Expanding the Differential During the COVID-19 Pandemic: Fatal West Nile Virus Neuroinvasive Disease

Stephen J. Titus, MD; Robert N. Suter, DO; Anh T. Hoang, DO; Paul A. Figel, DO


J Am Board Fam Med. 2021;34(3):661-662. 

In This Article

Abstract and Introduction


The ever-evolving pandemic of Coronavirus disease 2019 (COVID-19) has the potential to drown out other viruses continuing to infect communities. To highlight this, we present 2 cases of fatal West Nile virus neuroinvasive disease that occurred within 2 weeks of each other. Since the first positive case of West Nile virus in the United States, there have been 2 epidemics in the past 2 decades, most often occurring in regions of North Texas and Southern California, which have been areas of high-incidence for COVID-19. It is important for the health care provider to recognize diagnostic biases and maintain broad differentials for the patient presenting with fever and other symptoms associated with COVID-19.


Amid the COVID-19 pandemic, it is important to remember that many viruses, such as West Nile virus (WNV), are still present. WNV infection is usually self-limited. However, less than 1% of cases develop neuroinvasion, which presents in 1 of 3 forms: meningitis, encephalitis, or acute flaccid paralysis. COVID-19 is similar to WNV infection in that they both have a high incidence in the southwestern United States, have a higher virulence pattern in older populations, and can present with the symptoms of fever and altered mental status. To illustrate this, we discuss 2 cases of fatal neuroinvasive WNV in elderly adults that presented within the same week to our service in Dallas, Texas.