Guillain-Barré syndrome in the United States, 1978-1981: additional observations from the national surveillance system

Risk of Guillain-Barré syndrome following herpes zoster, United States, 2010-2018

Epidemiologic data regarding the risk of Guillain-Barré syndrome (GBS) following herpes zoster (HZ) are limited. We conducted a self-controlled case series analysis using two large national data sources to evaluate the risk of GBS following HZ among U.S. adults. We analyzed medical claims from the IBM® MarketScan® Commercial Claims and Encounters (persons 18-64 years during 2010-2018) and Centers for Medicare and Medicaid Services Medicare (persons ≥65 years during 2014-2018) databases. HZ cases were defined as persons with an outpatient claim with a primary or secondary ICD-9 or ICD-10 diagnostic code for HZ. GBS cases were defined as persons with an inpatient claim with a principle diagnostic code for GBS and an associated procedural code. We compared the rates of GBS following HZ in the 1-42-day risk window versus primary (100-365-day) or secondary (43-99-day) control windows. We identified 489,516 persons 18-64 years of age and 650,229 persons ≥65 years of age with HZ, among whom 11 and 41, respectively, developed GBS 1-365 days following HZ. The risk of GBS following HZ was increased during the risk window as compared to the primary control window for both groups, with a rate ratio of 6.3 (95% CI, 1.8-21.9) for those 18-64 years and 4.1 (95% CI, 1.9-8.7) for those ≥65 years. This study provides new and methodologically rigorous epidemiologic support for an association between HZ and GBS, and useful context regarding the benefits versus potential risks of zoster vaccination.

Influenza vaccination in autoimmune neuromuscular diseases: A survey of current practices and perceptions

INTRODUCTION

Recommendations for receiving the influenza vaccination in patients with autoimmune neuromuscular disorders, such as myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), or Guillain-Barré syndrome (GBS), may vary among neurology practitioners. This survey examined the current practices and perceptions of neurologists regarding the influenza vaccination in these patients.

METHODS

We performed an Internet-based survey among neurologists across the United States through online forums for neurologists.

RESULTS

Across practice settings, 184 neurologists followed 6465 MG, 2313 CIDP, and 1907 GBS patients. Among the respondents, 82.6%, 58.8%, and 42.3% reported that they recommend the influenza vaccine for all patients with MG, CIDP, and GBS, respectively. Respondents practicing for more than 10 y were more conservative in recommending the influenza vaccine for all patients with MG. A history of exacerbation following the influenza vaccine was regarded as the most important factor influencing vaccine recommendation for MG and CIDP.

DISCUSSION

Influenza vaccination recommendation practices varied between surveyed neurologists, despite existing guidelines. Clearer professional society recommendations and education are an unmet need based on this apparent knowledge gap.

Guillain-Barré syndrome and antecedent cytomegalovirus infection, USA 2009-2015

OBJECTIVE

To describe incidence and clinical characteristics of cases of Guillain-Barré syndrome (GBS) in the USA during 2009-2015, and characteristics of GBS cases with antecedent cytomegalovirus (CMV) infection among persons with employer-sponsored insurance.

METHODS

We analyzed medical claims from IBM Watson MarketScan® databases. GBS patients were defined as enrollees with an inpatient claim with GBS as the principal diagnosis code, based on ICD-9 or ICD-10, and ≥ 1 claim for lumbar puncture or EMG/nerve conduction study. We assessed intensive care unit (ICU) hospitalization, intubation, dysautonomia, and death. We also assessed selected infectious illness within 60 days prior to the first GBS-coded inpatient claim.

RESULTS

We identified 3486 GBS patients; annual incidence was 1.0-1.2/100,000 persons during 2009-2015. GBS incidence was higher in males (1.2/100,000) than in females (0.9/100,000) (p = 0.006) and increased with age, from 0.4/100,000 in persons 0-17 years old to 2.1/100,000 in persons ≥ 65 years old (p < 0.001). Half of GBS patients were hospitalized in the ICU, 8% were intubated, 2% developed dysautonomia, and 1% died. Half had a claim for antecedent illness, but only 125 (3.5%) had a claim for specific infectious pathogens. The mean age among 18 GBS patients with antecedent CMV infection was 39 years versus 47 years among those without antecedent  CMV infection (p = 0.038).

CONCLUSIONS

Incidence of GBS using a large national claims database was comparable to that reported in the literature, but cases appeared to be less severe. Half of GBS patients reported prior infectious illness, but only a minority had a specific pathogen identified.

Role of IV Immunoglobulin in Indian Children With Guillain-Barré Syndrome

OBJECTIVES

To evaluate the outcome of Indian children with Guillain-Barré syndrome who received IV immunoglobulin compared with those who did not receive any specific therapy.

DESIGN

Single center, prospective cross-sectional study.

SETTING

Tertiary care neurology teaching hospital.

PATIENTS

Children (≤ 18 yr old) with Guillain-Barré syndrome were included from a prospectively maintained Guillain-Barré syndrome registry from January 2008 to April 2017. Children were classified into acute inflammatory demyelinating polyradiculoneuropathy, acute motor axonal neuropathy, acute motor-sensory axonal neuropathy, and inexcitable motor nerves based on nerve conduction study.

INTERVENTIONS

Out of 138 pediatric Guillain-Barré syndrome, 50 received IV immunoglobulin and another 50 age and peak disability matched controls (who did not receive IV immunoglobulin or plasmapheresis) were selected from the same registry for comparison.

MEASUREMENTS AND MAIN RESULTS

Outcome at 3 and 6 months was defined on the basis of a 0-10 Clinical Grading Scale into complete (Clinical Grading Scale < 3), partial (Clinical Grading Scale 3-5), and poor (Clinical Grading Scale > 5) recovery. The primary outcome was proportion of patients with complete recovery at 3 and 6 months in IV immunoglobulin and non-IV immunoglobulin groups. Secondary outcomes included in-hospital deaths, duration of mechanical ventilation, and hospital stay. Subgroup analysis was done in acute motor axonal neuropathy and acute inflammatory demyelinating polyradiculoneuropathy groups. The baseline characteristics were similar except for shorter duration of illness and higher proportion of facial palsy in IV immunoglobulin group. Hospital deaths, duration of mechanical ventilation, hospital stay, and outcome at 3 and 6 months were not different between the two groups. Children with acute motor axonal neuropathy had better recovery at 6 months on IV immunoglobulin (58.3% vs 11.1%; p = 0.03), but not those with acute inflammatory demyelinating polyradiculoneuropathy (58.3% vs 72.2%; p = 0.22). In nonambulatory Guillain-Barré syndrome children, complete recovery at 6 months was similar in IV immunoglobulin and non-IV immunoglobulin group (57.4% vs 57.1%; p = 0.98).

CONCLUSIONS

In Indian children with Guillain-Barré syndrome, the outcome at 6 months in IV immunoglobulin treated group was similar to non-IV immunoglobulin group. Children with acute motor axonal neuropathy responded better to IV immunoglobulin.

Vaccines for preventing influenza in the elderly

BACKGROUND

The consequences of influenza in the elderly (those age 65 years or older) are complications, hospitalisations, and death. The primary goal of influenza vaccination in the elderly is to reduce the risk of death among people who are most vulnerable. This is an update of a review published in 2010. Future updates of this review will be made only when new trials or vaccines become available. Observational data included in previous versions of the review have been retained for historical reasons but have not been updated because of their lack of influence on the review conclusions.

OBJECTIVES

To assess the effects (efficacy, effectiveness, and harm) of vaccines against influenza in the elderly.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 11), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1966 to 31 December 2016); Embase (1974 to 31 December 2016); Web of Science (1974 to 31 December 2016); CINAHL (1981 to 31 December 2016); LILACS (1982 to 31 December 2016); WHO International Clinical Trials Registry Platform (ICTRP; 1 July 2017); and ClinicalTrials.gov (1 July 2017).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing efficacy against influenza (laboratory-confirmed cases) or effectiveness against influenza-like illness (ILI) or safety. We considered any influenza vaccine given independently, in any dose, preparation, or time schedule, compared with placebo or with no intervention. Previous versions of this review included 67 cohort and case-control studies. The searches for these trial designs are no longer updated.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed risk of bias and extracted data. We rated the certainty of evidence with GRADE for the key outcomes of influenza, ILI, complications (hospitalisation, pneumonia), and adverse events. We have presented aggregate control group risks to illustrate the effect in absolute terms. We used them as the basis for calculating the number needed to vaccinate to prevent one case of each event for influenza and ILI outcomes.

MAIN RESULTS

We identified eight RCTs (over 5000 participants), of which four assessed harms. The studies were conducted in community and residential care settings in Europe and the USA between 1965 and 2000. Risk of bias reduced our certainty in the findings for influenza and ILI, but not for other outcomes.Older adults receiving the influenza vaccine may experience less influenza over a single season compared with placebo, from 6% to 2.4% (risk ratio (RR) 0.42, 95% confidence interval (CI) 0.27 to 0.66; low-certainty evidence). We rated the evidence as low certainty due to uncertainty over how influenza was diagnosed. Older adults probably experience less ILI compared with those who do not receive a vaccination over the course of a single influenza season (3.5% versus 6%; RR 0.59, 95% CI 0.47 to 0.73; moderate-certainty evidence). These results indicate that 30 people would need to be vaccinated to prevent one person experiencing influenza, and 42 would need to be vaccinated to prevent one person having an ILI.The study providing data for mortality and pneumonia was underpowered to detect differences in these outcomes. There were 3 deaths from 522 participants in the vaccination arm and 1 death from 177 participants in the placebo arm, providing very low-certainty evidence for the effect on mortality (RR 1.02, 95% CI 0.11 to 9.72). No cases of pneumonia occurred in one study that reported this outcome (very low-certainty evidence). No data on hospitalisations were reported. Confidence intervaIs around the effect of vaccines on fever and nausea were wide, and we do not have enough information about these harms in older people (fever: 1.6% with placebo compared with 2.5% after vaccination (RR 1.57, 0.92 to 2.71; moderate-certainty evidence)); nausea (2.4% with placebo compared with 4.2% after vaccination (RR 1.75, 95% CI 0.74 to 4.12; low-certainty evidence)).

AUTHORS' CONCLUSIONS

Older adults receiving the influenza vaccine may have a lower risk of influenza (from 6% to 2.4%), and probably have a lower risk of ILI compared with those who do not receive a vaccination over the course of a single influenza season (from 6% to 3.5%). We are uncertain how big a difference these vaccines will make across different seasons. Very few deaths occurred, and no data on hospitalisation were reported. No cases of pneumonia occurred in one study that reported this outcome. We do not have enough information to assess harms relating to fever and nausea in this population.The evidence for a lower risk of influenza and ILI with vaccination is limited by biases in the design or conduct of the studies. Lack of detail regarding the methods used to confirm the diagnosis of influenza limits the applicability of this result. The available evidence relating to complications is of poor quality, insufficient, or old and provides no clear guidance for public health regarding the safety, efficacy, or effectiveness of influenza vaccines for people aged 65 years or older. Society should invest in research on a new generation of influenza vaccines for the elderly.

Guillain-Barré Syndrome After Elective Spinal Surgery

Guillain-Barré syndrome is a rare autoimmune condition characterized by ascending motor weakness of the extremities that can ascend to the diaphragm, causing substantial morbidity and mortality. This case report describes a 57-year-old man who exhibited characteristics of Guillain-Barré syndrome 9 days after undergoing lumbar fusion at L3-S1. The diagnosis was based on the patient's ascending motor weakness and areflexia and was confirmed with electromyography. The patient progressed to respiratory failure, requiring mechanical ventilation. He regained motor function and ambulation within 6 months. Although the syndrome typically manifests initially as ascending paralysis, this patient's initial symptom was new-onset atrial fibrillation, a sign of autonomic dysfunction. Because it can cause paralysis and respiratory failure, Guillain-Barré syndrome should be included in the differential diagnosis whenever motor weakness is observed after lumbar surgery. The timing of symptoms, imaging results, and the development of atypical symptoms can help distinguish this rare possibility from other postoperative spinal complications.

Pathophysiology and diagnosis of Guillain-Barré syndrome - challenges and needs

Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy which presents with acute onset and rapid progression of flaccid, hyporeflexi quadriparesis. Both sensory and autonomic nerve involvement is seen. GBS has various subtypes that vary in their pathophysiology. The pathogenesis involves an immune response triggered by a preceding event which may be an infection, immunisation or surgical procedure. Clinical diagnosis has been largely the primary diagnosing criterion for GBS along with electrodiagnosis, which has several pitfalls and is supported by ancillary testing of cerebrospinal fluid (CSF) analysis and Nerve Conduction Studies. Measurement of anti-ganglioside antibodies is also an effective tool in its diagnosis. Further understanding of pathophysiology and better diagnostic methods are required for better management of GBS.

Weakness and the inability to ambulate in a 14-month-old female: a case report and concise review of guillain-barre syndrome

Guillain-Barre syndrome (GBS) is an acquired disease of the peripheral nervous system which causes demyelination and leads to weakness, ataxia, and areflexia. There are a variety of forms of the syndrome, and although it is found in all age groups, it is rare in children less than two years of age. The present complaint of weakness, ataxia, or lower extremity pain in the pediatric population should cause the practitioner to consider GBS in the differential. We describe a case of a 14-month-old girl presenting with weakness and the inability to ambulate who was diagnosed with GBS. The purpose of this paper is to review the emergency medicine diagnosis and management of Guillain-Barre syndrome in children.

No evidence of a link between influenza vaccines and Guillain-Barre syndrome-associated antiganglioside antibodies

Please cite this paper as: Wang et al. (2011) No evidence of a link between influenza vaccines and Guillain–Barre syndrome–associated antiganglioside antibodies. Influenza and Other Respiratory Viruses 6(3), 159–166.

Background  Guillain–Barre syndrome (GBS) is a rare autoimmune disease characterized by acute, progressive peripheral neuropathy and is commonly associated with the presence of antiganglioside antibodies. Previously, influenza vaccination was linked with the increased incidence of GBS; however, whether antiganglioside antibodies are subsequently induced remains unresolved.

Methods  Sera from human subjects vaccinated with seasonal influenza vaccines from the 2007–2008, 2008–2009, or 1976–1977 influenza seasons were screened for the induction of immunity to influenza and the presence of antiganglioside antibodies pre‐ and post‐vaccination. Likewise, sera from mice vaccinated with seasonal influenza vaccines (1988–1989, 2007–2008) or “swine flu” pandemic vaccines (1976, 2009) were assessed in the same manner. Viruses were also screened for cross‐reacting ganglioside epitopes.

Results  Antiganglioside antibodies were found to recognize influenza viruses; this reactivity correlated with virus glycosylation. Antibodies to influenza viruses were detected in human and mouse sera, but the prevalence of antiganglioside antibodies was extremely low.

Conclusions  Although the correlation between antiganglioside antibody cross‐reactivity and glycosylation of viruses suggests the role of shared carbohydrate epitopes, no correlation was observed between hemagglutinin‐inhibition titers and the induction of antiganglioside antibodies after influenza vaccination.

Evaluation of Guillain-Barré Syndrome among recipients of influenza vaccine in 2000 and 2001

BACKGROUND

The 1976-1977 swine influenza vaccine was associated with an elevated risk of Guillain-Barré Syndrome (GBS), especially within 6 weeks after vaccination. A 2004 IOM report concluded that evidence was inadequate to accept or reject a causal relationship between subsequent influenza vaccine formulations and GBS. Studies published after the IOM report have been limited by passively reported data or lack of validation of coded diagnoses.

PURPOSE

To evaluate whether influenza vaccine is associated with GBS.

METHODS

Controlled observational study using national data from the Medicare program, which ensures a predominantly elderly population. People included had a Medicare claim for influenza vaccination during September-December in 2000 or 2001. Medical records were reviewed to classify definite, probable, or possible GBS (or not a case) using a standardized case definition. In a risk interval design, the incidence rate of GBS during Weeks 0-6 after vaccination (exposed period) was compared to Weeks 9-14 after vaccination (comparison period). Data collection occurred during 2003-2007, and analysis was conducted during 2007-2009.

RESULTS

Primary analysis included 22.2 million vaccinees, among whom 164 definite or probable GBS cases with onset during Weeks 0-6 or 9-14 were identified. The incidence rate ratio (IRR [95% CIs]) based on the GBS rate in the vaccine-exposed versus comparison periods, was 1.04 (0.76, 1.43) for combined years; 0.86 (0.52, 1.41) among people vaccinated in 2000; and 1.21 (0.79, 1.86) among people vaccinated in 2001. Secondary analysis additionally included 74 possible GBS cases; results were similar.

CONCLUSIONS

Overall, the results do not support an association between influenza vaccine receipt and GBS among the elderly for the years studied (2000-2001 and 2001-2002 formulations).

Vaccines for preventing influenza in the elderly

BACKGROUND

Vaccines have been the main global weapon to minimise the impact of influenza in the elderly for the last four decades and are recommended worldwide for individuals aged 65 years or older. The primary goal of influenza vaccination in the elderly is to reduce the risk of complications among persons who are most vulnerable.

OBJECTIVES

To assess the effectiveness of vaccines in preventing influenza, influenza-like illness (ILI), hospital admissions, complications and mortality in the elderly. To identify and appraise comparative studies evaluating the effects of influenza vaccines in the elderly. To document types and frequency of adverse effects associated with influenza vaccines in the elderly.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register (The Cochrane Library 2009, issue 4); MEDLINE (January 1966 to October Week 1 2009); EMBASE (1974 to October 2009) and Web of Science (1974 to October 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs, cohort and case-control studies assessing efficacy against influenza (laboratory-confirmed cases) or effectiveness against influenza-like illness (ILI) or safety. Any influenza vaccine given independently, in any dose, preparation or time schedule, compared with placebo or with no intervention was considered.

DATA COLLECTION AND ANALYSIS

We grouped reports first according to the setting of the study (community or long-term care facilities) and then by level of viral circulation and vaccine matching. We further stratified by co-administration of pneumococcal polysaccharide vaccine (PPV) and by different types of influenza vaccines. We analysed the following outcomes: influenza, influenza-like illness, hospital admissions, complications and deaths.

MAIN RESULTS

We included 75 studies. Overall we identified 100 data sets. We identified one RCT assessing efficacy and effectiveness. Although this seemed to show an effect against influenza symptoms it was underpowered to detect any effect on complications (1348 participants). The remainder of our evidence base included non-RCTs. Due to the general low quality of non-RCTs and the likely presence of biases, which make interpretation of these data difficult and any firm conclusions potentially misleading, we were unable to reach clear conclusions about the effects of the vaccines in the elderly.

AUTHORS' CONCLUSIONS

The available evidence is of poor quality and provides no guidance regarding the safety, efficacy or effectiveness of influenza vaccines for people aged 65 years or older. To resolve the uncertainty, an adequately powered publicly-funded randomised, placebo-controlled trial run over several seasons should be undertaken.

"Prepandemic" immunization for novel influenza viruses, "swine flu" vaccine, Guillain-Barré syndrome, and the detection of rare severe adverse events

The availability of immunogenic, licensed H5N1 vaccines and the anticipated development of vaccines against "swine" influenza A(H1N1) have stimulated debate about the possible use of these vaccines for protection of those exposed to potential pandemic influenza viruses and for immunization or "priming" of populations in the so-called "prepandemic" (interpandemic) era. However, the safety of such vaccines is a critical issue in policy development for wide-scale application of vaccines in the interpandemic period. For example, wide-scale interpandemic use of H5N1 vaccines could lead to millions of persons receiving vaccines of uncertain efficacy potentially associated with rare severe adverse events and against a virus that may not cause a pandemic. Here, we first review aspects of the 1976 National Influenza Immunization Programme against "swine flu" and its well-documented association with Guillain-Barré syndrome as a case study illustration of a suspected vaccine-associated severe adverse event in a mass interpandemic immunization setting. This case study is especially timely, given the recent spread of a novel influenza A(H1N1) virus in humans in Mexico and beyond. Following this, we examine available safety data from clinical trials of H5N1 vaccines and briefly discuss how vaccine safety could be monitored in a postmarketing surveillance setting.

Epidemiology of Guillain-Barré syndrome in the province of Quebec

BACKGROUND

In the province of Quebec, a population-based study of Guillain-Barré syndrome (GBS) was conducted at the time of a mass immunization campaign against meningococcal disease, in 2001.

METHODS

The study population included residents aged 2 months to 20 years observed from November 1st, 2000 to December 31, 2002, representing 4,075,465 person-years of observation. GBS cases were identified in the provincial hospital database Med-Echo and medical records were reviewed.

RESULTS

Thirty-three incident GBS cases were identified, including 27 cases of acute inflammatory demyelinating polyradiculopathy. The overall GBS incidence rate was 0.8/100,000 person-years, higher in persons aged 1 to 4 years (2.1/100,000) than in those 5 years or more (0.6/100,000). There was a female preponderance and no significant seasonal variation. All patients survived.

CONCLUSION

Results could be used to interpret reports of adverse events associated with the introduction of new vaccines in this age-group in Canada.

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute, demyelinating polyneuropathy involving the spinal roots, peripheral nerves, and often the cranial nerves. Although its exact mechanism remains unclear, an autoimmune etiopathology is theorized. It is characterized by rapidly progressing, symmetrical muscular weakness starting in the legs and ascending to the trunk and arms. Additionally, deep tendon reflexes are lost. Approximately half of the patients with GBS have cranial nerve palsies, with unilateral or bilateral facial nerve (CN VII) palsy being the most common. Paralysis of the muscles of the tongue, lips, palate, larynx, and pharynx from lesions involving cranial nerves IX, X, and XI and weakness of the muscles of mastication (CN V) are the next most common cranial nerve abnormalities. Ocular muscle palsy is not common, only occurring in approximately 10% of patients. The Miller Fisher variant of GBS is a distinct syndrome in which the only neurologic deficits are oculomotor palsies, areflexia, and ataxia. We present the rare case of a 45-year-old woman with GBS whose ocular muscles were affected. The oculomotor disturbance and limb weakness occurred within a few days of one another. Basic anatomic considerations are reviewed along with the pathophysiology and clinical features of GBS.

Vaccines for preventing influenza in the elderly

BACKGROUND

Influenza vaccination of elderly individuals is recommended worldwide and has been targeted toward the elderly and those at serious risk of complications.

OBJECTIVES

Our aim was to review the evidence of efficacy, effectiveness and safety of influenza vaccines in individuals aged 65 years or older.

SEARCH STRATEGY

We searched the following databases on The Cochrane Library, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effectiveness (Issue 1, 2006); MEDLINE (January 1966 to March Week 3 2006); EMBASE (Dialog 1974 to 1979; SilverPlatter 1980 to December 2005); Biological Abstracts (SilverPlatter 1969 to December 2004); and Science Citation Index (Web of Science 1974 to December 2004).

SELECTION CRITERIA

We considered randomised, quasi-randomised, cohort and case-control studies assessing efficacy against influenza (laboratory-confirmed cases) or effectiveness against influenza-like illness (ILI) or safety. Any influenza vaccine given independently, in any dose, preparation or time schedule, compared with placebo or with no intervention was considered.

DATA COLLECTION AND ANALYSIS

We grouped reports first according to the setting of the study (community or long-term care facilities) and then by level of viral circulation and vaccine matching. We further stratified by co-administration of pneumococcal polysaccharide vaccine (PPV) and by different types of influenza vaccines. We analysed the following outcomes: influenza, influenza-like illness, hospital admissions, complications and deaths.

MAIN RESULTS

Sixty-four studies were included in the efficacy / effectiveness assessment, resulting in 96 data sets. In homes for elderly individuals (with good vaccine match and high viral circulation) the effectiveness of vaccines against ILI was 23% (6% to 36%) and non-significant against influenza (RR 1.04: 95% CI 0.43 to 2.51). We found no correlation between vaccine coverage and ILI attack rate. Well matched vaccines prevented pneumonia (VE 46%; 30% to 58%), hospital admission (VE 45%; 16% to 64%) and deaths from influenza or pneumonia (VE 42%, 17% to 59%). In elderly individuals living in the community, vaccines were not significantly effective against influenza (RR 0.19; 95% CI 0.02 to 2.01), ILI (RR 1.05: 95% CI 0.58 to 1.89), or pneumonia (RR 0.88; 95% CI 0.64 to 1.20). Well matched vaccines prevented hospital admission for influenza and pneumonia (VE 26%; 12% to 38%) and all-cause mortality (VE 42%; 24% to 55%). After adjustment for confounders, vaccine performance was improved for admissions to hospital for influenza or pneumonia (VE* 27%; 21% to 33%), respiratory diseases (VE* 22%; 15% to 28%) and cardiac disease (VE* 24%; 18% to 30%); and for all-cause mortality (VE* 47%; 39% to 54%). The public health safety profiles of the vaccines appear to be acceptable.

AUTHORS' CONCLUSIONS

In long-term care facilities, where vaccination is most effective against complications, the aims of the vaccination campaign are fulfilled, at least in part. However, according to reliable evidence the usefulness of vaccines in the community is modest. The apparent high effectiveness of the vaccines in preventing death from all causes may reflect a baseline imbalance in health status and other systematic differences in the two groups of participants.

Guillain-Barré syndrome

Guillain-Barré syndrome consists of at least four subtypes of acute peripheral neuropathy. Major advances have been made in understanding the mechanisms of some of the subtypes. The histological appearance of the acute inflammatory demyelinating polyradiculoneuropathy (AIDP) subtype resembles experimental autoimmune neuritis, which is predominantly caused by T cells directed against peptides from the myelin proteins P0, P2, and PMP22. The role of T-cell-mediated immunity in AIDP remains unclear and there is evidence for the involvement of antibodies and complement. Strong evidence now exists that axonal subtypes of Guillain-Barré syndrome, acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN), are caused by antibodies to gangliosides on the axolemma that target macrophages to invade the axon at the node of Ranvier. About a quarter of patients with Guillain-Barré syndrome have had a recent Campylobacter jejuni infection, and axonal forms of the disease are especially common in these people. The lipo-oligosaccharide from the C jejuni bacterial wall contains ganglioside-like structures and its injection into rabbits induces a neuropathy that resembles acute motor axonal neuropathy. Antibodies to GM1, GM1b, GD1a, and GalNac-GD1a are in particular implicated in acute motor axonal neuropathy and, with the exception of GalNacGD1a, in acute motor and sensory axonal neuropathy. The Fisher's syndrome subtype is especially associated with antibodies to GQ1b, and similar cross-reactivity with ganglioside structures in the wall of C jejuni has been discovered. Anti-GQ1b antibodies have been shown to damage the motor nerve terminal in vitro by a complement-mediated mechanism. Results of international randomised trials have shown equivalent efficacy of both plasma exchange and intravenous immunoglobulin, but not corticosteroids, in hastening recovery from Guillain-Barré syndrome. Further research is needed to discover treatments to prevent 20% of patients from being left with persistent and significant disability.

Epidemiology of Campylobacter jejuni isolated from patients with Guillain-Barré and Fisher syndromes in Japan

Campylobacter jejuni isolation is the standard for the diagnosis of this type of bacterial infection, but there have been no epidemiological studies of a large number of C. jejuni isolates from patients with Guillain-Barre syndrome (GBS) and Fisher syndrome (FS). For 13 years, stool specimens from GBS/FS patients have been sent from 378 hospitals throughout Japan to the Tokyo Metropolitan Institute of Public Health. A total of 113 strains (11%) were isolated from the stool specimens from 1,049 patients. The isolation rate did not differ by region. The rates were 22% for 449 patients with a history of diarrhea and 2% for the others. An additional 18 isolates were provided by various hospitals. There was no noticeable seasonal distribution in the onset of C. jejuni isolated from patients with GBS/FS. The male/female ratios were 1.7:1 for GBS and 2.2:1 for FS. The patient age range showed a peak in 10- to 30-year-old subjects who had GBS and in 10- to 20-year-old subjects who had FS. The predominance of young adults and male patients who had C. jejuni-associated GBS/FS may be related to the preponderance of young adults and male patients who had C. jejuni enteritis. The median interval from diarrhea onset to neurologic symptom onset was 10 days for GBS/FS. Penner's C. jejuni serotype HS:19 was more frequently present in GBS (67%) than in enteritis (6%) patients. HS:2 was more frequent in FS (41%) than in enteritis (14%) patients. These findings suggest that certain C. jejuni strains specifically trigger GBS and that others specifically trigger FS.

A clinical and electrophysiologic survey of childhood Guillain-Barré syndrome

In this 16-year (1986-2001) retrospective study, 23 childhood patients were identified with Guillain-Barré syndrome. According to clinical and electrophysiologic findings, 18 patients manifested acute inflammatory demyelinating polyradiculoneuropathy, 2 had Miller Fisher syndrome, 1 had axonal forms, and 2 were unclassified. Seasonal preponderance was evident in 39% of patients with Guillain-Barré syndrome, developing the disease in the winter (November to January) with upper respiratory infection the most frequent preceding event. The most common manifestation was limb weakness, with various degrees of motor weakness in 22 patients. Bulbar involvement was the most common cranial palsy, and it was evident in 30% of the episodes. Only one of these progressed to mechanical ventilation during hospitalization. Altogether, approximately 61% of the episodes exhibited sensory symptoms. At a follow-up of 1 year or more, 20 patients recovered and 3 had residua. Furthermore, no fatality occurred in our study. Our study also demonstrates that the clinical course of childhood Guillain-Barré syndrome has a shorter recovery time as compared with an adult patient group. Therapeutic outcome is favorable for patients who receive prompt treatment.

Guillain-Barré syndrome in southern Taiwan: clinical features, prognostic factors and therapeutic outcomes

To determine the clinical features, prognostic factors, and therapeutic results of Guillain-Barré syndrome (GBS) in order to improve the therapeutic strategy for this disease. We retrospectively reviewed the electrodiagnostic study and medical records of patients with GBS admitted to Chang Gung Memorial Hospital, Kaohsiung, between January 1986 and December 2000. Outcomes and prognosis were followed-up after 1 year. Ninety-six patients were enrolled in this study. According to the clinical and electrophysiological findings, 77 patients were acute inflammatory demyelinating polyradiculoneuropathy, seven were Miller Fisher syndrome, and six were axonal forms, and six were unclassified. At a follow-up of 1 year, 61 patients (64%) recovered, 30 (31%) had residua and five (5%) died. Amongst these 30 had residua, including unassisted gait in 19, assisted gait in four, and wheel/bed bound in seven. According to the statistical analysis, disabilities at the nadir (P < 0.0001) and at admission (P = 0.014) were significant prognostic factors. Variables used for the stepwise logistic regression, and the results revealed that after analysis for all the above variables, only disability at the nadir (P < 0.0001) was independently associated with the treatment failure rate. Our study revealed 27% of cases in need of respiratory support during hospitalization, and 5% of hospital-treated patients die from the complications. Furthermore, 31% had residua at a follow-up of 1 year or more. If prognostic factors are considered, disability at the nadir during hospitalization demonstrates consistently poor therapeutic outcomes. Therefore, early diagnosis, choice of appropriate treatment, and preventing complications during acute stages are essential to maximize the potential for survival.

Epidemiology of childhood Guillain-Barré syndrome as a cause of acute flaccid paralysis in Honduras: 1989-1999

The objective of this study was to investigate the incidence of acute flaccid paralysis in the pediatric population of Honduras over an 11-year period, determine what percentage of acute flaccid paralysis was Guillain-Barré syndrome, and identify the epidemiologic features of Guillain-Barré syndrome. There were 546 childhood cases of acute flaccid paralysis seen between January 1989 and December 1999 at the Hospital Escuela Materno-Infantil in Tegucigalpa, Honduras. Of these cases with acute flaccid paralysis, 394 (72.2%) were diagnosed with Guillain-Barré syndrome. Our incidence of Guillain-Barré syndrome in the Honduran pediatric population (1.37/100,000 per year) is higher than that shown in other studies. There was a significantly higher incidence of Guillain-Barré syndrome in younger children (ages 1-4 years), a significant preponderance of cases from rural areas, and a mild predominance in boys but a typical clinical presentation. The Honduran pediatric Guillain-Barré syndrome population had an increased mortality rate. Guillain-Barré syndrome has become the leading cause of childhood paralysis in Honduras. A better understanding of the population at highest risk and opportunities for earlier intervention with more effective therapeutic modalities may permit reducing the mortality among Honduran children who develop Guillain-Barré syndrome.

Epidemiology of the Guillain-Barré syndrome

This review focuses on recent epidemiological findings on Guillain-Barré syndrome regarding incidence, antecedent events related to the disease, prognosis and prognostic indicators, and treatment. Moreover, this review summarizes recent observations on clinical variants of Guillain-Barré syndrome and their relationship with the prevailing clinical presentation of the disease. The epidemiological observations which have advanced the understanding of the pathogenesis of Guillain-Barré syndrome are also discussed.

Pathogenesis of Guillain-Barré syndrome

Recent neurophysiological and pathological studies have led to a reclassification of the diseases that underlie Guillain-Barré syndrome (GBS) into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor and sensory axonal neuropathy (AMSAN) and acute motor axonal neuropathy (AMAN). The Fisher syndrome of ophthalmoplegia, ataxia and areflexia is the most striking of several related conditions. Significant antecedent events include Campylobacter jejuni (4-66%), cytomegalovirus (5-15%), Epstein-Barr virus (2-10%), and Mycoplasma pneumoniae (1-5%) infections. These infections are not uniquely associated with any clinical subtype but severe axonal degeneration is more common following C. jejuni and severe sensory impairment following cytomegalovirus. Strong evidence supports an important role for antibodies to gangliosides in pathogenesis. In particular antibodies to ganglioside GM1 are present in 14-50% of patients with GBS, and are more common in cases with severe axonal degeneration associated with any subtype. Antibodies to ganglioside GQ1b are very closely associated with Fisher syndrome, its formes frustes and related syndromes. Ganglioside-like epitopes exist in the bacterial wall of C. jejuni. Infection by this and other organisms triggers an antibody response in patients with GBS but not in those with uncomplicated enteritis. The development of GBS is likely to be a consequence of special properties of the infecting organism, since some strains such as Penner 0:19 and 0:41 are particularly associated with GBS but not with enteritis. It is also likely to be a consequence of the immunogenetic background of the patient since few patients develop GBS after infection even with one of these strains. Attempts to match the subtypes of GBS to the fine specificity of anti-ganglioside antibodies and to functional effects in experimental models continue but have not yet fully explained the pathogenesis. T cells are also involved in the pathogenesis of most or perhaps all forms of GBS. T cell responses to any of three myelin proteins, P2, PO and PMP22, are sufficient to induce experimental autoimmune neuritis. Activated T cells are present in the circulation in the acute stage, up-regulate matrix metalloproteinases, cross the blood-nerve barrier and encounter their cognate antigens. Identification of the specificity of these T cell responses is still at a preliminary stage. The invasion of intact myelin sheaths by activated macrophages is difficult to explain according to a purely T cell mediated mechanism. The different patterns of GBS are probably due to the diverse interplay between antibodies and T cells of differing specificities.

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is viewed as a reactive, self-limited, autoimmune disease triggered by a preceding bacterial or viral infection. Campylobacter jejuni, a major cause of bacterial gastroenteritis worldwide, is the most frequent antecedent pathogen. It is likely that immune responses directed towards the infecting organisms are involved in the pathogenesis of GBS by cross-reaction with neural tissues. The infecting organism induces humoral and cellular immune responses that, because of the sharing of homologous epitopes (molecular mimicry), cross-react with ganglioside surface components of peripheral nerves. Immune reactions against target epitopes in Schwann-cell surface membrane or myelin result in acute inflammatory demyelinating neuropathy (85% of cases); reactions against epitopes contained in the axonal membrane cause the acute axonal forms of GBS (15% of cases). Care for such patients may be challenging, yet the prognosis overall is favourable. Optimal supportive care and anticipation and prevention of complications are the mainstay of therapy. Admission to the intensive-care unit is necessary in 33% of patients who require intubation and assisted ventilation. Immunomodulation with infusions of IgG or plasma exchange treatments foreshorten the disease course.

Antibodies to gangliosides and galactocerebroside in patients with Guillain-Barré syndrome with preceding Campylobacter jejuni and other identified infections

The relationship between preceding infections and antibodies to glycolipids was investigated in 205 Japanese patients with Guillain-Barré syndrome (GBS). Serological evidence of recent Campylobacter jejuni (C. jejuni) infection was found in 45% of the patients, compared with 1% in healthy controls. In contrast, recent infection of cytomegalovirus (CMV), Mycoplasma pneumoniae (M. pneumoniae) and Epstein-Barr virus (EBV) was detected in only 5%, 2% and none of the patients, respectively. C. jejuni-associated GBS was more frequent in early spring than in other seasons. All stool specimens positive for C. jejuni isolation were obtained within 10 days after the onset of GBS symptoms. Of 13 C. jejuni isolates from GBS patients, 10 (77%) belonged to Penner serotype 19 (heat-stable, HS-19). Elevated titers of anti-GM1 antibody were found in 8 (80%) of 10 GBS patients whose C. jejuni isolates belonged to HS-19 and in none of those infected with non-HS-19 C. jejuni (P = 0.04), and in 49% of 92 patients with C. jejuni infection and 25% of patients without infection of C. jejuni, CMV, EBV, or M. pneumoniae (P = 0.0007). The frequencies of elevated antibody titers to GD1a, GD1b and GQ1b were also significantly higher in GBS patients associated with C. jejuni than those not associated with C. jejuni, CMV, EBV, and M. pneumoniae. GBS in Japan seems to be associated more frequently with C. jejuni and less frequently with CMV than in Europe and North America.

Epidemiological features of Guillain-Barré syndrome in Sweden, 1978-93

OBJECTIVES

To describe the incidence of Guillain-Barré syndrome in Sweden during the period 1978-93 and its temporal and geographical variations.

METHODS

Stratified and Poisson regression analyses and tests for detection of small epidemics were applied to population based hospital discharge data from 2257 incident cases of Guillain-Barré syndrome in Sweden during the study period.

RESULTS

The incidence of Guillain-Barré syndrome was (1) 1.77 per 100000 person-years when age adjusted to the European population; (2) higher in males; and (3) stable across time, although occasional increases of annual incidence rates were found-namely, in 1978 (relative risk (RR) 1.30 (95% CI 1.10-1.54)), and in 1983 (RR 1.24 (95% CI 1.06-1.40)). The incidence increased with age and was bimodal, with peaks at 20-24 and 70-74 years. There was a moderate but significant seasonality with a peak in August, particularly among the young age groups. The age adjusted incidence by county varied from 1.11 to 2.57 per 100000 person-years. Neither temporal nor spatial clustering was significant, except during the period July-September in 1983 at ages below 40 years.

CONCLUSIONS

The incidence of Guillain-Barré syndrome in Sweden during the period 1978-93 had a magnitude similar to those described in other surveys, a bimodal distribution by age, and modest geographical and temporal variations with significantly high rates in 1978 and 1983 and in autumn. Minor outbreaks might have passed unnoticed up to the present. Whereas reported drug induced cases of Guillain-Barré syndrome may in part explain the high incidence in 1983, the cause of the aberrant incidence in 1978 remains unknown. Epidemiological surveillance of Guillain-Barré syndrome in Sweden might have been useful.

Guillain-Barré syndrome in Stockholm County, 1973-1991

In order to describe the incidence of Guillain-Barré syndrome (GBS) in Stockholm County (SC) and hospital use by GBS patients, we conducted a retrospective epidemiological study on GBS covering 1973-1991, using the Hospital Inpatient Register in SC. There were 556 patients, bona fide residents in the county during the study period, discharged from hospitals with GBS diagnosis. The mean annual incidence, age-adjusted to the European population, was 1.84 (2.15 for males and 1.57 for females) per 100,000 population. The incidence increased with age and showed a bimodal distribution with peaks in the 10-29 and 70-79 age-groups. Annual incidence rates were highest in 1978 and 1983. Neither heterogeneity of annual or monthly rates nor linear trends during the period were found to be significant, except in 1978 for patients below 40 years of age, RR 1.72 (95% CI 1.08-2.71) and in 1983 for patients at ages 40 years and over, RR 1.48 (95% CI 1.02-2.16), when compared with GBS incidences in the same age-groups during the remaining study period. The mean +/- SD duration of hospital stay, including long-term care or rehabilitation institutions, for GBS patients, was 86 +/- 210 days, with considerably longer duration for the elderly. The rate of hospital use by GBS patients was 162 days per 100,000 inhabitants per year. In accordance with results of prior studies in South-West Stockholm and described GBS epidemics in Sweden, this study supports that an etiologically different subgroup of GBS exists at ages below 40 years, and that relevant but small time-space variations, such as the reported zimeldine epidemic in 1983, resist detection by hospital data analysis of pooled GBS cases. Efficient epidemiological surveillance of GBS may require targeted development of clinico-epidemiological tools.

Guillain-Barré syndrome in children: a cooperative study in Taiwan

Seventy-two children with Guillain-Barré syndrome (GBS), diagnosed at 11 major teaching hospitals in Taiwan during the period 1986-1990, were studied retrospectively. There were 44 males and 28 females ranging in age from 7 months to 15 years. Preceding events could be traced in 61 patients (85%), including antecedent infection in 59 patients and previous vaccination in 2. As well as the consistent pictures of progressive weakness and generalized hyporeflexia, there were sensory complaints (26%), cranial nerve lesions (46%), respiratory failure (14%) and autonomic dysfunction (25%). Motor symptoms reached a maximum within 20 days in 88% of the patients, with the plateau lasting less than 2 weeks in 75%, and became stable within 3 months in 76%. Overall outcome showed complete recovery in 73% of the patients within 6 months after onset. Four (5.6%) had recurrence, and there was no mortality. The present study revealed that the annual incidence of GBS in Taiwan can be estimated roughly as 0.66 per 100,000 and that the course of childhood GBS is relatively benign.

Guillain-Barré syndrome: diagnostic criteria, epidemiology, clinical course and prognosis

Thirty-four patients were identified with Guillain-Barré syndrome (GBS) on review of 266 neuropathy cases admitted to a Copenhagen county hospital from June 1977 to January 1984. The age-adjusted incidence rate of GBS is 2.0 x 10(-5) years-1. The natural history of the disease, antecedent events, symptoms and signs, autonomic dysfunction, sequelae, CSF findings and mortality are described. Six cancer patients with GBS differed significantly from the non-cancer patients in a more protracted disease course and failure to improve. The National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for the diagnosis of GBS are discussed, and it is concluded that the criteria, although useful in comparative studies, are too restrictive when used in clinical practice.

Adult-onset muscle weakness. How to identify the underlying cause

When adults present with muscle weakness as the predominant symptom and sign, the causes can usually be narrowed down to four disorders: amyotrophic lateral sclerosis, Guillain-Barré syndrome, myasthenia gravis, and inflammatory myopathy. Perhaps the most difficult task for the clinician is identifying which of these patients are actually weak and which are describing generalized fatigue. This task should be made easier by keeping in mind the definition of muscle weakness--a loss of power resulting in reduction of motor function--and by performing careful functional muscle testing.