Role of immune aging in susceptibility to West Nile virus
Yao, Y., Montgomery, R.R.
West Nile virus (WNV) is a mosquito-borne enveloped positive-strand RNA virus belonging to the family Flaviviridae, which includes Yellow fever, hepatitis C, and Dengue viruses. WNV was first isolated in Uganda in 1937, and emerged into the United States in 1999. From 1999–2014, WNV spread across North America, South America, and the Caribbean leading to > 41,000 cases, including 1,753 fatalities. While the majority of WNV infections are asymptomatic (~80%), some infected patients develop mild symptoms of West Nile fever (~20%), and a small subset (<1%) develop severe neuroinvasive disease, including meningitis, encephalitis, and acute flaccid paralysis. Currently, no vaccine or specific antiviral treatments against WNV are available. Notably, advanced age remains a dominant risk factor for WNV infection and elderly individuals are more susceptible to severe infection with neurological involvement. Among patients over 70 years of age, the case-fatality rate ranges from 15% to 29%.
Yao, Y., Montgomery, R.R. "Role of immune aging in susceptibility to West Nile virus" Methods in Molecular Biology (2016): 235–47