WEST NILE VIRUS Rachel Fick Parice Juntdadetdoungdee

It was a hot summer day and Cindy was out swimming in a lake surrounded by a heavily forested area. Once home she noticed a red itchy bite caused by a mosquito. She applied hydrocortisone and did not think much of it. WEST NILE VIRUS: CASE STUDY

One week later… Cindy felt tired, had body aches, a fever, and was vomiting. She suspected that she had the flu. Days went on and the symptoms got worse. She felt disorientated and experienced mild paralysis in her limbs. WEST NILE VIRUS: CASE STUDY

It was time for Cindy to go to the hospital… After evaluating Cindy, Doctors ran a blood test and discovered a virus-specific antibody Immunoglobulin M (IgM) testing positive for West Nile Virus (WNV). There are no antiviral treatments to treat West Nile Virus. Cindy remained in the hospital for one day where she received Intravenous fluids, pain medication, and nursing care. WEST NILE VIRUS: CASE STUDY

The next day… Cindy was released from the hospital with pain medication and instructed to rest for the next week. Cindy made a full recovery and now uses preventative measures by using Mosquito repellent when outside. WEST NILE VIRUS: CASE STUDY

 First identified in Uganda in 1937, the virus is most commonly found in Africa, West Asia, and the Middle East  Had not been reported in the United States until 1999 when an outbreak occurred in New York resulting in 62 known cases  Had not reached Oregon until 2004 when 3 cases were reported  Since 2004, 3 positive cases have been reported in Marion county, but all infections were acquired out of state HISTORY OF WEST NILE VIRUS

TO THIS DATE ALASKA AND HAWAII HAVE NOT HAD ANY CASES REPORTED WEST NILE VIRUS ACTIVITY BY STATE AS OF JULY 9, 2013

 Cycle begins when a mosquito Feeds on a West Nile infected bird  Virus spreads rapidly throughout mosquito’s body and replicates in salivary glands  Mosquitos then feeds on human blood transferring the virus to the human host via saliva. MODE OF TRANSMISSION * West Nile Virus cannot be transmitted from person to person

LESS THAN 1% OF ALL MOSQUITOES ARE ACTUALLY CARRYING WEST NILE VIRUS

 A species of the Flavivirdae family  Single-standed RNA virus icosohedral in shape  50 nanometers in length  No staining characteristics  Contains a protein coat called a capsid, that prevents the host’s immune system from detecting the virus VIRULENCE FACTORS & CHARACTERISTICS

 Immature Virus: contains 60 glycoprotein spikes that prevent premature fusion with cell membrane. Once virus enters a favorable environment maturation begins  Mature Virus: Conformational changes occur and spikes recede creating a smooth surface for attachment to cell membrane PATHOPHYSIOLOGY

 Once bound to target cell, WNV enters the cell via receptor- mediated endocytosis  Virus releases its copy of RNA into cytoplasm for translation into polypeptides  WNV is replicated in the endoplasmic reticulum of the host cell, and generates a negative strand RNA. This serves as template for developing positive strand RNA synthesis.  The positive strand of RNA is packaged or used to translate additional viral proteins  WNV invades the body and enters the bloodstream to the nerve cells of the brain and target tissues/organs by exocytosis.  Incubation time for the Virus is 3-14 days PATHOPHYSIOLOGY

MILD SYMPTOMS  Fever  Headache  Body aches  Fatigue  Back Pain  Skin Rash  Swollen Lymph glands Mild symptoms will resolve on their own in a few days SEVERE SYMPTOMS  High fever  Encephalitis  Disorientation  Tremors  Coma  Pain  Partial paralysis Severe symptoms last weeks & need medical attention SYMPTOMS RANGE FROM NONE TO SEVERE * 80% of infected individuals do not show any symptoms

 Testing of cerebrospinal fluid to detect West Nile Virus specific IgM Antibodies (antibodies present 3-8 days after onset of illness)  Complete blood count  Head CT scan  Head MRI scan DIAGNOSIS

 There is currently no treatment available for West Nile virus  Medical attention is advised for severe symptoms such as encephalitis and high fever for monitoring, pain control, intravenous fluids, & monitoring of secondary infections  Mild symptoms can be managed with over the counter pain relievers TREATMENT

 No West Nile Virus vaccines are licensed for use in humans  Personal protection: mosquito repellents, wear long sleeve shirts and long pants, & limiting outdoor exposure from duck to dawn  Community Level Mosquito control programs to reduce vector densities  Screening of blood & organ donors  Have a strong immune system PREVENTION

 West Nile virus effects more than just humans…  Birds & bats  Most domesticated animals (cats, dogs, horses, etc.)  Rodents, squirrels, rabbits  Alligators  Since 1999, 13,000 people have become seriously ill and 1,200 people have died in the U.S. alone  OHSU is developing a vaccine for West Nile Virus that could reach human clinical trials within 3 years  Scientists are currently researching interferon therapy as treatment for encephalitis caused by West Nile Virus and is showing promising results IMPORTANCE OF WEST NILE VIRUS

Center for Disease Control. (2013, July). West Nile Virus. Retrieved from  Provided an overview of the disease, history, and nationwide statistics D’ Angiolillo, Matthew. (2011, May). West Nile Virus: Epidemiology and Structure. Retrieved from  Information on structure, virulence factors, and Epidemiology MetaPathogen. (2013, May). West Nile Virus. Retrieved from  Pathophysiology of the disease and virus life cycle Oregon Department of Fish and Wildlife. (2013, July). West Nile Virus and Wildlife. Retrieved from  Effect the virus has on wildlife populations Oregon Health Authority. (2013) West Nile Virus Activity. Retrieved from  Statistics of virus in Oregon including counties Oregon Health & Science University. (2013) OHSU,WUSM, NTI to Develop New West Nile Virus Vaccine as Another Virus Season Approaches. Retrieved from  Current research and vaccine progress for the virus REFERENCES