west nile virus Rabia Ayub

2. PRESENTATION OF VIROLORY
Mam Raeesa Sattar 

3. EMERGING VIRUSES
An emergent virus is a virus that has adapted and emerged as a new
disease/pathogenic strain, with attributes facilitating pathogenicity in a field not
normally associated with that virus. This includes viruses that are the cause of
a diseases which has notably increased in incidence; this is often a result of a wide
variety of causes from both the influence of man and nature.

5. WEST NILE VIRUS
West Nile (WN) virus is an arthropod-borne flavivirus, a
member of the Japanese encephalitis virus antigenic
complex transmitted by Culex mosquitoes

6. EPIDEMIOLOGY
◦ Its initial isolation in Uganda in 1937 through the present, WNV has
become an important cause of human and animal disease worldwide.
◦ The first outbreak of neuroinvasive disease caused by WNV was
reported among the elderly in Israel in 1957.
◦ The virus has propagated to a vast region of the globe and is now
considered the most important causative agent of viral encephalitis
worldwide

7. VIRAL STRUCTURE AND
GENOME:
◦ GENUS; Flavi-virus
◦ FAMILY: Flavi-viridae
◦ Member of the Japanese encephalitis serocomplex, which also
includes Japanese encephalitis virus.
◦ WNV has a single stranded positive-polarity icosahedral envelope RNA
genome.

8. PATHOGENICITY
WNV is thought to replicate at the site of inoculation and
then spread to lymph nodes and the bloodstream. Viral
penetration of the central nervous system appears to
follow stimulation of toll-like receptors and increased
levels of tumor necrosis. WNV directly infects neurons,
particularly in deep nuclei and gray matter of the brain

9. Transmission
◦ WNV may be transmitted to humans via the following-
◦  Bite of an infected mosquito
◦  Maternal-fetal transmission
◦  Blood product transfusion
◦  Organ transplantation
◦  Breast milk
◦  Unidentified means in a dialysis center.

11. Diagnosis
◦ The diagnosis of WNV infection is based largely on clinical criteria and testing for antibody
responses. The incubation period for WNV infection is thought to range from about 2 to 14
days.
◦ Routine Investigations
◦ Serology
◦ Serum or CSF
◦ IgM capture ELISA (MAC ELISA)- cross reactivity
◦ Plaque reduction neutralization test (PRNT)
◦ Detection of virus, antigen, or nucleic acids
◦ RT-PCR

12. ◦ There is no specific antiviral drug treatment for WNV infection
◦ Management consists of rest and supportive treatment including drinking fluids to prevent
dehydration and administration of Paracetamol to relieve fever and pain
TREATMENT:

13. REFERENCES;
◦ Byron E. E. Martina, et al. "West Nile Virus: Immunity and Pathogenesis." Viruses (1999-
4915) 3.6 (2011): 811-828. Academic Search Complete. EBSCO. Web. 28 Sept. 2011.
◦ Carson PJ, Borchardt SM, Custer B, et al. Neuroinvasive disease and West Nile virus infection,
North Dakota, USA, 1999-2008. Emerg Infect Dis 2012; 18:684

14. THANKYOU 