Severe West Nile Virus Neuroinvasive Disease: Clinical Characteristics, Short- and Long-Term Outcomes

Denial

A 51-year-old man presented with decreased vision, fever, confusion, headaches, agitation, nausea, vomiting and diarrhea. Magnetic resonance imaging of the brain demonstrated bilateral T2 hyperintense lesions in the region of the mesial temporal lobe and optic radiations. There was a predominantly polymorphonuclear leukocyte pleocytosis in the cerebrospinal fluid (CSF) with hyperproteinorachia. A meningoencephalitis was diagnosed. Intravenous fluorescein angiography (IVFA) demonstrated a multifocal chorioretinitis that was in a linear pattern in the left eye. CSF enzyme-linked immunosorbent assay was positive for West Nile virus (WNV) IgM. We review the clinical manifestations of WNV disease and highlight the value of IVFA in determining the diagnosis.

George K, Hoang HE, Thakur KT. Clinical and Diagnostic Features of West Nile Virus Neuroinvasive Disease in New York City

West Nile virus (WNV) neuroinvasive disease (WNND) occurs in approximately 1 percent of WNV-infected patients and typically presents as encephalitis, meningitis, or acute flaccid paralysis (AFP). WNND remains a difficult inpatient diagnosis, creating significant challenges for prognostication and therapy selection. We characterized the clinical and diagnostic features of WNND cases at two major academic medical centers in New York City in routine clinical practice. We retrospectively reviewed the charts of thirty-six patients with WNND, including twenty-six encephalitis, four meningitis, and six AFP cases. The most common presenting symptoms were fever (86.1%) and gastrointestinal symptoms (38.9%) in addition to altered mental status (72.2%), lethargy (63.9%), gait disturbances (46.2%), and headache (44.4%). Fourteen (48.3%) patients displayed acute magnetic resonance imaging (MRI) findings, particularly T2 hyperintensities in the bilateral thalami, brainstem, and deep white matter. New York State Department of Health WNV CSF IgM testing was utilized for diagnosis in 58.3% of patients; however, just 38.1% had the result by discharge, compared to 85.6% of those who underwent serum IgM testing. The median length of stay was 13.5 days, 38.9% were intubated, and three patients (8.9%) died during acute hospitalization. Our findings underscore the morbidity, mortality, and diagnostic challenges of WNND, suggesting the potential utility of serum IgM testing in combination with confirmatory CSF testing to expedite diagnosis in the acute setting.

Proinflammatory Chemokine Levels in Cerebrospinal Fluid of Patients with Neuroinvasive Flavivirus Infections

Tick-borne encephalitis virus (TBEV) and West Nile virus (WNV) are the most important neuroinvasive arboviruses detected in Europe. In this study, we analyzed cerebrospinal fluid (CSF) concentrations of 12 proinflammatory chemokines (CCL2, CCL3, CCL4, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, and CXCL11) in 77 patients with neuroinvasive diseases (NIDs). Flavivirus infection was confirmed in 62 patients (TBEV and WNV in 31 patients each), while in 15 patients the etiology of NID was not determined (NDE). Similar patterns of high-level expression of chemokines regulating monocyte/macrophage responses (CCL2), neutrophil recruitment (CXCL1 and CXCL8), and interferon-inducible chemoattractants for leukocytes (CXCL10 and CXCL11) have been observed in WNV and TBEV groups. None of the tested chemokines significantly differed between patients with TBEV or WNV. Concentrations of CCL17, CCL20, CXCL5, CXCL10, and CXCL11 were significantly lower in both WNV and TBEV groups compared to NID NDE patients. The logistic regression model showed that CSF concentrations of CXCL11, CXCL5, and CXCL10 could potentially be used for the classification of patients into the WNV or TBEV group versus groups with other NIDs. This study identified, for the first time, similar patterns of CSF chemokine expression in WNV and TBEV infections, suggesting common immunopathogenic mechanisms in neuroinvasive flavivirus infections that should be further evaluated.

Rehabilitation approaches in West Nile Virus survivors: a systematic review

INTRODUCTION

Periodic increases in West Nile virus (WNV) infections have been documented. Proper rehabilitative management is essential for these patients, who may experience limitations in daily activities even after the resolution of the acute infection. Since there are currently no globally accepted guidelines, our aim is to conduct a best-evidence synthesis on rehabilitative management for patients with neuroinvasive WNV.

EVIDENCE ACQUISITION

We screened the literature with two independent researchers conducting searches on PubMed, Embase, SCOPUS, and Google Scholar databases for WNV-related studies in the field of rehabilitation. Suitable studies were identified and selected through a rigorous process. The review includes original research articles published up to August 15, 2023.

EVIDENCE SYNTHESIS

Despite the potential for bias in the studies, the literature suggests that a comprehensive and interdisciplinary rehabilitation program, which includes physical therapy with neuromotor and respiratory interventions, occupational therapy, neurocognitive interventions, and speech therapy for dysphagia and communication issues, can lead to functional improvement in WNV patients. This program should be tailored to address each patient's specific challenges, and the duration of the rehabilitation program may vary depending on the individual patient's needs.

CONCLUSIONS

Even if additional research with larger cohorts and higher evidence levels is needed for a comprehensive understanding of WNV patient rehabilitation, an early and comprehensive rehabilitation approach addressing respiratory, neuromuscular, and cognitive aspects appears effective for WNV patient recovery.

Neurological and neuromuscular manifestations in patients with West Nile neuroinvasive disease, Belgrade area, Serbia, season 2022

INTRODUCTION

We aimed to describe neurological manifestations and functional outcome at discharge in patients with West Nile neuroinvasive disease.

METHODS

This retrospective study enrolled inpatients treated in the University Clinic for Infectious and Tropical Diseases in Belgrade, Serbia, from 1 June until 31 October 2022. Functional outcome at discharge was assessed using modified Rankin scale.

RESULTS

Among the 135 analyzed patients, encephalitis, meningitis and acute flaccid paralysis (AFP) were present in 114 (84.6%), 20 (14.8%), and 21 (15.6%), respectively. Quadriparesis/quadriplegia and monoparesis were the most frequent forms of AFP, present in 9 (6.7%) and 6 (4.4%) patients, respectively. Fourty-five (33.3%) patients had cerebellitis, 80 (59.3%) had rhombencephalitis, and 5 (3.7%) exhibited Parkinsonism. Ataxia and wide-based gait were present in 79 (58.5%) patients each. Fifty-one (37.8%) patients had tremor (41 (30.3%) had postural and/or kinetic tremor, 10 (7.4%) had resting tremor). Glasgow coma score (GCS) ≤ 8 and respiratory failure requiring mechanical ventilation developed in 39 (28.9%), and 33 (24.4%) patients, respectively. Quadriparesis was a risk factor for prolonged ventilator support (29.5 ± 16.8 vs. 12.4 ± 8.7 days, p = 0.001). At discharge, one patient with monoparesis recovered full muscle strength, whereas 8 patients with AFP were functionally dependent. Twenty-nine (21.5%) patients died. All of the succumbed had encephalitis, and 7 had quadriparesis. Ataxia, tremor and cognitive deficit persisted in 18 (16.9%), 15 (14.2%), and 22 (16.3%) patients at discharge, respectively. Age, malignancy, coronary disease, quadriparesis, mechanical ventilation, GCS ≤ 8 and healthcare-associated infections were risk factors for death (p = 0.001; p = 0.019; p = 0.004; p = 0.001; p < 0.001; p < 0.001, and p < 0.001, respectively).

A chimeric vaccine protects farmed saltwater crocodiles from West Nile virus-induced skin lesions

West Nile virus (WNV) causes skin lesions in farmed crocodiles leading to the depreciation of the value of their hides and significant economic losses. However, there is no commercially available vaccine designed for use in crocodilians against WNV. We tested chimeric virus vaccines composed of the non-structural genes of the insect-specific flavivirus Binjari virus (BinJV) and genes encoding the structural proteins of WNV. The BinJV/WNV chimera, is antigenically similar to wild-type WNV but replication-defective in vertebrates. Intramuscular injection of two doses of BinJV/WNV in hatchling saltwater crocodiles (Crocodylus porosus) elicited a robust neutralising antibody response and conferred protection against viremia and skin lesions after challenge with WNV. In contrast, mock-vaccinated crocodiles became viraemic and 22.2% exhibited WNV-induced lesions. This suggests that the BinJV/WNV chimera is a safe and efficacious vaccine for preventing WNV-induced skin lesions in farmed crocodilians.

Bilateral Upper Extremity Tremors in West Nile Encephalitis

West Nile encephalitis is a rare complication of infection from the West Nile virus (WNv). Viral encephalitis can mimic manifestations of other neurologic diseases. The purpose of this article is to report a case of a 60-year-old female who developed bilateral upper extremity tremors with West Nile encephalitis. She presented to a hospital in Southern Louisiana with persistent high fevers and new onset confusion. She soon developed tremors which persisted throughout her hospitalization. Computerized tomography (CT) of the head revealed no abnormalities. Cerebral spinal fluid (CSF) was remarkable for WNv IgM, and supportive care was pursued. After nearly three weeks, she was transferred to a skilled nursing facility for further care. The presentation of movement disorder with confusion usually raises concern for injury to the brain or spinal cord or other neurologic illnesses. Despite the presentation of movement disorders or other neurologic manifestations, viral etiologies should remain high on the differential when the patient has additional symptoms, such as fever and elevated white blood cell (WBC) count, to limit inappropriate diagnostic testing and treatment.

Nanosystems for gene therapy targeting brain damage caused by viral infections

Several human pathogens can cause long-lasting neurological damage. Despite the increasing clinical knowledge about these conditions, most still lack efficient therapeutic interventions. Gene therapy (GT) approaches comprise strategies to modify or adjust the expression or function of a gene, thus providing therapy for human diseases. Since recombinant nucleic acids used in GT have physicochemical limitations and can fail to reach the desired tissue, viral and non-viral vectors are applied to mediate gene delivery. Although viral vectors are associated to high levels of transfection, non-viral vectors are safer and have been further explored. Different types of nanosystems consisting of lipids, polymeric and inorganic materials are applied as non-viral vectors. In this review, we discuss potential targets for GT intervention in order to prevent neurological damage associated to infectious diseases as well as the role of nanosized non-viral vectors as agents to help the selective delivery of these gene-modifying molecules. Application of non-viral vectors for delivery of GT effectors comprise a promising alternative to treat brain inflammation induced by viral infections.

Quantification of Antiviral Cytokines in Serum, Cerebrospinal Fluid and Urine of Patients with Tick-Borne Encephalitis in Croatia

BACKGROUND

Tick-borne encephalitis virus (TBEV) is one of the most significant arboviruses affecting the human central nervous system (CNS) in Europe. Data on cytokine response in TBEV infection are limited.

METHODS

We analyzed the cytokine response in serum, cerebrospinal fluid (CSF) and urine samples of patients with TBE. The control group consisted of patients with 'febrile headache' who had normal CSF cytology. The panel included 12 cytokines: TNF-α, IL-6, Th1 (IL-2, IFN-γ), Th2 (IL-4, IL-5, IL-13), Th9 (IL-9), Th17 (IL-17A, IL-17F), Th22 (IL-22) cytokines and IL-10.

RESULTS

TBE patients were more likely to have increased levels of IL-6 and IFN-γ in CSF compared to controls (85.7% vs. 58.8% and 85.7% vs. 47.1%, respectively). However, concentrations of IL-6 (the most abundant cytokine in the CSF of both groups), IL-10 and IL-9 were lower in TBEV patients compared with controls, but the difference was statistically significant for IL-9 only (p = 0.001). By analyzing the cytokine levels in different clinical samples, all measured cytokines were detected in the serum, with the highest concentrations found for IFN-γ, TNF-α, IL-10, IL-17F and IL-22. Higher concentrations of cytokines in the CSF compared with serum were observed for IL-5, IL-6 and IL-22. All cytokines except IL-13 were detectable in urine but in a small proportion of patients, except for IL-22, which was detectable in 95.8% of patients.

CONCLUSIONS

Cytokine composition in different clinical samples of TBE patients reveals a different network of early innate immune response cytokines, Th1, Th2, Th9, Th22, Th17 and anti-inflammatory cytokines.

West Nile Disease Symptoms and Comorbidities: A Systematic Review and Analysis of Cases

West Nile virus (WNV) is a mosquito-borne flavivirus that has emerged as a major cause of viral encephalitis and meningitis, rarely leading to death. Several risk factors have been discussed in the past concerning the severity of the disease, while few reports have focused on precipitating conditions that determine of WNV-related death. Studies on cohorts of patients suffering of West Nile disease (WND) usually encompass low numbers of deceased patients as a result of the rarity of the event. In this systematic review and critical analysis of 428 published case studies and case series, we sought to evaluate and highlight critical parameters of WND-related death. We summarized the symptoms, comorbidities, and treatment strategies related to WND in all published cases of patients that included clinical features. Symptoms such as altered mental status and renal problems presented increased incidence among deceased patients, while these patients presented increased cerebrospinal fluid (CSF) glucose. Our analysis also highlights underestimated comorbidities such as pulmonary disease to act as precipitating conditions in WND, as they were significantly increased amongst deceased patients. CSF glucose and the role of pulmonary diseases need to be revaluated either retrospectively or prospectively in WND patient cohorts, as they may be linked to increased mortality risk.

Neuroinvasive West Nile Virus (WNV) Encephalitis With Anton Syndrome: Epidemiology and Pathophysiology Review

The West Nile virus (WNV) belongs to the genus of flaviviruses and is known to cause irreversible neurologic deficits. Neuroinvasive WNV cases continue to be rare and have a higher prevalence in South America, Africa, and Asia. Here we report a 55-year-old female from North America who presented with acute-onset encephalopathy, fever, myalgias, and Anton syndrome. Neuroradiographic findings included diffuse white matter abnormalities of both cortical and subcortical structures and the patient was diagnosed with posterior reversible encephalopathy syndrome (PRES). Further workup revealed WNV antibodies in both cerebrospinal fluid (CSF) and serum. Management of WNV encephalitis continues to be poor and thus the patient was referred to a long-term care facility. Furthermore, Anton syndrome is a rare focal neurologic deficit that has never been previously associated with the WNV. This case aims to highlight the epidemiology of WNV in the United States, the mechanisms of WNV encephalitis, and an overview of Anton syndrome.