The west nile virus treatment

Facebook Twitter LinkedIn Syndicate. Minus Related Pages. Symptoms No symptoms in most people. Symptoms of severe illness include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. Severe illness can occur in people of any age; however, people over 60 years of age are at greater risk for severe illness if they are infected 1 in 50 people.

People with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants, are also at greater risk.

Recovery from severe illness might take several weeks or months. Some effects to the central nervous system might be permanent. About 1 out of 10 people who develop severe illness affecting the central nervous system die. Diagnosis See your healthcare provider if you develop the symptoms described above.

This review discusses the following treatment modalities: ribavirin, interferon-alpha, intravenous immunoglobulin IVIG , and other less-used drugs. More studies about ribavirin are needed to know if the drug is useful for WNV encephalitis. Interferon-alpha has been shown to have both protective and disease limiting properties. Keywords: neuroinvasive west nile virus.

This data extrapolates to an estimated 3 to 5 million cases of infection. The virus is transmitted when the mosquito feeds, passing infected saliva into the host. The early phase following transmission includes viral replication in dermal dendritic cells and keratinocytes.

This phase is followed by the visceral-organ dissemination phase, which includes viral replication in draining lymph nodes, viremia, and spread to the visceral organs. The third and final phase spreads to the central nervous system CNS. The mechanism for viral CNS entry is unclear but may include a direct crossing of the blood-brain barrier, passive transport through the endothelium, infected macrophages crossing the blood-brain barrier or direct axonal retrograde transport.

Once in the CNS the virus primarily induces inflammation and a subsequent loss of neurons within the spinal cord and brainstem gray matter. The incubation period of the West Nile virus varies from days. The clinical presentation of West Nile virus in most cases include myalgia, malaise, and a low-grade fever. However, in rare cases, the virus can cause neurologic symptoms, including severe muscle weakness, changes in mental status, seizures, or flaccid paralysis.

Even with aggressive supportive treatment, the mortality rate following a case of neuroinvasive West Nile infection is high. Most people infected with West Nile virus have a history of travel to an area where the virus is endemic during the summer or fall.

However, this includes areas on most continents, as listed in the epidemiology section. The West Nile virus incubation period is two to 14 days. The typical infection includes a fever for five days, headache for 10 days and fatigue for around a month. Routine labs may reveal leukocytosis and other non-specific findings secondary to the viral infection.

A plaque reduction neutralization test PRNT can distinguish serologic cross-reactions. Neuroinvasive West Nile virus will typically have findings consistent with viral meningitis on lumbar puncture.

Analysis of CSF shows elevated protein and leucocyte levels, with a possible predominance of neutrophils early, transitioning to a lymphocytic predominance accompanied by normal glucose levels. In patients with a high suspicion of viral infection and an initial negative test, a repeat should be performed 10 days later as IgM levels may take time to elevate to the levels necessary to be detectable. Imaging: CT of the brain will typically not show any acute findings of the disease. MRI may show abnormalities after several weeks of acute neuroinvasive disease.

Treatment of West Nile virus is primarily supportive care. Researchers have tried several agents including interferon, ribavirin, and intravenous immunoglobulin. No clear efficacy data exists as only one controlled study has been performed to date. Once the clinician has made a diagnosis of West Nile virus, individuals with milder cases can be managed symptomatically as outpatients and tend to have an excellent prognosis. However, toxic patients with neurologic symptoms usually require long-term ICU care.

These patients will typically require long-term physical and occupational therapy at rehabilitation centers. After the infection, neurologic injury from the West Nile virus may include gross motor, cognitive, and fine motor abnormalities. Many patients have residual neurologic deficits, which can take a long time to recover, and some deficits may be permanent. When the CNS is involved, many patients become bed ridden and hence pressure sores, aspiration and DVT are common; thus prophylaxis is warranted.

The differential for the West Nile virus is extensive, and investigation should include a careful travel history [10] :. Most infected patients are asymptomatic. Those who develop West Nile fever tend to have symptoms of a viral syndrome. It is a self-limited illness with most symptoms lasting up to 10 days. However, the rare and most serious clinical manifestation, neuroinvasive disease, has a mortality of approximately 10 percent.

The geriatric population has the highest risk for neuroinvasive WNV. The neuroinvasive disease includes a wide spectrum of neurologic deficits, and some of these may persist for years or even become permanent.

Severe disease tends to affect the elderly and the greatest risk factor for death is neurological involvement. Since WNV is transmitted almost exclusively through a mosquito vector, avoiding mosquito bites is the primary method of prevention. Current methods of deterrence consist of two main components, personal protective measures and mosquito control. Insect repellants containing DEET or picaridin, permethrin-treated clothing, and avoiding exposure to endemic or high-risk areas with mosquitoes are the mainstays of personal protection.

Mosquito control programs may also help decrease exposure along with reducing high-risk conditions, such as standing water around the home. The prognosis after severe neuroinvasive WNV infection is often guarded. Most individuals require long-term rehabilitation, and some neurologic deficits may be permanent. There is no clear evidence for effective treatment beyond supportive care at this time. WNV infection is challenging to diagnose and can quickly progress to neurologically devastating and even fatal disease.

This condition is best managed by an interprofessional team that includes an emergency medicine physician, an internist for inpatient management, a critical care physician if needing ICU management, an infectious disease physician, along with pharmacy and nursing support.

The care is primarily supportive, and the diagnosis is often difficult to make due to the variable presentation and overall rarity of the disease. To summarize, West Nile virus infection requires an interprofessional team approach, including physicians, specialists, specialty-trained nurses, and pharmacists, all collaborating across disciplines to achieve optimal patient results.