scholarly journals Epidemiology and Clinical Presentation of West Nile Virus Infection in Horses in South Africa, 2016–2017

Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 20
Author(s):  
Freude-Marié Bertram ◽  
Peter N. Thompson ◽  
Marietjie Venter

Although West Nile virus (WNV) is endemic to South Africa (RSA), it has only become recognized as a significant cause of neurological disease in humans and horses locally in the past 2 decades, as it emerged globally. This article describes the epidemiological and clinical presentation of WNV in horses across RSA during 2016–2017. In total, 54 WNV-positive cases were identified by passive surveillance in horses with febrile and/or neurological signs at the Centre for Viral Zoonoses, University of Pretoria. They were followed up and compared to 120 randomly selected WNV-negative controls with the same case definition and during the same time period. Of the WNV-positive cases, 52% had fever, 92% displayed neurological signs, and 39% experienced mortality. Cases occurred mostly in WNV-unvaccinated horses <5 years old, during late summer and autumn after heavy rain, in the temperate to warm eastern parts of RSA. WNV-positive cases that had only neurological signs without fever were more likely to die. In the multivariable analysis, the odds of WNV infection were associated with season (late summer), higher altitude, more highly purebred animals, younger age, and failure to vaccinate against WNV. Vaccination is currently the most effective prophylactic measure to reduce WNV morbidity and mortality in horses.


2010 ◽  
Vol 35 (6) ◽  
pp. 601-605 ◽  
Author(s):  
A. J. GUTHRIE ◽  
P. G. HOWELL ◽  
I. A. GARDNER ◽  
R. E. SWANEPOEL ◽  
J. P. NURTON ◽  
...  


2019 ◽  
Vol 25 (2) ◽  
pp. 367-369 ◽  
Author(s):  
Vivak Parkash ◽  
Kate Woods ◽  
Liana Kafetzopoulou ◽  
Jane Osborne ◽  
Emma Aarons ◽  
...  


2021 ◽  
pp. 194187442199537
Author(s):  
Devin Simon

West Nile Neuroinvasive Disease (WNND) is a rare complication of West Nile Virus infection with the capability of mimicking other neurologic diseases. This infection should be considered in the differential diagnosis for patients presenting in the late summer months with altered mentation, fever, and focal neurologic deficits without an otherwise clear etiology. A 63-year-old male presented with acute onset fever, confusion, falls, ataxia, vertical nystagmus, and right leg weakness. Although magnetic resonance imaging of the brain and cervical spine were unremarkable, the lumbar spine revealed enhancement of ventral nerve roots in the cauda equina. Cerebrospinal fluid (CSF) analysis was significant for elevated protein without pleocytosis, which was more suggestive of albuminocytologic dissociation. Both serum and CSF IgM labs testing for West Nile Virus were positive. Despite a 5 day course of immunoglobulin therapy, his symptoms did not significantly improve. He eventually was transferred to inpatient rehabilitation for several days prior to returning home. This case highlights the variable presentations of acute West Nile Virus infection in the rare setting of neuroinvasive disease, which can make diagnosis difficult. The CSF analysis may also not always show results consistent with an acute viral infection, which can make determining the underlying etiology more challenging.



Author(s):  
Ana-Luiza Sayao ◽  
Oksana Suchowersky ◽  
Ali Al-Khathaami ◽  
Brian Klassen ◽  
Nili R. Katz ◽  
...  

AbstractBackground:Between August 25 and September 25, 2003 seven patients with West Nile virus neurological manifestations were identified through the hospital neurology consultation services in Calgary, Alberta, Canada. Three of the seven patients were treated with interferon alpha-2b (IFN alpha-2b). In this report we document the clinical characteristics of these seven cases.Methods:Clinical and laboratory information was obtained from a retrospective review of patient hospital and clinic charts. Patients were included if they had serological evidence of West Nile virus infection and had clinical evidence of aseptic meningitis, encephalomyelitis, cerebellar syndrome or motor neuronopathy. Three patients received a treatment course of three million units IFN alpha-2b, administered by subcutaneous injection once per day for 14 days.Results:Four patients had cerebellar signs without change in consciousness, two had both encephalitis and neuromuscular weakness, and one patient had focal lower motor neuron arm weakness. The mean age was 52 (range 24 - 73). All patients had flu-like illness and fever as presenting symptoms and six had severe headaches. Two patients were immunocompromised prior to infection. Two patients with cerebellar signs (one with opsoclonus-myoclonus) improved spontaneously and exhibited only mild residual deficits on discharge. The other two patients with cerebellar findings developed brainstem involvement, one coinciding with and one subsequent to the cerebellar symptoms. Within one week of treatment with IFN alpha-2b these latter two patients showed marked improvement. One patient with encephalitis and neuromuscular weakness, was treated with IFN alpha-2b and subsequently recovered.Interpretation:In this case review of seven patients, multiple neurological symptoms occurred in each patient and the neurological presentation was varied. Four patients had predominant cerebellar findings and one patient had opsoclonus-myoclonus, not previously reported. The marked improvement in three patients who received IFN alpha-2b raises preliminary optimism towards this potential treatment.



2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Robert D. Stewart ◽  
Stefanie N. Bryant ◽  
Jeanne S. Sheffield

A recent outbreak of West Nile virus has allowed for observations as to the clinical course of this emerging pathogen during pregnancy. We present three cases of West Nile virus infection during pregnancy. Case 1 presented at term with focal subjective weakness and fever. With supportive care, her symptoms were resolved within 7 days, and she subsequently delivered an unaffected term infant. Case 2 presented in the first trimester with fever and headache. Her symptoms were resolved in 8 days with supportive care. Case 3 was diagnosed during the first trimester during workup of nonspecific respiratory symptoms, with resolution of all symptoms in 24 days. Obstetricians need to be aware of the varied clinical presentation of West Nile virus during pregnancy.



2016 ◽  
Vol 54 (1) ◽  
pp. 155-158 ◽  
Author(s):  
G. Rimoldi ◽  
A. Mete ◽  
J. M. Adaska ◽  
M. L. Anderson ◽  
K. P. Symmes ◽  
...  

West Nile virus (WNV) infection has been detected in many species of birds and mammals, but scant information is available about the disease in small ruminants. West Nile virus was diagnosed in 6 sheep with neurological signs and encephalitis, in California between 2002 and 2014. All sheep had severe lymphoplasmacytic meningoencephalitis. Lymphoplasmacytic myelitis was also detected in 2 sheep where the spinal cord was examined. Brain tissue was positive for WNV detected by polymerase chain reaction in 6 of 6 sheep and by immunohistochemistry (IHC) in 5 of 6 sheep. Viral antigen was not detected by IHC in extraneural tissues in the 3 sheep examined. West Nile virus RNA was sequenced from 2 of 6 sheep, and each one clusters closely with WNV isolated from mosquito pools from nearby locations at similar times. West Nile virus was the most common cause of viral encephalitis in sheep diagnosed at this laboratory between 2002 and 2014, accounting for 6 of 9 sheep.



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