West Nile Season in Full Swing

West Nile virus detection reported in 38 states so far in 2013

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Those buzzing mosquitos are annoying and their bites cause an uncomfortable itch. But when the West Nile virus is involved, mosquito bites can be more than just annoying.

West Nile virus, which is spread through mosquito bites, can sometimes lead to serious illness and death. West Nile season is currently in full swing, as most infections typically occur between June and August.

According to the Centers for Disease Control and Prevention (CDC), 99 human infections with West Nile have been reported so far across the US this year. 

"Empty any standing water from containers around your home."

The CDC reported that as of August 6, 38 states and the District of Columbia have reported cases of the West Nile virus in people, birds or mosquitos.

Most of the states reporting human cases have seen single digit numbers of infections. Only three states' counts have reached the double digits — South Dakota has reported 21 cases, California has reported 18 and Minnesota has reported 11.

Of the 99 human cases, 45 were considered neuroinvasive cases, meaning that serious issues involving inflammation and swelling of the brain (such as meningitis or encephalitis) have occurred. The remaining 54 cases were considered non-neuroinvasive.

According to the CDC, around 70 to 80 percent of people who develop a West Nile infection do not experience any symptoms. Around one in five infected people will experience flu-like symptoms including fever, body aches, vomiting or rash.

Less than 1 percent of people develop the neuroinvasive illness, which may involve symptoms like high fever, disorientation, neck stiffness, coma and seizures. The CDC estimated that around 10 percent of people with a neuroinvasive infection will die. 

So far in 2013, four deaths have been reported due to West Nile, two of which occurred in California, and one each in Mississippi and Nevada. 

According to the CDC, during the 2012 calendar year, there were 5,674 reported human West Nile virus infections and 286 deaths. 

There are a number of steps the CDC recommends the public should take to protect themselves from West Nile infections, including wearing insect repellent, long sleeves and long pants. 

It can also be effective to make sure that screens covering windows and doors are properly installed to keep the insects outside of the home. 

In a statement from the Minnesota Department of Health (MDH), David Neitzel, an MDH epidemiologist, noted that the elderly and people with weakened immune systems have the highest risk of developing serious illness after becoming infected with West Nile.

"[These high-risk groups] need to be especially diligent about protecting themselves from mosquitoes," said Neitzel.

Review Date: 
August 7, 2013
Last Updated:
August 9, 2013