Severe Neuroinvasive West Nile Virus in Association With Anti-CD20 Monotherapy for Multiple Sclerosis.

OBJECTIVES: The objective of this study was to report on the development of neuroinvasive West Nile virus (WNV) infection in the context of anti-CD20 monotherapy for multiple sclerosis (MS). METHODS: This is a case series study. RESULTS: In 2021-2022, we observed 4 cases of neuroinvasive WNV infection in our patient population of 2009 patients with MS on ocrelizumab, compared with a total of 46 cases of neuroinvasive WNV infection reported in Pennsylvania and 40 in New Jersey. Odds were 258 times that of the general population (95% confidence interval 97-691), χ2 p < 0.0001). All were women aged 41-61 years with variable disease duration, level of disability, and duration of anti-CD20 therapy. All presented in summer/early fall with fever, headache, and encephalopathy consistent with meningoencephalitis. Three patients had acute cerebellitis. Two had anterior nerve root involvement progressing to quadriparesis, and 1 developed refractory nonconvulsive status epilepticus. All required intubation and experienced significant morbidity. All had CSF pleocytosis. Two patients were WNV IgM positive in both the serum and CSF, 1 patient had positive serum IgM and CSF metagenomic next-generation sequencing (mNGS), while 1 had positive CSF mNGS with negative serum and CSF antibodies. DISCUSSION: Neuroinvasive WNV infection can develop with anti-CD20 monotherapy in the absence of additional immunosuppression. WNV serologies may be negative in the setting of anti-CD20 treatment; in the appropriate clinical context, one should consider direct detection methods such as PCR or mNGS-based testing.

Pharmacological Elevation of Cellular Dihydrosphingomyelin Provides a Novel Antiviral Strategy against West Nile Virus Infection.

The flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our collection of polyphenols against West Nile virus (WNV), a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (half-maximal effective concentrations [EC50s] of 2.2 and 0.24 µM, respectively, in Vero cells; EC50s of 2.2 and 1.9 µM, respectively, in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely, Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1), promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles in membrane properties. The addition of exogenous dhSM or Des1 blockage by using the reference inhibitor GT-11 {N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide} confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection.

Is Intravenous Immunoglobulin Effective in Reducing the Risk of Mortality and Morbidity in Neuroinvasive West Nile Virus Infection?: A Critically Appraised Topic.

BACKGROUND: The clinical benefit of intravenous immunoglobulin (IVIG) in adult individuals with neuroinvasive West Nile virus (niWNV) infection is not well substantiated. We sought to critically assess current evidence regarding the efficacy of IVIG in treating patients with niWNV. METHODS: The objective was addressed through the development of a critically appraised topic that included a clinical scenario, structured question, literature search strategy, critical appraisal, assessment of results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and a content expert in the field of neuro-infectious diseases. RESULTS: The appraised study enrolled 62 participants with suspected niWNV, randomized into 3 different arms [37 participants in the Omr-IgG-am group, 12 in the Polygam group, and 13 in the normal saline (NS) group]. Omr-IgG-am and Polygam are different formulations of IVIG. IVIG safety, measured as rates of serious adverse events, was the primary study outcome while IVIG efficacy, measured as rates of unfavorable outcomes, was a secondary endpoint. The estimated rates of SAE were statistically similar in all groups (51.4% Omr-IgG-am, 58.3% Polygam, and 23.1% NS groups). Unfavorable outcomes also occurred at a similar rate between all the groups (51.5% Omr-IgG-am, 54.5% Polygam, and 27.3% NS). CONCLUSIONS: The appraised trial showed that Omr-IgG-am and Polygam are as safe as NS. Data on efficacy from this trial were limited by a small sample size. Phase III clinical trials on IVIG efficacy in NiWNV infection are needed.

West Nile Virus Infection in Liver Transplant Recipient With Neither De Novo Infection nor Donor-Derived Infection: A Case Report.

West Nile virus was first described in 1937 and has sinceperiodically appearedin variousparts oftheworld by infecting people and horses. Reported infection symptoms and signs may be highly variable, ranging from fever and myalgias to meningoencephalitis. A 59-year-old patient was admitted to the University Clinical Centre of Serbia, Belgrade, in September 2018, where livertransplantwasperformedtotreat cirrhosisof ethyl etiology. Immunosuppressive therapy was started immediately after successful transplant, with the patientreceiving methylprednisolone, tacrolimus, and mycophenolate mofetil. Mycophenolate mofetil was excluded from therapy on postoperative day 3 because of progressively worse white blood cell count. The patient became febrile on postoperative day 11 (39.6 °C), and arm tremor, nausea, vomiting, and frequent fluid stools occurred. He complained of pain in the muscles and joints of the lower extremities. The next day he experienced occasional disorientation. Neurological findings revealed no signs of acute focal neurological deficit. We performed culture tests to isolate pathological microorganisms, and results were negative in cultures of the blood, urine, feces, ascites, and a smear of the wound and tip of the central venous catheter. Lumbar puncture resulted in a clear cerebrospinal fluid that was sent for analysis that showed significant increases in white blood cell count (94 × 106 cells/L), total proteins (1.61 g/L), and microalbumin (504.5 mg/L), with a reduction of immunoglobulin G. On postoperative day 15, positive serology of West Nile virus immunoglobulin M in cerebrospinal fluid was verified. Intensive monitoring and symptomatic and supportive therapy resulted in clinical and laboratory improvement, and the patient was discharged in good general condition on postoperative day 22. Considering the high risk of posttransplant complications, there remains the question of whether all donors and recipients should be tested forWest Nile virus atthe onset oftransplant.

Identification of West Nile virus RNA-dependent RNA polymerase non-nucleoside inhibitors by real-time high throughput fluorescence screening.

West Nile virus (WNV) is a re-emergent mosquito-borne RNA virus that causes major outbreaks of encephalitis around the world. However, there is no therapeutic treatment to struggle against WNV, and the current treatment relies on alleviating symptoms. Therefore, due to the threat virus poses to animal and human health, there is an urgent need to come up with fast strategies to identify and assess effective antiviral compounds. A relevant target when developing drugs against RNA viruses is the viral RNA-dependent RNA polymerase (RdRp), responsible for the replication of the viral genome within a host cell. RdRps are key therapeutic targets based on their specificity for RNA and their essential role in the propagation of the infection. We have developed a fluorescence-based method to measure WNV RdRp activity in a fast and reliable real-time way. Interestingly, rilpivirine has shown in our assay inhibition of the WNV RdRp activity with an IC50 value of 3.3 µM and its antiviral activity was confirmed in cell cultures. Furthermore, this method has been extended to build up a high-throughput screening platform to identify WNV polymerase inhibitors. By screening a small chemical library, novel RdRp inhibitors 1-4 have been identified. When their antiviral activity was tested against WNV in cell culture, 4 exhibited an EC50 value of 2.5 µM and a selective index of 12.3. Thus, rilpivirine shows up as an interesting candidate for repurposing against flavivirus. Moreover, the here reported method allows the rapid identification of new WNV RdRp inhibitors.

Severe Arboviral Neuroinvasive Disease in Patients on Rituximab Therapy: A Review.

With increasing use of rituximab and other B-cell depleting monoclonal antibodies for multiple indications, infectious complications are being recognized. We summarize clinical findings of patients on rituximab with arboviral diseases identified through literature review or consultation with the Centers for Disease Control and Prevention. We identified 21 patients on recent rituximab therapy who were diagnosed with an arboviral disease caused by West Nile, tick-borne encephalitis, eastern equine encephalitis, Cache Valley, Jamestown Canyon, and Powassan viruses. All reported patients had neuroinvasive disease. The diagnosis of arboviral infection required molecular testing in 20 (95%) patients. Median illness duration was 36 days (range, 12 days to 1 year), and 15/19 (79%) patients died from their illness. Patients on rituximab with arboviral disease can have a severe or prolonged course with an absence of serologic response. Patients should be counseled about mosquito and tick bite prevention when receiving rituximab and other B-cell depleting therapies.

Searching for Blockers of Dengue and West Nile Virus Viroporins.

Flavivirus infections, such as those caused by dengue and West Nile viruses, emerge as new challenges for the global healthcare sector. It has been found that these two viruses encode ion channels collectively termed viroporins. Therefore, drug molecules that block such ion-channel activity can serve as potential antiviral agents and may play a primary role in therapeutic purposes. We screened 2839 FDA-approved drugs and compounds in advanced experimental phases using three bacteria-based channel assays to identify such ion channel blockers. We primarily followed a negative genetic screen in which the channel is harmful to the bacteria due to excessive membrane permeabilization that can be relieved by a blocker. Subsequently, we cross-checked the outcome with a positive genetic screen and a pH-dependent assay. The following drugs exhibited potential blocker activities: plerixafor, streptomycin, tranexamic acid, CI-1040, glecaprevir, kasugamycin, and mesna were effective against dengue virus DP1. In contrast, idasanutlin, benzbromarone, 5-azacytidine, and plerixafor were effective against West Nile Virus MgM. These drugs can serve as future antiviral therapeutic agents following subsequent in vitro and in vivo efficacy studies.

Acute Fever of Unknown Origin: A Presentation of West Nile Encephalitis.

INTRODUCTION: West Nile virus is an asymptomatic infection in most cases, but it can present with a rare complication of deadly neuroinvasive disease. CASE PRESENTATION: A 81-year-old White man presented with altered mental status and fever of unknown origin. After extensive workup, he was diagnosed with West Nile encephalitis based on positive serology, lumbar puncture, and clinical presentation. DISCUSSION: West Nile virus is a mosquito-borne RNA arbovirus that, in rare cases, can lead to encephalitis, which is a challenging diagnosis. There is no current treatment; however, a 5-day course of intravenous immunoglobulin seemed to show acute clinical improvement in both mentation and magnetic resonance imaging of the head and no long-term effects. CONCLUSION: We report this case to increase awareness among clinicians to include West Nile virus in the differential diagnosis of encephalitis with fever of unknown origin, particularly in endemic areas.

Effects of ivermectin treatment of backyard chickens on mosquito dynamics and West Nile virus transmission.

BACKGROUND: Vector control strategies typically rely on pesticides to target mosquitoes involved in enzootic and zoonotic transmission of West Nile virus (WNV). Nevertheless, increasing insecticide resistance and a desire to reduce pesticide usage provide the impetus for developing alternative strategies. Ivermectin (IVM), an antiparasitic drug which is widely used in human and veterinary medicine, is a potential alternative for targeted control because Culex mosquitoes experience increased mortality following ingestion of IVM in bloodmeals. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a randomized field trial to investigate the impact of treating backyard chicken flocks with IVM in urban neighborhoods across Davis, California on mosquito populations and WNV transmission dynamics. We observed a significant reduction in WNV seroconversions in treated vs. untreated chickens, suggesting a reduction in WNV transmission intensity around treated flocks. We also detected a reduction in parity rates of Cx. tarsalis near treated vs. untreated flocks and increased mortality in wild mosquitoes following a bloodmeal on treated chickens (IVM serum concentration > 5ng/mL) vs. chickens with IVM serum concentrations < 5 ng/mL. However, we did not find a significant difference in abundance or infection prevalence in mosquitoes between treatment groups associated with the reductions in seroconversions. Mosquito immigration from surrounding larval habitat, relatively low WNV activity in the study area, and variable IVM serum concentrations likely contributed to uncertainty about the impact. CONCLUSIONS/SIGNIFICANCE: Taken together, our results point to a reduction in WNV transmission due to the impact of IVM on Culex mosquito populations and support the ongoing investigation of oral administration of IVM to wild birds for local control of WNV transmission, although further work is needed to optimize dosing and understand effects on entomological endpoints.

Unusual Movement Disorders and Atypical Magnetic Resonance Imaging (MRI) Findings in Patients with West Nile Encephalitis: Case Reports of 2 Patients with Evidence of Clinical and Imaging Resolution with IVIG.

BACKGROUND West Nile virus (WNv) is the leading cause of epidemic arbovirus encephalitis in the continental United States. Movement disorders (MDs) have been reported in 20% to 40% of patients with WNv and about 37% of patients with WNv encephalitis have changes on magnetic resonance imaging (MRI). We report 2 unusual cases of neuroinvasive WNv in patients with unusual MDs and unreported MRI findings. CASE REPORT In the first case, a 34-year-old man presented with a 1-week history of disinhibition, agitation, opsoclonus-myoclonus and ataxia syndrome (OMAS), tremor, and facial agnosia. Evaluation of his cerebrospinal fluid (CSF) revealed elevated immunoglobulin (Ig)M against WNv, a high level of protein (98 mg/dL), and an elevated white blood cell (WBC) count (134, 37% lymphocytes). An MRI of the brain showed an area of diffusion restriction in the splenium of the corpus callosum. The patient's MRI findings and OMA improved significantly after 2 treatments with i.v. IG (IVIG). In the second case, a 57-year-old woman presented with fever, headaches, psychosis, and ataxia; she was subsequently intubated for airway protection. Analysis of her CSF showed elevated IgM against WNv, a high level of protein (79 mg/dL), and elevated WBC count (106, 90% lymphocytes). One week after the onset of symptoms, the patient experienced facial dyskinesia. Later, she developed proximal bilateral lower extremity weakness. An MRI of her lumbar spine showed evidence of myeloradiculitis with contrast enhancement of the conus medullaris and ventral nerve roots. After a single treatment with IVIG, she had partial improvement in weakness. CONCLUSIONS MDs and changes on MRI have been reported in patients with neuroinvasive WNv disease. Our patient with OMAS also had transient splenial diffusion restriction on imaging, which, to the best of our knowledge, has not been previously reported with WNv infection. In both patients, treatment with IVIG resulted in improvement in symptoms.

West Nile Viral Meningoencephalitis in an Immunocompetent Female: A Case Report from Western Rajasthan, India.

BACKGROUND: West Nile virus (WNV) is a positive-sense single-stranded RNA virus of the family Flaviviridae and genus Flavivirus. The virus is transmitted primarily by the bite of Culex species mosquito and is of global concern. The infection is associated with a wide spectrum of signs and symptoms and is more fatal in the elderly, infants, and immunocompromised individuals. CASE PRESENTATION: We report a case of WNV meningoencephalitis in an immunocompetent female who presented with features of acute meningitis with a 5-days history. After the radiological suspicion of viral meningoencephalitis, viral serology was performed and was reactive for IgM antibody against WNV, delaying the diagnosis for at least 5 days. CONCLUSION: The purpose of this case report is to prime the treating physicians on the usefulness of viral serology in such a scenario. Viral serology is a simple and relatively rapid technique to diagnose or rule out the suspected viral cause of meningoencephalitis and minimize the time gap between diagnosis and start of supporting treatment wherever appropriate antivirals are not available for clinical use.

[West-Nile-Virus Infection acquired in Germany in a Kidney Transplant Recipient]. / In Deutschland erworbene West-Nil-Virusinfektion bei einem nierentransplantierten Patienten.

BACKGROUND: West-Nile-Virus (WNV) is a widely distributed flavivirus that is mainly transmitted between birds through different mosquito species (e. g. Culex, Aedes), but may also be transmitted to mammals including humans. WNV causes a spectrum of disease, ranging from asymptomatic infection to encephalitis in a minority of cases. Risk factors for severe disease are older age, cardiovascular disease and an immunocompromised state. MEDICAL HISTORY AND CLINICAL EXAMINATION: Here we report about a 60-year-old male patient who was referred to the University Hospital of Halle (Saale) with severe fever two years after kidney transplantation due to hypertensive nephropathy. No infection focus could be found and by day 6 in the course of his illness the patient developed neurologic symptoms and viral encephalitis was suspected. TREATMENT AND COURSE: The patient was initially treated with aciclovir. After initial reduction of immunosuppression, coincident graft dysfunction was treated with methylprednisolon. WNV-infection was suspected due to recent emerging human cases in the nearby area of the city of Leipzig. WNV lineage 2 was detected in the patient's urine by RT-PCR and seroconversion with presence of anti WNV IgM and IgG could be demonstrated. Consecutively, aciclovir treatment was stopped. The patient fully recovered and the transplanted kidney regained adequate function. Kidney biopsy did not reveal gross rejection of the transplant. CONCLUSION: This case highlights the need to consider rarer causes of illness like WNV-infection particularly in risk groups for more severe outcomes of infectious disease. WNV may be detected by PCR in the blood and cerebrospinal fluid early in the course of infection but it is also excreted for a prolonged period of time in the urine. Seroconversion to anti WNV IgG and IgM may be shown but serologic cross-reactivity among members of the flaviviridae family must be considered.

New avenues for therapeutic discovery against West Nile virus.

Introduction: West Nile virus (WNV) is a neurotropic mosquito-borne flavivirus, which is endemic in many countries, especially in Europe and in North America, where the virus has increased its activity in the recent years. No vaccines nor antiviral drugs are available for the prevention and treatment of WNV infection in humans.Areas covered: This review article describes viral and host targets that have been addressed by anti-WNV drug discovery studies and summarizes the most relevant anti-WNV candidate compounds identified so far, focusing on those showing antiviral efficacy in in vivo models and broad-spectrum anti-flavivirus activity.Expert opinion: The most promising anti-WNV drug candidates target conserved enzymatic motifs in viral NS3 protease and NS5 polymerase and are effective against different flaviviruses. Targeting host factors required for viral infection and replication and modulation of host innate antiviral response are also promising approaches, which may lead to the development of compounds with broad-spectrum antiviral activity, a desirable feature for an antiviral drug.

Lack of Efficacy of High-Titered Immunoglobulin in Patients with West Nile Virus Central Nervous System Disease.

West Nile Virus (WNV) can result in clinically severe neurologic disease. There is no treatment for WNV infection, but administration of anti-WNV polyclonal human antibody has demonstrated efficacy in animal models. We compared Omr-IgG-am, an immunoglobulin product with high titers of anti-WNV antibody, with intravenous immunoglobulin (IVIG) and normal saline to assess safety and efficacy in patients with WNV neuroinvasive disease as part of a phase I/II, randomized, double-blind, multicenter study in North America. During 2003-2006, a total of 62 hospitalized patients were randomized to receive Omr-IgG-am, standard IVIG, or normal saline (3:1:1). The primary endpoint was medication safety. Secondary endpoints were morbidity and mortality, measured using 4 standardized assessments of cognitive and functional status. The death rate in the study population was 12.9%. No significant differences were found between groups receiving Omr-IgG-am compared with IVIG or saline for either the safety or efficacy endpoints.

Targeting host metabolism by inhibition of acetyl-Coenzyme A carboxylase reduces flavivirus infection in mouse models.

Flaviviruses are (re)-emerging RNA viruses strictly dependent on lipid metabolism for infection. In the search for host targeting antivirals, we explored the effect of pharmacological modulation of fatty acid metabolism during flavivirus infection. Considering the central role of acetyl-Coenzyme A carboxylase (ACC) on fatty acid metabolism, we analyzed the effect of three small-molecule ACC inhibitors (PF-05175157, PF-05206574, and PF-06256254) on the infection of medically relevant flaviviruses, namely West Nile virus (WNV), dengue virus, and Zika virus. Treatment with these compounds inhibited the multiplication of the three viruses in cultured cells. PF-05175157 induced a reduction of the viral load in serum and kidney in WNV-infected mice, unveiling its therapeutic potential for the treatment of chronic kidney disease associated with persistent WNV infection. This study constitutes a proof of concept of the reliability of ACC inhibitors to become viable antiviral candidates. These results support the repositioning of metabolic inhibitors as broad-spectrum antivirals.

Arenaviruses and West Nile Virus in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the epidemiology, diagnosis, prevention, and management of infection due to Arenaviruses and West Nile Virus (WNV) in the pre- and post-transplant period. Arenaviruses and WNV have been identified as causes of both donor-derived and post-transplant infection. Most data related to these infections have been published in case reports and case series. Transplant recipients may become infected with Arenaviruses if they, or their donors, are exposed to wild rodents or infected pet rodents. Lymphocytic choriomeningitis virus is the most commonly recognized Arenavirus among transplant recipients and should be considered when transplant recipients present with fever, hepatitis, meningitis/encephalitis, and/or multisystem organ failure. WNV is a mosquito-borne virus, and as such, its incidence varies yearly depending on environmental conditions. WNV in transplant recipients typically presents with fever, myalgias, and rash; approximately one in 40 develop neuroinvasive disease. Due to its morbidity, the Organ Procurement and Transplantation Network recently mandated that transplant centers screen living donors for WNV infection in endemic areas. Little is known about the optimal treatment of Arenaviruses or WNV; reduction in immunosuppression and supportive care are the mainstays of management at present.