CDC: West Nile infections climb another 25 percent

Courtesy of the Centers for Disease Control and Prevention.

More than 1,900 cases of West Nile virus have been reported in the U.S., up 25 percent from the previous week, according to the Centers for Disease Control and Prevention, or CDC.

This number is up from about 1,500 reported August 28. Of the 1,993 cases reported Tuesday, 1,069 (54 percent) were classified as neuroinvasive, which can lead to meningitis or encephalitis. The remainder are classified as non-neuroinvasive. Included in that number is another grim figure – 87 deaths related to West Nile also have been reported.

More than 70 percent of the cases have been reported from six states: Michigan, Louisiana, Mississippi, Oklahoma, Texas and South Dakota. About 45 percent of the cases have been in Texas. As of Tuesday, 48 states had reported confirmed infections in people, birds or mosquitoes, according to the CDC.

This is the worst outbreak of West Nile virus since it was first detected in the U.S. in 1999.

The majority of people – about 80 percent – do not exhibit symptoms of West Nile infection, with about 20 percent exhibiting mild symptoms such as rash, fever and headache. One in 150 people develop a severe form of the illness that presents with neurological symptoms such as tremors, vision loss and numbness, according to the CDC.

CDC officials say they expect the outbreak to continue into October and for the numbers to continue to climb, according to media reports.

West Nile is not spread through “casual touch” but rather through mosquitoes and medical procedures such as transfusions when blood is exchanged (this is rare as blood is screened for the virus), according to the CDC.

West Nile also affects horses, and has an up to 40 percent fatality rate in the animals, whether they die from the resulting illness or must be euthanized.

To read more Neogen blog posts regarding West Nile, click here.

For tips on how to prevent West Nile infection, click here.

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