A cross-sectional study of horse owners' awareness and perceived risk of exotic diseases in the United Kingdom.

The international nature of the equine industry provides opportunities for the spread of infectious diseases between countries. While incursions of exotic diseases into the United Kingdom (UK) equine population have been rare, the potential socioeconomic and welfare impacts are a significant concern. However, little is known about leisure horse owners' ability or willingness to prepare for an exotic disease incursion. The objectives of this study were to describe UK leisure horse owners' awareness and perceptions of exotic diseases, and to identify clusters of horse owners characterised by their awareness and perceived risk of exotic diseases. A cross-sectional study of leisure horse owners in the UK was conducted between April and July 2018. Participants (n = 403) completed an online questionnaire with questions pertaining to demographics, experiences with endemic diseases, and awareness and perceptions of exotic diseases. Hierarchical cluster analysis was used to identify groups of participants that were similar in regard to their awareness and perceived risk of exotic diseases. Participants identified a median of 3 (IQR 2-4) exotic diseases, with the most recognised exotic diseases being African horse sickness and West Nile virus. The most frequently mentioned clinical signs that participants thought were associated with exotic diseases included high temperature (57.2%), discharge (46.5%), and lack of energy (41.2%). Hierarchical cluster analysis identified three clusters of participants: 1) those who were aware of exotic diseases and perceived a high amount of risk (n = 78); 2) those who were aware of exotic diseases but perceived a low amount of risk (n = 111); and 3) those who were less aware of exotic diseases and perceived a low amount of risk (n = 214). Efforts to communicate the relevance and consequences of exotic diseases to horse owners should consider the potential difference in receptiveness among horse owners in each cluster. Further investigations are required to determine the implications of horse owners' perceived risk on exotic disease preparedness.

T cells promote microglia-mediated synaptic elimination and cognitive dysfunction during recovery from neuropathogenic flaviviruses.

T cells clear virus from the CNS and dynamically regulate brain functions, including spatial learning, through cytokine signaling. Here we determined whether hippocampal T cells that persist after recovery from infection with West Nile virus (WNV) or Zika virus (ZIKV) impact hippocampal-dependent learning and memory. Using newly established models of viral encephalitis recovery in adult animals, we show that in mice that have recovered from WNV or ZIKV infection, T cell-derived interferon-γ (IFN-γ) signaling in microglia underlies spatial-learning defects via virus-target-specific mechanisms. Following recovery from WNV infection, mice showed presynaptic termini elimination with lack of repair, while for ZIKV, mice showed extensive neuronal apoptosis with loss of postsynaptic termini. Accordingly, animals deficient in CD8+ T cells or IFN-γ signaling in microglia demonstrated protection against synapse elimination following WNV infection and decreased neuronal apoptosis with synapse recovery following ZIKV infection. Thus, T cell signaling to microglia drives post-infectious cognitive sequelae that are associated with emerging neurotropic flaviviruses.

Understanding Knowledge, Attitudes, and Behaviors Toward West Nile Virus Prevention: A Survey of High-Risk Adults in Maryland.

OBJECTIVE: To assess knowledge, attitudes, and behaviors toward West Nile virus (WNV) prevention among Maryland adults ≥60 years old who are at increased risk of severe WNV disease utilizing the health belief model. METHODS: Using a stratified random sample of households from zip codes with ≥2 human WNV cases, we conducted a telephone survey of 211 Maryland adults ≥60 years old between October and December 2012. RESULTS: Participants expressing worry about WNV were over thrice more likely to use insect repellent in the prior 90 days (adjusted odds ratio [aOR] = 3.46, 95% confidence interval [CI] = 1.33-8.95) and nearly thrice more likely to drain standing water around their homes than those not worried (aOR = 2.86, 95% CI = 1.25-6.52). Respondents perceiving a benefit in paying less for WNV vaccine were more likely to support mosquito control programs (aOR = 16.00, 95% CI = 1.50-170.68). CONCLUSIONS: Future interventions to promote WNV prevention among older adults should seek to enhance perceptions of vulnerability to WNV through risk communication, including media outreach and written messaging, emphasizing the benefits of personal protective behaviors. Community partnerships may aid in outreach to this population.

Health-related quality of life in persons with West Nile virus infection: a longitudinal cohort study.

BACKGROUND: West Nile virus (WNV) infections are predominantly asymptomatic, although almost 1% become neuroinvasive and debilitating. We describe the impact of neuroinvasive and non-neuroinvasive disease on patient health-related quality of life (HRQoL). METHODS: Short Form 36 questionnaire data came from a Canadian WNV cohort (Loeb 2008) of 154 patients followed for up to three years. We generated health utilities using the SF-6D. We calculated mean utility scores throughout follow-up and examined predictors using a linear mixed-effects model. We summarized HRQoL post-acute infection as: (i) long-term utility (mean of scores one year onward); (ii) area under the curve (AUC) one year onward. We examined predictors using beta regression. We used multiple imputation for sensitivity analysis. RESULTS: Mean utility scores improved from 0.59 (95% CI: 0.38, 0.93) at baseline to 0.77 (0.53, 1) at six months, before plateauing for the remaining two years. Mean long-term utility was 0.81 (0.78, 0.85) and mean AUC was 0.80 (0.76, 0.84). Patients with neuroinvasive disease had consistently worse scores than their non-neuroinvasive counterparts, with the gap nearly closed after six months. After adjusting for confounding, neuroinvasive disease was not a significant predictor of HRQoL either throughout follow-up or post-acute infection. Rather, number of comorbidities and baseline utility scores were. Sensitivity analysis showed similar findings. CONCLUSIONS: Patients with WNV infection reported low HRQoL during acute illness, but improved rapidly by six months, regardless of neuroinvasive disease status. This is the first study reporting health utilities for WNV infection.

Functional recovery from neuroinvasive West Nile Virus: A tale of two courses.

OBJECTIVE: In 2012, the highest numbers of West Nile Virus (WNV) cases were reported by the Center for Disease Control since 2003. This outbreak included over half of the identified patients being classified with one of the more debilitating neuroinvasive subtypes of WNV. Despite improvements in diagnosis and treatment options in symptom management, longitudinal research on WNV neurocognitive and functional outcomes is limited by sample size, retrospective review, and/or reliance on self-report measures for cognitive status and level of independence. This study describes the cases of 2 patients diagnosed with WNV as they complete rehabilitation across the continuum of care. RESEARCH METHOD: Review of two cases that experience different rehabilitation outcomes 4-18 months post diagnosis. RESULTS: The cases presented here demonstrate the potentially differential courses of recovery and outcomes for physical (e.g., balance, ambulation, upper extremity function), cognitive (e.g., attention, executive functions, memory, language, visuospatial), and emotional functioning, as assessed via measures administered by the patient's physical therapists and neuropsychologists. These patients were evaluated as part of the standard clinical practice to monitor changes, track recovery, and provide recommendations across the continuum of care from admission to discharge from acute inpatient rehabilitation, during outpatient day neurorehabilitation, and while receiving outpatient neuropsychology services. CONCLUSIONS: These cases highlight the variability in rehabilitative course for individuals diagnosed with WNV. Consistent follow-up with patients is recommended to ensure management of remitting and chronic symptoms.

Findings of long-term depression up to 8 years post infection from West Nile virus.

OBJECTIVE: To examine the psychological sequelae following West Nile virus (WNV) infection among a large cohort of participants over an 8-year period. DESIGN: We conducted a longitudinal study to assess mental health outcomes among a cohort of 171 WNV-positive participants in Houston, Texas. RESULTS: We found 35% of participants met the Center for Epidemiologic Studies Depression scale definition for new onset clinical depression. Multivariate analysis found that severe depression was significantly associated with gender and physical disability (Barthel index score <100) at 5 years post-WNV infection. CONCLUSIONS: Practitioners should be aware of depression as a possible outcome in patients who were infected with WNV and include this as a part of their routine assessment.

An investigation of depression and fatigue post West Nile virus infection.

INTRODUCTION: The purpose of this study was to examine depression and fatigue in individuals with a seropositive confirmed history of West Nile virus (WNV) infection. METHODS: The South Dakota State Epidemiologist sent 218 letters inviting residents with a diagnosis of WNV to participate in the study. Forty-five subjects were tested. An occupational therapist and a physical therapist met with each participant to assess performance parameters, including depression and fatigue levels. Subjects (n=42) completed the Revised Center for Epidemiologic Studies Depression Scale (CES-D) during the assessment. The Modified Fatigue Impact Scale (MFIS) was sent to participants as a follow-up questionnaire, and 29 were returned. Subjects were placed within one of three diagnosis groups: West Nile Fever (WNF), West Nile Neuroinvasive Disease (WNND) and WNV without fever or neuroinvasive disease (clinical/unspecified). RESULTS: Frequency of those reporting low risk of depression was similar between diagnosis groups (each approximating 75 percent). Depression severity differences were noted, with subjects diagnosed with WNND more likely to report "severe" risk for depression. Low correlations between depression and overall fatigue, depression and cognitive fatigue, and depression and psychosocial fatigue indicators were found. There was little if any correlation between depression and physical fatigue indicators. Mean CES-D scores for subjects between 13 to 18 months post infection fell within the mild-moderate risk for depression category. CONCLUSIONS: Identifying depression risk is useful for patient referral purposes and may help minimize symptoms of depression correlated with fatigue, especially following hospitalization for WNV infection.

Coping and health behaviours in times of global health crises: lessons from SARS and West Nile.

We examined perceived threats of Severe Acute Respiratory Syndrome and West Nile Virus using an Internet-based questionnaire. Higher levels of perceived threats of diseases were associated with increases in a variety of ways of coping, including empathic responding and wishful thinking. In turn, we examined how coping with the perceived health threat was related to two specific health related behaviours: taking recommended precautions, and avoiding people in an attempt to avoid disease. The findings from linear regression indicated that empathic responding, in response to the threat of a virulent agent, was related to taking recommended and effective health precautions. On the other hand, wishful thinking was associated with those behaviours that may potentially lead to economic hardship in afflicted areas, such as avoiding people perceived to be at risk for an infectious agent. Implications for health promotion are discussed.

Prognosis after West Nile virus infection.

BACKGROUND: The long-term prognosis of patients infected with West Nile virus is not well understood. OBJECTIVE: To describe the patterns of physical and mental function after infection with West Nile virus and to determine factors associated with recovery. DESIGN: Longitudinal cohort study. SETTING: Data were collected during home visits and from ambulatory clinics in 4 Canadian provinces. PARTICIPANTS: 156 persons with West Nile virus infection. MEASUREMENTS: Scores on the Physical Component Summary and Mental Component Summary of the Short Form-36, Depression Anxiety Stress Scale, and Fatigue Severity Scale. RESULTS: Physical and mental function, as well as mood and fatigue, seemed to return to normal within 1 year of symptom onset. Participants with neuroinvasive disease took slightly longer to recover. Maximum predicted recovery or rate of recovery in any domain did not differ between participants with meningoencephalitis and those with encephalitis. Lack of preexisting comorbid conditions was associated with faster recovery of physical function, whereas lack of comorbid conditions and male sex were associated with faster recovery of mental function. LIMITATIONS: The analysis excluded 7 patients who died shortly after diagnosis, so the study's estimates of prognosis may be overoptimistic. The authors did not formally assess neuropsychological difficulties. The estimates of recovery are relative to the U.S. population, not to participants' function levels before West Nile virus infection. CONCLUSION: Physical and mental outcome measures seem to normalize within approximately 1 year in patients with West Nile virus. The presence of preexisting comorbid conditions is associated with longer recovery.

Misrepresentation of health risks by mass media.

BACKGROUND: Mass media are a leading source of health information for general public. We wished to examine the relationship between the intensity of media coverage for selected health topics and their actual risk to public health. METHODS: Mass media reports in the United States on emerging and chronic health hazards (severe acute respiratory syndrome (SARS), bioterrorism, West Nile Fever, AIDS, smoking and physical inactivity) were counted for the year 2003, using LexisNexis database. The number of media reports for each health risk was correlated with the corresponding death rate as reported by the Centers for Disease Control and Prevention. RESULTS: The number of media reports inversely correlated with the actual number of deaths for the health risks evaluated. SARS and bioterrorism killed less than a dozen people in 2003, but together generated over 100 000 media reports, far more than those covering smoking and physical inactivity, which killed nearly a million Americans. CONCLUSIONS: Emerging health hazards are over-reported in mass media by comparison to common threats to public health. Since premature mortality in industrialized societies is most often due to well-known risks such as smoking and physical inactivity, their under-representation on public agendas may cause suboptimal prioritization of public health resources.

West Nile Virus: the buzz on Ottawa residents' awareness, attitudes and practices.

BACKGROUND: In 2002, the City of Ottawa was interested in the public perception of West Nile Virus (WNV) and mosquito control. Their objectives were to assess: awareness of WNV, practices to reduce mosquito sources, personal protective measures, and attitudes towards community-based insecticide programs. METHODS: In July 2002, we administered a telephone survey to a random, stratified sample of urban, suburban and rural Ottawa households. RESULTS: Surveys were completed for 491 households. Most (77.2%) respondents reported they had heard of WNV, and of these, 58.3% reported WNV was an important health issue. Mosquito repellent was the most common personal protective measure, reported among 72.5% of respondents, of whom 76.9% used DEET products. Multivariate regression analyses showed that age was a significant predictor of repellent use, with respondents aged less than 51 years more likely to use repellent than older respondents (ORadj =2.0; 95% CI: 1.2-2.3). This age group was also more likely to use at least one personal protective behaviour (ORadj = 2.5; 95% CI: 1.4-4.5). Of 315 people selecting a justified time to larvicide, 4.8% chose "larvicides should never be used in Ottawa"; 33.4% stated that larviciding would be appropriate "when WNV was detected in birds or mosquitoes"; one third "needed more information" on the health and environmental effects of insecticides, prior to selecting a response. CONCLUSIONS: Our findings highlight the need for public education reinforcing WNV importance, emphasizing the health and environmental effects of insecticides as well as appropriate personal protective behaviours. Such messages should target older and urban residents.

Viral encephalitis: neuropsychiatric and neurobehavioral aspects.

Viral encephalitis, a condition in which a virus infects the brain and produces an inflammatory response, affects approximately 20,000 individuals per year in the United States. The viral encephalidities include sporadic and epidemic acute viral encephalidities and subacute and chronic/progressive viral encephalitis or encephalomyelitis. In people who survive these conditions, postencephalitic impairments of elemental neurologic, cognitive, emotional, and behavioral function are common. This article will provide a brief overview of the diagnosis and acute management of acute viral infections of the central nervous system. The neurologic and neuropsychiatric features, neuropathologies, and treatments of two of the more common types of acute viral encephalitis in North America--herpes simplex encephalitis and West Nile encephalitis--will be reviewed. The current and future role of psychiatrists and neuropsychiatrists in the care and study of individuals with these conditions will be discussed.

West nile virus encephalitis involving the substantia nigra: neuroimaging and pathologic findings with literature review.

West Nile virus has become a medically important arbovirus in the continental United States with its debut in 1999 in the New York City area. We present neuroimaging features and pathologic findings in 2 patients who were severely affected out of the more that 100 documented cases at our institution. Both patients showed striking involvement of the substantia nigra, a finding not previously reported for West Nile virus.

Risk communication, the West Nile virus epidemic, and bioterrorism: responding to the communication challenges posed by the intentional or unintentional release of a pathogen in an urban setting.

The intentional or unintentional introduction of a pathogen in an urban setting presents severe communication challenges. Risk communication--a science-based approach for communicating effectively in high-concern situations--provides a set of principles and tools for meeting those challenges. A brief overview of the risk communication theoretical perspective and basic risk communication models is presented here, and the risk communication perspective is applied to the West Nile virus epidemic in New York City in 1999 and 2000 and to a possible bioterrorist event. The purpose is to provide practical information on how perceptions of the risks associated with a disease outbreak might be perceived and how communications would be best managed.