West Nile Virus Symptoms: Disturbing Spike in West Nile Cases Prompts Questions


West Nile Virus deaths in 2012 have more than tripled in the first few days of August, according to news reports. 

As of July 31, only four deaths in the U.S. had been attributed to West Nile, with 241 cases reported in 22 states. Sixty percent of these cases were in Texas. The next weekly report is due to be out on Tuesday, in which the death count may rise to at least 13.

Five additional deaths in Texas were reported by news agencies this past week, all centered around the Dallas-Fort Worth area. This brings the total count in the Lone Star state to seven.

Dallas has 123 new cases of West Nile, a 63% increase from last week. Neighboring Tarrant County now has 86 confirmed cases compared to 61 a week ago.

The six reported fatalities in Dallas County have already broken its annual record. West Nile cases typically peak in mid-August.  

An elderly woman in Tarrant County, another in California, and an elderly man in Kansas are among the August fatalities. Compromised immunity in the old and sick play a large part in a victim’s vulnerability to the disease.

The West Nile virus can cause two illnesses: the more serious neuroinvasive form, which can cause encephalitis and meningitis, and West Nile fever, which has milder symptoms. One-hundred forty-four of the 241 cases reported so far are reported to be neuroinvasive, the highest number reported in the U.S. since 2004, which will undoubtedly be surpassed in the next CDC report.

Less than 1% of victims get the more serious symptoms, and only 10% of those will die as a result. Others may suffer from permanent brain damage and neurological disorders.  Chronic kidney disease was recently shown (in the journal PloS One) to be a long-term affect in many people that have been infected.

Another two deaths were reported in Louisiana this past week, the state’s first since 2008. A spike in cases of the disease was also observed.

State health departments are required to investigate cases to determine if they match standards set by the Centers for Disease Control and Prevention (CDC).

Sustained warmth throughout the calendar year is a likely culprit, according to CDC’s Roger Nasci.

"The conditions were just right to really kick up the number of infected mosquitoes," Nasci told NPR. "That translates into the greater likelihood that infected mosquitoes are going to bite people and then they get infected and a proportion of them show these symptoms."

State health departments are required to investigate cases to determine if they match standards set by the Centers For Disease Control and Prevention.

Citizens are advised to observe the “Three D’s” of preventing mosquito-borne illness:

Defense – Use mosquito repellent and cover exposed skin when possible Drain – Eliminate mosquito breeding areas by getting rid of all standing water Dusk and Dawn – Just stay inside during these most active times of the day for the pesky vectors

Up to 80% of those affected by West Nile may never know it, exhibiting fever, body aches or rash.  Many will exhibit no noticeable symptoms at all. However, there is no treatment or vaccine for the disease.