West Nile Fever
什么是West Nile Fever？
West Nile fever is an infectious disease caused by West Nile fever virus. It occurs most commonly in the Middle East but may now be found worldwide, including North America. Although it is generally a mild disease (approximately 8 out of 10 infected persons have mild or no symptoms), it may cause encephalitis (brain inflammation), especially among the elderly.
如何获得West Nile Fever？
West Nile virus is acquired through the bite of an infected mosquito. The mosquitoes become infected when feeding on infected birds. Very rarely, West Nile virus has been spread through blood transfusions, organ transplants, breastfeeding, and during pregnancy from mother to baby. Pregnant women should seek medical advice if they develop any symptoms of West Nile virus. West Nile virus is not transmitted through casual person-to-person contact.
易感性和抗性
Susceptibility is universal. Anyone can acquire West Nile virus. Individuals who contract West Nile virus become immune to further infections, so those who are most susceptible in endemic areas are mainly foreigners and young children.
症状是什么？
Asymptomatic cases of West Nile fever are very common. Approximately 80 percent of people who are infected with the virus do not show any symptoms at all. Up to 20 percent of those infected develop a mild illness involving fever, headache, muscle and joint aches, nausea, vomiting, and sometimes swollen lymph nodes or a skin rash appearing on the stomach, chest, and back. These symptoms can last from only a few days to several weeks.
Approximately one in 150 people who become infected with West Nile virus develop a very severe illness involving inflammation of the brain (encephalitis). Symptoms include high fever, headache, neck stiffness, stupor, disorientation, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis. Coma can occur. These symptoms can last several weeks, and the neurological effects can be permanent. Medical attention should be sought immediately if any of these more severe symptoms occur.
预防措施
预防西尼罗河病毒的最佳预防措施是通过使用驱虫剂，蚊帐和防护服避免蚊虫叮咬。
处理
There is no specific treatment for viral infections of West Nile virus other than treating the symptoms. Milder disease improves on its own through rest and symptomatic treatment (e.g., analgesics for muscle and joint pain). Severe West Nile disease usually require hospitalization and supportive care such as intravenous fluids and nursing care.
它常见于哪里？
西尼罗河病毒广泛分布于非洲，北美，中东，印度，东南亚，欧洲，加勒比海地区，中南美洲和澳大利亚（在这里被称为Kunjin病毒）。在加拿大，捷克共和国，埃及，法国，意大利，印度，以色列，罗马尼亚，俄罗斯和美国均可见到暴发。
