West Nile Virus and Snakes

I always thought that the West Nile virus was a tropical disease that only affected rugged explorers of the Nile River–I mean it has to be called the West Nile virus for a reason.   This virus has certainty made is presence known in the US, since as of October 4^th 2016 the CDC reported 1,162 cases of West Nile Virus infection. The virus’s name does offer some historical insight as WNV was first identified in the West Nile region of Uganda in a woman in 1937.  The virus mysteriously made its way to the US in 1999, and within five years it spread to Canada, the Caribbean, and Central America. While the virus affects humans, it is also capable of infecting birds. 

However, a recent journal has reported that wild snakes can harbor WNV. This study also raised important questions in the role of snakes in the eco-epidemiology of WNV, while also reporting that oral swabs of snakes can successfully report WNV infection.  

This study was important as it offered an explanation for why the WNV outbreak in the northeastern US was unusually severe this year.  According to the study, infected snakes that hibernate over the winter incubate the virus, and then mosquitos bite the snakes and pass the virus to birds and humans.

Establishing the link between snakes and WNV is good news for control efforts, since controlling the snake virus reservoir could reduce WNV human infection rates. 

I think a round of applause is in order for the researchers who did mouth swabs of snakes to help further our understanding of WNV.

  

A cottonmouth snake, which has been shown to harbor West Nile Virus (Image credit)

-Cynthia Taylor