Spinal Cord Neuropathology in Human West NileVirus Infection

2004 ◽  
Vol 128 (5) ◽  
pp. 533-537 ◽  
Author(s):  
Jonathan D. Fratkin ◽  
A. Arturo Leis ◽  
Dobrivoje S. Stokic ◽  
Sally A. Slavinski ◽  
Roger W. Geiss

Abstract Context.—During the 1999 New York City West Nile virus (WNV) outbreak, 4 patients with profound muscle weakness, attributed to Guillain-Barré syndrome, were autopsied. These cases were the first deaths caused by WNV, a flavivirus, to be reported in the United States. The patients' brains had signs of mild viral encephalitis; spinal cords were not examined. During the 2002 national epidemic, several patients in Mississippi had acute flaccid paralysis. Electrophysiologic studies localized the lesions to the anterior horn cells in the spinal gray matter. Four of 193 infected patients in Mississippi died and were autopsied. All 4 experienced muscular weakness and respiratory failure that required intubation. Postmortem examinations focused on the spinal cord. Objective.—To emphasize apparent tropism of WNV for the ventral gray matter of the spinal cord. Design.—Cerebral hemispheres, basal ganglia, diencephalon, brainstem, cerebellum, and spinal cord sections were stained with hematoxylin-eosin and incubated with antibodies to T cells, B cells, and macrophages/microglial cells. Results.—We identified neuronophagia, neuronal disappearance, perivascular chronic inflammation, and microglial proliferation in the ventral horns of the spinal cord, especially in the cervical and lumbar segments. Loss of ganglionic neurons, nodules of Nageotte, and perivascular lymphocyte aggregates were found in dorsal root and sympathetic ganglia. Severity of cellular reaction was proportional to the interval length between patient presentation and death. Conclusion.—West Nile virus caused poliomyelitis. Injury to spinal and sympathetic ganglia mirrored the damage to the spinal gray matter. The disappearance of sympathetic neurons could lead to the autonomic instability observed in some WNV patients, including labile vital signs, hypotension, and potentially lethal cardiac arrhythmias.

2006 ◽  
Vol 13 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Janet L. Fox ◽  
Stuart L. Hazell ◽  
Leslie H. Tobler ◽  
Michael P. Busch

ABSTRACT In 1999 West Nile virus (WNV) surfaced in the United States in the city of New York and spread over successive summers to most of the continental United States, Canada, and Mexico. Because WNV immunoglobulin M (IgM) antibodies have been shown to persist for up to 1 year, residents in areas of endemicity can have persistent WNV IgM antibodies that are unrelated to a current illness with which they present. We present data on the use of IgG avidity testing for the resolution of conflicting data arising from the testing of serum or plasma for antibodies to WNV. Thirteen seroconversion panels, each consisting of a minimum of four samples, were used. All samples were tested for the presence of WNV IgM and IgG antibodies, and the avidity index for the WNV IgG-positive samples was calculated. Panels that exhibited a rise in the WNV IgM level followed by a sequential rise in the WNV IgG level were designated “primary.” Panels that exhibited a marked rise in the WNV IgG level followed by a sequential weak WNV IgM response and that had serological evidence of a prior flavivirus infection were designated “secondary.” All samples from the “primary” panels exhibited low avidity indices (less than 40%) for the first 20 to 30 days after the recovery of the index sample (the sample found to be virus positive). All of the “secondary” samples had elevated WNV IgG levels with avidity indices of ≥55%, regardless of the number of days since the recovery of the index sample. These data demonstrate that it is possible to differentiate between recent and past exposure to WNV or another flavivirus through the measurement of WNV IgG avidity indices.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 193 ◽  
Author(s):  
Fengwei Bai ◽  
E. Ashley Thompson ◽  
Parminder J. S. Vig ◽  
A. Arturo Leis

West Nile virus (WNV) is the most common mosquito-borne virus in North America. WNV-associated neuroinvasive disease affects all ages, although elderly and immunocompromised individuals are particularly at risk. WNV neuroinvasive disease has killed over 2300 Americans since WNV entered into the United States in the New York City outbreak of 1999. Despite 20 years of intensive laboratory and clinical research, there are still no approved vaccines or antivirals available for human use. However, rapid progress has been made in both understanding the pathogenesis of WNV and treatment in clinical practices. This review summarizes our current understanding of WNV infection in terms of human clinical manifestations, host immune responses, neuroinvasion, and therapeutic interventions.


2017 ◽  
Author(s):  
Crystal M. Hepp ◽  
Jill Hager Cocking ◽  
Michael Valentine ◽  
Steven J. Young ◽  
Dan Damien ◽  
...  

AbstractWest Nile Virus (WNV) has been detected annually in Maricopa County, Arizona, since 2003. With this in mind, we sought to determine if contemporary strains are established within the county or are annually imported. As part of this effort, we developed a new protocol for tiled amplicon sequencing of WNV to efficiently attain greater than 99% coverage of 14 WNV genomes collected directly from positive mosquito pools distributed throughout Maricopa County between 2014 and 2017. Bayesian phylogenetic analyses revealed that the contemporary genomes fall within two major lineages, NA/WN02 and SW/WN03. We found that all of the Arizona strains possessed a mutation known to be under positive selection (NS5-K314R), which has arisen independently four times. The SW/WN03 strains exhibited transient behavior, with at least 10 separate introductions into Arizona when considering both historical and contemporary strains. However, NA/WN02 strains are geographically differentiated and appear to be established in Arizona, with likely origins in New York. The clade of New York and Arizona strains looks to be the most ancestral extant lineage of WNV still circulating in the United States. The establishment of WNV strains in Maricopa County provides the first evidence of local overwintering by a WNV strain over the course of several years in Arizona.


2006 ◽  
Vol 42 (3) ◽  
pp. 170-177 ◽  
Author(s):  
Reid Gerhardt

The accidental introduction of West Nile Virus into New York City from the Old World in 1999 resulted in an epidemic in humans, horses, and birds that swept to the west coast in just 3 years. The virus is transmitted by infective mosquitoes among susceptible native birds, which serve as amplifying hosts. Clinical disease occurs in humans and horses, but not enough virus is produced in their blood to infect other mosquitoes; therefore, humans and horses are considered dead-end hosts. Humans can best protect themselves by remaining indoors during periods of high mosquito activity and/or by using recommended repellents. Effective vaccines are available for horses.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S239-S239
Author(s):  
Arunmozhi S Aravagiri ◽  
Scott Kubomoto ◽  
Ayutyanont Napatkamon ◽  
Sarah Wilson ◽  
Sudhakar Mallela

Abstract Background Aseptic meningitis can be caused by an array of microorganisms, both bacterial and non-bacterial, as well as non-infectious conditions. Some etiologies of aseptic meningitis require treatment with antibiotics, antiviral, antifungals, anti-parasitic agents, immunosuppressants, and or chemotherapy. There are limited diagnostic tools for diagnosing certain types of aseptic meningitis, therefore knowing the differential causes of aseptic meningitis, and their relative percentages may assist in diagnosis. Review of the literature reveals that there are no recent studies of etiologies of aseptic meningitis in the United States (US). This is an epidemiologic study to delineate etiologies of aseptic meningitis in a large database of 185 HCA hospitals across the US. Methods Data was collected from January 2016 to December 2019 on all patients diagnosed with meningitis. CSF PCR studies, and CSF antibody tests were then selected for inclusion. Results Total number of encounters were 3,149 hospitalizations. Total number of individual labs analyzed was 10,613, and of these 262 etiologies were identified. 23.6% (62) of cases were due to enterovirus, 18.7% (49) due to HSV-2, 14.5% (38) due to West Nile virus, 13.7% (36) due to Varicella zoster (VZV), 10.5% (27) due to Cryptococcus. Additionally, we analyzed the rate of positive test results by region. Nationally, 9.7% of tests ordered for enterovirus were positive. In contrast, 0.5% of tests ordered for HSV 1 were positive. The southeastern United States had the highest rate of positive tests for HSV 2 (7% of tests ordered for HSV 2 were positive). The central United States had the highest rate of positive test for West Nile virus (11% of tests ordered for West Nile were positive). The northeastern region and the highest rate of positive tests for varicella zoster (18%). Table 1: Percentage of positive CSF tests (positive tests/tests ordered) Table 2: Lists the number of HIV patients and transplant patients that had positive CSF PCR/serologies Figure 1: Percentage of positive CSF tests in each region Conclusion Approximately 40% of aseptic meningitis population had treatable etiologies. A third of the Cryptococcus meningitis population had HIV. Furthermore, enteroviruses had the majority of cases within the US, which are similar to studies done in other parts of the world. Disclosures All Authors: No reported disclosures


2015 ◽  
Vol 92 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Micah B. Hahn ◽  
Roger S. Nasci ◽  
Mark J. Delorey ◽  
Rebecca J. Eisen ◽  
Andrew J. Monaghan ◽  
...  

2004 ◽  
Vol 112 (11) ◽  
pp. 1183-1187 ◽  
Author(s):  
Adam M. Karpati ◽  
Mary C. Perrin ◽  
Tom Matte ◽  
Jessica Leighton ◽  
Joel Schwartz ◽  
...  

Acta Tropica ◽  
2018 ◽  
Vol 185 ◽  
pp. 242-250 ◽  
Author(s):  
Justin K. Davis ◽  
Geoffrey P. Vincent ◽  
Michael B. Hildreth ◽  
Lon Kightlinger ◽  
Christopher Carlson ◽  
...  

2013 ◽  
pp. 1170-1182
Author(s):  
Kevin P. McKnight ◽  
Joseph P. Messina ◽  
Ashton M. Shortridge ◽  
Meghan D. Burns ◽  
Bruce W. Pigozzi

West Nile Virus is a vector-borne flavivirus that affects mainly birds, horses, and humans. The disease emerged in the United States in 1999 and by 2001 had reached Michigan. In clinical human cases, the most common symptoms are fever, weakness, nausea, headache, and changes in mental state. The crow is the most common wildlife host in the life cycle of the virus. The state of Michigan, through the Michigan Department of Community Health, collected the spatial locations of over 8,000 dead birds (Corvidae), statewide, during 2002. The large number of samples made spatial and temporal hotspot detection possible. However, the volunteer reporting method produced a dataset with a direct correlation between the numbers and locations of the dead birds and human population density and accurately identifying hotspots remains a challenge. Geographic variation in dead bird intensity was modeled using both global and local spatial clustering algorithms. Statistical models identified overall spatial structure and local clustering. Identification of hotspots was confounded by limited information about the collection procedures, data availability and quality, and the limitations of each method.


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