A Security Guard With West Nile Virus Encephalitis

Abstract

A 57-year-old male working as a security supervisor in an office building was seen for return to work by the on-site occupational health nurse. He was observed to have slow gait as he entered the clinic waiting area, was pale, diaphoretic, and slow in responding to questions. His return to work note stated he was recovering from West Nile Virus (WNV). Implications for return to work are presented.

BF, a 57-year-old male, was employed as a security supervisor in an office building located in a large metropolitan area. As BF walked into the cafeteria, the occupational health nurse observed that his gait was very slow. Upon entering the clinic, BF walked slowly, was pale, slightly diaphoretic, complained of shortness of breath, and stated he “did not feel well.” He immediately sat down in the waiting room and did not communicate any further. He had a physician’s release in his hand which stated he was recovering from West Nile Virus (WNV) but could return to work. After a 5-minute rest, BF seemed to recover. He conveyed he had been ill for the past 4 weeks at home, and was recovering from WNV. He stated he attended an off-site work event at an enclosed facility and the next day awoke with flu-like symptoms and excruciating joint pain. He stated that the pain was unlike any pain he had ever experienced and caused him to lose consciousness several times. He saw his primary care physician who had seen a patient the day before with exactly the same symptoms as the security officer. The physician examined BF, and BF was told he probably had WNV. Blood was drawn and sent to the county health department for WNV testing and confirmation; the diagnosis was confirmed as WNV. He was sent home with pain medications and Prednisone. Over the next 4 weeks, BF’s wife took care of him at home. He intermittently ran a temperature of 105 °F and developed severe headaches. While on bed rest, his wife assisted with fluid intake, nutritional needs, and medications for fever. BF stated he did not feel like himself and was not ready to return to work but convinced his doctor to release him. BF stated he was fearful of losing his job as he was recently promoted to his supervisory position; many changes were occurring in the workplace, and he believed he needed to return to work.

During the return to work examination, BF was pale and short of breath but recovered after sitting for several minutes, was oriented to time and place, and had normal range vital signs, including temperature. He had a health history of osteoarthritis and sleep apnea. He denied any other physical, emotional, or psychological problems. He stated he liked to garden and this was the most likely place he was bitten by a mosquito. He stated today was his first day of walking any distance or engaging in any activity other than bed rest. He did not remember driving himself to work. BF explained he lived in the zip code where two other residents had already died from WNV infection. As the assessment continued, BF was observed having difficulty answering questions, staring, and not participating any further in the assessment questions.

A call was placed to his primary care physician, and he was transported to his office. He was then diagnosed with WNV encephalopathy and admitted to the hospital. The zip code in which BF was living was later declared a WNV encephalitis epidemic area.

WNV Etiology

WNV, an RNA virus belonging to the Flavivirus genus which also includes Japanese Encephalitis, St. Louis Encephalitis, and Dengue viruses, causes a mosquito-borne illness that occurs in 65 mosquito species (Centers for Disease and Prevention [CDC], 2013). Birds are the known vertebrae host in the environment.

WNV was first isolated in 1937 in Uganda and in 1999 was first recognized in New York. Since that time, the virus has spread throughout the United States. The Culex mosquito breeds in containers and pools of standing water and are the most common carrier of WNV. The mosquito becomes infected from feeding on WNV-infected birds and can infect humans directly through a bite. At the site of a mosquito bite infected with WNV, the virus will replicate and spread to near-by lymph nodes and then into the blood stream. Some individuals may experience neuro-invasive disease when the virus spreads to the central nervous system.

Humans can also be infected with WNV from blood transfusions or organ transplantation. Although mentioned in the literature, Rabe (2012) stated that infection from human milk or intrauterine transmission is uncommon. Laboratory workers may be exposed through percutaneous or aerosol exposure while working with positive WNV samples.

WNV Symptoms

The incubation period for WNV is 2 days to 14 days between the time of the bite and onset of symptoms. Most cases resolve within a week but other cases have persisted for weeks or months. According to Rabe (2012), 70% to 80% of individuals are asymptomatic. Symptoms include a high fever (20%-30%), headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, loss of vision, numbness, and paralysis (Pochat-Debroux, 2008). Less than 1% of individuals develop neuro-invasive disease. Most fatalities occur in the aging population with underlying health conditions.

Diagnosis

The preferred test for WNV is the anti-WNV IgM antibodies in serum or cerebrospinal fluid (CDC, 2013). WNV antibodies are detectable within 3 days to 8 days and can persist for 30 days to 90 days or longer. Due to testing and interpretation limitations, all suspected WNV should be tested in a state public health laboratory or the CDC (CDC, 2015).

Treatment

No WNV vaccine for human use has been approved. Antiviral therapy for WNV has not been shown to be effective. Treatment of WNV is supportive care and management of complications. Supportive care includes reducing fever, controlling nausea, nutrition, fluid intake and rest. If encephalitis or other neuro-invasive symptoms begin, the individual may need inpatient treatment and observation.

Risk Factors

According to Lindsey, Staples, Lehman, and Fischer (2012), risk factors for severe WNV disease include age 60 years or older, diabetes, hypertension, history of cancer, chronic renal disease, and chronic alcohol abuse.

Prevention

Most communities have developed mosquito control programs through the use of larvicides, adulticides, or larvae-eating fish. Community leaders with health department guidance decide whether to implement mosquito spraying programs. Workplaces should assess their mosquito prevention program and make changes or additions as needed.

Implications for Practice

Occupational health nurses must understand the etiology and complications of WNV so they can appropriately assess and evaluate employees returning to work. Employees with WNV complications may not be ready to return to work full duty and may need a flexible return to work or accommodations via a reduced work schedule until fully recovered. The goal is to provide support for employees recovering from WNV when they return to an appropriate level of work.

Conclusion

The return to work assessment revealed that BF was experiencing complications from WNV, was not ready to return to work, and needed further evaluation prior to returning to work. Working with the employee, physician, and manager, the occupational health nurse established a progressive return to work plan agreed to by all parties. Instead of physically returning to the workplace, BF began working from home 3 hours a day for 1 week and 4 hours a day during Week 2. By Week 3, BF was working from home 5 hours per day and then increased to 6 hours per day at Week 4. BF continued to improve after 4 weeks of working from home. He began commuting to the office after the progressive work from home schedule and worked 6 hours per day for 2 more weeks to build his stamina. He then returned to regular duty. He continues to have intermittent residual joint pain.