclusions/SignificanceInfluenza vaccination during pregnancy does not appear to increase the risk of foetal death. This study therefore supports the continued recommendation of influenza vaccination of pregnant women.