Since the emergence of West Nile virus (WNV) in North America in 1999, understanding of the clinical features, spectrum of illness and eventual functional outcomes of human illness has increased ...tremendously. Most human infections with WNV remain clinically silent. Among those persons developing symptomatic illness, most develop a self-limited febrile illness. More severe illness with WNV (West Nile neuroinvasive disease, WNND) is manifested as meningitis, encephalitis or an acute anterior (polio) myelitis. These manifestations are generally more prevalent in older persons or those with immunosuppression. In the future, a more thorough understanding of the long-term physical, cognitive and functional outcomes of persons recovering from WNV illness will be important in understanding the overall illness burden.
Since its introduction to North America in 1999, human infection with West Nile virus (WNV) has resulted in considerable acute morbidity and mortality. Although the ongoing epidemic has resulted in a ...great increase in our understanding of the acute clinical features of human illness and helped to define associated clinical syndromes, far less is known about potential long-term clinical and functional sequelae. Several recent assessments, however, suggest that patients-even those with apparently mild cases of acute disease-frequently have subjective, somatic complaints following WNV infection. Persistent movement disorders, cognitive complaints, and functional disability may occur after West Nile neuroinvasive disease. West Nile poliomyelitis may result in limb weakness and ongoing morbidity that is likely to be long term. Although further assessment is needed, the long-term neurological and functional sequelae of WNV infection are likely to represent a considerable source of morbidity in patients long after their recovery from acute illness.
Guillain-Barré syndrome (GBS) is a rare, but potentially fatal, immune-mediated disease of the peripheral nerves and nerve roots that is usually triggered by infections. The incidence of GBS can ...therefore increase during outbreaks of infectious diseases, as was seen during the Zika virus epidemics in 2013 in French Polynesia and 2015 in Latin America. Diagnosis and management of GBS can be complicated as its clinical presentation and disease course are heterogeneous, and no international clinical guidelines are currently available. To support clinicians, especially in the context of an outbreak, we have developed a globally applicable guideline for the diagnosis and management of GBS. The guideline is based on current literature and expert consensus, and has a ten-step structure to facilitate its use in clinical practice. We first provide an introduction to the diagnostic criteria, clinical variants and differential diagnoses of GBS. The ten steps then cover early recognition and diagnosis of GBS, admission to the intensive care unit, treatment indication and selection, monitoring and treatment of disease progression, prediction of clinical course and outcome, and management of complications and sequelae.
Nerve agents and neurobiological weapons are among the most devastating and lethal of weapons. Acetylcholinesterase inhibitors act by increasing the amount of acetylcholine in the neuromuscular ...junction, resulting in flaccid paralysis. Tabun, VX, soman, and sarin are the major agents in this category. Exposure to nerve agents can be inhalational or through dermal contact. Neurotoxins may have peripheral and central effects on the nervous system. Atropine is an effective antidote to nerve agents. Neurobiological weapons entail using whole organisms or organism-synthesized toxins as agents. Some organisms that can be used as biological weapons include smallpox virus.
Population incidence of Guillain-Barré syndrome (GBS) is required to assess changes in GBS epidemiology, but published estimates of GBS incidence vary greatly depending on case ascertainment, ...definitions, and sample size. We performed a meta-analysis of articles on GBS incidence by searching Medline (1966-2009), Embase (1988-2009), Cinahl (1981-2009) and CABI (1973-2009) as well as article bibliographies. We included studies from North America and Europe with at least 20 cases, and used population-based data, subject matter experts to confirm GBS diagnosis, and an accepted GBS case definition. With these data, we fitted a random-effects negative binomial regression model to estimate age-specific GBS incidence. Of 1,683 nonduplicate citations, 16 met the inclusion criteria, which produced 1,643 cases and 152.7 million person-years of follow-up. GBS incidence increased by 20% for every 10-year increase in age; the risk of GBS was higher for males than females. The regression equation for calculating the average GBS rate per 100,000 person-years as a function of age in years was exp-12.0771 + 0.01813(age in years) × 100,000. Our findings provide a robust estimate of background GBS incidence in Western countries. Our regression model may be used in comparable populations to estimate the background age-specific rate of GBS incidence for future studies.
...the decrease in burden of illness due to stroke and other cerebrovascular diseases in high-income countries might have resulted from better control of high blood pressure, cessation of tobacco ...use, and earlier interventions in the setting of acute stroke. ...in both low-income and high-income countries, the overall burden of neurological disease is inevitably going to continue to increase as populations increase and grow older. Public health professionals and health-care policy makers must now implement much-needed public health interventions to address the growing need for neurological care across all ages and socioeconomic classes.
The big three pathogens—Haemophilus influenzae type b, Neisseria meningitidis (meningococcal), and Streptococcus pneumoniae (pneumococcal)—are responsible for a considerable share of endemic and ...epidemic meningitis globally. ...this fact is bittersweet: during the same period, the decreases in death rates from other vaccine-preventable diseases, such as measles (a 93% decrease) and tetanus (91% decrease), dwarf the progress made in preventing deaths from meningitis.3 Incidence of and deaths due to pneumococcal meningitis (the largest cause of years of life lived with disability among survivors) decreased over time, again attributable to increased widespread availability of polyvalent pneumococcal vaccines.1 Pneumococcal conjugate vaccines can result in herd immunity by preventing nasopharyngeal carriage of the bacteria targeted by the vaccine, although bacteria not covered by the vaccine are not affected, highlighting the need for continued work on even more multivalent pneumococcal vaccines. The GBD 2016 Meningitis Collaborators astutely note barriers to the control of meningitis in resource-limited areas, including limited capacity for CSF analysis, the challenge of making a clinical diagnosis of meningitis in neonates and young children, and limitations in laboratory diagnostics that can be done on site.1 In addition to the focus on implementing aggressive vaccination campaigns, attention should be paid to addressing these other challenges.
Background. During late summer/fall 2014, pediatric cases of acute flaccid myelitis (AFM) occurred in the United States, coincident with a national outbreak of enterovirus D68 (EV-D68)-associated ...severe respiratory illness. Methods. Clinicians and health departments reported standardized clinical, epidemiologic, and radiologic information on AFM cases to the Centers for Disease Control and Prevention (CDC), and submitted biological samples for testing. Cases were ≤21 years old, with acute onset of limb weakness 1 August-31 December 2014 and spinal magnetic resonance imaging (MRI) showing lesions predominantly restricted to gray matter. Results. From August through December 2014, 120 AFM cases were reported from 34 states. Median age was 7.1 years (interquartile range, 4.8–12.1 years); 59% were male. Most experienced respiratory (81%) or febrile (64%) illness before limb weakness onset. MRI abnormalities were predominantly in the cervical spinal cord (103/118). All but 1 case was hospitalized; none died. Cerebrospinal fluid (CSF) pleocytosis (>5 white blood cells/μL) was common (81%). At CDC, 1 CSF specimen was positive for EV-D68 and Epstein-Barr virus by real-time polymerase chain reaction, although the specimen had >3000 red blood cells/μL. The most common virus detected in upper respiratory tract specimens was EV-D68 (from 20%, and 47% with specimen collected ≤7 days from respiratory illness/fever onset). Continued surveillance in 2015 identified 16 AFM cases reported from 13 states. Conclusions. Epidemiologic data suggest this AFM cluster was likely associated with the large outbreak of EV-D68-associated respiratory illness, although direct laboratory evidence linking AFM with EV-D68 remains inconclusive. Continued surveillance will help define the incidence, epidemiology, and etiology of AFM.
Background.Infectious diseases (IDs) cause widespread morbidity and mortality. We describe the epidemiology of ID hospitalizations in the United States with use of a nationally representative ...database. Methods.First-listed ID hospitalizations in the United States were analyzed using the Nationwide Inpatient Sample for 1998–2006. Hospitalization rates were calculated overall for IDs and for specific ID groups. Results.An estimated 40,085,978 (standard error, 255,418) hospitalizations with a first-listed ID occurred during 1998–2006, for an age-adjusted hospitalization rate of 154.4 (95% confidence interval, 153.3–155.5) hospitalizations per 10,000 persons. The rate increased slightly over the study period (152.5 95% confidence interval, 149.6–155.4 in 1998 vs 162.2 95% confidence interval, 158.7–165.5 in 2006); an increase was seen for both sexes, for older patients, and for Hispanic patients. Among those aged 5–39 years, female patients had a significantly higher hospitalization rate than did male patients; male patients had higher rates among the youngest children and adults aged ⩾40 years. Approximately 4.5 million hospital days and $865 billion in hospital charges were associated with primary ID hospitalizations over the study period. Lower respiratory tract infections were the most commonly listed ID (34.4%), followed by kidney, urinary tract, and bladder infections; cellulitis; and abdominal and rectal infections. Conclusions.The ID hospitalization rate increased during 1998–2006, reflecting an increase in ID hospitalizations among adults aged ⩾30 years, particularly older adults. Differences in trends and patterns of ID hospitalizations were noted by sex, age group, and race. Lower respiratory tract infections accounted for the largest proportion of ID hospitalizations. Future efforts should focus on preventive measures and improving early interventions for IDs.
Countries with ongoing outbreaks of Zika virus have observed a notable rise in reported cases of Guillain-Barré syndrome (GBS), with mounting evidence of a causal link between Zika virus infection ...and the neurological syndrome. However, the risk of GBS following a Zika virus infection is not well characterized. In this work, we used data from 11 locations with publicly available data to estimate the risk of GBS following an infection with Zika virus, as well as the location-specific incidence of infection and the number of suspect GBS cases reported per infection.
We built a mathematical inference framework utilizing data from 11 locations that had reported suspect Zika and GBS cases, two with completed outbreaks prior to 2015 (French Polynesia and Yap) and nine others in the Americas covering partial outbreaks and where transmission was ongoing as of early 2017.
We estimated that 2.0 (95% credible interval 0.5-4.5) reported GBS cases may occur per 10,000 Zika virus infections. The frequency of reported suspect Zika cases varied substantially and was highly uncertain, with a mean of 0.11 (95% credible interval 0.01-0.24) suspect cases reported per infection.
These estimates can help efforts to prepare for the GBS cases that may occur during Zika epidemics and highlight the need to better understand the relationship between infection and the reported incidence of clinical disease.
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